JP2017044683A - Relative angle detection device, torque sensor, electric power steering device and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relative angle detection device suitable to enlarge a torque detection range, a torque sensor, an electric power steering device, and a vehicle.SOLUTION: A rotation angle θis is calculated by an inverse tangent function, from a first sin signal sinθis and a first cos signal cosθis according to the rotation angle θis of a first multipolar ring magnet 10 synchronously rotating with an input shaft 22a out of the input shaft 22a and an output shaft 22b arranged coaxially; a rotation angle θos is calculated by an inverse tangent function, from a second sin signal sinθos and a second cos signal cosθos according to the rotation angle θos of a second multipolar ring magnet 11 synchronously rotating with the output shaft 22b; and thereby a relative angle Δθ between the input shaft 22a and the output shaft 22b is calculated from a differential value between the rotation angle θis and the rotation angle θos.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a relative angle detection device, a torque sensor, an electric power steering device, and a vehicle.

  Conventionally, multipolar ring magnets are arranged at both ends of the torsion bar, magnetic flux corresponding to the rotational displacement of these multipolar ring magnets is detected by a magnetic sensor, and the twist angle generated in the torsion bar is calculated from the detected magnetic flux. As a technique for detecting a torque value from this twist angle, for example, there is one disclosed in Patent Document 1 below. In this technique, each of the multipolar ring magnets is provided with two magnetic sensors having a phase difference of 90 ° in electrical angle, and sin Δθ (square value addition value Z) with respect to the torsion angle from the outputs of the four magnetic sensors in total. And the torque value is detected from this sin Δθ.

JP 2013-24638 A

However, the prior art of Patent Document 1 calculates only sin Δθ (square value addition value Z) and uses the straight line portion as a torque value. This is because the torsion angle cannot be uniquely calculated in the torsion angle region exceeding the linear portion of sin Δθ. Therefore, there exists a subject that the area | region exceeding a linear part cannot be utilized as a torque detection range.
Accordingly, the present invention has been made paying attention to such an unsolved problem of the conventional technology, and a relative angle detection device suitable for expanding a torque detection range, and this relative angle detection device are provided. An object of the present invention is to provide a torque sensor, an electric power steering device, and a vehicle.

In order to achieve the above object, according to the first aspect of the present invention, of the first rotating shaft and the second rotating shaft in which different magnetic poles are alternately arranged in the circumferential direction and arranged coaxially. The first multi-pole ring magnet that rotates synchronously with the first rotation shaft and the magnetic poles that are different in the circumferential direction are alternately arranged equally, and the second rotation shaft of the first rotation shaft and the second rotation shaft A second multipole ring magnet that rotates synchronously with the first multipole ring magnet, and detects a magnetic flux corresponding to the rotation angle θ ₁ of the first multipole ring magnet and outputs a _first sin signal representing sin θ ₁ and a first cos signal representing cos θ _1. A first rotation angle sensor and a second rotation angle sensor for detecting a magnetic flux corresponding to the rotation angle θ ₂ of the second multipolar ring magnet and outputting a _second sin signal representing sin θ ₂ and a _second cos signal representing cos θ ₂ And the first sin signal and the first cos signal A plurality of relative angle calculation units for calculating a relative angle Δθ between the first rotation axis and the second rotation axis based on the second sin signal and the second cos signal, and the plurality of relative angle calculation units The rotation angle θ ₁ is calculated based on the first sin signal and the first cos signal, and the rotation angle θ ₂ is calculated based on the second sin signal and the second cos signal, and the rotation angle θ ₁ and the a first calculating a relative angle .DELTA..theta.1 1 or more first relative angle calculating portion from the difference value between the first rotary shaft and the second rotation axis and the rotation angle theta _2, the first 1sin signal, said first Based on the 1 cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to the relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan (sin Δθ / cos Δθ), and one or more second relative angle calculation units that calculate a second relative angle Δθ2 between the first rotation axis and the second rotation axis, and the first relative angle calculation unit calculates Any one of the first relative angle Δθ1 and the second relative angle Δθ2 calculated by the second relative angle calculation unit is set as the third relative angle Δθref, and the third relative angle There is provided a relative angle detection device including an abnormality determination unit that determines an abnormality based on a difference value between Δθref and the remaining relative angles among the first relative angle Δθ1 and the second relative angle Δθ2.

In order to achieve the above object, according to the second aspect of the present invention, the first rotating shaft and the second rotating shaft in which different magnetic poles are alternately arranged in the circumferential direction and are arranged coaxially. First multi-pole ring magnets that rotate synchronously with the first rotating shaft, and magnetic poles that are different in the circumferential direction are alternately arranged, and the second of the first rotating shaft and the second rotating shaft. a second multipolar ring magnets which rotates the rotary shaft and synchronously, the second 1cos signal representative of the first 1sin signal and cos [theta] ₁ represents detect and sin [theta ₁ the magnetic flux corresponding to the rotation angle theta ₁ of the first multipole ring magnet A first rotation angle sensor for outputting, and a second rotation for detecting a magnetic flux corresponding to the rotation angle θ ₂ of the second multipolar ring magnet and outputting a _second sin signal representing sin θ ₂ and a _second cos signal representing cos θ _2. An angle sensor, the first sin signal, and the first co A plurality of relative angle calculation units for calculating a relative angle Δθ between the first rotation axis and the second rotation axis based on the signal, the second sin signal, and the second cos signal, and the plurality of relative angle calculations. The unit calculates sin Δθ and cos Δθ according to a relative angle Δθ between the first rotating shaft and the second rotating shaft based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, A plurality of second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from Δθ2 = arctan (sin Δθ / cos Δθ), One of the plurality of second relative angles Δθ2 calculated by the angle calculation unit is set as a third relative angle Δθref, and the third relative angle Δθref and the remaining second relative angles Δθ2 Small The relative angle detection apparatus comprising an abnormality determination unit determining abnormality based on Kutomo one of the difference value is provided.

According to the third aspect of the present invention, the relative angle detection device according to the first aspect or the second aspect of the present invention detects the relative angle between the input shaft and the output shaft connected by the torsion bar. A torque sensor is provided that includes a torque calculator that calculates torque generated on the input shaft and the output shaft from the relative angle.
Moreover, according to the 4th aspect of this invention, an electric power steering apparatus provided with the torque sensor which concerns on the 3rd aspect of this invention is provided.
Moreover, according to the 5th aspect of this invention, the vehicle provided with the electric power steering device which concerns on the 4th aspect of this invention is provided.

  According to the present invention, it is possible to expand the torque detection range and to calculate a more accurate torque value.

1 is a block diagram illustrating a configuration example of a vehicle according to a first embodiment of the present invention. It is a perspective view which shows one structural example of the 1st sensor part of the 1st relative angle detection apparatus which concerns on 1st Embodiment of this invention. (A) is the schematic diagram which looked at the 1st sensor part of the 1st relative angle detection device concerning a 1st embodiment of the present invention from the front, and (b) is an AA section of (a). FIG. 4C is a sectional view taken along line BB in FIG. It is a block diagram showing an example of 1 composition of the 1st torque sensor concerning a 1st embodiment of the present invention. It is a block diagram which shows the example of 1 structure of the sensor calculating part which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the relationship between an input twist angle and calculation twist angle (DELTA) (theta). (A) is a waveform diagram showing sin θis, and (b) is a waveform diagram showing cos θis. (A) is a waveform diagram showing sin Δθ, and (b) is a waveform diagram showing cos Δθ. It is a perspective view which shows one structural example of the 2nd sensor part of the 2nd relative angle detection apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram showing an example of 1 composition of the 2nd torque sensor concerning a 2nd embodiment of the present invention. It is a perspective view which shows one structural example of the 3rd sensor part of the 3rd relative angle detection apparatus which concerns on 3rd Embodiment of this invention. (A) is the schematic diagram which looked at the 3rd sensor part of the 3rd relative angle detection device concerning a 3rd embodiment of the present invention from the front, and (b) is a CC section of (a). FIG. 4C is a sectional view taken along the line DD of FIG. It is a block diagram showing an example of 1 composition of the 3rd torque sensor concerning a 3rd embodiment of the present invention. (A) is a perspective view which shows one structural example of the 4th sensor part of the 4th relative angle detection apparatus which concerns on 4th Embodiment of this invention, (b) is the 1st sin optical of (a). It is an axial direction fragmentary sectional view containing a sensor. It is a block diagram which shows one structural example of the 4th torque sensor which concerns on 4th Embodiment of this invention. (A) is a perspective view which shows one structural example of the 5th sensor part of the 5th relative angle detection apparatus which concerns on 5th Embodiment of this invention, (b) is 5th rotation of (a). It is the top view which looked at the angle sensor from the surface side, (c) is the top view which looked at the 5th rotation angle sensor of (a) from the back surface side. It is a figure which shows the example of 1 structure of the 5th torque sensor which concerns on 5th Embodiment of this invention. (A) is a perspective view which shows one structural example of the 6th sensor part of the 6th relative angle detection apparatus which concerns on 6th Embodiment of this invention, (b) is the 7th rotation of (a). It is the top view which looked at the angle sensor from the curved surface side, (c) is the top view which looked at the 7th rotation angle sensor of (a) from the surface on the opposite side to a curved surface. It is a figure which shows one structural example of the 6th torque sensor which concerns on 6th Embodiment of this invention. It is a block diagram which shows one structural example of the 2nd sensor calculating part which concerns on 7th Embodiment of this invention. It is a block diagram which shows one structural example of the 3rd sensor calculating part which concerns on 8th Embodiment of this invention. It is a block diagram which shows one structural example of the 4th sensor calculating part which concerns on 9th Embodiment of this invention. It is a block diagram which shows the example of 1 structure of the 5th sensor calculating part which concerns on 10th Embodiment of this invention. It is a block diagram which shows the example of 1 structure of the 6th sensor calculating part which concerns on 11th Embodiment of this invention. It is a block diagram which shows the example of 1 structure of the 7th sensor calculating part which concerns on 12th Embodiment of this invention. It is a block diagram which shows one structural example of the 8th sensor calculating part which concerns on 13th Embodiment of this invention.

  Next, first to fourth embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the vertical and horizontal dimensions and scales of members or portions are different from actual ones. Therefore, specific dimensions and scales should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  In addition, the following first to fourth embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the material of components, The shape, structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

(First embodiment)
(Constitution)
The vehicle 3 according to the first embodiment includes front wheels 3FR and 3FL and rear wheels 3RR and 3RL as shown in FIG. Steered. As shown in FIG. 1, the electric power steering apparatus 2 includes a steering wheel 21, a steering shaft 22, a first torque sensor 1, a first universal joint 24, a lower shaft 25, and a second universal joint. 26. The electric power steering apparatus 2 further includes a pinion shaft 27, a steering gear 28, a tie rod 29, and a knuckle arm 30. The knuckle arm 30 is attached to each of the front wheels 3FR and 3FL.

  The steering force that the driver steers the steering wheel 21 is transmitted to the steering shaft 22. The steering shaft 22 has an input shaft 22a and an output shaft 22b. One end of the input shaft 22 a is connected to the steering wheel 21, and the other end is connected to one end of the output shaft 22 b via the first torque sensor 1. Accordingly, the steering force transmitted to the output shaft 22 b of the steering shaft 22 is transmitted to the lower shaft 25 via the first universal joint 24 and further transmitted to the pinion shaft 27 via the second universal joint 26. The The steering force transmitted to the pinion shaft 27 is transmitted to the tie rod 29 via the steering gear 28. Further, the steering force transmitted to the tie rod 29 is transmitted to the knuckle arm 30 to steer the front wheels 3FR and 3FL.

  Here, the steering gear 28 is configured in a rack and pinion type having a pinion 28a connected to the pinion shaft 27 and a rack 28b meshing with the pinion 28a. Accordingly, the steering gear 28 converts the rotational motion transmitted to the pinion 28a into a straight motion in the vehicle width direction by the rack 28b. Further, a steering assist mechanism 31 that transmits a steering assist force to the output shaft 22b is connected to the output shaft 22b of the steering shaft 22. The steering assist mechanism 31 is connected to the output shaft 22b, for example, a reduction gear 32 constituted by a worm gear mechanism, an electric motor 33 connected to the reduction gear 32 to generate a steering assist force, and a housing of the electric motor 33. And an electric power steering (hereinafter referred to as an EPS: Electronic Power Steering) control unit 34 fixedly supported.

  The electric motor 33 is a three-phase brushless motor, and includes an annular motor rotor and an annular motor stator (not shown). The motor stator includes a plurality of pole teeth protruding radially inward at equal intervals in the circumferential direction, and an excitation coil is wound around each pole tooth. A motor rotor is coaxially disposed inside the motor stator. The motor rotor includes a plurality of magnets on the outer peripheral surface that are opposed to the pole teeth of the motor stator with a slight gap (air gap) and are provided at equal intervals in the circumferential direction. This motor rotor is fixed to the motor rotation shaft, and by passing a three-phase alternating current through the motor stator coil via the EPS control unit 34, each tooth of the motor stator is excited in a predetermined order to rotate the motor rotor. Along with this rotation, the motor rotation shaft rotates.

  The EPS control unit 34 includes a current command calculation circuit and a motor drive circuit. Further, as shown in FIG. 1, the EPS control unit 34 is input with the vehicle speed V detected by the vehicle speed sensor 35 and the direct current from the battery 36 as a direct current voltage source. The current command calculation circuit is a current for driving the electric motor 33 based on the vehicle speed V from the vehicle speed sensor 35, the steering torque Ts from the first torque sensor 1, and the motor rotation angle θm from the electric motor 33. Calculate the command value. The motor drive circuit is composed of, for example, a three-phase inverter circuit, and drives the electric motor 33 based on the current command value from the current command calculation circuit.

  The first torque sensor 1 detects a steering torque Ts applied to the steering wheel 21 and transmitted to the input shaft 22a. Specifically, as shown in FIG. 4, the first torque sensor 1 includes a first relative angle detection device 100 and a torque calculation unit 19. The first relative angle detection device 100 includes a first sensor unit 101 and a sensor calculation unit 180. As shown in FIG. 2, the first sensor unit 101 includes a first multipolar ring magnet 10 and a second multipolar ring magnet 11, and a torsion bar 22c made of an elastic member such as spring steel. . Further, the first sensor unit 101 is provided on the radially outer side of the first multipole ring magnet 10 and detects the rotation angle of the first multipole ring magnet 10, and the second multipole. And a second rotation angle sensor 13 that is provided on the outer side in the radial direction of the ring magnet 11 and detects the rotation angle of the second multipolar ring magnet 11.

  In the first embodiment, the first multipolar ring magnet 10 is attached so as to be able to rotate synchronously with the input shaft 22a at the end of the input shaft 22a on the output shaft 22b side (ideally, the connection position of the torsion bar 22c). Further, the second multipolar ring magnet 11 is attached to the output shaft 22b at the end of the output shaft 22b on the input shaft 22a side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b. Further, the first multipolar ring magnet 10 and the second multipolar ring magnet 11 of the first embodiment are alternately attached to one magnetic pole of the S pole and the N pole at equal intervals, for example, on the outer peripheral surface of the magnetic ring. Obtained by magnetizing. Specifically, the first multipolar ring magnet 10 and the second multipolar ring magnet 11 are shown in FIGS. 3B and 3C, which are AA and BB sectional views of FIG. ), Different magnetic poles are alternately arranged in the circumferential direction such that, for example, the shaded portion in the figure is an N pole and the non-shaded portion is an S pole. That is, a magnetic pole pair is constituted by a set of S poles and N poles adjacent to each other in the circumferential direction of the first multipole ring magnet 10 and the second multipole ring magnet 11. In addition, the 1st multipolar ring magnet 10 and the 2nd multipolar ring magnet 11 can be comprised from a neodymium magnet, a ferrite magnet, a samarium cobalt magnet etc. according to a required magnetic flux density, for example.

  The 1st rotation angle sensor 12 and the 2nd rotation angle sensor 13 are attached to the fixed part which does not rotate synchronously with the input shaft 22a which is a 1st rotating shaft, and the output shaft 22b which is a 2nd rotating shaft. The first rotation angle sensor 12 and the second rotation angle sensor 13 are respectively a sin (sine) signal and cos (cosine) according to the rotation angles of the first multipolar ring magnet 10 and the second multipolar ring magnet 11. A signal is output. Specifically, as shown in FIG. 2 and FIG. 3B, the first rotation angle sensor 12 is phase-shifted by 90 degrees in electrical angle with respect to the magnetic pole pitch of the first multipolar ring magnet 10 ( A first sin magnetic sensor 14 and a first cos magnetic sensor 15 arranged in a state having a phase difference of 90 °. Further, as shown in FIG. 2 and FIG. 3C, the second rotation angle sensor 13 shifts the phase by 90 ° in terms of electrical angle with respect to the magnetic pole pitch of the second multipolar ring magnet 11 (90 °). The second sin magnetic sensor 16 and the second cos magnetic sensor 17 are provided. The first sin magnetic sensor 14 outputs a first sin signal according to the rotation angle of the first multipolar ring magnet 10, and the first cos magnetic sensor 15 outputs the first sin signal according to the rotation angle of the first multipolar ring magnet 10. 1 cos signal is output. The second sin magnetic sensor 16 outputs a second sin signal according to the rotation angle of the second multipole ring magnet 11, and the second cos magnetic sensor 17 outputs the second sin signal according to the rotation angle of the second multipole ring magnet 11. 2 cos signal is output.

  In the first embodiment, the first sin magnetic sensor 14 and the first cos magnetic sensor 15 are arranged with respect to the first multipole ring magnet 10 such that these magnetic flux detectors face the magnetic pole surface of the first multipole ring magnet 10. In the radial direction. In addition, the second sin magnetic sensor 16 and the second cos magnetic sensor 17 are arranged in a radial direction with respect to the second multipole ring magnet 11 so that these magnetic flux detection portions face the magnetic pole surface of the second multipole ring magnet 11. They are placed facing each other. The first sin magnetic sensor 14, the first cos magnetic sensor 15, the second sin magnetic sensor 16, and the second cos magnetic sensor 17 include, for example, a Hall element, a Hall IC, a magnetoresistance effect (MR) sensor, and the like. It is possible to use.

  As shown in FIG. 5, the sensor calculation unit 180 includes a first relative angle calculation unit 18 and a second relative angle calculation unit 18r. Here, the first sin signal, the first cos signal, the second sin signal, and the second cos signal output from the first sin magnetic sensor 14, the first cos magnetic sensor 15, the second sin magnetic sensor 16, and the second cos magnetic sensor 17, Are input to the relative angle calculation unit 18 and the second relative angle calculation unit 18r.

  The first relative angle calculator 18 is a relative angle between the first multipolar ring magnet 10 and the second multipolar ring magnet 11 based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, that is, an input. The relative angle between the shaft 22a and the output shaft 22b is calculated as the first relative angle Δθ. Then, the first relative angle calculation unit 18 outputs the calculated first relative angle Δθ to the torque calculation unit 19.

  The torque calculator 19 calculates the steering torque Ts based on the first relative angle Δθ input from the first relative angle calculator 18. That is, if the relative angle between the two shafts connected by the torsion bar 22c, that is, the input shaft 22a and the output shaft 22b, is obtained, the cross-sectional secondary pole moment, transverse elastic modulus, length, diameter, etc. of the torsion bar 22c are used. The torque can be calculated by a known calculation method.

On the other hand, the second relative angle calculation unit 18r is different from the first relative angle calculation unit 18 based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal. The relative angle with respect to 22b is calculated as the second relative angle Δθref.
As shown in FIG. 5, the first relative angle calculation unit 18 includes an input shaft rotation angle (θis in the drawing) calculation unit 181, an output shaft rotation angle (θos in the drawing) calculation unit 182, and a first relative angle ( In the figure, a Δθ) calculation unit 183 is provided. In the first embodiment, the rotation angle of the first multi-pole ring magnet 10 (electrical angle) and θis (= θ _1), the rotation angle of the second multipole ring magnet 11 (electrical angle) the θos (= θ ₂₎ And Since the first multipole ring magnet 10 rotates in synchronization with the input shaft 22a, the rotation angle θis of the first multipole ring magnet 10 is the rotation angle θis of the input shaft 22a, and the second multipole ring magnet 11 has the output shaft 22b. Therefore, the rotation angle θos of the second multipolar ring magnet 11 is the rotation angle θos of the output shaft 22b.

The first sin magnetic sensor 14 outputs sin θis (= sin θ ₁ ) as the _first sin signal with respect to the rotation angle θis of the first multipolar ring magnet 10, and the first cos magnetic sensor 15 outputs cos θis (= cos θ ₁ ) as the _first cos signal. Is output. In the input shaft rotation angle calculation unit 181 to which the first sin signal sin θis and the first cos signal cos θis are input, an arctangent function of a value obtained by dividing the first sin signal sin θis by the first cos signal cos θis, that is, θis = arctan (sin θis / cos θis). The rotation angle θis of the first multipolar ring magnet 10, that is, the input shaft 22a is calculated.

Further, the second sin magnetic sensor 16 outputs sin θos (= sin θ ₂ ) as the _second sin signal with respect to the rotation angle θos of the second multipole ring magnet 11, and the second cos magnetic sensor 17 outputs cos θos (= cos θ) as the second cos signal. ₂ ) is output. In the output shaft rotation angle calculation unit 182 to which the second sin signal sin θos and the second cos signal cos θos are input, an arctangent function obtained by dividing the second sin signal sin θos by the second cos signal cos θos, that is, θos = arctan (sin θos / cos θos). The rotation angle θos of the second multipolar ring magnet 11, that is, the output shaft 22b is calculated.

  As will be described later, if the rotation angle θis of the input shaft 22a is expressed by θis = θos + Δθ with respect to the rotation angle θos of the output shaft 22b, the first relative angle calculation unit 183 determines from the rotation angle θis of the input shaft 22a. The first relative angle Δθ can be calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value obtained by subtracting the rotation angle θos of the output shaft 22b. The calculated first relative angle (twist angle) Δθ is an angle having a 1: 1 relationship with the input twist angle, as shown in FIG. That is, the first relative angle calculator 18 calculates the first relative angle Δθ as the relative angle between the input shaft 22a and the output shaft 22b, so that the twist angle (relative angle) independent of the steering angle of the steering wheel 21 can be obtained. Calculation is possible.

  On the other hand, as shown in FIG. 5, the second relative angle calculator 18r includes a relative angle sine value (sin Δθ in the figure) calculator 181r, a relative angle cosine value (cos Δθ in the figure) calculator 182r, and a second relative angle. And an angle (Δθref in the figure) calculation unit 183r. For example, when the steering wheel 21 is steered and the input shaft 22a rotates, the rotation angle θos of the second multipolar ring magnet 11, that is, the output shaft 22b is fixed at a predetermined angle, and the first multipolar ring magnet 10, that is, the input It is assumed that the rotation angle θis of the shaft 22a changes. In this case, using the second relative angle Δθref as the relative angle between the input shaft 22a and the output shaft 22b, it can be expressed as sin θis = sin (θos + Δθref), cos θis = cos (θos + Δθref).

Accordingly, the relative angle sine value calculation unit 181r calculates the relative angle sine value sin Δθ according to the following equations (1) and (2).
TMs = (sin θos + cos (θos + Δθref)) ² + (cos θos−sin (θos + Δθref)) ² (1)
sin Δθ = −TMs / 2 + 1 (2)

  Specifically, the relative angle sine value calculation unit 181r uses the second sin input from the second sin magnetic sensor 16 as the cos (θos + Δθref) as the first cos signal cos θis input from the first cos magnetic sensor 15 according to the above equation (1). The square value of the addition value with the signal sin θos is calculated. Further, the first sin signal sin θis input from the first sin magnetic sensor 14 is set as sin (θos + Δθref), and the square value of the subtraction value from the second cos signal cos θos input from the second cos magnetic sensor 17 is calculated. Then, TMs is calculated by adding these calculated square values. Next, the relative angle sine value sin Δθ is calculated by subtracting from 1 the value obtained by dividing the calculated TMs by 2, according to the above equation (2). The calculated relative angle sine value sinΔθ is output to the second relative angle calculation unit 183r. The above equation (2) is an equation obtained by transforming the above equation (1) using a trigonometric addition theorem.

Further, the relative angle cosine value calculation unit 182r calculates the relative angle cosine value cosΔθ according to the following equations (3) and (4).
TMc = (sin θos + sin (θos + Δθref)) ² + (cos θos + cos (θos + Δθref)) ² (3)
cos Δθ = TMc / 2-1 (4)

  Specifically, the relative angle cosine value calculation unit 182r sets the first sin signal sin θis input from the first sin magnetic sensor 14 as sin (θos + Δθref) according to the above equation (3), and the second sin input from the second sin magnetic sensor 16. The square value of the addition value with the signal sin θos is calculated. Further, the first cos signal cos θis input from the first cos magnetic sensor 15 is set as cos (θos + Δθref), and the square value of the addition value with the second cos signal cos θos input from the second cos magnetic sensor 17 is calculated. Then, TMc is calculated by adding these calculated square values. Next, the relative angle cosine value cos Δθ is calculated by subtracting 1 from the value obtained by dividing the calculated TMc by 2 according to the above equation (4). The calculated relative angle cosine value cosΔθ is output to the second relative angle calculation unit 183r. The above expression (4) is an expression obtained by transforming the above expression (3) using an addition theorem of trigonometric functions.

  For example, when the steering wheel 21 is steered and the input shaft 22a rotates from the state where the steering wheel 21 is in the neutral position, the rotation angle θos of the output shaft 22b is fixed at “0 °” and the input shaft 22a rotates. Assume that the angle θis changes. In the state of “sin θos = 0” and “cos θos = 1” where θos is fixed at “0 °”, as shown in FIG. 7A, sinθis is a neutral position and Δθ is “0 °” as shown in FIG. It becomes “0” when Δθ is “90 °”, and becomes “−1” when Δθ is “−90 °”. On the other hand, as shown in FIG. 7B, cos θis becomes “1” when the steering wheel 21 is in the neutral position and Δθ is “0 °”, and when Δθ is “90 °” and Δθ is “−90”. “0” when “°”.

  In this case, sin Δθ calculated according to the above equations (1) and (2) is “0” when the steering wheel 21 is in the neutral position and Δθ is “0 °”, as shown in FIG. 8A, for example. The value on the sine wave curve is “1” when Δθ is “90 °” and “−1” when Δθ is “−90 °”. Further, cos Δθ calculated according to the above equations (3) and (4) is “1” when the steering wheel 21 is in the neutral position and Δθ is “0 °” as shown in FIG. When Δθ is “90 °” and when Δθ is “−90 °”, the value is “0” on the cosine wave curve.

The second relative angle calculation unit 183r calculates the second relative angle Δθref according to the following equation (5).
Δθref = arctan (sin Δθ / cos Δθ) (5)
Specifically, the second relative angle calculation unit 183r includes the relative angle sine value sin Δθ input from the relative angle sine value calculation unit 181r and the relative angle cosine value cos Δθ input from the relative angle cosine value calculation unit 182r. The second relative angle Δθref is calculated by calculating an arctangent function of a value obtained by dividing the relative angle sine value sinΔθ by the relative angle cosine value cosΔθ according to the above equation (5). The calculated second relative angle Δθref is output to the abnormality determination unit 20 via the first adder / subtractor 190. In the abnormality determination unit 20, a first adder / subtracter 190 calculates a difference value between the first relative angle Δθ calculated by the first relative angle calculation unit 183 and the second relative angle Δθref calculated by the second relative angle calculation unit 183 r. Calculate with. Then, when the absolute value of the difference value between the two is equal to or greater than a preset specified value, it is determined that there is an abnormality somewhere in the relative angle detection device.

(Operation)
Next, the operation of the first embodiment will be described.
Now, when the steering wheel 21 is steered by the driver of the vehicle 3 and this steering force is transmitted to the steering shaft 22, first, the input shaft 22a rotates in a direction corresponding to the steering direction. With this rotation, the end of the torsion bar 22c on the input shaft 22a side (hereinafter referred to as “input end”) rotates, and the first multipolar ring magnet 10 provided at the input end of the torsion bar 22c Rotate. The magnetic flux corresponding to the rotational displacement due to this rotation is detected as the first sin signal sin θis and the first cos signal cos θis by the first sin magnetic sensor 14 and the first cos magnetic sensor 15, respectively. These detection signals are input to the first relative angle calculation unit 18 and the second relative angle calculation unit 18r.

  On the other hand, the steering force that has passed through the input end is transmitted to the end on the output shaft 22b side (hereinafter referred to as “output end”) via torsion (elastic deformation) of the torsion bar 22c, and the output end rotates. . That is, the input end (input shaft 22a) and the output end (output shaft 22b) are relatively displaced in the rotation direction. Thereby, the 2nd multipolar ring magnet 11 provided in the output end of torsion bar 22c rotates. The magnetic flux corresponding to the rotational displacement due to the rotation is detected as the second sin signal sin θos and the second cos signal cos θos by the second sin magnetic sensor 16 and the second cos magnetic sensor 17, respectively. These detection signals are also input to the first relative angle calculation unit 18 and the second relative angle calculation unit 18r.

  The first relative angle calculation unit 18 divides the input first sin signal sin θis by the first cos signal cos θis, and calculates the rotation angle θis of the first multipole ring magnet 10, that is, the input shaft 22 a from the arc tangent function of the value. Calculate. Further, the second sin signal sin θos is divided by the second cos signal cos θos, and the rotation angle θos of the second multipole ring magnet 11, that is, the output shaft 22b, is calculated from the arctangent function of the value. Then, the relative angle between the input shaft 22a and the output shaft 22b is calculated as the first relative angle Δθ from the difference value between the rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b. The first relative angle calculation unit 18 outputs the calculated first relative angle Δθ to the torque calculation unit 19 and the first adder / subtractor 190.

  The torque calculator 19 calculates the steering torque Ts from the first relative angle Δθ from the first relative angle calculator 18. For example, when the torsion bar 22c is a solid cylindrical member, the steering torque Ts related to the torsion bar 22c is calculated from “Δθ = 32 · Ts · L / (π · D4 · G)”. Note that L is the length of the torsion bar 22c, D is the diameter of the torsion bar 22c, and G is the transverse elastic modulus of the torsion bar 22c. The torque calculation unit 19 outputs the calculated steering torque Ts to the EPS control unit 34.

  The EPS control unit 34 calculates a current command value in the current command calculation circuit based on the steering torque Ts from the torque calculation unit 19, the vehicle speed V from the vehicle speed sensor 35, and the motor rotation angle θm from the electric motor 33. Furthermore, the EPS control unit 34 generates a three-phase alternating current according to the current command value calculated by the current command calculation circuit in the motor drive circuit, supplies the generated three-phase alternating current to the electric motor 33, and A steering assist force is generated in the motor 33.

  On the other hand, the second relative angle calculator 18r calculates the relative angle from the input first sin signal sin θis, first cos signal cos θis, second sin signal sin θos, and second cos signal cos θos according to the above equations (1) to (4). A sine value sin Δθ and a relative angle cosine value cos Δθ are calculated. Then, from the calculated relative angle sine value sin Δθ and relative angle cosine value cos Δθ, the second relative angle Δθref is calculated from the arctangent function of the value obtained by dividing the relative angle sine value sin Δθ by the relative angle cosine value cos Δθ according to the above equation (5). Calculate. Further, the calculated second relative angle Δθref is output to the first adder / subtractor 190. The abnormality determination unit 20 determines that there is an abnormality in the system when the absolute value of the difference value between the first relative angle Δθ and the second relative angle Δθref calculated by the first adder / subtractor 190 is equal to or greater than a specified value. .

Here, in the first embodiment, the rotation angle θis the first multipole ring magnet 10, corresponding to the rotational angle theta ₁ in means for solving the scope and object of the appended claims, the second multipole ring magnet 11 rotation angle θos is corresponding to the rotation angle theta ₂ in the means for solving the scope and object of the appended claims. In the first embodiment, the first relative angle Δθ corresponds to the first relative angle Δθ1 in the means for solving the claims and the problem, and the second relative angle Δθref is defined in the claims and This corresponds to the second relative angle Δθ2 and the third relative angle Δθref in the means for solving the problem.

(Effect of 1st Embodiment)
The first relative angle detection device 100 according to the first embodiment synchronizes with the input shaft 22a among the input shaft 22a and the output shaft 22b that are arranged on the same axis with different magnetic poles alternately arranged in the circumferential direction. The first multipole ring magnet 10 that rotates, the second multipole ring magnet 11 that rotates alternately in synchronization with the output shaft 22b of the input shaft 22a and the output shaft 22b, and the first multipole ring magnet 11 that rotates in synchronization with the output shaft 22b of the output shaft 22b. The first rotation angle sensor 12 that detects the magnetic flux according to the rotation angle θis of the multipolar ring magnet 10 and outputs the first sin signal sinθis and the first cos signal cosθis, and the rotation angle θos of the second multipole ring magnet 11 A second rotation angle sensor 13 for detecting the detected magnetic flux and outputting a second sin signal sin θos and a second cos signal cos θos; and θis based on the first sin signal sin θis and the first cos signal cos θis. The rotation angle θis is calculated from arctan (sin θis / cos θis) and the rotation angle θos is calculated from θos = arctan (sin θos / cos θos) based on the second sin signal sin θos and the second cos signal cos θos, and the rotation angle θis and the rotation angle θos are calculated. And a first relative angle calculation unit 18 that calculates a first relative angle Δθ as a relative angle between the input shaft 22a and the output shaft 22b.

  With this configuration, the rotation angle θis is calculated from the arctangent function obtained by dividing the first sin signal sinθis by the first cos signal cosθis, and the arctangent function obtained by dividing the second sin signal sinθos by the second cos signal cosθos. The rotation angle θos can be calculated, and the first relative angle Δθ can be calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value between the calculated rotation angle θis and the rotation angle θos. As a result, the torque can be calculated even in a twist angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the first relative angle Δθ can be calculated with a small number of calculations, a more accurate torque value can be calculated.

  Further, in the first relative angle detection device 100 according to the first embodiment, the first multipolar ring magnet 10 and the second multipolar ring magnet 11 are magnetized to magnetic poles that are alternately different in the circumferential direction on the outer peripheral surface. Configured. In addition, the first rotation angle sensor 12 is disposed so that the magnetic flux detector (of the first sin magnetic sensor 14 and the first cos magnetic sensor 15) faces the magnetic pole surface formed on the outer peripheral surface of the first multipolar ring magnet 10. ing. In addition, the second rotation angle sensor 13 has a magnetic flux detector (of the second sin magnetic sensor 16 and the second cos magnetic sensor 17) opposed to the magnetic pole surface formed on the outer peripheral surface of the second multipolar ring magnet 11. Has been placed. With this configuration, for example, when the arrangement space in the axial direction cannot be taken with respect to the ring magnet, the rotation angle sensor can be arranged in a radial opposed manner.

  Further, in the first relative angle detection device 100 according to the first embodiment, the first rotation angle sensor 12 has a phase difference of 90 ° in electrical angle with respect to the pitch of the magnetic poles of the first multipolar ring magnet 10. And a first sin magnetic sensor 14 that outputs a first sin signal sin θis and a first cos magnetic sensor 15 that outputs a first cos signal cos θis. In addition, the second rotation angle sensor 13 is arranged with a phase difference of 90 ° in electrical angle with respect to the pitch of the magnetic poles of the second multipolar ring magnet 11 and outputs a second sin signal sin θos. A sensor 16 and a second cos magnetic sensor 17 that outputs a second cos signal cos θos are included. With this configuration, the first sin magnetic sensor 14 and the first cos magnetic sensor 15 can easily output the first sin signal sin θis and the first cos signal cos θis corresponding to the rotation angle θis of the first multipolar ring magnet 10. Become. Further, the second sin magnetic sensor 16 and the second cos magnetic sensor 17 can easily output the second sin signal sin θos and the second cos signal cos θos corresponding to the rotation angle θos of the second multipolar ring magnet 11.

  In the first relative angle detection device 100 according to the first embodiment, the first rotation angle sensor 12 and the second rotation angle sensor 13 output the first rotation angle sensor 12 when the relative angle Δθ is 0 °. And the output of the 2nd rotation angle sensor 13 is provided so that it may become the same phase. With this configuration, the relative angle Δθ can be simply and accurately calculated using the signals output from the first rotation angle sensor 12 and the second rotation angle sensor 13 as they are.

  In addition, the first relative angle detection device 100 according to the first embodiment is configured so that the relative angle between the input shaft 22a and the output shaft 22b is based on the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos. A second relative angle calculator 18r that calculates sin Δθ and cos Δθ according to Δθ, and calculates a second relative angle Δθref as a relative angle between the input shaft 22a and the output shaft 22b from Δθref = arctan (sinΔθ / cosΔθ); An abnormality determination unit 20 that determines abnormality based on a difference value between the first relative angle Δθ calculated by the first relative angle calculation unit 18 and the second relative angle Δθref calculated by the second relative angle calculation unit 18r. With. With this configuration, a system abnormality is detected when the difference value between the first relative angle Δθ and the second relative angle Δθref calculated by a method different from the first relative angle Δθ is equal to or greater than a preset specified value. can do.

  In the first relative angle detection device 100 according to the first embodiment, the second relative angle calculation unit 18r calculates the relative angle sine value sin Δθ based on the above equations (1) to (2), Based on the equations (3) to (4), the relative angle cosine value cosΔθ is calculated. With this configuration, the relative angle sine value sinΔθ and the relative angle cosine value cosΔθ are simply and accurately calculated by calculation using the signals output from the first rotation angle sensor 12 and the second rotation angle sensor 13 as they are. Can do.

  Further, the first torque sensor 1 according to the first embodiment uses the first relative angle detection device 100 according to the first embodiment as a relative angle between the input shaft 22a and the output shaft 22b connected by the torsion bar 22c. A torque calculation unit 19 is provided that detects a first relative angle Δθ and calculates a steering torque Ts generated in the input shaft 22a and the output shaft 22b from the first relative angle Δθ. With this configuration, operations and effects equivalent to those of the first relative angle detection device 100 can be obtained.

Moreover, the electric power steering apparatus 2 according to the first embodiment includes the first torque sensor 1 according to the first embodiment. With this configuration, it is possible to drive the electric motor 33 with high-accuracy steering torque Ts corresponding to a wide torque detection range and generate appropriate steering assist torque. As a result, it is possible to perform good steering assist such as steering feeling.
Further, the vehicle 3 according to the first embodiment includes the electric power steering device 2 according to the first embodiment. If it is this structure, the effect | action and effect equivalent to the said electric power steering apparatus 2 will be acquired.

(Second Embodiment)
(Constitution)
The second embodiment of the present invention has the same configuration as that of the first embodiment except that a second sensor unit 401 having a partially different configuration is provided instead of the first sensor unit 101 of the first embodiment. Become. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.

As shown in FIG. 10, the second torque sensor 4 according to the second embodiment includes a second relative angle detection device 400, and the second relative angle detection device 400 includes a second sensor unit 401, A sensor calculation unit 180.
As shown in FIG. 9, the second sensor unit 401 includes a third multipole ring magnet 40 and a fourth multipole ring magnet 40 in place of the first multipole ring magnet 10 and the second multipole ring magnet 11 of the first embodiment. A multipolar ring magnet 41 is provided. Unlike the first multipolar ring magnet 10 and the second multipolar ring magnet 11 of the first embodiment, the third multipolar ring magnet 40 and the fourth multipolar ring magnet 41 have the axial end faces of the ring magnet in the circumferential direction. In this configuration, different magnetic poles are alternately magnetized. The mounting positions of the third multipolar ring magnet 40 and the fourth multipolar ring magnet 41 are the same as those of the first multipolar ring magnet 10 and the second multipolar ring magnet 11 of the first embodiment. Moreover, the 3rd multipolar ring magnet 40 and the 4th multipolar ring magnet 41 are comprised from the multipolar ring magnet of the same structure.

  As shown in FIG. 9, the third multipolar ring magnet 40 and the fourth multipolar ring magnet 41 are arranged such that, for example, the shaded portion is N pole and the non-shaded portion is S pole. Magnetic poles different in direction are alternately arranged. A pair of magnetic poles is composed of a set of S and N poles adjacent to each other in the circumferential direction of the third multipole ring magnet 40 and the fourth multipole ring magnet 41. Moreover, the 3rd multipolar ring magnet 40 and the 4th multipolar ring magnet 41 can be comprised from a neodymium magnet, a ferrite magnet, a samarium cobalt magnet etc. according to a required magnetic flux density, for example.

  The second sensor unit 401 according to the second embodiment includes the first rotation angle sensor 12 and the second rotation angle sensor 13 that are the same as the first sensor unit 101 of the first embodiment. Is different from the first embodiment. Specifically, as shown in FIG. 9, the first sin magnetic sensor 14 and the first cos magnetic sensor 15 of the first rotation angle sensor 12 are arranged so as to face the magnetic pole surface of the third multipolar ring magnet 40. The pole ring magnet 40 is arranged so as to face the axial direction. Further, the second sin magnetic sensor 16 and the second cos magnetic sensor 17 of the second rotation angle sensor 13 are axially oriented with respect to the fourth multipole ring magnet 41 so as to face the magnetic pole surface of the fourth multipole ring magnet 41. It is arranged to face.

  Further, as shown in FIG. 9, the first sin magnetic sensor 14 and the first cos magnetic sensor 15 of the second embodiment are shifted in phase by 90 ° in electrical angle with respect to the magnetic pole pitch (a phase difference of 90 ° is set). Arranged). Further, as shown in FIG. 9, the second sin magnetic sensor 16 and the second cos magnetic sensor 17 of the second embodiment are shifted in phase by 90 ° in electrical angle with respect to the magnetic pole pitch (the phase difference of 90 ° is changed). Arranged). In addition, the 1st rotation angle sensor 12 and the 2nd rotation angle sensor 13 of 2nd Embodiment are attached to the fixed site | part which does not rotate synchronously with the input shaft 22a and the output shaft 22b.

Here, in the second embodiment, the third multipole ring magnet 40, that is, the rotation angle θis of the input shaft 22a is corresponding to the rotational angle theta ₁ in means for solving the scope and object of the appended claims, the fourth multipole ring magnet 41, that is, the rotation angle θos of the output shaft 22b is corresponding to the rotation angle theta ₂ in the means for solving the scope and object of the appended claims. In the second embodiment, the first relative angle Δθ corresponds to the first relative angle Δθ1 in the means for solving the claims and the problems, and the second relative angle Δθref is defined in the claims and This corresponds to the second relative angle Δθ2 and the third relative angle Δθref in the means for solving the problem.

(Effect of 2nd Embodiment)
In addition to the effects of the first embodiment, the second embodiment has the following effects.
The second relative angle detection device 400 according to the second embodiment includes a third multipole ring magnet 40 and a fourth multipole that are formed by magnetizing one end face portion in the axial direction to different magnetic poles alternately in the circumferential direction. A ring magnet 41 is provided. In the first rotation angle sensor 12, the magnetic flux detection part (of the first sin magnetic sensor 14 and the first cos magnetic sensor 15) faces a magnetic pole surface formed on one end face in the axial direction of the third multipolar ring magnet 40. Has been placed. Further, in the second rotation angle sensor 13, the magnetic flux detection unit (of the second sin magnetic sensor 16 and the second cos magnetic sensor 17) faces the magnetic pole surface formed on one end surface in the axial direction of the fourth multipolar ring magnet 41. Are arranged. With this configuration, for example, when the arrangement space in the radial direction cannot be taken with respect to the ring magnet, the rotation angle sensor can be arranged in an axially opposed manner.

(Third embodiment)
(Constitution)
The third embodiment of the present invention is the first embodiment, except that a third sensor unit 501 that uses a resolver for detecting a relative angle is provided instead of the first sensor unit 101 of the first embodiment. It becomes the same composition as. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.

As shown in FIG. 13, the third torque sensor 5 according to the third embodiment includes a third relative angle detection device 500, and the third relative angle detection device 500 includes a third sensor unit 501, A sensor calculation unit 180.
As shown in FIGS. 11 and 12A, the third sensor unit 501 includes a first resolver 50, a second resolver 51, and an excitation signal supply unit 56. In the example shown in FIG. 12B, the first resolver 50 is attached to the first rotor 52 having 12 teeth on the outer circumference and the fixed portion where neither the input shaft 22a nor the output shaft 22b rotates synchronously. And a first stator 53 having 16 armature windings (magnetic poles) formed by winding a coil around each of 16 poles equally distributed on the inner periphery. In the example shown in FIG. 12 (c), the second resolver 51 is attached to the second rotor 54 having 12 teeth on the outer circumference and the fixed portion where neither the input shaft 22a nor the output shaft 22b rotates synchronously. And a second stator 55 having 16 armature windings (magnetic poles) formed by winding a coil around each of 16 poles equally distributed on the inner periphery. In the first resolver 50 and the second resolver 51, the number of teeth is not limited to 12, but may be 11 or less or 13 or more. Further, the number of armature windings is not limited to 16, and may be 15 or less or 17 or more.

  The first rotor 52 is attached to the input shaft 22a so as to be able to rotate synchronously with the input shaft 22a, and the second rotor 54 is attached to the output shaft 22b so as to be able to rotate synchronously with the output shaft 22b. The first rotor 52 and the first stator 53 are arranged such that the first stator 53 is concentrically arranged outside the first rotor 52, and each tooth of the first rotor 52 and each armature winding of the first stator 53 have a diameter. They are arranged so as to face each other with a predetermined air gap in the direction. The second rotor 54 and the second stator 55 are arranged such that the second stator 55 is disposed concentrically outside the second rotor 54, and each tooth of the second rotor 54 and each armature winding of the second stator 55 have a diameter. They are arranged so as to face each other with a predetermined air gap in the direction. In the third embodiment, the first rotor 52 is attached so as to be able to rotate synchronously with the input shaft 22a at the end of the input shaft 22a on the output shaft 22b side (ideally, the connection position of the torsion bar 22c). Further, the second rotor 54 is attached so as to be able to rotate synchronously with the output shaft 22b at the end of the output shaft 22b on the input shaft 22a side (ideally, the connection position of the torsion bar 22c). The excitation signal supply unit 56 supplies a sinusoidal excitation signal to the coils of the armature windings of the first stator 53 and the second stator 55.

  In the third embodiment, the first resolver 50 and the second resolver 51 are four-phase resolvers. That is, the poles of the first stator 53 and the second stator 55 are provided with a ¼ pitch shift from an integral multiple of the tooth pitch of the first rotor 52 and the second rotor 54. Thus, when the coil outputs of the 16 armature windings of the first stator 53 and the second stator 55 are divided into four 90 ° portions in the circumferential direction, four armature windings within the divided 90 ° circumferential direction are obtained. The output of the line coil is a sine wave (or cosine wave) signal that is 90 degrees out of phase between adjacent armature windings. In 3rd Embodiment, the coil which outputs the same signal among the coils of each armature winding is connected in series. That is, assuming that the rotation angle of the first rotor 52 is θis, the first sin signal representing sin θis and the first cos signal representing cos θis are obtained from the output of the coil of the first stator 53. When the rotation angle of the second rotor 54 is θos, a second sin signal representing sin θos and a second cos signal representing cosθos are obtained from the output of the coil of the second stator 55. The first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos output from each coil are connected to the first relative angle calculation unit 18 and the second second in the sensor calculation unit 180 via the resolver cable. The value is input to the relative angle calculation unit 18r.

  The first relative angle calculation unit 18 of the third embodiment includes a first sin signal sin θis, a first cos signal cos θis, a second sin signal sin θos, and a second cos input from the first stator 53 and the second stator 55 via a resolver cable. From the signal cos θos, the rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b are calculated as in the first embodiment. Then, the first relative angle Δθ is calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value between the calculated rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b. Then, the calculated first relative angle Δθ is output to the torque calculation unit 19 and the first adder / subtractor 190.

  On the other hand, the second relative angle calculator 18r of the third embodiment calculates the above equations (1) to (4) from the input first sin signal sin θis, first cos signal cos θis, second sin signal sin θos, and second cos signal cos θos. The relative angle sine value sin Δθ and the relative angle cosine value cos Δθ are calculated based on the above. Further, from the calculated relative angle sine value sin Δθ and relative angle cosine value cos Δθ, the second relative angle Δθref is calculated as the relative angle between the input shaft 22a and the output shaft 22b according to the above equation (5).

Similarly to the first embodiment, the difference value between the second relative angle Δθref calculated by the second relative angle calculator 18 r and the first relative angle Δθ calculated by the first relative angle calculator 18 is obtained. Based on this, the abnormality determination unit 20 performs abnormality determination.
Here, in the third embodiment, the rotation angle θis the first rotor 52, i.e. the input shaft 22a is corresponding to the rotational angle theta ₁ in the appended claims, the rotation angle of the second rotor 54, that is, the output shaft 22b Shitaos Corresponds to the rotation angle θ ₂ in the claims. In the third embodiment, the first relative angle Δθ corresponds to the first relative angle Δθ1 in the claims, and the second relative angle Δθref corresponds to the second relative angle Δθ2 and the second relative angle in the claims. 3 relative angle Δθref.

(Effect of the third embodiment)
The third embodiment has the following effects in addition to the effects of the first embodiment and the second embodiment.
The third relative angle detection device 500 according to the third embodiment is synchronized with the input shaft 22a of the input shaft 22a and the output shaft 22b that have a plurality of teeth on the outer periphery at equal intervals and are arranged coaxially. A rotating first rotor 52 and a second rotor 54 that are alternately arranged with different magnetic poles in the circumferential direction and rotate synchronously with the output shaft 22b of the input shaft 22a and the output shaft 22b are provided. Further, the first rotor 52 is arranged outside the first rotor 52 concentrically with the first rotor 52, and a plurality of poles are formed on the inner circumference at equal intervals, and an armature winding is formed by a coil wound around each pole. The stator 53 and the second rotor 54 are arranged concentrically with the second rotor 54, and a plurality of poles are evenly formed on the inner periphery, and an armature winding is formed by a coil wound around each pole. A second stator 55. Still further, an excitation signal supply unit 56 that supplies an excitation signal to the coils of the first stator 53 and the second stator 55, and a coil of the first stator 53 that is output from the coil of the first stator 53 when the excitation signal is supplied. Based on the first sin signal representing sin θis corresponding to the rotation angle θis and the first cos signal representing cos θis, the rotation angle θis is calculated from θis = arctan (sin θis / cos θis), and the second stator when the excitation signal is supplied The rotation angle θos is calculated from θos = arctan (sinθos / cosθos) based on the second sin signal representing sin θos and the second cos signal representing cosθos output from the 55 coils and corresponding to the rotation angle θos of the second rotor 54, As a relative angle between the input shaft 22a and the output shaft 22b from the difference value between the rotation angle θis and the rotation angle θos, the first relative And a first relative angle calculation unit 18 that calculates the angle Δθ.

  With this configuration, the rotation angle θis is calculated from the arctangent function obtained by dividing the first sin signal sinθis by the first cos signal cosθis, and the arctangent function obtained by dividing the second sin signal sinθos by the second cos signal cosθos. The rotation angle θos can be calculated, and the first relative angle Δθ can be calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value between the calculated rotation angle θis and the rotation angle θos. As a result, the torque can be calculated even in a twist angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the first relative angle Δθ can be calculated with a small number of calculations, a more accurate torque value can be calculated.

  Further, in the third relative angle detection device 500 according to the third embodiment, the first stator 53 and the second stator 55 are configured such that the coil output of the first stator 53 and the second stator when the relative angle Δθ is 0 °. The outputs of the 55 coils are provided in the same phase. With this configuration, the relative angle Δθ can be calculated simply and accurately using the signals output from the coils (detection coils) of the first stator 53 and the second stator 55 as they are.

  In addition, the third relative angle detection device 300 according to the third embodiment is configured so that the relative angle between the input shaft 22a and the output shaft 22b is based on the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos. A second relative angle calculator 18r that calculates sin Δθ and cos Δθ according to Δθ, and calculates a second relative angle Δθref as a relative angle between the input shaft 22a and the output shaft 22b from Δθref = arctan (sinΔθ / cosΔθ); An abnormality determination unit 20 that determines abnormality based on a difference value between the first relative angle Δθ calculated by the first relative angle calculation unit 18 and the second relative angle Δθref calculated by the second relative angle calculation unit 18r. With. With this configuration, a system abnormality is detected when the difference value between the first relative angle Δθ and the second relative angle Δθref calculated by a method different from the first relative angle Δθ is equal to or greater than a preset specified value. can do.

(Fourth embodiment)
The fourth embodiment of the present invention includes the fourth sensor unit 601 that uses an optical encoder to detect the rotation angle instead of the first sensor unit 101 of the first embodiment. It becomes the same structure as 1 embodiment. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.

As shown in FIG. 15, the fourth torque sensor 6 according to the fourth embodiment includes a fourth relative angle detection device 600, and the fourth relative angle detection device 600 includes a fourth sensor unit 601, A sensor calculation unit 180.
As shown in FIG. 14A, the fourth sensor unit 601 detects the rotation angle of the first code wheel 60 and the first and second code wheels 60 and 61 having an annular shape and a thin plate shape. 3 rotation angle sensor 62 and 4th rotation angle sensor 63 which detects the rotation angle of the 2nd code wheel 61 are provided.

In the first code wheel 60, a plurality of slits 60 s formed of rectangular through holes in a plan view are formed in the vicinity of the outer peripheral portion of the plate surface at equal intervals along the circumferential direction. In the second code wheel 61, a plurality of slits 61s each having a rectangular through hole in a plan view are formed in the vicinity of the outer peripheral portion of the plate surface at equal intervals along the circumferential direction.
Moreover, in 4th Embodiment, the 1st code wheel 60 is attached to the input shaft 22a at the output-shaft 22b side edge part (ideally the connection position of the torsion bar 22c) of the input shaft 22a so that synchronous rotation with the input shaft 22a is possible. Further, the second code wheel 61 is attached to the output shaft 22b at the end of the output shaft 22b on the input shaft 22a side (ideally, the connecting position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b.

  The third rotation angle sensor 62 and the fourth rotation angle sensor 63 are attached to a fixed portion that does not rotate synchronously with either the input shaft 22a or the output shaft 22b. The third rotation angle sensor 62 and the fourth rotation angle sensor 63 output sine wave signals and cosine wave signals according to the rotation angles of the first code wheel 60 and the second code wheel 61, respectively. Specifically, the third rotation angle sensor 62 is arranged by shifting the phase by an electrical angle of 90 ° with respect to the slit pitch (in a state having a phase difference of 90 °) and the first sin optical sensor 64. 1 cos optical sensor 65 is provided. Further, the fourth rotation angle sensor 63 shifts the phase by an electrical angle of 90 ° with respect to the slit pitch (in a state having a phase difference of 90 °) and the second sin optical sensor 66 and the second cos optical. A sensor 67 is provided. The first sin optical sensor 64 outputs a first sin signal according to the rotation angle of the first code wheel 60, and the first cos optical sensor 65 outputs a first cos signal according to the rotation angle of the first code wheel 60. The second sin optical sensor 66 outputs a second sin signal according to the rotation angle of the second code wheel 61, and the second cos optical sensor 67 outputs a second cos signal according to the rotation angle of the second code wheel 61. To do.

  As shown in FIG. 14B, the first sin optical sensor 64 includes a detection frame 64a having a substantially U-shaped axial section, a light source 64b, and a light receiving unit 64c. The light source 64b is in the recess provided in the upper frame portion of the two frame portions facing the upper and lower sides inside the detection frame 64a, and the light receiving portion 64c is in the recess provided in the lower frame portion. The light receiving unit 64c is arranged so as to face the light emitted from 64b so as to receive light. As shown in FIG. 14A, the first sin optical sensor 64 is arranged so that the entire slit (through hole) 60s passes through the space between the light source 64b and the light receiving unit 64c inside the detection frame 64a. The area including the slit formation position at the outer peripheral end of the one code wheel 60 is arranged so as to be sandwiched between the two frame portions of the detection frame 64a. That is, as shown in FIG. 14B, the light emitted from the light source 64b is disposed so as to be received by the light receiving portion 64c through the slit 60s. The first cos optical sensor 65, the second sin optical sensor 66, and the second cos optical sensor 67 have a detection frame code of 65a, 66a, and 67a, a light source code of 65b, 66b, and 67b, and a light receiving unit code of 65c. , 66c, and 67c, the configuration is the same as that of the first sin optical sensor 64, and a description thereof will be omitted.

In the fourth embodiment, similarly to the first embodiment, the rotation angle (electrical angle) of the first code wheel 60 is θis (= θ ₁ ), and the rotation angle (electrical angle) of the second code wheel 61 is set. Is θos (= θ ₂ ). Since the first code wheel 60 rotates synchronously with the input shaft 22a, the rotation angle θis of the first code wheel 60 is the rotation angle θis of the input shaft 22a, and the second code wheel 61 rotates synchronously with the output shaft 22b. The rotation angle θos of the two code wheel 61 is the rotation angle θos of the output shaft 22b. The first sin optical sensor 64 outputs sin θis as the first sin signal and the first cos optical sensor 65 outputs cos θis as the first cos signal with respect to the rotation angle θis of the first code wheel 60. The second sin optical sensor 66 outputs sin θos as the second sin signal and the second cos optical sensor 67 outputs cos θos as the second cos signal with respect to the rotation angle θos of the second code wheel 61. The first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos are output to the first relative angle calculation unit 18 and the second relative angle calculation unit 18r in the sensor calculation unit 180.

  The first relative angle calculation unit 18 of the fourth embodiment includes the first sin signal sin θis and the first cos input from the first sin optical sensor 64, the first cos optical sensor 65, the second sin optical sensor 66, and the second cos optical sensor 67. The rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b are calculated from the signal cos θis, the second sin signal sin θos, and the second cos signal cos θos, as in the first embodiment. Then, the first relative angle Δθ is calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value between the calculated rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b. Then, the calculated first relative angle Δθ is output to the torque calculation unit 19.

  On the other hand, the second relative angle calculator 18r of the fourth embodiment calculates the above equations (1) to (4) from the input first sin signal sin θis, first cos signal cos θis, second sin signal sin θos, and second cos signal cos θos. The relative angle sine value sin Δθ and the relative angle cosine value cos Δθ are calculated based on the above. Further, from the calculated relative angle sine value sin Δθ and relative angle cosine value cos Δθ, the second relative angle Δθref is calculated as the relative angle between the input shaft 22a and the output shaft 22b according to the above equation (5).

Similarly to the first embodiment, the difference value between the second relative angle Δθref calculated by the second relative angle calculator 18 r and the first relative angle Δθ calculated by the first relative angle calculator 18 is obtained. Based on this, the abnormality determination unit 20 performs abnormality determination.
Here, in the fourth embodiment, the first code wheel 60, that is, the rotation angle θis of the input shaft 22a is corresponding to the rotational angle theta ₁ in the appended claims, the rotation of the second code wheel 61, that is, the output shaft 22b angle θos is corresponding to the rotation angle theta ₂ in the appended claims. In the fourth embodiment, the first relative angle Δθ corresponds to the first relative angle Δθ1 in the claims, and the second relative angle Δθref corresponds to the second relative angle Δθ2 and the second relative angle in the claims. 3 relative angle Δθref.

(Effect of 4th Embodiment)
The fourth embodiment has the following effects in addition to the effects of the first to third embodiments.
The fourth relative angle detection device 600 according to the fourth embodiment includes a plurality of slits 60s formed at equal intervals in the circumferential direction, and is arranged among the input shaft 22a and the output shaft 22b arranged coaxially. The first code wheel 60 that rotates synchronously with the input shaft 22a and a plurality of slits 61s formed at equal intervals in the circumferential direction, and rotates synchronously with the output shaft 22b of the input shaft 22a and the output shaft 22b. A second code wheel 61. Further, the light source (light sources 64b and 65b) and the light emitted from the light source receive the transmitted light that has passed through the slit 60s of the first code wheel 60, and represent the sin θis corresponding to the rotation angle θis of the first code wheel 60. A third rotation angle sensor 62 having a light receiving portion (light receiving portions 64c and 65c) that outputs a 1 sin signal and a first cos signal representing cos θis, a light source (light sources 66b and 67b), and light emitted from the light source is a second code wheel A light receiving portion (light receiving portions 66c and 67c) that receives the transmitted light that has passed through the slit 61s of 61 and outputs a second sin signal that represents sin θos corresponding to the rotation angle θos of the second code wheel 61 and a second cos signal that represents cos θos. And a fourth rotation angle sensor 63. Furthermore, the rotation angle θis is calculated from θis = arctan (sinθis / cosθis) based on the first sin signal sinθis and the first cos signal cosθis, and θos = arctan (sinθos / cosθos based on the second sin signal sinθos and the second cos signal cosθos. ) From the difference value between the rotation angle θis and the rotation angle θos, and calculates a first relative angle Δθ as a relative angle between the input shaft 22a and the output shaft 22b; Is provided.

  With this configuration, the rotation angle θis is calculated from the arctangent function obtained by dividing the first sin signal sinθis by the first cos signal cosθis, and the arctangent function obtained by dividing the second sin signal sinθos by the second cos signal cosθos. The rotation angle θos can be calculated, and the first relative angle Δθ can be calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value between the calculated rotation angle θis and the rotation angle θos. As a result, the torque can be calculated even in a twist angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the first relative angle Δθ can be calculated with a small number of calculations, a more accurate torque value can be calculated.

  Further, in the fourth relative angle detection device 600 according to the fourth embodiment, the third rotation angle sensor 62 and the fourth rotation angle sensor 63 output the third rotation angle sensor 62 when the relative angle Δθ is 0 °. And the output of the 4th rotation angle sensor 63 is provided so that it may become the same phase. With this configuration, the relative angle Δθ can be calculated simply and accurately using the signals output from the third rotation angle sensor 62 and the fourth rotation angle sensor 63 as they are.

  In addition, the fourth relative angle detection device 600 according to the fourth embodiment is configured such that the input shaft 22a and the output shaft 22b are based on the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos. A second relative angle calculator 18r that calculates sin Δθ and cos Δθ according to Δθ, and calculates a second relative angle Δθref as a relative angle between the input shaft 22a and the output shaft 22b from Δθref = arctan (sinΔθ / cosΔθ); An abnormality determination unit 20 that determines abnormality based on a difference value between the first relative angle Δθ calculated by the first relative angle calculation unit 18 and the second relative angle Δθref calculated by the second relative angle calculation unit 18r. With. With this configuration, a system abnormality is detected when the difference value between the first relative angle Δθ and the second relative angle Δθref calculated by a method different from the first relative angle Δθ is equal to or greater than a preset specified value. can do.

(Fifth embodiment)
5th Embodiment of this invention replaces the 1st sensor part 101 of the said 1st Embodiment, and is equipped with the 5th sensor part 701 which uses an eddy current for the detection of a rotation angle, said 1st above-mentioned. It becomes the same structure as embodiment.
Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.

As shown in FIG. 17, the fifth torque sensor 7 according to the fifth embodiment includes a fifth relative angle detection device 700, and the fifth relative angle detection device 700 includes a fifth sensor unit 701, A sensor calculation unit 180.
As illustrated in FIG. 16A, the fifth sensor unit 701 includes a first target 70 and a second target 71, a fifth rotation angle sensor 72 that detects a rotation angle of the first target 70, and a second target. And a sixth rotation angle sensor 73 for detecting the rotation angle of 71.

The first target 70 is a sine wave shape along the circumferential direction of the first annular conductor 70a composed of an annular and thin plate-shaped conductor and the outer diameter side end of the first annular conductor 70a in plan view from the axial direction. And a first sine wave-like portion 70b formed in a shape that changes to the above. That is, the first sinusoidal portion 70b has a shape in which the radial width changes in a sinusoidal shape.
The second target 71 has a sine wave shape along the circumferential direction of the second annular conductor 71a composed of an annular and thin plate-shaped conductor and the outer diameter side end of the second annular conductor 71a in plan view from the axial direction. And a second sinusoidal portion 71b formed in a shape that changes to the above. That is, the second sinusoidal portion 71b has a shape in which the radial width changes in a sinusoidal shape.

The 1st target 70 and the 2nd target 71 can be comprised from conductors, such as metals, such as aluminum, steel, copper, or a plastic material containing a metal, for example.
In the fifth embodiment, the first target 70 is attached to the end of the input shaft 22a on the output shaft 22b side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the input shaft 22a. Further, the second target 71 is attached to the end of the output shaft 22b on the input shaft 22a side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b.

The fifth rotation angle sensor 72 and the sixth rotation angle sensor 73 are provided at a fixed portion where neither the input shaft 22a nor the output shaft 22b rotates synchronously. The fifth rotation angle sensor 72 and the sixth rotation angle sensor 73 output a sin signal and a cos signal according to the rotation angles of the first target 70 and the second target 71, respectively.
Specifically, the fifth rotation angle sensor 72 includes a substrate 72s as shown in FIG. Furthermore, the planar coils L1, L2 mounted on the front side surface 72a of the substrate 72s at positions where the change in inductance becomes + Sin, + Cos, -Sin, -Cos with respect to the first sinusoidal portion 70b of the first target 70. , L3, L4.

Further, as shown in FIG. 16C, the fifth rotation angle sensor 72 includes an ASIC (Application Specific IC) 72c and a peripheral circuit 72d mounted on the back side surface 72b of the substrate 72s.
In the fifth embodiment, the fifth rotation angle sensor 72 is arranged in the axial direction with respect to the first target 70 such that the planar coils L1 to L4 face the first sine wave portion 70b of the first target 70. They are placed facing each other. The sixth rotation angle sensor 73 is disposed so as to face the second target 71 in the axial direction so that the planar coils L1 to L4 face the second sine wave portion 71b of the second target 71. Yes.

  The fifth rotation angle sensor 72 applies current to the planar coils L1 to L4 to excite these planar coils, and generates an eddy current in the first target 70 by the magnetic flux generated by this excitation. Then, the peripheral circuit 72d detects a voltage change (eddy current loss) when the inductance of the planar coils L1 to L4 decreases due to the generated eddy current. This voltage change is detected as a differential signal of + Sin, + Cos, -Sin, and -Cos by the peripheral circuit 72d. The fifth rotation angle sensor 72 converts a differential signal corresponding to the rotation angle of the first target 70 detected by the peripheral circuit 72d into a single-ended signal by the ASIC 72c. Then, a first sin signal sin θis and a first cos signal cos θis, which are converted signals, are output.

On the other hand, the sixth rotation angle sensor 73 is the same as the fifth rotation angle sensor 72 in that the substrate code is 73s, the front side code is 73a, the back side code is 73b, and the ASIC code is 73c. Is replaced with 73d, and the configuration is the same as that of the fifth rotation angle sensor 72, and the description thereof is omitted.
The sixth rotation angle sensor 73 converts a differential signal corresponding to the rotation angle of the second target 71 detected by the peripheral circuit 73d into a single-ended signal in the ASIC 73c. Then, a second sin signal sin θos and a second cos signal cos θos, which are converted signals, are output.

The output first sin signal sin θis, first cos signal cos θis, second sin signal sin θos and second cos signal cos θos are sent to the first relative angle calculator 18 and the second relative angle calculator 18r in the sensor calculator 180. Entered.
The first relative angle calculator 18 of the fifth embodiment includes a first sin signal sin θis, a first cos signal cos θis, a second sin signal sin θos, and a second cos signal input from the fifth rotation angle sensor 72 and the sixth rotation angle sensor 73. From cos θos, the rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b are calculated as in the first embodiment. Then, the first relative angle Δθ is calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value between the calculated rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b. Then, the calculated first relative angle Δθ is output to the torque calculation unit 19.

  On the other hand, the second relative angle calculator 18r of the fifth embodiment calculates the above equations (1) to (4) from the input first sin signal sin θis, first cos signal cos θis, second sin signal sin θos, and second cos signal cos θos. The relative angle sine value sin Δθ and the relative angle cosine value cos Δθ are calculated based on the above. Further, from the calculated relative angle sine value sin Δθ and relative angle cosine value cos Δθ, the second relative angle Δθref is calculated as the relative angle between the input shaft 22a and the output shaft 22b according to the above equation (5).

Similarly to the first embodiment, the difference value between the second relative angle Δθref calculated by the second relative angle calculator 18 r and the first relative angle Δθ calculated by the first relative angle calculator 18 is obtained. Based on this, the abnormality determination unit 20 performs abnormality determination.
Here, in the fifth embodiment, the rotation angle θis the first target 70, i.e. the input shaft 22a is corresponding to the rotational angle theta ₁ in the appended claims, the rotation angle of the second target 71, that is, the output shaft 22b Shitaos Corresponds to the rotation angle θ ₂ in the claims. Further, the planar coils L1, L2, L3, and L4 correspond to inductance elements in the claims. In the fifth embodiment, the first relative angle Δθ corresponds to the first relative angle Δθ1 in the claims, and the second relative angle Δθref corresponds to the second relative angle Δθ2 and the second relative angle in the claims. 3 relative angle Δθref.

(Effect of 5th Embodiment)
In addition to the effects of the first to fourth embodiments, the fifth embodiment has the following effects.
The fifth relative angle detection device 700 according to the fifth embodiment has an annular first sine wave portion 70b whose radial width changes in a sine wave shape along the circumferential direction, and is arranged coaxially. Of the input shaft 22a and the output shaft 22b, the first target 70 that rotates synchronously with the input shaft 22a is provided. Furthermore, the second target 71 has an annular second sine wave portion 71b whose diametrical width changes in a sine wave shape along the circumferential direction, and rotates synchronously with the output shaft 22b of the input shaft 22a and the output shaft 22b. Is provided. Furthermore, it has a plurality of inductance elements (planar coils L1 to L4) arranged on the fixed side with a predetermined gap from the first sinusoidal portion 70b, and an eddy current loss corresponding to the rotation angle θis of the first target 70 And a fifth rotation angle sensor 72 that outputs a first sin signal representing sin θis and a first cos signal representing cos θis. Furthermore, it has a plurality of inductance elements (planar coils L1 to L4) arranged to face the fixed side with a predetermined gap from the second sinusoidal portion 71b, and eddy current loss according to the rotation angle θos of the second target 71 And a sixth rotation angle sensor 73 that outputs a second sin signal representing sin θos and a second cos signal representing cosθos. Furthermore, the rotation angle θis is calculated from θis = arctan (sinθis / cosθis) based on the first sin signal sinθis and the first cos signal cosθis, and θos = arctan (sinθos / cosθos based on the second sin signal sinθos and the second cos signal cosθos. ) From the difference value between the rotation angle θis and the rotation angle θos, and calculates a first relative angle Δθ as a relative angle between the input shaft 22a and the output shaft 22b; Is provided.

  With this configuration, it is possible to calculate the first relative angle Δθ by calculating both sin Δθ and cos Δθ, and calculating the arc tangent of the value obtained by dividing the calculated sin Δθ by cos Δθ. As a result, the torque can be calculated even in the torsional angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the first relative angle Δθ can be calculated with a small number of calculations, a more accurate torque value can be calculated.

  In the fifth relative angle detection device 700 according to the fifth embodiment, the first target 70 is a plan view of the first annular conductor 70a and the outer diameter side end of the first annular conductor 70a in plan view from the axial direction. And a first sine wave portion 70b formed in a shape that changes in a sine wave shape. Further, the second target 71 is formed by forming a second annular conductor 71a and an outer diameter side end portion of the second annular conductor 71a into a shape that changes in a sinusoidal shape in plan view from the axial direction. 71b. Further, the fifth rotation angle sensor 72 is arranged in the axial direction of the first target 70 so that the plurality of inductance elements (planar coils L1 to L4) of the fifth rotation angle sensor 72 are opposed to the first sine wave portion 70b. It arrange | positions facing one end surface. Further, the sixth rotation angle sensor 73 is arranged in the axial direction of the second target 71 such that the plurality of inductance elements (planar coils L1 to L4) of the sixth rotation angle sensor 73 are opposed to the second sine wave portion 71b. It arrange | positions facing one end surface.

With this configuration, for example, when the arrangement space in the radial direction cannot be taken with respect to the target, the rotation angle sensor can be arranged in the axially opposed manner.
In the fifth relative angle detection device 700 according to the fifth embodiment, the fifth rotation angle sensor 72 and the sixth rotation angle sensor 73 output the fifth rotation angle sensor 72 when the relative angle Δθ is 0 °. And the output of the 6th rotation angle sensor 73 is provided so that it may become the same phase. With this configuration, the relative angle Δθ can be calculated simply and accurately using the signals output from the fifth rotation angle sensor 72 and the sixth rotation angle sensor 73 as they are.

  Further, the fifth relative angle detection device 700 according to the fifth embodiment is configured such that the relative angle between the input shaft 22a and the output shaft 22b is based on the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos. A second relative angle calculator 18r that calculates sin Δθ and cos Δθ according to Δθ, and calculates a second relative angle Δθref as a relative angle between the input shaft 22a and the output shaft 22b from Δθref = arctan (sinΔθ / cosΔθ); An abnormality determination unit 20 that determines abnormality based on a difference value between the first relative angle Δθ calculated by the first relative angle calculation unit 18 and the second relative angle Δθref calculated by the second relative angle calculation unit 18r. With. With this configuration, a system abnormality is detected when the difference value between the first relative angle Δθ and the second relative angle Δθref calculated by a method different from the first relative angle Δθ is equal to or greater than a preset specified value. can do.

(Sixth embodiment)
The sixth embodiment of the present invention is the same as the first embodiment except that, instead of the first sensor unit 101 of the first embodiment, a sixth sensor unit 801 that uses an eddy current to detect the rotation angle is provided. It becomes the same structure as embodiment.
Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.

As shown in FIG. 18, the sixth torque sensor 8 according to the sixth embodiment includes a sixth relative angle detection device 800, and the sixth relative angle detection device 800 includes a sixth sensor unit 801, A sensor calculation unit 180.
As illustrated in FIG. 17A, the sixth sensor unit 801 includes a third target 80 and a fourth target 81, a seventh rotation angle sensor 82 that detects a rotation angle of the third target 80, and a fourth target. And an eighth rotation angle sensor 83 that detects a rotation angle of 81.
The third target 80 is provided with a cylindrical first cylindrical body 80a and an annular outer circumferential portion of the first cylindrical body 80a along the circumferential direction, and two sine waves are vertically symmetrical with each other in plan view. And a third sine wave portion 80b having a shape. That is, the third sinusoidal portion 80b has a shape in which the axial width changes in a sinusoidal shape.

The fourth target 81 includes a cylindrical second cylindrical body 81a and two sine wave shapes that are provided in an annular shape along the circumferential direction on the outer peripheral portion of the second cylindrical body 81a so that the two sine wave shapes are symmetrical with each other in a plan view. And a fourth sine wave-shaped portion 81b having the shape. That is, the fourth sinusoidal portion 81b has a shape in which the axial width changes to a sinusoidal shape.
The 3rd sine wave-shaped part 80b and the 4th sine wave-shaped part 81b can be comprised from conductors, such as metals, such as aluminum, steel, copper, or a plastic material containing a metal, for example.

In the sixth embodiment, the third target 80 is attached to the end of the input shaft 22a on the output shaft 22b side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the input shaft 22a. Furthermore, the fourth target 81 is attached to the end of the output shaft 22b on the input shaft 22a side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b.
The seventh rotation angle sensor 82 and the eighth rotation angle sensor 83 are provided at a fixed portion where neither the input shaft 22a nor the output shaft 22b rotates synchronously. The seventh rotation angle sensor 82 and the eighth rotation angle sensor 83 output a sin signal and a cos signal according to the rotation angles of the third target 80 and the fourth target 81, respectively.

Specifically, as shown in FIG. 17A, the seventh rotation angle sensor 82 has a curved surface along the outer peripheral surface that faces the outer peripheral surface of the third target 80. And the 7th rotation angle sensor 82 is provided with the planar coils L1, L2, L3, L4 provided on the curved surface 82a, as shown in FIG.17 (b).
That is, in the sixth embodiment, as shown in FIG. 17A, the seventh rotation angle sensor 82 is configured such that the planar coils L1 to L4 leave a predetermined gap in the third sine wave portion 80 b of the third target 80. In order to face each other, the third target 80 is arranged to face the third target 80 in the radial direction.

Here, the planar coils L <b> 1 to L <b> 4 provided on the curved surface 82 a are arranged in a positional relationship such that the change in inductance is + Sin, + Cos, −Sin, −Cos with respect to the third sine wave-shaped portion 80 b of the third target 80. Has been.
Further, as shown in FIG. 17C, the seventh rotation angle sensor 82 includes a substrate 82s inside as viewed from the surface 82b opposite to the curved surface 82a. On the surface of the substrate 82s on the curved surface 82a side. And an ASIC 82c and a peripheral circuit 82d.

  The seventh rotation angle sensor 82 applies current to the planar coils L1 to L4 to excite these planar coils, and generates an eddy current in the third target 80 by the magnetic flux generated by this excitation. Then, the peripheral circuit 82d detects a voltage change (eddy current loss) when the inductance of the planar coils L1 to L4 decreases due to the generated eddy current. This voltage change is detected as a differential signal of + Sin, + Cos, -Sin, and -Cos by the peripheral circuit 82d.

That is, the seventh rotation angle sensor 82 detects the differential signal corresponding to the rotation angle of the third target 80 by the peripheral circuit 82d, and converts the detected differential signal into a single-ended signal by the ASIC 82c. And the 1st sin signal and 1st cos signal which are the signals after conversion are output.
On the other hand, as shown in FIG. 17A, the eighth rotation angle sensor 83 has a curved surface along the outer peripheral surface that faces the outer peripheral surface of the fourth target 81.

Here, the eighth rotation angle sensor 83 has the curved surface code 83a, the surface opposite the curved surface 82a code 83b, the substrate code 83S, the ASIC code 83c, and the peripheral circuit code. Since the configuration is the same as that of the seventh rotation angle sensor 82 only by replacing with 83d, description thereof will be omitted.
And in 6th Embodiment, as shown to Fig.17 (a), as for the 8th rotation angle sensor 83, the planar coils L1-L4 leave a predetermined gap in the 4th sine wave-shaped part 81b of the 4th target 81. FIG. It arrange | positions so that it may oppose with respect to the 4th target 81 in the radial direction so that it may oppose.

Further, the eighth rotation angle sensor 83 detects a differential signal corresponding to the rotation angle of the fourth target 81 by the peripheral circuit 83d, and converts the detected differential signal into a single-ended signal by the ASIC 83c. And the 2nd sin signal and 2nd cos signal which are the signals after conversion are output.
That is, in the sixth embodiment, the seventh rotation angle sensor 82 outputs a first sin signal representing sin θis and a first cos signal representing cos θis. The eighth rotation angle sensor 83 outputs a second sin signal representing sin θos and a second cos signal representing cos θos.

These output sin θis, cos θis, sin θos, and cos θos are input to the first relative angle calculation unit 18 and the second relative angle calculation unit 18r in the sensor calculation unit 180, as shown in FIG.
The first relative angle calculation unit 18 of the sixth embodiment includes a first sin signal sin θis, a first cos signal cos θis, a second sin signal sin θos, and a second cos signal input from the seventh rotation angle sensor 82 and the eighth rotation angle sensor 83. From cos θos, the rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b are calculated as in the first embodiment. Then, the first relative angle Δθ is calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value between the calculated rotation angle θis of the input shaft 22a and the rotation angle θos of the output shaft 22b. Then, the calculated first relative angle Δθ is output to the torque calculation unit 19.

  On the other hand, the second relative angle calculator 18r of the sixth embodiment includes the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second input from the seventh rotation angle sensor 82 and the eighth rotation angle sensor 83. The relative angle sine value sin Δθ and the relative angle cosine value cos Δθ are calculated from the 2 cos signal cos θos based on the above equations (1) to (4). Further, from the calculated relative angle sine value sin Δθ and relative angle cosine value cos Δθ, the second relative angle Δθref is calculated as the relative angle between the input shaft 22a and the output shaft 22b according to the above equation (5).

Similarly to the first embodiment, the difference value between the second relative angle Δθref calculated by the second relative angle calculator 18 r and the first relative angle Δθ calculated by the first relative angle calculator 18 is obtained. Based on this, the abnormality determination unit 20 performs abnormality determination.
Here, in the sixth embodiment, the rotation angle θis the third target 80, i.e. the input shaft 22a is corresponding to the rotational angle theta ₁ in the appended claims, the rotation angle of the fourth target 81, that is, the output shaft 22b Shitaos Corresponds to the rotation angle θ ₂ in the claims. Further, the planar coils L1, L2, L3, and L4 correspond to inductance elements. In the sixth embodiment, the first relative angle Δθ corresponds to the first relative angle Δθ1 in the claims, and the second relative angle Δθref corresponds to the second relative angle Δθ2 and the second relative angle Δθ2 in the claims. 3 relative angle Δθref.

(Effect of 6th Embodiment)
In addition to the effects of the first to fifth embodiments, the sixth embodiment has the following effects.
The sixth relative angle detection device 800 according to the sixth embodiment has an annular third sine wave portion 80b whose axial width changes in a sine wave shape along the circumferential direction, and is arranged coaxially. Of the input shaft 22a and the output shaft 22b, the third target 80 that rotates synchronously with the input shaft 22a is provided. Further, the fourth target 81 has an annular fourth sine wave portion 81b whose axial width changes in a sine wave shape along the circumferential direction, and rotates synchronously with the output shaft 22b of the input shaft 22a and the output shaft 22b. Is provided. Furthermore, it has a plurality of inductance elements (planar coils L1 to L4) arranged on the fixed side with a predetermined gap from the third sinusoidal portion 80b, and eddy current loss according to the rotation angle θis of the third target 80 And a seventh rotation angle sensor 82 that outputs a first sin signal representing sin θis and a first cos signal representing cos θis. Furthermore, it has a plurality of inductance elements (planar coils L1 to L4) arranged on the fixed side with a predetermined gap from the fourth sinusoidal portion 81b, and eddy current loss according to the rotation angle θos of the fourth target 81 And an eighth rotation angle sensor 83 that outputs a second sin signal representing sin θos and a second cos signal representing cosθos. Furthermore, the rotation angle θis is calculated from θis = arctan (sinθis / cosθis) based on the first sin signal sinθis and the first cos signal cosθis, and θos = arctan (sinθos / cosθos based on the second sin signal sinθos and the second cos signal cosθos. ) From the difference value between the rotation angle θis and the rotation angle θos, and calculates a first relative angle Δθ as a relative angle between the input shaft 22a and the output shaft 22b; Is provided.

  With this configuration, it is possible to calculate the first relative angle Δθ by calculating both sin Δθ and cos Δθ, and calculating the arc tangent of the value obtained by dividing the calculated sin Δθ by cos Δθ. As a result, the torque can be calculated even in the torsional angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the first relative angle Δθ can be calculated with a small number of calculations, a more accurate torque value can be calculated.

  In the sixth relative angle detection device 800 according to the sixth embodiment, the third target 80 is provided on the outer peripheral surface of the first cylindrical body 80a and the first cylindrical body 80a in plan view. A third sine wave-shaped portion 80b having a shape that changes in a sine wave shape along the circumferential direction. Further, the fourth target 81 is provided on the outer peripheral surface of the second cylindrical body 81a and the second cylindrical body 81a, and the fourth target 81 changes in a sinusoidal shape along the circumferential direction when the outer peripheral surface is viewed in plan. And a sine wave portion 81b. The seventh rotation angle sensor 82 faces the outer peripheral surface of the third target 80 so that the plurality of inductance elements (planar coils L1 to L4) of the seventh rotation angle sensor 82 face the third sine wave portion 80b. Are arranged. Further, the eighth rotation angle sensor 83 is arranged on the outer peripheral surface of the fourth target 81 so that the plurality of inductance elements (planar coils L1 to L4) of the eighth rotation angle sensor 83 are opposed to the fourth sine wave portion 81b. Opposed to each other.

With this configuration, for example, when the arrangement space in the axial direction cannot be taken with respect to the target, the rotation angle sensor can be arranged in the radial direction.
Further, in the sixth relative angle detection device 800 according to the sixth embodiment, the seventh rotation angle sensor 82 and the eighth rotation angle sensor 83 output the seventh rotation angle sensor 82 when the relative angle Δθ is 0 °. And the output of the 8th rotation angle sensor 83 is provided so that it may become the same phase. With this configuration, the relative angle Δθ can be calculated easily and accurately using the signals output from the seventh rotation angle sensor 82 and the eighth rotation angle sensor 83 as they are.

  In addition, the sixth relative angle detection apparatus 800 according to the sixth embodiment includes a relative angle between the input shaft 22a and the output shaft 22b based on the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos. A second relative angle calculator 18r that calculates sin Δθ and cos Δθ according to Δθ, and calculates a second relative angle Δθref as a relative angle between the input shaft 22a and the output shaft 22b from Δθref = arctan (sinΔθ / cosΔθ); An abnormality determination unit 20 that determines abnormality based on a difference value between the first relative angle Δθ calculated by the first relative angle calculation unit 18 and the second relative angle Δθref calculated by the second relative angle calculation unit 18r. With. With this configuration, a system abnormality is detected when the difference value between the first relative angle Δθ and the second relative angle Δθref calculated by a method different from the first relative angle Δθ is equal to or greater than a preset specified value. can do.

(Seventh embodiment)
The seventh embodiment of the present invention includes a second sensor calculation unit 180 ′ having a partially different configuration instead of the sensor calculation unit 180 of the first embodiment, and the torque calculation unit 19 is a second sensor calculation unit. The configuration is the same as in the first embodiment except that the steering torque Ts is calculated based on the relative angle input from 180 ′.

Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
Although the seventh torque sensor 90 of the seventh embodiment is not shown in the drawing, the seventh torque sensor 1 of the first embodiment replaces the first relative angle detection device 100 with a seventh relative angle detection in the first torque sensor 1. The apparatus 102 has a configuration. The seventh relative angle detection device 102 according to the seventh embodiment includes a second sensor calculation unit 180 ′ instead of the sensor calculation unit 180 in the first relative angle detection device 100 according to the first embodiment. It has become.

As shown in FIG. 20, the second sensor calculation unit 180 ′ of the seventh embodiment uses the second relative angle Δθref calculated by the second relative angle calculation unit 18r as a torque in addition to the first adder / subtractor 190. It outputs also to the calculating part 19. The other configuration is the same as that of the sensor calculation unit 180 of the first embodiment.
On the other hand, the torque calculator 19 of the seventh embodiment includes a first relative angle Δθ input from the first relative angle calculator 18 and a second relative angle Δθref input from the second relative angle calculator 18r. The steering torque Ts is calculated based on That is, the steering torque Ts is calculated from the first relative angle Δθ and the second relative angle Δθref calculated by different calculation methods. For example, an average value Δθave between the first relative angle Δθ and the second relative angle Δθref is calculated, and the steering torque Ts is calculated from the average value Δθave.

Here, in the seventh embodiment, the first relative angle Δθ corresponds to the first relative angle Δθ1 in the means for solving the claims and the problems, and the second relative angle Δθref is the claim. This corresponds to the second relative angle Δθ2 and the third relative angle Δθref in the means for solving the problem.
In addition, the structure of 2nd sensor calculating part 180 'of 7th Embodiment and the torque calculating part 19 is applicable not only to 1st Embodiment but 2nd-6th Embodiment.

(Effect of 7th Embodiment)
In addition to the effects of the first to sixth embodiments, the seventh embodiment has the following effects.
In the seventh relative angle detection device 102 according to the seventh embodiment, the second relative angle calculation unit 18r adds the calculated second relative angle Δθref to the first adder / subtractor 190 and the torque calculation unit 19 as well. Output. The seventh torque sensor 90 according to the seventh embodiment includes a first relative angle Δθ input from the first relative angle calculation unit 18 and a second relative angle input from the second relative angle calculation unit 18r. A steering torque Ts generated in the input shaft 22a and the output shaft 22b is calculated from the angle Δθref.

  With this configuration, it is possible to calculate the steering torque Ts with higher accuracy than when only the first relative angle Δθ is used as the relative angle. For example, by calculating an average value Δθave between the first relative angle Δθ and the second relative angle Δθref, it is possible to calculate a relative angle with higher accuracy. From this average value Δθave, steering with higher accuracy can be performed. The torque Ts can be calculated.

(Eighth embodiment)
The eighth embodiment of the present invention includes a third sensor calculation unit 180A having a different configuration instead of the sensor calculation unit 180 of the first embodiment, and the torque calculation unit 19 is input from the third sensor calculation unit 180A. The configuration is the same as that of the first embodiment except that the steering torque Ts is calculated based on the relative angle.

Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
Although the eighth torque sensor 91 of the eighth embodiment is not shown in the drawing, an eighth relative angle detection is used in place of the first relative angle detection device 100 in the first torque sensor 1 of the first embodiment. The apparatus 103 is provided with a configuration. The eighth relative angle detection device 103 according to the eighth embodiment is configured to include a third sensor calculation unit 180A instead of the sensor calculation unit 180 in the first relative angle detection device 100 according to the first embodiment. ing.

As shown in FIG. 21, the third sensor calculation unit 180A of the eighth embodiment includes a third relative angle calculation unit 18A and a fourth relative angle calculation unit 18Ar.
The third relative angle calculator 18A has the same configuration as the second relative angle calculator 18r of the first embodiment. The fourth relative angle calculation unit 18Ar has the same configuration as that of the first relative angle calculation unit 18 of the first embodiment.

  Specifically, as shown in FIG. 21, the third relative angle calculator 18A includes a relative angle sine value (sin Δθ in the figure) calculator 181A, a relative angle cosine value (cos Δθ in the figure) calculator 182A, 1 relative angle (Δθ in the figure) calculation unit 183A. For example, when the steering wheel 21 is steered and the input shaft 22a rotates, if the rotation angle θos of the output shaft 22b is fixed at a predetermined angle and the rotation angle θis of the input shaft 22a changes, the input shaft 22a and the output Using the first relative angle Δθ as the relative angle to the shaft 22b, it can be expressed as sin θis = sin (θos + Δθ), cos θis = cos (θos + Δθ).

Accordingly, the relative angle sine value calculation unit 181A calculates the relative angle sine value sin Δθ according to the above equations (1) and (2), similarly to the relative angle sine value calculation unit 181r of the first embodiment. However, in the above equation (1), Δθref is replaced with Δθ.
Specifically, the relative angle sine value calculation unit 181A calculates the square value of the addition value with the input second sin signal sin θos, using the input first cos signal cos θis as cos (θos + Δθ) according to the above equation (1). To do. Further, the square value of the subtracted value from the input second cos signal cos θos is calculated using the input first sin signal sin θis as sin (θos + Δθ). Then, TMs is calculated by adding these calculated square values. Next, the relative angle sine value sin Δθ is calculated by subtracting from 1 the value obtained by dividing the calculated TMs by 2, according to the above equation (2). The calculated relative angle sine value sin Δθ is output to the first relative angle calculation unit 183A.

Further, the relative angle cosine value calculation unit 182A calculates the relative angle cosine value cosΔθ according to the above equations (3) and (4). However, in the above equation (3), Δθref is replaced with Δθ.
Specifically, the relative angle cosine value calculation unit 182A sets the input first sin signal sin θis as sin (θos + Δθ) according to the above equation (3), and squares the sum of this signal and the input second sin signal sin θos. Calculate the value. Further, the input first cos signal cos θis is set as cos (θos + Δθ), and the square value of the added value of this signal and the input second cos signal cos θos is calculated. Then, TMc is calculated by adding these calculated square values. Next, the relative angle cosine value cos Δθ is calculated by subtracting 1 from the value obtained by dividing the calculated TMc by 2 according to the above equation (4). The calculated relative angle cosine value cosΔθ is output to the first relative angle calculation unit 183A.

The first relative angle calculation unit 183A calculates the first relative angle Δθ according to the above equation (5). However, in the above equation (5), Δθref is replaced with Δθ.
Specifically, the first relative angle calculation unit 183A includes the relative angle sine value sin Δθ input from the relative angle sine value calculation unit 181A and the relative angle cosine value cos Δθ input from the relative angle cosine value calculation unit 182A. According to the above equation (5), the first relative angle Δθ is calculated as the relative angle between the input shaft 22a and the output shaft 22b by calculating the arc tangent function of the value obtained by dividing the relative angle sine value sin Δθ by the relative angle cosine value cos Δθ. To do. The calculated first relative angle Δθ is output to the torque calculator 19 and the first adder / subtractor 190.

The torque calculator 19 of the eighth embodiment calculates the steering torque Ts based on the first relative angle Δθ input from the third relative angle calculator 18A.
On the other hand, as shown in FIG. 21, the fourth relative angle calculation unit 18Ar of the eighth embodiment includes an input shaft rotation angle (θis in the drawing) calculation unit 181Ar and an output shaft rotation angle (θos in the drawing) calculation unit 182Ar. And a second relative angle (Δθref in the figure) calculation unit 183Ar.

The input shaft rotation angle calculation unit 181Ar calculates the rotation angle θis of the input shaft 22a from the arctangent function of the value obtained by dividing the input first sin signal sinθis by the first cos signal cosθis, that is, θis = arctan (sinθis / cosθis). . The calculated rotation angle θis is output to the second relative angle calculation unit 183Ar.
The output shaft rotation angle calculation unit 182Ar calculates the rotation angle θos of the output shaft 22b from the arctangent function of the value obtained by dividing the input second sin signal sinθos by the second cos signal cosθos, that is, θos = arctan (sinθos / cosθos). . The calculated rotation angle θos is output to the second relative angle calculation unit 183Ar.

The second relative angle calculation unit 183Ar calculates the second relative angle Δθref as a relative angle between the input shaft 22a and the output shaft 22b from a difference value obtained by subtracting the rotation angle θos of the output shaft 22b from the rotation angle θis of the input shaft 22a. . Then, the calculated second relative angle Δθref is output to the first adder / subtractor 190.
The first adder / subtractor 190 of the eighth embodiment is a difference value between the first relative angle Δθ calculated by the first relative angle calculator 183A and the second relative angle Δθref calculated by the second relative angle calculator 183Ar. Is calculated. Then, the calculated difference value is output to the abnormality determination unit 20.

When the absolute value of the difference value between the first relative angle Δθ and the second relative angle Δθref is equal to or greater than a predetermined value, the abnormality determination unit 20 of the eighth embodiment is somewhere in the relative angle detection device. It is determined that there is an abnormality.
Here, in the eighth embodiment, the first relative angle Δθ corresponds to the second relative angle Δθ2 in the means for solving the claims and the problems, and the second relative angle Δθref is the claims. This corresponds to the first relative angle Δθ1 and the third relative angle Δθref in the means for solving the problem.
Note that the configurations of the third sensor calculation unit 180A and the torque calculation unit 19 of the eighth embodiment are not limited to the first embodiment, and can be applied to the second to sixth embodiments.

(Effect of 8th Embodiment)
In addition to the effects of the first to sixth embodiments, the eighth embodiment has the following effects.
The eighth relative angle detection device 103 according to the eighth embodiment is the same as the eighth relative angle detection device 103, based on the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos. There is provided a third relative angle calculator 18A that calculates sin Δθ and cos Δθ according to the relative angle Δθ of 22a and the output shaft 22b, and calculates the first relative angle Δθ from Δθ = arctan (sin Δθ / cos Δθ).

The eighth torque sensor 91 according to the eighth embodiment calculates the steering torque Ts generated in the input shaft 22a and the output shaft 22b from the first relative angle Δθ calculated by the third relative angle calculation unit 18A.
With this configuration, it is possible to calculate torque even in a twist angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the first relative angle Δθ can be calculated with a small number of calculations, a more accurate torque value can be calculated.

Further, the eighth relative angle detection device 103 according to the eighth embodiment calculates the rotation angle θis from θis = arctan (sinθis / cosθis) based on the first sin signal sinθis and the first cos signal cosθis, and the second sin signal sinθos. The rotation angle θos is calculated from θos = arctan (sin θos / cos θos) based on the second cos signal cos θos, and the second relative angle Δθref between the input shaft 22a and the output shaft 22b is calculated from the difference value between the rotation angle θis and the rotation angle θos. Is provided with a fourth relative angle calculation unit 18Ar. In addition, an abnormality for determining abnormality based on a difference value between the first relative angle Δθ calculated by the third relative angle calculation unit 18A and the second relative angle Δθref calculated by the fourth relative angle calculation unit 18Ar. A determination unit 20 is provided.
With this configuration, a system abnormality is detected when the difference value between the first relative angle Δθ and the second relative angle Δθref calculated by a method different from the first relative angle Δθ is equal to or greater than a preset specified value. can do.

(Ninth embodiment)
The ninth embodiment of the present invention includes a fourth sensor calculation unit 180A ′ having a partially different configuration in place of the third sensor calculation unit 180A of the eighth embodiment, and the torque calculation unit 19 includes the fourth sensor calculation unit 180A. The configuration is the same as that of the eighth embodiment except that the steering torque Ts is calculated based on the relative angle input from the sensor calculation unit 180A ′.

Hereinafter, the same components as those in the eighth embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
Although the ninth torque sensor 92 of the ninth embodiment is not shown, the ninth torque sensor 91 of the eighth embodiment replaces the eighth relative angle detection device 103 with the ninth relative angle detection. The device 104 is configured to be provided. The ninth relative angle detection device 104 of the ninth embodiment includes a fourth sensor calculation unit 180A ′ instead of the third sensor calculation unit 180A in the eighth relative angle detection device 103 of the eighth embodiment. It becomes the composition.

As shown in FIG. 22, the fourth sensor calculation unit 180A ′ of the ninth embodiment uses the second relative angle Δθref calculated by the fourth relative angle calculation unit 18Ar as a torque in addition to the first adder / subtractor 190. It outputs also to the calculating part 19. Other configurations are the same as those of the third sensor calculation unit 180A of the eighth embodiment.
On the other hand, the torque calculator 19 of the ninth embodiment includes a first relative angle Δθ input from the third relative angle calculator 18A and a second relative angle Δθref input from the fourth relative angle calculator 18Ar. Based on this, the steering torque Ts is calculated. That is, the steering torque Ts is calculated from the first relative angle Δθ and the second relative angle Δθref calculated by different calculation methods. For example, an average value Δθave between the first relative angle Δθ and the second relative angle Δθref is calculated, and the steering torque Ts is calculated from the average value Δθave.

Here, in the ninth embodiment, the first relative angle Δθ corresponds to the second relative angle Δθ2 in the means for solving the claims and the problems, and the second relative angle Δθref is the claim. This corresponds to the first relative angle Δθ1 and the third relative angle Δθref in the means for solving the problem.
Note that the configurations of the fourth sensor calculation unit 180A ′ and the torque calculation unit 19 of the ninth embodiment are not limited to the first embodiment, and can be applied to the second to sixth embodiments.

(Effect of 9th Embodiment)
The ninth embodiment has the following effects in addition to the effects of the eighth embodiment.
In the ninth relative angle detection device 104 according to the ninth embodiment, the fourth relative angle calculation unit 18Ar adds the calculated second relative angle Δθref to the first adder / subtractor 190 and the torque calculation unit 19 as well. Output. The ninth torque sensor 92 according to the ninth embodiment includes the first relative angle Δθ input from the first relative angle calculation unit 18 and the second relative angle input from the second relative angle calculation unit 18r. A steering torque Ts generated in the input shaft 22a and the output shaft 22b is calculated from the angle Δθref.

  With this configuration, it is possible to calculate the steering torque Ts with higher accuracy than when only the first relative angle Δθ is used as the relative angle. For example, by calculating an average value Δθave between the first relative angle Δθ and the second relative angle Δθref, it is possible to calculate a relative angle with higher accuracy. From this average value Δθave, steering with higher accuracy can be performed. The torque Ts can be calculated.

(10th Embodiment)
The tenth embodiment of the present invention includes a fifth sensor calculation unit 180B having a partially different configuration instead of the sensor calculation unit 180 of the first embodiment, and the torque calculation unit 19 is a fifth sensor calculation unit 180B. The configuration is the same as that of the first embodiment except that the steering torque Ts is calculated based on the relative angle input from.

Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
Although the tenth torque sensor 93 of the tenth embodiment is not illustrated, the tenth relative angle detection is performed in place of the first relative angle detection device 100 in the first torque sensor 1 of the first embodiment. The apparatus 105 is provided with a configuration. The tenth relative angle detection device 105 of the tenth embodiment is configured to include a fifth sensor calculation unit 180B instead of the sensor calculation unit 180 in the first relative angle detection device 100 of the first embodiment. ing.

As shown in FIG. 23, the fifth sensor calculation unit 180B of the tenth embodiment includes the third relative angle calculation unit 18A of the eighth embodiment and the second relative angle calculation unit of the first embodiment. 18r.
The third relative angle calculation unit 18A of the tenth embodiment calculates Δθref from the input first sin signal sin θis, first cos signal cos θis, second sin signal sin θos, and second cos signal cos θos, as in the eighth embodiment. The relative angle sine value sin Δθ and the relative angle cosine value cos Δθ are calculated based on the above equations (1) to (4) replaced with Δθ. Further, the first relative angle Δθ is calculated from the calculated relative angle sine value sin Δθ and relative angle cosine value cos Δθ according to the above equation (5) in which Δθref is replaced with Δθ. The calculated first relative angle Δθ is output to the torque calculator 19 and the first adder / subtractor 190.

The torque calculator 19 of the tenth embodiment calculates the steering torque Ts based on the first relative angle Δθ input from the third relative angle calculator 18A.
On the other hand, the second relative angle calculation unit 18r of the tenth embodiment uses the input first sin signal sin θis, first cos signal cos θis, second sin signal sin θos, and second cos signal cos θos as in the first embodiment. The relative angle sine value sin Δθ and the relative angle cosine value cos Δθ are calculated based on the above equations (1) to (4). Further, the second relative angle Δθref is calculated from the calculated relative angle sine value sin Δθ and the relative angle cosine value cos Δθ according to the above equation (5). The calculated second relative angle Δθref is output to the first adder / subtractor 190.

In addition, the first adder / subtracter 190 of the tenth embodiment uses the first relative angle Δθ calculated by the first relative angle calculator 183A and the second relative angle Δθref calculated by the second relative angle calculator 183r. Calculate the difference value. Then, the calculated difference value is output to the abnormality determination unit 20.
When the absolute value of the difference value between the first relative angle Δθ and the second relative angle Δθref is equal to or larger than a predetermined value, the abnormality determination unit 20 of the tenth embodiment is somewhere in the relative angle detection device. It is determined that there is an abnormality.

Here, in the tenth embodiment, the second relative angle Δθref is the second relative angle Δθ2 of any one of the plurality of second relative angles Δθ2 in the means for solving the claims and the problems, and This corresponds to the third relative angle Δθref. The first relative angle Δθ corresponds to the remaining second relative angle Δθ2 among the plurality of second relative angles Δθ2 in the means for solving the claims and the problems.
In addition, the structure of the 5th sensor calculating part 180B and the torque calculating part 19 of 10th Embodiment is applicable not only to 1st Embodiment but 2nd-6th Embodiment.

(Effect of 10th Embodiment)
In addition to the effects of the first to sixth embodiments, the tenth embodiment has the following effects.
The tenth relative angle detection device 105 according to the tenth embodiment is synchronized with the input shaft 22a among the input shaft 22a and the output shaft 22b that are arranged on the same axis and are alternately arranged with different magnetic poles in the circumferential direction. The first multipole ring magnet 10 that rotates, the second multipole ring magnet 11 that rotates alternately in synchronism with the output shaft 22b of the input shaft 22a and the output shaft 22b, and the first multipole ring magnet 11 that rotates in synchronization with the output shaft 22b The first rotation angle sensor 12 that detects the magnetic flux according to the rotation angle θis of the multipolar ring magnet 10 and outputs the first sin signal sinθis and the first cos signal cosθis, and the rotation angle θos of the second multipole ring magnet 11 The second rotation angle sensor 13 for detecting the detected magnetic flux and outputting the second sin signal sin θos and the second cos signal cos θos, the first sin signal sin θis, the first cos signal cos θis, and the second si Based on the signal sinθos and the second cos signal cosθos, sinΔθ and cosΔθ corresponding to the relative angle Δθ between the input shaft 22a and the output shaft 22b are calculated, and a first relative angle Δθ is calculated from Δθ = arctan (sinΔθ / cosΔθ). The relative angle calculation unit 18A is provided.

  With this configuration, the rotation angle θis is calculated from the arctangent function obtained by dividing the first sin signal sinθis by the first cos signal cosθis, and the arctangent function obtained by dividing the second sin signal sinθos by the second cos signal cosθos. The rotation angle θos can be calculated, and the first relative angle Δθ can be calculated as the relative angle between the input shaft 22a and the output shaft 22b from the difference value between the calculated rotation angle θis and the rotation angle θos. As a result, the torque can be calculated even in a twist angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the first relative angle Δθ can be calculated with a small number of calculations, a more accurate torque value can be calculated.

  Further, the tenth relative angle detection device 105 according to the tenth embodiment includes a relative angle between the input shaft 22a and the output shaft 22b based on the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos. The sin Δθ and cos Δθ corresponding to Δθ are calculated, and calculated by the second relative angle calculation unit 18r that calculates the second relative angle Δθref from Δθref = arctan (sin Δθ / cos Δθ) and the third relative angle calculation unit 18A. And an abnormality determination unit 20 that determines an abnormality based on a difference value between the first relative angle Δθ and the second relative angle Δθref calculated by the second relative angle calculation unit 18r.

With this configuration, a system abnormality is detected when the difference value between the first relative angle Δθ and the second relative angle Δθref calculated by the same method as the first relative angle Δθ is equal to or greater than a preset specified value. can do. Thereby, it is possible to reduce an error due to a difference in calculation method.
In the tenth relative angle detection device 105 according to the tenth embodiment, the second relative angle calculation unit 18r and the third relative angle calculation unit 18A are based on the above formulas (1) to (2). The angle sine value sin Δθ is calculated, and the relative angle cosine value cos Δθ is calculated based on the above equations (3) to (4). With this configuration, the relative angle sine value sinΔθ and the relative angle cosine value cosΔθ are simply and accurately calculated by calculation using the signals output from the first rotation angle sensor 12 and the second rotation angle sensor 13 as they are. Can do.

  In addition, the tenth torque sensor 93 according to the tenth embodiment is a first relative of the input shaft 22a and the output shaft 22b that are connected by the torsion bar 22c by the tenth relative angle detection device 105 according to the tenth embodiment. A torque calculation unit 19 is provided that detects the angle Δθ and calculates the steering torque Ts generated in the input shaft 22a and the output shaft 22b from the first relative angle Δθ. With this configuration, operations and effects equivalent to those of the tenth relative angle detection device 105 can be obtained.

(Eleventh embodiment)
The eleventh embodiment of the present invention includes a sixth sensor calculation unit 180B ′ having a partially different configuration instead of the fifth sensor calculation unit 180B of the tenth embodiment, and the torque calculation unit 19 includes a sixth sensor calculation unit 180B. The configuration is the same as that of the tenth embodiment except that the steering torque Ts is calculated based on the relative angle input from the sensor calculation unit 180B ′.

Hereinafter, the same components as those in the tenth embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
Although the eleventh torque sensor 94 of the eleventh embodiment is not shown in the figure, the tenth torque sensor 93 of the tenth embodiment replaces the tenth relative angle detection device 105 with an eleventh relative angle detection. The apparatus 106 is provided. The eleventh relative angle detection device 106 of the eleventh embodiment includes a sixth sensor calculation unit 180B ′ instead of the fifth sensor calculation unit 180B in the tenth relative angle detection device 105 of the tenth embodiment. It becomes the composition.

As shown in FIG. 24, the sixth sensor calculation unit 180B ′ of the eleventh embodiment uses the second relative angle Δθref calculated by the second relative angle calculation unit 18r as a torque in addition to the first adder / subtractor 190. It outputs also to the calculating part 19. Other configurations are the same as those of the fifth sensor calculation unit 180B of the tenth embodiment.
On the other hand, the torque calculator 19 of the eleventh embodiment includes a first relative angle Δθ input from the third relative angle calculator 18A and a second relative angle Δθref input from the second relative angle calculator 18r. Based on this, the steering torque Ts is calculated. That is, the steering torque Ts is calculated from the first relative angle Δθ and the second relative angle Δθref calculated by the same calculation method. For example, an average value Δθave between the first relative angle Δθ and the second relative angle Δθref is calculated, and the steering torque Ts is calculated from the average value Δθave.

Here, in the eleventh embodiment, the second relative angle Δθref is the second relative angle Δθ2 of any one of the plurality of second relative angles Δθ2 in the means for solving the claims and the problems, and This corresponds to the third relative angle Δθref. The first relative angle Δθ corresponds to the remaining second relative angle Δθ2 among the plurality of second relative angles Δθ2 in the means for solving the claims and the problems.
Note that the configurations of the sixth sensor calculation unit 180B ′ and the torque calculation unit 19 of the eleventh embodiment are not limited to the first embodiment and can be applied to the second to sixth embodiments.

(Effect of 11th Embodiment)
The eleventh embodiment has the following effects in addition to the effects of the tenth embodiment.
In the eleventh relative angle detection device 106 according to the eleventh embodiment, the second relative angle calculation unit 18r adds the calculated second relative angle Δθref to the first adder / subtractor 190 and the torque calculation unit 19 as well. Output. The eleventh torque sensor 94 detects the first relative angle Δθ and the second relative angle Δθref of the input shaft 22a and the output shaft 22b connected by the torsion bar 22c, and detects the detected first relative angle Δθ and second A steering torque Ts generated in the input shaft 22a and the output shaft 22b is calculated from the relative angle Δθref.

  With this configuration, it is possible to calculate the steering torque Ts with higher accuracy than when only the first relative angle Δθ is used as the relative angle. For example, by calculating an average value Δθave between the first relative angle Δθ and the second relative angle Δθref, it is possible to calculate a relative angle with higher accuracy. From this average value Δθave, steering with higher accuracy can be performed. The torque Ts can be calculated.

(Twelfth embodiment)
The twelfth embodiment of the present invention includes a seventh sensor calculation unit 180C having a partially different configuration in place of the sensor calculation unit 180 of the first embodiment, and the torque calculation unit 19 is a seventh sensor calculation unit 180C. The configuration is the same as that of the first embodiment except that the steering torque Ts is calculated based on the relative angle input from.

Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
Although the twelfth torque sensor 95 of the twelfth embodiment is not shown, in the first torque sensor 1 of the first embodiment described above, a twelfth relative angle detection is used instead of the first relative angle detection device 100. The device 107 is provided. The twelfth relative angle detection device 107 of the twelfth embodiment is configured to include a seventh sensor calculation unit 180C instead of the sensor calculation unit 180 in the first relative angle detection device 100 of the first embodiment. ing.

As shown in FIG. 25, the seventh sensor calculation unit 180C of the twelfth embodiment is the same as the sensor calculation unit 180 of the first embodiment, except that the fifth relative angle calculation unit 18B, the second adder / subtractor 191, The third adder / subtractor 192 is added.
The first relative angle calculator 18 of the twelfth embodiment calculates the first relative angle Δθ by the same calculation method as in the first embodiment. Then, the calculated first relative angle Δθ is output to the first adder / subtracter 190 and the third adder / subtractor 192.

The second relative angle calculation unit 18r of the twelfth embodiment calculates the second relative angle Δθref by the same calculation method as in the first embodiment. The calculated second relative angle Δθref is output to the first adder / subtractor 190 and the second adder / subtractor 191.
On the other hand, the fifth relative angle calculator 18B of the twelfth embodiment has the same configuration as the second relative angle calculator 18r of the first embodiment.

Specifically, as shown in FIG. 25, the fifth relative angle calculation unit 18B includes a relative angle sine value (sin Δθ in the figure) calculation unit 181B, a relative angle cosine value (cos Δθ in the figure) calculation unit 182B, 3 relative angle (Δθx in the figure) calculation unit 183B.
The relative angle sine value calculation unit 181B calculates the relative angle sine value sin Δθ according to the above equations (1) and (2), similarly to the relative angle sine value calculation unit 181r of the first embodiment. However, in the above equation (1), Δθref is replaced with Δθx.

  Specifically, the relative angle sine value calculation unit 181B sets the input first cos signal cos θis as cos (θos + Δθx) according to the above equation (1), and squares the sum of this signal and the input second sin signal sin θos. Calculate the value. Further, the input first sin signal sin θis is set as sin (θos + Δθx), and the square value of the subtraction value from this signal and the input second cos signal cos θos is calculated. Then, TMs is calculated by adding these calculated square values. Next, the relative angle sine value sin Δθ is calculated by subtracting from 1 the value obtained by dividing the calculated TMs by 2, according to the above equation (2). The calculated relative angle sine value sinΔθ is output to the third relative angle calculation unit 183B.

Further, the relative angle cosine value calculation unit 182B calculates the relative angle cosine value cosΔθ according to the above equations (3) and (4). However, in the above equation (3), Δθref is replaced with Δθx.
Specifically, the relative angle cosine value calculation unit 182B sets the input first sin signal sin θis as sin (θos + Δθx) according to the above equation (3), and squares the sum of this signal and the input second sin signal sin θos. Calculate the value. Further, the input first cos signal cos θis is set as cos (θos + Δθx), and the square value of the addition value of this signal and the input second cos signal cos θos is calculated. Then, TMc is calculated by adding these calculated square values. Next, the relative angle cosine value cos Δθ is calculated by subtracting 1 from the value obtained by dividing the calculated TMc by 2 according to the above equation (4). The calculated relative angle cosine value cosΔθ is output to the third relative angle calculation unit 183B.

The third relative angle calculation unit 183B calculates the third relative angle Δθx according to the above equation (5). However, in the above equation (5), Δθref is replaced with Δθx.
Specifically, the third relative angle calculation unit 183B includes the relative angle sine value sin Δθ input from the relative angle sine value calculation unit 181B and the relative angle cosine value cos Δθ input from the relative angle cosine value calculation unit 182B. The relative angle between the input shaft 22a and the output shaft 22b is calculated as the third relative angle Δθx by calculating the arctangent function of the value obtained by dividing the relative angle sine value sin Δθ by the relative angle cosine value cos Δθ according to the above equation (5). To do. The calculated third relative angle Δθx is output to the second adder / subtractor 191 and the third adder / subtractor 192.

The torque calculator 19 of the twelfth embodiment calculates the steering torque Ts based on the first relative angle Δθ input from the first relative angle calculator 18.
The first adder / subtracter 190 of the twelfth embodiment is a first difference between the first relative angle Δθ calculated by the first relative angle calculator 183 and the second relative angle Δθref calculated by the second relative angle calculator 183r. The difference value of is calculated. Then, the calculated first difference value is output to the abnormality determination unit 20.

On the other hand, the second adder / subtractor 191 of the twelfth embodiment uses the second relative angle Δθref calculated by the second relative angle calculator 183r and the third relative angle Δθx calculated by the third relative angle calculator 183B. The second difference value is calculated. Then, the calculated second difference value is output to the abnormality determination unit 20.
The third adder / subtractor 192 of the twelfth embodiment uses the first relative angle Δθ calculated by the first relative angle calculator 183 and the third relative angle Δθx calculated by the third relative angle calculator 183B. A third difference value is calculated. Then, the calculated third difference value is output to the abnormality determination unit 20.

  The abnormality determination unit 20 of the twelfth embodiment includes a first difference value between the first relative angle Δθ and the second relative angle Δθref, and a second difference value between the second relative angle Δθref and the third relative angle Δθx. The abnormality determination is performed based on the third difference value between the first relative angle Δθ and the third relative angle Δθx. For example, if the absolute value of any one difference value is greater than or equal to a preset specified value, it is determined that there is an abnormality somewhere in the relative angle detection device, and if both are less than the specified value, It is determined that the angle detection device is normal.

Here, in the twelfth embodiment, the second relative angle Δθref is one of the first relative angle Δθ1 and the second relative angle Δθ2 in the means for solving the claims and the problem. This corresponds to the third relative angle Δθref (here, the second relative angle Δθ2).
In the twelfth embodiment, the first relative angle Δθ and the third relative angle Δθx are the remaining of the first relative angle Δθ1 and the second relative angle Δθ2 in the means for solving the claims and the problem. Corresponds to the relative angle.
The configurations of the seventh sensor calculation unit 180C and the torque calculation unit 19 of the twelfth embodiment are not limited to the first embodiment, and can be applied to the second to sixth embodiments.

(Effect of 12th Embodiment)
In addition to the effects of the first to sixth embodiments, the twelfth embodiment has the following effects.
The twelfth relative angle detection device 107 according to the twelfth embodiment is synchronized with the input shaft 22a out of the input shaft 22a and the output shaft 22b that are arranged on the same axis and arranged with different magnetic poles alternately in the circumferential direction. The first multipole ring magnet 10 that rotates, the second multipole ring magnet 11 that rotates alternately in synchronization with the output shaft 22b of the input shaft 22a and the output shaft 22b, and the first multipole ring magnet 11 that rotates in synchronization with the output shaft 22b of the output shaft 22b. The first rotation angle sensor 12 that detects the magnetic flux according to the rotation angle θis of the multipolar ring magnet 10 and outputs the first sin signal sinθis and the first cos signal cosθis, and the rotation angle θos of the second multipole ring magnet 11 Based on the second rotation angle sensor 13 that detects the detected magnetic flux and outputs the second sin signal sin θos and the second cos signal cos θos, and the first sin signal sin θis and the first cos signal cos θis. The rotation angle θis is calculated from θis = arctan (sin θis / cos θis), and the rotation angle θos is calculated from θos = arctan (sin θos / cos θos) based on the second sin signal sin θos and the second cos signal cos θos, and the rotation angle θis and the rotation angle are calculated. A first relative angle calculation unit 18 that calculates a first relative angle Δθ between the input shaft 22a and the output shaft 22b from a difference value from θos is provided.

  With this configuration, the rotation angle θis is calculated from the arctangent function obtained by dividing the first sin signal sinθis by the first cos signal cosθis, and the arctangent function obtained by dividing the second sin signal sinθos by the second cos signal cosθos. The rotation angle θos is calculated, and the first relative angle Δθ between the input shaft 22a and the output shaft 22b can be calculated from the difference value between the calculated rotation angle θis and the rotation angle θos. As a result, the torque can be calculated even in a twist angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the first relative angle Δθ can be calculated with a small number of calculations, a more accurate torque value can be calculated.

  In addition, the twelfth relative angle detection device 107 according to the twelfth embodiment is configured such that the input shaft 22a and the output shaft 22b are based on the first sin signal sin θis, the first cos signal cos θis, the second sin signal sin θos, and the second cos signal cos θos. A sin Δθ and a cos Δθ corresponding to Δθ are calculated, a second relative angle calculation unit 18r for calculating a second relative angle Δθref from Δθref = arctan (sin Δθ / cos Δθ), a first sin signal sin θis, a first cos signal cos θis, and a second sin Based on the signal sinθos and the second cos signal cosθos, sinΔθ and cosΔθ corresponding to the relative angle Δθ between the input shaft 22a and the output shaft 22b are calculated, and a third relative angle Δθx is calculated from Δθ2 = arctan (sinΔθ / cosΔθ). Relative angle calculation unit 18B and the first relative angle calculation unit 18 The first difference value between the calculated first relative angle Δθ and the second relative angle Δθref calculated by the second relative angle calculation unit 18r, and the second relative value calculated by the second relative angle calculation unit 18r. The second difference value between the angle Δθref and the third relative angle Δθx calculated by the fifth relative angle calculation unit 18B, the first relative angle Δθ calculated by the first relative angle calculation unit 18, and the fifth And an abnormality determination unit 20 that determines abnormality based on the third difference value from the third relative angle Δθx calculated by the relative angle calculation unit 18B.

  With this configuration, for example, when the first difference value between the first relative angle Δθ and the second relative angle Δθref calculated by a method different from the first relative angle Δθ is equal to or larger than a preset specified value, or When the second difference value between the second relative angle Δθref and the third relative angle Δθx calculated by the same method as the second relative angle Δθref is equal to or greater than a specified value, or the first relative angle Δθ and the third relative angle A system abnormality can be detected when the third difference value from Δθx is equal to or greater than a specified value. On the other hand, for example, when any difference value is less than a specified value, it can be determined that the system is normal. Further, by comparing the three difference values of the first difference value, the second difference value, and the third difference value, it is possible to determine which relative angle calculation unit has an abnormality.

  In the twelfth relative angle detection device 107 according to the twelfth embodiment, the second relative angle calculation unit 18r and the fifth relative angle calculation unit 18B are based on the above equations (1) to (2). The angle sine value sin Δθ is calculated, and the relative angle cosine value cos Δθ is calculated based on the above equations (3) to (4). With this configuration, the relative angle sine value sinΔθ and the relative angle cosine value cosΔθ are simply and accurately calculated by calculation using the signals output from the first rotation angle sensor 12 and the second rotation angle sensor 13 as they are. Can do.

(13th Embodiment)
The thirteenth embodiment of the present invention includes an eighth sensor calculation unit 180C ′ having a partially different configuration in place of the seventh sensor calculation unit 180C of the twelfth embodiment, and the torque calculation unit 19 has an eighth configuration. The configuration is the same as that of the twelfth embodiment except that the steering torque Ts is calculated based on the relative angle input from the sensor calculation unit 180C ′.

Hereinafter, the same components as those in the twelfth embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
Although the thirteenth torque sensor 96 of the thirteenth embodiment is not shown in the drawing, the twelfth torque sensor 95 of the twelfth embodiment replaces the twelfth relative angle detection device 107 with a thirteenth relative angle detection. The apparatus 108 is provided. The thirteenth relative angle detection device 108 of the thirteenth embodiment includes an eighth sensor calculation unit 180C ′ instead of the seventh sensor calculation unit 180C in the twelfth relative angle detection device 107 of the twelfth embodiment. It becomes the composition.

  As shown in FIG. 26, the eighth sensor calculation unit 180C ′ of the thirteenth embodiment uses the second relative angle Δθref calculated by the second relative angle calculation unit 18r as a torque in addition to the first adder / subtractor 190. It outputs also to the calculating part 19. In addition, the third relative angle Δθx calculated by the fifth relative angle calculation unit 18B is output to the torque calculation unit 19 in addition to the second adder / subtractor 191. Other configurations are the same as those of the seventh sensor calculation unit 180C of the twelfth embodiment.

  On the other hand, the torque calculator 19 of the thirteenth embodiment includes a first relative angle Δθ input from the first relative angle calculator 18 and a second relative angle Δθref input from the second relative angle calculator 18r. The steering torque Ts is calculated based on the third relative angle Δθx input from the fifth relative angle calculation unit 18B. That is, steering is performed from the first relative angle Δθ, the second relative angle Δθref calculated by a different calculation method from the first relative angle Δθ, and the third relative angle Δθx calculated by the same calculation method as the second relative angle Δθref. Torque Ts is calculated. For example, an average value Δθave of the first relative angle Δθ, the second relative angle Δθref, and the third relative angle Δθx is calculated, and the steering torque Ts is calculated from the average value Δθave.

Here, in the thirteenth embodiment, the second relative angle Δθref is one of the first relative angle Δθ1 and the second relative angle Δθ2 in the means for solving the claims and the problem. This corresponds to the third relative angle Δθref (here, the second relative angle Δθ2).
In the thirteenth embodiment, the first relative angle Δθ and the third relative angle Δθx are the remaining of the first relative angle Δθ1 and the second relative angle Δθ2 in the means for solving the claims and the problem. Corresponds to the relative angle.
Note that the configurations of the eighth sensor calculation unit 180C ′ and the torque calculation unit 19 of the thirteenth embodiment are not limited to the first embodiment, and can be applied to the second to sixth embodiments.

(Effect of 13th Embodiment)
The thirteenth embodiment has the following effects in addition to the effects of the twelfth embodiment.
In the thirteenth relative angle detection device 108 according to the thirteenth embodiment, the second relative angle calculation unit 18r adds the calculated second relative angle Δθref to the first adder / subtractor 190 and the torque calculation unit 19 also. Output. In addition, the fifth relative angle calculation unit 18B outputs the calculated third relative angle Δθx to the torque calculation unit 19 in addition to the second adder / subtractor 191. The twelfth torque sensor 95 according to the thirteenth embodiment includes the first relative angle Δθ input from the first relative angle calculation unit 18 and the second relative angle input from the second relative angle calculation unit 18r. The steering torque Ts generated in the input shaft 22a and the output shaft 22b is calculated from the angle Δθref and the third relative angle Δθx input from the fifth relative angle calculation unit 18B.

  With this configuration, it is possible to calculate the steering torque Ts with higher accuracy than when only the first relative angle Δθ is used as the relative angle. For example, by calculating the average value Δθave of the first relative angle Δθ, the second relative angle Δθref, and the third relative angle Δθx, it is possible to calculate a relative angle with higher accuracy, and this average value Δθave Therefore, it is possible to calculate the steering torque Ts with higher accuracy.

(Modification)
In the fourth embodiment, the first code wheel 60 and the second code wheel 61 are provided with a plurality of slits in the vicinity of the outer peripheral portion of the plate surface along the circumferential direction, and light source light passing through the slits is received. However, the present invention is not limited to this configuration. For example, an annular thin plate of the first code wheel 60 and the second code wheel 61 is formed of a non-reflective member, and the reflective shape of, for example, the same shape is used instead of a slit along the circumferential direction in the vicinity of the outer peripheral portion of the plate surface. It is good also as a structure which provides a member and receives the reflected light of the light source light which injected into the reflective member in a light-receiving part.

  In the fourth embodiment, the first sin optical sensor 64 and the first cos optical sensor 65 are phase-shifted by 90 ° in electrical angle with respect to the pitch of the slits 60s (in a state having a phase difference of 90 °). And a configuration in which the second sin optical sensor 66 and the second cos optical sensor 67 are phase-shifted by 90 ° in electrical angle with respect to the pitch of the slit 61s (with a phase difference of 90 °). did. Not limited to this configuration, two slit rows having the same pitch are provided in the radial direction, and the other slit phase is shifted in phase in the radial direction by an electrical angle of 90 ° (having a phase difference of 90 °). It is good also as a structure arrange | positioned in a state. In the case of this configuration, for example, two optical sensors are arranged in the radial direction and fixedly arranged in the same phase, and the optical sensors are arranged so as to be able to receive the light source light transmitted through the slits for each slit row. However, the sensor on the inner diameter side cannot be made U-shaped due to installation problems, so the sensor configuration must be changed.

  In the first and second embodiments, the first sin signal and the first cos signal are output by the two magnetic sensors of the first sin magnetic sensor and the first cos magnetic sensor, and the two sin sensors of the second sin magnetic sensor and the second cos magnetic sensor are output. Although the second sin signal and the second cos signal are output by the magnetic sensor, the present invention is not limited to this configuration. For example, the first sin signal and the first cos signal may be output from one first magnetic sensor, and the second sin signal and the second cos signal may be output from one second magnetic sensor.

  In the fifth embodiment, the first and second sinusoidal portions 70b and 71b are formed at the outer diameter side ends of the first and second annular conductors 70a and 71a. However, the present invention is not limited to this configuration. Absent. For example, an annular conductor pattern whose radial width changes in a sinusoidal shape along the circumferential direction is attached to one axial end surface of a cylindrical body (not limited to a conductor) that rotates synchronously with the input shaft 22a or the output shaft 22b. It is good also as another structure, such as setting it as the structure provided.

  In the sixth embodiment, the third and fourth sinusoidal portions 80b and 81b are provided on the outer peripheral surfaces of the first and second cylindrical bodies 80a and 81a. However, the present invention is not limited to this configuration. For example, the third and fourth sinusoidal portions 80b and 81b may be provided on the inner peripheral surfaces of the first and second cylindrical bodies 80a and 81a. In this configuration, the seventh and eighth rotation angle sensors 82 and 83 are also provided inside the first and second cylindrical bodies 80a and 81a.

Further, in each of the above embodiments, the EPS control unit 34 is described as an example of a configuration in which the EPS control unit 34 is fixedly supported on the housing of the electric motor 33. Other configurations, such as disposing at a position, may be used.
In each of the above embodiments, a three-phase brushless motor has been described as an example of the electric motor 33. However, the present invention is not limited to this configuration, and the electric motor 33 may be configured by a brushless motor having four or more phases, or a brush motor. It is good also as other structures, such as comprising.
In each of the above embodiments, the example in which the present invention is applied to a column assist type electric power steering apparatus has been described. However, the present invention is not limited to this configuration, and is applied to, for example, a rack assist type or pinion assist type electric power steering apparatus. It is good also as a structure.

DESCRIPTION OF SYMBOLS 1 1st torque sensor 2 Electric power steering apparatus 3 Vehicle 4 2nd torque sensor 5 3rd torque sensor 6 4th torque sensor 7 5th torque sensor 8 6th torque sensor 10 1st multipole ring magnet DESCRIPTION OF SYMBOLS 11 2nd multipolar ring magnet 12 1st rotation angle sensor 13 2nd rotation angle sensor 14 1st sin magnetic sensor 15 1st cos magnetic sensor 16 2sin magnetic sensor 17 2nd cos magnetic sensor 18 1st relative angle calculating part 18r 2nd Relative angle calculation unit 19 torque calculation unit 20 abnormality determination unit 21 steering wheel 22 steering shaft 22a input shaft 22b output shaft 22c torsion bar 40 third multipolar ring magnet 41 fourth multipolar ring magnet 50 first resolver 51 second resolver 52 1st rotor 53 1st stator 54 2nd 55 Second stator 56 Excitation signal supply unit 60 First code wheel 61 Second code wheel 62 Third rotation angle sensor 63 Fourth rotation angle sensor 64 First sin optical sensor 65 First cos optical sensor 66 Second sin optical sensor 67 First 2 cos optical sensor 70 first target 70b first sine wave portion 71 second target 71b second sine wave portion 72 fifth rotation angle sensor 73 sixth rotation angle sensor 80 third target 80b third sine wave portion 81 fourth target 81b Fourth sinusoidal portion 82 Seventh rotation angle sensor 83 Eighth rotation angle sensor 90 Seventh torque sensor 91 Eighth torque sensor 92 Ninth torque sensor 93 Tenth torque sensor 94 Eleventh torque sensor 95 Torque sensor 96 thirteenth torque sensor 1 00 first relative angle detection device 102 seventh relative angle detection device 103 eighth relative angle detection device 104 ninth relative angle detection device 105 tenth relative angle detection device 106 eleventh relative angle detection device 107 first Twelve relative angle detection devices 108 Thirteenth relative angle detection device 180 Sensor calculation unit 180 ′ Second sensor calculation unit 180A Third sensor calculation unit 180A ′ Fourth sensor calculation unit 180B Fifth sensor calculation unit 180B ′ Sixth sensor calculation unit 180C Seventh sensor calculation unit 180C ′ Eighth sensor calculation unit 400 Second relative angle detection device 500 Third relative angle detection device 600 Fourth relative angle detection device 700 Fifth relative Angle detection device 800 Sixth relative angle detection device

Claims (22)

A first multipolar ring magnet that rotates synchronously with the first rotating shaft of the first rotating shaft and the second rotating shaft that are alternately arranged in the circumferential direction and that are arranged coaxially;
Magnetic poles different from each other in the circumferential direction are alternately arranged, and a second multipolar ring magnet that rotates synchronously with the second rotating shaft of the first rotating shaft and the second rotating shaft;
A first rotation angle sensor that detects a magnetic flux corresponding to the rotation angle θ ₁ of the first multipolar ring magnet and outputs a first sin signal representing sin θ ₁ and a first cos signal representing cos θ ₁ ;
A second rotation angle sensor for detecting a magnetic flux corresponding to the rotation angle θ ₂ of the second multipolar ring magnet and outputting a _second sin signal representing sin θ ₂ and a _second cos signal representing cos θ ₂ ;
A plurality of relative angle calculators for calculating a relative angle Δθ between the first rotating shaft and the second rotating shaft based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal; Prepared,
The plurality of relative angle calculation units are
The rotation angle θ ₁ is calculated based on the first sin signal and the first cos signal, and the rotation angle θ ₂ is calculated based on the second sin signal and the second cos signal, and the rotation angle θ ₁ and the rotation are calculated. One or more first relative angle calculation units for calculating a first relative angle Δθ1 between the first rotation axis and the second rotation axis from a difference value with respect to the angle θ ₂ ;
Based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan One or more second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from (sin Δθ / cos Δθ),
Either one of the first relative angle Δθ1 calculated by the first relative angle calculation unit and the second relative angle Δθ2 calculated by the second relative angle calculation unit is set as a third relative angle. As the angle Δθref, an abnormality determination unit is provided that determines an abnormality based on a difference value between the third relative angle Δθref and the remaining relative angles among the first relative angle Δθ1 and the second relative angle Δθ2. Relative angle detection device. A first multipolar ring magnet that rotates synchronously with the first rotating shaft of the first rotating shaft and the second rotating shaft that are alternately arranged in the circumferential direction and that are arranged coaxially;
Magnetic poles different from each other in the circumferential direction are alternately arranged, and a second multipolar ring magnet that rotates synchronously with the second rotating shaft of the first rotating shaft and the second rotating shaft;
A first rotation angle sensor that detects a magnetic flux corresponding to the rotation angle θ ₁ of the first multipolar ring magnet and outputs a first sin signal representing sin θ ₁ and a first cos signal representing cos θ ₁ ;
A second rotation angle sensor for detecting a magnetic flux corresponding to the rotation angle θ ₂ of the second multipolar ring magnet and outputting a _second sin signal representing sin θ ₂ and a _second cos signal representing cos θ ₂ ;
A plurality of relative angle calculators for calculating a relative angle Δθ between the first rotating shaft and the second rotating shaft based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal; Prepared,
The plurality of relative angle calculation units are
Based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan A plurality of second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from (sin Δθ / cos Δθ);
Any one of the plurality of second relative angles Δθ2 calculated by the plurality of second relative angle calculation units is set as a third relative angle Δθref, and the third relative angle Δθref and each of the remaining ones. A relative angle detection device including an abnormality determination unit that determines abnormality based on a difference value with at least one of two relative angles Δθ2. The first multi-pole ring magnet and the second multi-pole ring magnet are formed by magnetizing portions of the outer peripheral surface to different magnetic poles alternately in the circumferential direction,
In the first rotation angle sensor, a magnetic flux detection unit of the first rotation angle sensor is disposed to face a magnetic pole surface formed on an outer peripheral surface of the first multipolar ring magnet,
3. The second rotation angle sensor is configured such that a magnetic flux detection unit included in the second rotation angle sensor is opposed to a magnetic pole surface formed on an outer peripheral surface of the second multipolar ring magnet. The relative angle detection device described in 1. The first multi-pole ring magnet and the second multi-pole ring magnet are formed by magnetizing a portion of one end face in the axial direction to different magnetic poles alternately in the circumferential direction,
The first rotation angle sensor is disposed so that a magnetic flux detection unit of the first rotation angle sensor is opposed to a magnetic pole surface formed on one end surface in the axial direction of the first multipolar ring magnet,
In the second rotation angle sensor, the magnetic flux detecting portion of the second rotation angle sensor is disposed to face a magnetic pole surface formed on one end surface in the axial direction of the second multipolar ring magnet. The relative angle detection device according to any one of claims 1 to 3. The first rotation angle sensor is disposed with a phase difference of 90 ° in electrical angle with respect to the magnetic pole pitch of the first multipolar ring magnet, and outputs the first sin signal. A first cos magnetic sensor for outputting the first cos signal;
The second rotation angle sensor is arranged with a phase difference of 90 ° in electrical angle with respect to the pitch of the magnetic poles of the second multi-pole ring magnet, and outputs a second sin signal. 5. The relative angle detection device according to claim 1, further comprising a second cos magnetic sensor that outputs the second cos signal. 6. A first rotor that has a plurality of teeth on the outer periphery at equal intervals and that is coaxially disposed and rotates synchronously with the first rotation shaft of the first rotation shaft and the second rotation shaft;
A second rotor in which different magnetic poles are alternately arranged in the circumferential direction, and rotates synchronously with the second rotation shaft of the first rotation shaft and the second rotation shaft;
A first stator that is arranged concentrically with the first rotor on the outside of the first rotor, has a plurality of poles formed at equal intervals on the inner periphery, and has an armature winding formed by a coil wound around each pole; ,
A second stator disposed concentrically with the second rotor on the outer side of the second rotor, with a plurality of poles formed at equal intervals on the inner periphery, and armature windings formed by coils wound around the poles; ,
An excitation signal supply unit for supplying an excitation signal to the coil;
A _first sin signal representing sin θ ₁ and a first cos signal representing cos θ _1, which are output from the coil of the first stator when the excitation signal is supplied and correspond to the rotation angle θ ₁ of the first rotor; Based on the second sin signal representing sin θ ₂ and the _second cos signal representing cos θ ₂ output from the coil of the second stator when the excitation signal is supplied and corresponding to the rotation angle θ ₂ of the second rotor. A plurality of relative angle calculation units for calculating a relative angle Δθ between the first rotation axis and the second rotation axis;
The plurality of relative angle calculation units are
The rotation angle θ ₁ is calculated based on the first sin signal and the first cos signal, and the rotation angle θ ₂ is calculated based on the second sin signal and the second cos signal, and the rotation angle θ ₁ and the rotation are calculated. One or more first relative angle calculation units for calculating a first relative angle Δθ1 between the first rotation axis and the second rotation axis from a difference value with respect to the angle θ ₂ ;
Based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan One or more second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from (sin Δθ / cos Δθ),
Either one of the first relative angle Δθ1 calculated by the first relative angle calculation unit and the second relative angle Δθ2 calculated by the second relative angle calculation unit is set as a third relative angle. As the angle Δθref, an abnormality determination unit is provided that determines an abnormality based on a difference value between the third relative angle Δθref and the remaining relative angles among the first relative angle Δθ1 and the second relative angle Δθ2. Relative angle detection device. A first rotor that has a plurality of teeth on the outer periphery at equal intervals and that is coaxially disposed and rotates synchronously with the first rotation shaft of the first rotation shaft and the second rotation shaft;
A second rotor in which different magnetic poles are alternately arranged in the circumferential direction, and rotates synchronously with the second rotation shaft of the first rotation shaft and the second rotation shaft;
A first stator that is arranged concentrically with the first rotor on the outside of the first rotor, has a plurality of poles formed at equal intervals on the inner periphery, and has an armature winding formed by a coil wound around each pole; ,
A second stator disposed concentrically with the second rotor on the outer side of the second rotor, with a plurality of poles formed at equal intervals on the inner periphery, and armature windings formed by coils wound around the poles; ,
An excitation signal supply unit for supplying an excitation signal to the coil;
A _first sin signal representing sin θ ₁ and a first cos signal representing cos θ _1, which are output from the coil of the first stator when the excitation signal is supplied and correspond to the rotation angle θ ₁ of the first rotor; Based on the second sin signal representing sin θ ₂ and the _second cos signal representing cos θ ₂ output from the coil of the second stator when the excitation signal is supplied and corresponding to the rotation angle θ ₂ of the second rotor. A plurality of relative angle calculation units for calculating a relative angle Δθ between the first rotation axis and the second rotation axis;
The plurality of relative angle calculation units are
Based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan A plurality of second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from (sin Δθ / cos Δθ);
Any one of the plurality of second relative angles Δθ2 calculated by the plurality of second relative angle calculation units is set as a third relative angle Δθref, and the third relative angle Δθref and each of the remaining ones. A relative angle detection device including an abnormality determination unit that determines an abnormality based on a difference value between two relative angles Δθ2. A first code wheel having a plurality of slits formed at equal intervals in the circumferential direction and rotating synchronously with the first rotating shaft among the first rotating shaft and the second rotating shaft arranged coaxially; ,
A second code wheel having a plurality of slits formed at equal intervals in the circumferential direction and rotating synchronously with the second rotation shaft of the first rotation shaft and the second rotation shaft;
Light source, and the 1sin signal and cos [theta] ₁ of emitted light represents sin [theta ₁ in accordance with the rotation angle theta ₁ of the first code the first code wheel by receiving the light transmitted through the slit of the wheel from the light source A first rotation angle sensor having a light receiving unit that outputs a first cos signal representing
A light source and a _second sin signal and cos θ ₂ representing sin θ ₂ corresponding to the rotation angle θ ₂ of the second code wheel by receiving the transmitted light transmitted from the slit of the second code wheel by the light emitted from the light source. A second rotation angle sensor having a light receiving unit that outputs a second cos signal representing
A plurality of relative angle calculators for calculating a relative angle Δθ between the first rotating shaft and the second rotating shaft based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal; Prepared,
The plurality of relative angle calculation units are
The rotation angle θ ₁ is calculated based on the first sin signal and the first cos signal, and the rotation angle θ ₂ is calculated based on the second sin signal and the second cos signal, and the rotation angle θ ₁ and the rotation are calculated. One or more first relative angle calculation units for calculating a first relative angle Δθ1 between the first rotation axis and the second rotation axis from a difference value with respect to the angle θ ₂ ;
Based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan One or more second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from (sin Δθ / cos Δθ),
Either one of the first relative angle Δθ1 calculated by the first relative angle calculation unit and the second relative angle Δθ2 calculated by the second relative angle calculation unit is set as a third relative angle. As the angle Δθref, an abnormality determination unit is provided that determines an abnormality based on a difference value between the third relative angle Δθref and the remaining relative angles among the first relative angle Δθ1 and the second relative angle Δθ2. Relative angle detection device. A first code wheel having a plurality of slits formed at equal intervals in the circumferential direction and rotating synchronously with the first rotating shaft among the first rotating shaft and the second rotating shaft arranged coaxially; ,
A second code wheel having a plurality of slits formed at equal intervals in the circumferential direction and rotating synchronously with the second rotation shaft of the first rotation shaft and the second rotation shaft;
Light source, and the 1sin signal and cos [theta] ₁ of emitted light represents sin [theta ₁ in accordance with the rotation angle theta ₁ of the first code the first code wheel by receiving the light transmitted through the slit of the wheel from the light source A first rotation angle sensor having a light receiving unit that outputs a first cos signal representing
A light source and a _second sin signal and cos θ ₂ representing sin θ ₂ corresponding to the rotation angle θ ₂ of the second code wheel by receiving the transmitted light transmitted from the slit of the second code wheel by the light emitted from the light source. A second rotation angle sensor having a light receiving unit that outputs a second cos signal representing
A plurality of relative angle calculators for calculating a relative angle Δθ between the first rotating shaft and the second rotating shaft based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal; Prepared,
The plurality of relative angle calculation units are
Based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan A plurality of second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from (sin Δθ / cos Δθ);
Any one of the plurality of second relative angles Δθ2 calculated by the plurality of second relative angle calculation units is set as a third relative angle Δθref, and the third relative angle Δθref and each of the remaining ones. A relative angle detection device including an abnormality determination unit that determines an abnormality based on a difference value between two relative angles Δθ2. The first rotating shaft and the second rotating shaft that have an annular first conductor portion whose width in the radial direction or the axial direction changes in a sine wave shape along the circumferential direction, and are arranged coaxially. A first target that rotates synchronously with the rotation axis;
It has an annular second conductor portion whose width in the radial direction or the axial direction changes in a sine wave shape along the circumferential direction, and rotates synchronously with the second rotation shaft among the first rotation shaft and the second rotation shaft A second target to
A plurality of inductance elements arranged on the fixed side with a predetermined gap from the first conductor portion, and detecting an eddy current loss corresponding to the rotation angle θ ₁ of the first target to express sin θ ₁ A first rotation angle sensor that outputs a ₁ sin signal and a _first cos signal representing cos θ ₁ ;
A plurality of inductance elements arranged opposite to the fixed side with a predetermined gap from the second conductor portion, and detecting an eddy current loss according to the rotation angle θ ₂ of the second target to express sin θ ₂ A second rotation angle sensor that outputs a ₂ sin signal and a _second cos signal representing cos θ ₂ ;
A plurality of relative angle calculators for calculating a relative angle Δθ between the first rotating shaft and the second rotating shaft based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal; Prepared,
The plurality of relative angle calculation units are
The rotation angle θ ₁ is calculated based on the first sin signal and the first cos signal, and the rotation angle θ ₂ is calculated based on the second sin signal and the second cos signal, and the rotation angle θ ₁ and the rotation are calculated. One or more first relative angle calculation units for calculating a first relative angle Δθ1 between the first rotation axis and the second rotation axis from a difference value with respect to the angle θ ₂ ;
Based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan One or more second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from (sin Δθ / cos Δθ),
Either one of the first relative angle Δθ1 calculated by the first relative angle calculation unit and the second relative angle Δθ2 calculated by the second relative angle calculation unit is set as a third relative angle. As the angle Δθref, an abnormality determination unit is provided that determines an abnormality based on a difference value between the third relative angle Δθref and the remaining relative angles among the first relative angle Δθ1 and the second relative angle Δθ2. Relative angle detection device. The first rotating shaft and the second rotating shaft that have an annular first conductor portion whose width in the radial direction or the axial direction changes in a sine wave shape along the circumferential direction, and are arranged coaxially. A first target that rotates synchronously with the rotation axis;
It has an annular second conductor portion whose width in the radial direction or the axial direction changes in a sine wave shape along the circumferential direction, and rotates synchronously with the second rotation shaft among the first rotation shaft and the second rotation shaft A second target to
A plurality of inductance elements arranged on the fixed side with a predetermined gap from the first conductor portion, and detecting an eddy current loss corresponding to the rotation angle θ ₁ of the first target to express sin θ ₁ A first rotation angle sensor that outputs a ₁ sin signal and a _first cos signal representing cos θ ₁ ;
A plurality of inductance elements arranged opposite to the fixed side with a predetermined gap from the second conductor portion, and detecting an eddy current loss according to the rotation angle θ ₂ of the second target to express sin θ ₂ A second rotation angle sensor that outputs a ₂ sin signal and a _second cos signal representing cos θ ₂ ;
A plurality of relative angle calculators for calculating a relative angle Δθ between the first rotating shaft and the second rotating shaft based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal; Prepared,
The plurality of relative angle calculation units are
Based on the first sin signal, the first cos signal, the second sin signal, and the second cos signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated, and Δθ2 = arctan A plurality of second relative angle calculation units for calculating a second relative angle Δθ2 between the first rotation axis and the second rotation axis from (sin Δθ / cos Δθ);
Any one of the plurality of second relative angles Δθ2 calculated by the plurality of second relative angle calculation units is set as a third relative angle Δθref, and the third relative angle Δθref and each of the remaining ones. A relative angle detection device including an abnormality determination unit that determines an abnormality based on a difference value between two relative angles Δθ2. The first conductor portion is formed in a shape that changes in a sinusoidal shape when viewed from the axial direction on the outer diameter side end portion of the first annular conductor,
The second conductor portion is formed in a shape that changes in a sinusoidal shape in plan view from the axial direction on the outer diameter side end portion of the second annular conductor,
The first rotation angle sensor is opposed to one end surface in the axial direction of the first target such that the plurality of inductance elements of the first rotation angle sensor are opposed to the sinusoidal portion of the first conductor portion. Arranged,
The second rotation angle sensor is opposed to one end surface in the axial direction of the second target such that the plurality of inductance elements of the second rotation angle sensor are opposed to the sinusoidal portion of the second conductor portion. The relative angle detection device according to claim 10 or 11, wherein the relative angle detection device is disposed. The first target includes a first cylindrical body, and the first conductor portion is provided on the outer peripheral surface of the first cylindrical body so as to change in a sinusoidal shape along the circumferential direction when the outer peripheral surface is viewed in plan view. And
The second target includes a second cylindrical body, and the second conductor portion is provided on the outer peripheral surface of the second cylindrical body so as to change in a sinusoidal shape along the circumferential direction when the outer peripheral surface is viewed in plan view. And
The first rotation angle sensor is disposed to face the outer peripheral surface of the first target so that the plurality of inductance elements of the first rotation angle sensor face the first conductor portion.
The second rotation angle sensor is disposed to face the outer peripheral surface of the second target so that the plurality of inductance elements of the second rotation angle sensor face the second conductor portion. Or the relative angle detection device according to 11.   The first rotation angle sensor and the second rotation angle sensor are provided so that the output of the first rotation angle sensor and the output of the second rotation angle sensor are in phase when the relative angle Δθ is 0 °. The relative angle detection device according to claim 1, wherein the relative angle detection device is used.   The first stator and the second stator are provided such that when the relative angle Δθ is 0 °, the output of the coil of the first stator and the output of the coil of the second stator are in phase. Item 8. The relative angle detection device according to Item 6 or 7.   The first rotation angle sensor and the second rotation angle sensor are provided so that the output of the first rotation angle sensor and the output of the second rotation angle sensor are in phase when the relative angle Δθ is 0 °. The relative angle detection device according to claim 8, wherein the relative angle detection device is used. The sin θ ₁ and the cos θ ₁ are defined as sin (θ ₂ + Δθ2) and cos (θ ₂ + Δθ2), respectively.
The second relative angle calculation unit calculates the sin Δθ based on the following equations (1) to (2), and calculates the cos Δθ based on the following equations (3) to (4). The relative angle detection device according to claim 1.
TMs = (sin θ ₂ + cos (θ ₂ + Δθ2)) ² + (cos θ ₂ −sin (θ ₂ + Δθ2)) ² (1)
sin Δθ = −TMs / 2 + 1 (2)
TMc = (sin θ ₂ + sin (θ ₂ + Δθ2)) ² + (cos θ ₂ + cos (θ ₂ + Δθ2)) ² (3)
cos Δθ = TMc / 2-1 (4)   The relative angle detection device according to any one of claims 1 to 17 detects a relative angle between an input shaft and an output shaft connected by a torsion bar, and the relative angle is generated in the input shaft and the output shaft. A torque sensor including a torque calculation unit that calculates torque.   The first relative angle Δθ1 and the second relative angle Δθ2 of the input shaft and the output shaft connected by the torsion bar are detected by the relative angle detection device according to any one of claims 1, 6, 8, and 10. And a torque sensor including a torque calculation unit that calculates torque generated in the input shaft and the output shaft from at least the first relative angle Δθ1 of the detected first relative angle Δθ1 and second relative angle Δθ2.   A plurality of second relative angles Δθ2 of the input shaft and the output shaft connected by the torsion bar are detected by the relative angle detection device according to any one of claims 2, 7, 9 and 11, and the detected plurality of A torque sensor comprising a torque calculator that calculates torque generated in the input shaft and the output shaft from at least one of the second relative angles Δθ2.   An electric power steering apparatus comprising the torque sensor according to any one of claims 18 to 20.   A vehicle comprising the electric power steering device according to claim 21.

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