JP2002122495A - Rotation angle detector, torque detector and steering system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation angle detector and a torque detector capable of detecting the damage of a target, the failure of a magnetic sensor or the failure of an arithmetic processing part in the event thereof, and to provide a steering system. SOLUTION: Two targets 2, 2 are disposed in a vertically spaced manner at an input shaft 31, and two targets 2, 2 are disposed in a vertically spaced manner at an output shaft 32. Magnetic sensors 1A, 1B, 1C, 1D, 2A, 2B, 2C, 2D are disposed to face the respective targets 2, 2, 2, 2. The output of the magnetic sensors 1A, 1C, 2A, 2C is supplied to an arithmetic processing part 42. The respective arithmetic processing parts 41, 42 individually compute the rotation angles of the input shaft 31 and output shaft 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle detecting device for detecting a rotation angle of a rotating shaft, a torque detecting device for detecting a rotating torque applied to the rotating shaft, and a steering device for an automobile provided with these devices.

[0002]

2. Description of the Related Art FIG. 6 is a schematic diagram showing a configuration of a main part of a conventional steering device. As shown in the figure, an input shaft 31 whose upper end is connected to a steering wheel (steering wheel) 30 and an output shaft 32 whose lower end is connected to a pinion 33 of a steering mechanism are coaxially connected via a torsion bar 34. A steering shaft 3 that is connected to communicate the steering wheel 30 and a steering mechanism is configured.

The input shaft 31 is provided with a magnetic target 2 having a plurality of inclined portions 20, 20,... Near the end on the side of connection with the output shaft 32. Inclined part 20, 2
0,... Each have a plate shape that is inclined at substantially the same angle with respect to the axial length direction of the input shaft 31, and the respective inclined portions 20, 2
0,... Are arranged such that the respective ends of the two adjacent inclined portions 20, 20 on the side adjacent to each other are substantially at the same position in the circumferential direction of the input shaft 31. Similarly, the output shaft 32 has a plurality of inclined portions 2 near the end on the connection side with the input shaft 31.
A target 2 made of a magnetic material having 0, 20,... Is provided.

[0004] Outside such targets 2 and 2,
At two different positions in the circumferential direction of the steering shaft 3, two sensor boxes 1 a,
1b is arranged. These sensor boxes 1a, 1b
Is fixedly supported on a stationary part such as a housing that supports the input shaft 31 and the output shaft 32.

In one sensor box 1a, a magnetic sensor 1A facing the target 2 on the input shaft 31 side is provided.
And a magnetic sensor 1B opposed to the target 2 on the output shaft 32 side are accommodated so as to be aligned in the circumferential direction. Similarly, inside the sensor box 1b, a magnetic sensor opposed to the target 2 on the input shaft 31 side is provided. The magnetic sensor 2 </ b> A and the magnetic sensor 2 </ b> B facing the target 2 on the output shaft 32 side are accommodated so as to be aligned in the circumferential direction.

[0006] Magnetic sensors 1A, 1B, 2A, 2B is configured to vary the output voltage in response to changes in the ambient magnetic field, these outputs _{V A, V B, v A} , v B , the microprocessor Is given to the arithmetic processing unit 4 using.

FIG. 7 is an explanatory diagram showing an output waveform of a magnetic sensor 1A used in a conventional steering device. When the target 2 has eight inclined portions 20, 20,..., The inclined portions 20, 20,. Part 2
The arrangement pattern of 0, 20,..., As shown in FIG. 7A, includes eight parallel plates that are inclined at substantially the same angle with respect to the axial length direction of the input shaft 31 (vertical direction in the figure). The adjacent ends of the adjacent plates are in the circumferential direction of the input shaft 31 (lateral direction in the figure).
The patterns are arranged as if they were aligned.

When the input shaft 31 rotates, the inclined portion 20,
20 pass near the magnetic sensor 1A. The magnetic sensor 1A generates a low output voltage when the portion of the inclined portion 20 passing therethrough that is closest to the magnetic sensor 1A is near the lower end of the inclined portion 20,
When the portion is near the upper end of the inclined portion 20, a high output voltage is generated. Further, between the vicinity of the lower end and the vicinity of the upper end, a magnetic material close to the upper end is provided. To generate an output voltage proportional to the vertical position.

Accordingly, the voltage waveform of the output _VA of the magnetic sensor 1A is substantially linear with a period corresponding to the circumferential length of the inclined portion 20 facing the magnetic sensor 1A, as shown in FIG. Waveform. Correspondence to the rotational angle of each 45 ° of input shaft 31 such an output V _A, the combined use of coefficients of lift count output V _A, is possible to detect the rotation angle of the input shaft 31 from the output V _A it can. The magnetic sensors 1B, 2A, and 2B have the same configuration.

The magnetic sensor 1A and the magnetic sensor 2A
Are arranged so that one is located near the end of the inclined portion 20 and the other is located near the center of the other inclined portion 20, and the magnetic sensor 1B and the magnetic sensor 2B have the same arrangement. It is in a state. Therefore, the magnetic sensor 1
When one of the outputs A and 2A (magnetic sensors 1B and 2B) is not in a linearly changing region (hereinafter, referred to as a linear changing region), the other output is in a linear changing region and always has two outputs. Are in the linearly changing region. Then, among the outputs of the magnetic sensors 1A and 2A (magnetic sensors 1B and 2B), an output in a linear change region is selected, and the rotation angle is detected using the selected output.

Then, by obtaining a difference between the detected rotation angle of the input shaft 31 and the rotation angle of the output shaft 32, the rotation torque applied to the steering wheel 30 is obtained, and the rotation angle and the rotation angle thus obtained are obtained. An electric motor (not shown) connected to the output shaft 32 is driven by using the rotational torque to perform steering assist.

[0012]

In the conventional steering apparatus as described above, one target 2, 2 is attached to the input shaft 31 and the output shaft 32, respectively. Two magnetic sensors 1A, 2A and 1B, 2B are provided in association with each other, and the arithmetic processing unit 4 determines the rotation angle and the rotation torque based on the outputs of these magnetic sensors 1A, 1B, 2A, 2B. , The target 2 is damaged and the magnetic sensors 1A,
If a failure occurs in any of 1B, 2A, 2B or a failure occurs in the arithmetic processing unit 4, damage to the target 2
The failure of the magnetic sensors 1A, 1B, 2A, 2B and the failure of the arithmetic processing unit 4 cannot be detected. Therefore, when such damage or failure occurs, the steering device malfunctions. There was a problem.

If the target 2 on the input shaft 31 side is damaged, or if any of the magnetic sensors 1A, 2A fails, the rotation angle of the input shaft 31 cannot be calculated accurately. If the target 2 on the output shaft 32 side is damaged, or if any of the magnetic sensors 1B, 2B fails, the rotation angle of the output shaft 32 cannot be accurately calculated.

Further, since only one arithmetic processing unit 4 is provided, if a failure occurs in this, the rotation angle of the input shaft 31, the rotation angle of the output shaft 32, and the rotation torque are determined. There was a problem that it was not possible to calculate accurately.

The present invention has been made in view of such circumstances, and has a plurality of targets provided on a rotating shaft, a detection unit for detecting a portion of a target close to each target, and each of the detection units Arithmetic units are provided for calculating the rotation angles individually based on the parts to be detected, and by determining whether or not the rotation angles calculated by these arithmetic units match each other, one of the targets is damaged, A rotation angle detection device that can detect any of these breakages or failures when a failure occurs in any of the units, or a failure occurs in any of the operation units, and can suppress the occurrence of malfunctions; An object of the present invention is to provide a torque detecting device that detects a rotational torque applied to a rotating shaft by using the same, and a steering device including the same.

Another object of the present invention is to provide a plurality of targets on a rotating shaft, a detection unit for detecting a portion of a target close to each target, and based on the portions detected by the respective detection units. By providing a calculation unit for calculating the rotation angle separately, one of these targets may be damaged, a failure may occur in any of the detection units, or a failure may occur in any of the calculation units. Also, a rotation angle detection device that can calculate an accurate rotation angle using another normal target, a detection unit, and a calculation unit, a torque detection device that detects a rotation torque applied to a rotation shaft using the rotation detection device, and It is to provide a steering device provided with these.

Still another object of the present invention is to provide a rotation angle detecting unit having targets provided at a plurality of positions on a rotating shaft, and a detecting unit arranged to face each of the targets and detecting a portion of the facing target. , Provided at each of two locations separated in the axial length direction of the rotation shaft, based on the portion detected by the detection unit of one rotation angle detection unit, calculates the rotation angle of the rotation shaft separately, the other A plurality of calculation units for individually calculating a rotation angle of the rotation shaft based on the portion detected by the detection unit of the rotation angle detection unit, wherein the rotation axis is calculated based on the rotation angle calculated by each calculation unit. By determining the rotational torque of any of these targets, even if one of these targets is damaged and a failure occurs in one of the detection units or a failure occurs in any of the calculation units, Normal Getto, detector, and to provide a steering apparatus comprising a torque detecting device, and it capable of calculating the precise rotational angle and torque by using an arithmetic unit.

[0018]

According to a first aspect of the present invention, there is provided a rotation angle detecting device provided on a rotating shaft so that a detected portion periodically and continuously changes as the rotating shaft rotates. And a rotation angle detection device including a detection unit that is disposed to face the target and detects a portion of the target facing the target, and a calculation unit that calculates a rotation angle of the rotation shaft based on the portion detected by the detection unit. The target is disposed at each of a plurality of positions in the axial direction of the rotation shaft, and the detection unit and the calculation unit are provided separately for each target. Is characterized in that it comprises a determination means for determining whether or not the calculated rotation angles match.

In the case of the rotation angle detecting device according to the first aspect of the invention, a plurality of targets are provided on the rotation shaft, a detection unit is provided for each target, and the rotation angles are individually determined based on the parts detected by the respective detection units. Are provided, and determination means for determining whether or not the rotation angles calculated by these calculation units match each other is provided. The rotation angles calculated by the respective calculation units should match, and if they do not match, one of the targets is damaged, a failure occurs in any of the detection units, or a change occurs in any of the calculation units. This is when a failure occurs. Therefore, when the determination means determines that the rotation angles do not match, it can be determined that the target has been damaged, the detection unit has failed, or the calculation unit has failed. Failure can be detected.

Further, a plurality of targets are provided on the rotating shaft,
By providing a detection unit for each target, and providing a calculation unit for calculating each rotation angle based on the target part detected by each detection unit, one of these targets is damaged, and the detection unit If one of them fails,
Or even if a failure occurs in any of the arithmetic units,
An accurate rotation angle can be calculated using another normal target, a detection unit, and a calculation unit, and occurrence of a malfunction of the device can be suppressed.

According to a second aspect of the present invention, there is provided a torque detecting device which is provided at a plurality of positions in a direction of an axis length of a rotating shaft, and a portion to be detected changes periodically and continuously as the rotating shaft rotates. And a rotation angle detector having a plurality of detectors respectively disposed opposite to the plurality of targets and respectively detecting portions of the targets facing each other, at two locations separated in the axial length direction of the rotation shaft. Based on the parts that are provided by the detection units that both rotation angle detection units have,
A torque detection device for detecting a rotation torque applied to the rotation shaft, wherein the first rotation calculates a rotation angle of the rotation shaft separately based on a part detected by each detection unit of one rotation angle detection unit. A plurality of calculation units each having a second rotation angle calculation unit for individually calculating the rotation angle of the rotation shaft based on a part detected by each of the detection units of the angle calculation unit and the other rotation angle detection unit; First determining means for determining whether the rotation angles calculated by the first rotation angle calculating means match each other, and determining whether the rotation angles calculated by the second rotation angle calculating means match each other. And a second determining means for determining the rotational torque based on a difference between the rotational angles calculated by the first rotational angle calculating means and the second rotational angle calculating means, respectively.

In the case of the torque detecting device according to the second invention, the first discriminating means discriminates whether or not the rotation angles calculated by each of the first rotation angle calculating means coincide with each other. By determining whether or not the rotation angles calculated by each of the two rotation angle calculation means match, the first rotation angle is calculated.
If the discriminating means or the second discriminating means determines that the rotation angles do not match, damage of the target, failure of the detection unit,
Alternatively, it can be determined that a failure has occurred in the arithmetic unit, and therefore, such breakage or failure can be detected.

Further, by providing a rotation angle detecting section having a plurality of targets and a plurality of detecting sections at two locations separated in the axial direction of the rotating shaft, respectively, and by providing a plurality of calculating sections, damage to the target can be achieved. Even if a failure of the detection unit or a failure of the calculation unit occurs, it is possible to obtain an accurate rotation angle and a rotation torque of the rotating shaft by using another normal target, the detection unit, and the calculation unit. Thus, occurrence of a malfunction of the device can be suppressed.

A torque detecting device according to a third aspect of the present invention is the torque detecting device according to the second aspect of the present invention, wherein the rotating shaft comprises a first shaft and a second shaft connected coaxially through a torsion bar.
The rotation angle detection unit is disposed near a connection between the first shaft and the second shaft.

In the case of the torque detecting device according to the third aspect of the present invention, the first axis and the second axis are provided with the rotation angle detecting parts, respectively, so that the torsion bar is twisted between the first axis and the second axis. The difference between the generated rotation angles is obtained based on the target portion detected by the detection units included in both the rotation angle detection units, and the rotation torque applied to the first axis and the second axis is detected using the result. Therefore, even when the target is damaged, a failure occurs in the detection unit, and a failure occurs in the calculation unit, an accurate rotation angle and rotation torque can be obtained, and occurrence of a malfunction of the device can be suppressed. Can be.

A torque detecting device according to a fourth aspect of the present invention is the torque detecting device according to the second or third aspect, wherein the first discriminating means or the second discriminating means determines that the rotation angles do not match. Based on the rotation angles calculated by each of the first rotation angle calculation means and each of the second rotation angle calculation means, the identification means for specifying a damaged target, a detection unit in which a failure has occurred, or an operation unit in which a failure has occurred, It is further characterized by being provided.

[0027] In the case of the torque detecting device according to the fourth aspect of the present invention, the specifying means uses the rotation angle calculated by each of the first rotation angle calculation means and each of the second rotation angle calculation means to determine whether the damaged target or the failure has occurred. Where the detection has occurred,
Alternatively, by specifying the calculation unit in which the failure has occurred, the result of the calculation unit that calculates the incorrect rotation angle and rotation torque can be prevented from being used. Therefore, even when the target is damaged, a failure occurs in the detection unit, and a failure occurs in the calculation unit, an accurate rotation angle and rotation torque can be obtained, and occurrence of a malfunction of the device can be suppressed. Can be.

According to a fifth aspect of the present invention, there is provided a steering device according to the first aspect, wherein a steering shaft for connecting a steering wheel and a steering mechanism is used as the rotation axis. It is characterized by including one or both of the torque detecting devices according to any of them.

In the case of the steering device according to the fifth invention, one or both of the rotation detection device according to the first invention and the torque detection device according to any one of the second to fourth inventions are used as a steering device for an automobile. By applying, even if a target is damaged, a detection unit fails, or a calculation unit fails, the rotation angle (steering angle) of the steering shaft and the rotation torque (steering torque) applied to the steering shaft To get accurate detection values for
Since these results can be used for various controls such as drive control of a steering assist motor, the occurrence of malfunction of the device can be suppressed.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. (Embodiment 1) FIG. 1 is a schematic diagram showing a configuration of a main part of Embodiment 1 of a steering device according to the present invention. As shown in the figure, an input shaft 31 whose upper end is connected to a steering wheel (steering wheel) 30 and an output shaft 32 whose lower end is connected to a pinion 33 of a steering mechanism are connected to a small-diameter torsion bar 34.
And a steering shaft 3 for connecting the steering wheel 30 and a steering mechanism coaxially with each other.

The input shaft 31 has two annular targets 2, 2 made of a magnetic material having a plurality of inclined portions 20, 20,... Near the connection end with the output shaft 32. It is coaxially fixed and spaced apart in the axial direction. Inclined part 2
, 0, 20,... Each have a plate shape that is inclined at substantially the same angle with respect to the axial length direction of the input shaft 31, and each of the inclined portions 2
, 0, 20,... Are arranged such that the ends of two adjacent inclined portions 20, 20 on the side close to each other are substantially at the same position in the circumferential direction of the input shaft 31. Similarly, output shaft 3
2, two targets 2, 2 made of a magnetic material having a plurality of inclined portions 20, 20,... Near the end on the connection side with the input shaft 31 are separated from each other in the axial direction of the output shaft 32. Is provided.

In the first embodiment, the target 2 is configured such that the inclined portions 20, 20,... Protrude outward. However, the present invention is not limited to this. For example, the input shaft 31 and the output shaft 32 may be provided around the entire circumference of the target 2 and groove-shaped inclined portions 20, 20,... May be provided.

Outside the targets 2, 2, 2, 2, two sensors are provided at two different positions in the circumferential direction of the steering shaft 3 so as to face the outer edges of the targets 2, 2, 2, 2, respectively. Boxes 1a and 1b are provided. The sensor boxes 1a and 1b are fixedly supported on a stationary part such as a housing that supports the input shaft 31 and the output shaft 32.

In one sensor box 1a, a magnetic sensor 1 facing the target 2 above the input shaft 31 is provided.
A, a magnetic sensor 1B facing the target 2 below the input shaft 31, a magnetic sensor 1C facing the target 2 above the output shaft 32, and a magnetic sensor facing the target 2 below the output shaft 32. 1D are accommodated in the sensor box 1b with the magnetic sensor 2A facing the target 2 above the input shaft 31 and the target 2 below the input shaft 31 inside the sensor box 1b. Opposite magnetic sensor 2B and target 2 above output shaft 32
The magnetic sensor 2C facing the target 2 and the magnetic sensor 2D facing the target 2 below the output shaft 32 are housed so as to be aligned in the circumferential direction.

Magnetic sensors 1A, 1B, 1C, 1D, 2
A, 2B, 2C, and 2D are magnetoresistive elements (MR elements).
Electrical characteristics (resistance) change due to the action of a magnetic field
Output in response to changes in the surrounding magnetic field.
These sensors are configured to change the force voltage.
Output V_A, V_B, V_C, V_D, V_A, V_B, V_C, V
_DIs pulled out of the sensor boxes 1a and 1b, and
Of these, the output V_A, V _C, V_A, V_CIs a micro
It is given to an arithmetic processing unit 41 using a processor,
Force V_B, V_D, V_B, V_DIs the same as the arithmetic processing unit 41
It is provided to the arithmetic processing unit 42 having the configuration.

FIG. 2 shows the magnetic sensors 1A, 1C, 2A, 2
FIG. 9 is an explanatory diagram showing an output waveform of C. In the figure, the horizontal axis indicates the rotation angle of the input shaft 31 or the output shaft 32, the solid line in the figure indicates the output voltages of the magnetic sensors 1A and 2A on the input shaft 31, and the broken line indicates the magnetic voltage on the output shaft 32 side. Sensor 1C, 2
The output voltage of C is shown.

As described above, the inclined portions 20, 20,.
The protrusions are made of a magnetic material and are arranged side by side on the outer periphery of the input shaft 31 and the output shaft 32 at a predetermined inclination angle with respect to the axial direction. Therefore, when the input shaft 31 and the output shaft 32 rotate around the axis, the magnetic sensors 1A, 1C, 2A, and 2C rotate the input shaft 31 or the output shaft 32 when the corresponding intermediate portion of the inclined portion 20 passes. A voltage signal that changes linearly according to a change in the angle is output. In addition, the magnetic sensors 1A, 1
As C, 2A, and 2C approach the end of the inclined portion 20, the output voltage starts to gradually change to the opposite side, and the magnetic sensors 1A, 1C, 2A, and 2C pass through the inclined portion 20, and When it reaches a position facing the end of the adjacent inclined portion 20, a voltage signal of the opposite polarity is output.
The output waveforms of the magnetic sensors 1B, 1D, 2B, and 2D are the same as those described above.

As a result, the magnetic sensors 1A, 1C, 2A,
As shown in FIG. 2, the output voltage of 2C (1B, 1D, 2B, 2D) changes linearly during the passage of the intermediate portion of each inclined portion 20 (linearly changing region), and the output voltage of each inclined portion 20 varies. A change which repeats a non-linear change area (non-linear change area) while passing near the end is shown. The cycle of this repetition corresponds to the number of juxtaposed inclined portions 20, 20,... On the outer periphery of the target 2, and eight targets 2
When 0, 20,... Are arranged side by side, repetition occurs in which one cycle is a period during which the input shaft 31 or the output shaft 32 rotates by 45 ° (= 360 ° / 8).

Output of the magnetic sensors 1A and 2A (1B and 2B)
Force voltage V_A, V_A(V_B, V_B) These are opposite
A target 2 having inclined portions 20, 20, ... is provided.
Corresponding to the rotation angle of the input shaft 31 and the magnetic sensor 1
Output voltage V of C, 2C (1D, 2D)_C, V_C(V_D,
v_D) Have inclined portions 20, 20,.
The rotation angle of the output shaft 32 provided with the target 2
Corresponding. Therefore, the magnetic sensors 1A, 2A (1B, 2
Output voltage V of B)_A, V_A(V_B, V_B) Based on
The rotation angle of the force shaft 31 is determined by the magnetic sensors 1C, 2C (1D,
2D) output voltage V _C, V_C(V_D, V_D)On the basis of the
The rotation angle of the output shaft 32 can be calculated separately.

On the other hand, the difference between the output voltage V _C of the output voltage V _A and the magnetic sensor 1C of the magnetic sensor 1A ΔV1 (= V _A -V
_C), or the difference between the output voltage v _C of the output voltage v _A magnetic sensor 2C of the magnetic sensor _{2A Δv1 (= v A -v C} ) is
.., The amount of positional deviation in the circumferential direction generated between the inclined portions 20, 20,... On the input shaft 31 side and the inclined portions 20, 20,. The relative angular displacement corresponds to the amount of twist generated in the torsion bar 34 connecting the input shaft 31 and the output shaft 32 under the action of the rotational torque applied to the input shaft 31. I do. Therefore, the above-described output voltage difference ΔV1
Alternatively, the rotational torque applied to the input shaft 31 can be calculated based on Δv1.

Similarly, the output voltage of the magnetic sensor 1B
V_BAnd the output voltage V of the magnetic sensor 1D _DΔV2 (=
V_B-V_D) Or the output voltage v of the magnetic sensor 2B_BAnd magnetism
Output voltage v of the air sensor 2D_DΔv2 (= v_B-V
_D) Corresponds to the relative angular displacement between the input shaft 31 and the output shaft 32
The relative angular displacement is the rotational torque applied to the input shaft 31.
The input shaft 31 and the output shaft 32 under the action of
This corresponds to the amount of twist generated in the torsion bar 34. Follow
The input shaft 3 based on the output voltage difference ΔV2 or Δv2.
1 can be calculated.

The calculation of the rotation angle and the rotation torque as described above is performed by the arithmetic processing unit 41 to which the output voltages of the magnetic sensors 1A, 1C, 2A, 2C are given, and the magnetic sensors 1B, 1
This is performed in the arithmetic processing unit 42 to which the output voltages of D, 2B, and 2D are applied. The calculation procedure is described in detail in Japanese Patent Application No. 11-288882 or the like by the present applicant, and the description thereof is omitted.

The two magnetic sensors 1 are provided outside the targets 2, 2, 2, 2 on the input shaft 31 and output shaft 32 sides.
A, 2A, 1B, 2B, 1C, 2C, and 1D, 2D are arranged side by side, so that an erroneous calculation of the rotational torque using an uncertain output obtained in the nonlinear change region shown in FIG. 2 is not performed. That's why. Four magnetic sensors 1A, 1B, 1C, 1D in one sensor box 1a
And four magnetic sensors 2 in the other sensor box 1b
A, 2B, 2C, and 2D are opposed to each other in the circumferential direction of each target 2 with a phase shift of about a half cycle, and as shown in FIG. Are in the linear change region. In the arithmetic processing unit 41, the magnetic sensors 1A, 1
One of the C and the magnetic sensors 2A and 2C in the linear change region is selected, and the rotation angle and the rotation torque are calculated using the output and the output difference of the selected side, respectively.
Similarly, in the arithmetic processing unit 42, the magnetic sensors 1B, 1
One of D and the magnetic sensors 2B and 2D in the linear change region is selected, and the rotation angle and the rotation torque are respectively calculated using the output and the output difference of the selected side.

The input shaft 31 calculated by the arithmetic processing unit 41
Rotation angle theta _11, the output shaft 32 of the rotation angle theta _12, and the rotating torque T _1, and the rotation angle theta ₂₁ of the input shaft 31, which is calculated by the arithmetic processing unit 42, the rotation angle theta ₂₂ of the output shaft 32 and, The rotation torque T ₂ is provided to an arithmetic processing unit 43 using a microprocessor. In the arithmetic processing unit 43, the input shaft 31 calculated by the arithmetic processing unit 41
Rotation angle theta _11, the rotation angle theta ₂₁ of the input shaft 31, which is calculated by the arithmetic processing unit 42 is compared, also, the arithmetic processing section 4 of the
The rotation angle θ ₁₂ of the output shaft 32 calculated in step 1 is compared with the rotation angle θ ₂₂ of the output shaft 32 calculated in the calculation processing unit 42. Then, based on these comparison results, the occurrence of breakage of the targets 2, 2, 2, 2, failure of the magnetic sensors 1A, 1B, 1C, 1D, 2A, 2B, 2C, 2D, or failure of the arithmetic processing units 41, 42 Is to be detected.

FIG. 3 is a flowchart showing a processing procedure of the arithmetic processing unit 43 in the first embodiment. First, the rotation angles θ ₁₁ , θ ₁₂ , θ ₂₁ , θ ₂₂ and the rotation torques T ₁ , T
₂ to accept (Step 1), determines whether or not the angle of rotation theta ₁₁ and the rotation angle theta ₂₁ match (Step 2). In Step 2, if it is determined matches a determines whether the rotation angle theta ₁₂ and the rotation angle theta ₂₂ match (Step 3). In step 2 or step 3,
If it is determined that they do not match, the process ends. If it is determined in step 3 that they match, the rotation angle θ ₁₂ and the rotation torque T ₁ calculated by the calculation processing section 41 are output (step 4), and the process ends.

Then, the rotation angle θ ₁₂ and the rotation torque T ₁ output as described above are given to a control unit (not shown), and this control unit drives an electric motor (not shown) connected to the output shaft 32. Control, which provides steering assistance.

Therefore, if it is determined in step 2 or step 3 of the processing procedure that they do not match,
The output of the rotation angle theta ₁₂ and the rotating torque T ₁ of the the control unit is stopped, thereby stopping the driving control of the electric motor,
Steering assistance is not performed.

In the first embodiment, the input shaft (first shaft) 31 connected via the torsion bar 34
Target 2, 2, 2, 2 to the output shaft (second shaft) 32
However, in the case where the target is a rotating shaft whose torsion characteristic is clear, the targets 2, 2, 2, and 2 are directly placed at positions separated in the axial direction of the rotating shaft. , And the rotational torques T ₁ and T ₂ may be calculated based on the output difference between the magnetic sensors disposed opposite to each other.

In the first embodiment, two targets 2, 2, 2
2 and 2, and magnetic sensors 1A, 2A, 1B, 2B, 1C, 2C,
1D, 2D are provided, the arithmetic processing unit 41 calculates the rotation angles of the input shaft 31 and the output shaft 32 from the outputs of the magnetic sensors 1A, 2A, 1C, 2C, and the arithmetic processing unit 42 calculates the magnetic sensors 1B, 2B, 1D, Input shaft 31 from 2D output
Although the configuration for calculating the rotation angle of the output shaft 32 has been described, the targets 2, 2, 2, 2 and the magnetic sensors 1A, 2
The numbers of A, 1B, 2B, 1C, 2C, 1D, and 2D, and the number of operation units 41 and 42 are not limited to those described above.
, A plurality of targets 2, 2,... Are arranged on the output shaft 32, and magnetic sensors are provided for each of the targets 2, 2,. And the arithmetic processing units may calculate the rotation angles of the input shaft 31 and the output shaft 32 by using the outputs of the magnetic sensors associated with the calculation units.

In the first embodiment, the targets 2, 2, 2, 2 and the magnetic sensors 1A, 2A, 1B, 2
By using B, 1C, 2C, 1D, and 2D, a signal corresponding to the rotation angles of the input shaft 31 and the output shaft 32 is transmitted to the magnetic sensor 1.
A, 2A, 1B, 2B, 1C, 2C, 1D, 2D has been described, but the present invention is not limited to this. For example, a signal corresponding to the rotation angle is obtained using a known technique such as a resolver. Needless to say, the configuration may be adopted.

In the first embodiment, the arithmetic processing unit 41 calculates the rotation torque T ₁ from the rotation angles θ ₁₁ and θ ₁₂ , and the arithmetic processing unit 42 calculates the rotation torque θ.
_Although the configuration is such that the rotation torque T ₂ is calculated from ₂₁ and θ ₂₂ , the present invention is not limited to this. The calculation processing units 41 and 42 do not calculate the rotation torques T ₁ and T ₂ , and the calculation processing unit 43 from the angle theta ₁₁ and theta ₁₂ may be configured for calculating a torque T _1.

In the first embodiment, the magnetic sensor 1 faces the magnetic targets 2, 2, 2, 2.
A, 2A, 1B, 2B, 1C, 2C, 1D, 2D are arranged, and the magnetic sensors 1A, 2A, 1B, 2B, 1C, 2C,
By detecting the magnetic field around each of 1D and 2D, the magnetic sensors 1A, 2A, 1B, 2B, 1C, 2C,
Targets 2, 2, passing in the vicinity of 1D and 2D respectively
Although the configuration for detecting the portions 2 and 2 is adopted, the present invention is not limited to this. For example, a wavy groove is provided on the entire peripheral surface of a cylindrical target, and only the bottom surface of the groove is compared with other surfaces. To lower the light reflectance, and in the state facing the peripheral surface of the target, pass the longitudinal direction in the axial direction of the target,
A line sensor in which a plurality of light receiving elements are arranged in a line may be provided, and the line sensor may detect the position of the groove of the target.

With the above configuration, the target 2
2, 2, 2 damage, magnetic sensors 1A, 1B, 1C, 1
Failure of D, 2A, 2B, 2C, 2D, and arithmetic processing unit 4
When a failure of 1,42 occurs, the arithmetic processing unit 43 detects this and stops the output of the rotation angle theta ₁₂ and the rotating torque T ₁ of the to the control unit, supplies power to the electric motor This prevents the occurrence of a malfunction.

(Embodiment 2) FIGS. 4 and 5 are flowcharts showing the processing procedure of the arithmetic processing unit 43 in Embodiment 2. In the second embodiment, the arithmetic processing unit 4
No. 1 and 42 do not calculate the rotational torque.
The arithmetic processing unit 43 firstly outputs the rotation angles θ ₁₁ , θ ₁₂ , θ ₂₁ ,
theta _22, the output _{V A, V B, V C} , V D, v A, v B,
v _C and v _D are received (step 201), and the rotation angle θ
_It is determined whether or not ₁₁ and the rotation angle θ ₂₁ match (step 202). In step 202, if it is determined not to match, it is determined whether the rotational angle theta ₁₂ and the rotation angle theta ₂₂ match (step 203). If it is determined in step 203 that they do not match, an abnormal signal indicating an abnormality is output (step 204), and the process ends.

On the other hand, in step 202, when it is determined matching with discriminates whether the rotational angle theta ₁₂ and the rotation angle theta ₂₂ match (step 205), in step 205, if a match and is determined Is calculated using the rotation angle θ ₁₁ and the rotation angle θ ₁₂ (step 206), and the rotation angle θ ₁₂ and the rotation torque T
Is output (step 207), and the process ends.

Also, in step 203,
Or in step 205, the
If it is determined that there is no_A-V_A≤V_SSatisfy
It is determined whether or not to execute (step 208). Where V_S
Is the output V_A, V_A, V_B, V_B, V_C, V_C,
V_D, V_DMaximum value V of each_MAXAnd the minimum value V_MINDifference
Value (V_MAX-V_MIN), That is, as amplitude. like this
The output V _A, V_AEither or both
Is the maximum value V_MAXOr the minimum value V_MINIs exceeded,
Since the condition of step 208 is not satisfied,
The target 2 above the force axis 31 or the magnetic sensor 1A,
2A is abnormal and output V_A, V_AEither or both
Detect this anomaly when they are not within the range
can do.

If it is determined in step 208 that the condition is not satisfied, an abnormal signal indicating that the target 2, the magnetic sensor 1A, or the magnetic sensor 2A above the input shaft 31 is abnormal is output (step 209). The rotation torque T is calculated using the rotation angle θ ₂₁ and the rotation angle θ ₁₂ (step 210), and the rotation angle θ ₁₂ and the rotation torque T are output (step 211), and the process ends.

[0058] In step 208, if it is determined that satisfy discriminates whether satisfy _{0 ≦ V B -v B ≦ V} S ( step 212), at step 212, if it is determined not satisfied An abnormal signal indicating that the target 2, the magnetic sensor 1B, or the magnetic sensor 2B below the input shaft 31 is abnormal is output (step 21).
3) The rotation torque T is calculated using the rotation angle θ ₁₁ and the rotation angle θ ₁₂ (step 214), and the rotation angle θ ₁₂ and the rotation torque T are output (step 215), and the process is terminated.

[0059] In step 212, if it is determined that satisfy discriminates whether satisfy _{0 ≦ V C -v C ≦ V} S ( step 216), at step 216, if it is determined not satisfied An abnormal signal indicating that the target 2, the magnetic sensor 1C, or the magnetic sensor 2C above the output shaft 32 is abnormal is output (step 21).
7) The rotation torque T is calculated using the rotation angle θ ₁₁ and the rotation angle θ ₂₂ (step 218), and the rotation angle θ ₂₂ and the rotation torque T are output (step 219), and the process is terminated.

[0060] In step 216, if it is determined that satisfy discriminates whether satisfy _{0 ≦ V D -v D ≦ V} S ( step 220), at step 220, if it is determined not satisfied And outputs an abnormal signal indicating that the target 2, the magnetic sensor 1D, or the magnetic sensor 2D below the output shaft 32 is abnormal (step 22).
1) The rotation torque T is calculated using the rotation angle θ ₁₁ and the rotation angle θ ₁₂ (step 222), the rotation angle θ ₁₂ and the rotation torque T are output (step 223), and the process is terminated.

If it is determined in step 220 that the condition is satisfied, the rotation torque T is calculated using the rotation angle θ ₁₁ and the rotation angle θ ₁₂ (step 224), and the rotation angle θ ₁₂ and the rotation torque T are calculated. Output (Step 22
5), end the processing.

The output abnormality signal is supplied to a control unit, and the control unit notifies the user that an abnormality has occurred. The other configuration of the steering device according to the second embodiment is the same as the configuration of the steering device according to the first embodiment, and a description thereof will not be repeated.

With the above configuration, the magnetic sensors 1A,
The output V _A of the 2A, v when _A is abnormal, the input shaft 3
1 of the upper target 2 detects that the magnetic sensors 1A, or abnormal in any of the magnetic sensors 2A occurs, when the magnetic sensor 1B, 2B of the output V _B, is v _B is abnormal, the input shaft 31 lower target 2, magnetic sensor 1
B, or detects that the abnormality in one of the magnetic sensors 2B occurs, the magnetic sensor 1C, when the output V _C of the magnetic sensor 2C, v _C is abnormal, the upper target second output shaft 32, Detecting that an abnormality has occurred in either the magnetic sensor 1C or the magnetic sensor 2C,
D, the output V _D of 2D, v when _D is abnormal, the lower side of the target 2 in the output shaft 32, to detect that the magnetic sensor 1D, or abnormal in any of the magnetic sensors 2D occurs Normal target 2, magnetic sensor 1
A, 1B, 1C, 1D, 2A, 2B, 2C, 2D and the arithmetic processing units 41, 42 can be used to calculate an accurate rotation angle, thereby suppressing occurrence of malfunction of the steering device. it can.

[0064]

As described in detail above, in the case of the rotation angle detecting device according to the first aspect of the present invention, a plurality of targets are provided on the rotating shaft, a detecting unit is provided for each target, and a target detected by each detecting unit is provided. Calculation units for calculating the rotation angles individually based on the parts, and determination means for determining whether or not the rotation angles calculated by these calculation units are the same. If it is determined that the angles do not match, damage to the target,
It can be determined that a failure of the detection unit or a failure of the calculation unit has occurred, and therefore, such a breakage or failure can be detected.

Further, a plurality of targets are provided on the rotating shaft,
By providing a detection unit for each target, and providing a calculation unit for calculating each rotation angle based on the target part detected by each detection unit, one of these targets is damaged, and the detection unit If one of them fails,
Or even if a failure occurs in any of the arithmetic units,
An accurate rotation angle can be calculated using another normal target, a detection unit, and a calculation unit, and occurrence of a malfunction of the device can be suppressed.

In the case of the torque detecting device according to the second invention, the first discriminating means discriminates whether or not the rotation angles calculated by the first rotation angle calculating means coincide with each other, and the second discriminating means determines whether or not the rotation angles match. By determining whether or not the rotation angles calculated by each of the two rotation angle calculation means match, the first rotation angle is calculated.
If the discriminating means or the second discriminating means determines that the rotation angles do not match, damage of the target, failure of the detection unit,
Alternatively, it can be determined that a failure has occurred in the arithmetic unit, and therefore, such breakage or failure can be detected.

Further, by providing a rotation angle detection unit having a plurality of targets and a plurality of detection units at two locations separated in the axial direction of the rotation shaft, and by providing a plurality of calculation units, damage to the target can be achieved. Even if a failure of the detection unit or a failure of the calculation unit occurs, it is possible to obtain an accurate rotation angle and a rotation torque of the rotating shaft by using another normal target, the detection unit, and the calculation unit. Thus, occurrence of a malfunction of the device can be suppressed.

In the case of the torque detecting device according to the third aspect of the present invention, the first axis and the second axis are provided with the rotation angle detecting sections, respectively, so that the torsion bar is twisted between the first axis and the second axis. The difference between the generated rotation angles is obtained based on the target portion detected by the detection units included in both the rotation angle detection units, and the rotation torque applied to the first axis and the second axis is detected using the result. Therefore, even when the target is damaged, a failure occurs in the detection unit, and a failure occurs in the calculation unit, an accurate rotation angle and rotation torque can be obtained, and occurrence of a malfunction of the device can be suppressed. Can be.

In the case of the torque detecting device according to the fourth aspect of the present invention, the specifying means detects the damaged target or the fault based on the rotation angles calculated by the first rotation angle calculation means and the second rotation angle calculation means. Where the detection has occurred,
Alternatively, by specifying the calculation unit in which the failure has occurred, the result of the calculation unit that calculates the incorrect rotation angle and rotation torque can be prevented from being used. Therefore, even when the target is damaged, a failure occurs in the detection unit, and a failure occurs in the calculation unit, an accurate rotation angle and rotation torque can be obtained, and occurrence of a malfunction of the device can be suppressed. Can be.

In the case of the steering device according to the fifth invention, one or both of the rotation detection device according to the first invention and the torque detection device according to any of the second to fourth inventions are used as a steering device for an automobile. By applying, even if a target is damaged, a detection unit fails, or a calculation unit fails, the rotation angle (steering angle) of the steering shaft and the rotation torque (steering torque) applied to the steering shaft To get accurate detection values for
Since these results can be used for various controls such as drive control of a steering assist motor, the present invention has excellent effects such as the occurrence of malfunction of the device can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a main part of a steering device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an output waveform of a magnetic sensor.

FIG. 3 is a flowchart illustrating a processing procedure of an arithmetic processing unit according to the first embodiment.

FIG. 4 is a flowchart illustrating a processing procedure of an arithmetic processing unit according to the second embodiment.

FIG. 5 is a flowchart illustrating a processing procedure of an arithmetic processing unit according to the second embodiment.

FIG. 6 is a schematic diagram showing a configuration of a main part of a conventional steering device.

FIG. 7 is an explanatory diagram showing an output waveform of a magnetic sensor used in a conventional steering device.

[Explanation of symbols]

1A, 1B, 1C, 1D, 2A, 2B, 2C, 2D Magnetic sensor 1a, 1b Sensor box 2 Target 3 Steering axis (rotary axis) 41, 42, 43 Arithmetic processing unit 20 Inclined part 30 Steering wheel 31 Input axis (first axis) Shaft) 32 Output shaft (second shaft) 34 Torsion bar

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G01B 21/22 G01B 21/22 3D033 G01L 5/22 G01L 5/22 // G01D 5/18 G01D 5/18 J B62D 113 : 00 B62D 113: 00 119: 00 119: 00 F term (reference) 2F051 AA01 AB05 AC07 BA03 2F063 AA36 AA50 BA08 BB03 BC06 CA02 CA28 DA01 DA04 DA08 DA30 DB07 DD06 EA03 GA53 GA67 GA69 GA70 KA01 KA05 KA06 LA23 2F069 AA86 A99 DD02 GG04 GG06 GG65 JJ17 MM11 NN00 RR03 2F077 AA04 JJ01 JJ09 JJ21 3D032 CC33 CC38 DA03 DA15 DB11 DD02 DE20 EB04 EB11 EC22 GG01 3D033 CA16 CA28 DB05

Claims (5)

[Claims] 1. A target provided on the rotating shaft and a target disposed opposite to the target so that a detected part changes periodically and continuously as the rotating shaft rotates.
A rotation angle detection device, comprising: a detection unit that detects a region of a target that faces the target, and a calculation unit that calculates a rotation angle of the rotation shaft based on the region detected by the detection unit. The target is provided at each of a plurality of locations in the direction, the detection unit and the calculation unit are provided separately for each target, and the rotation angles calculated by the respective calculation units match. A rotation angle detection device comprising a determination unit for determining whether or not the rotation angle is determined. 2. A plurality of targets which are respectively provided at a plurality of positions in a direction of an axis length of a rotating shaft, and a portion to be detected changes periodically and continuously as the rotating shaft rotates, and the plurality of targets. A rotation angle detection unit having a plurality of detection units respectively disposed to face each other and respectively detecting a portion of the target facing each other, at two locations separated in the axial length direction of the rotation shaft. Is a torque detecting device that detects a rotational torque applied to the rotating shaft based on a portion that is detected by a detecting unit that each has, based on a portion that is detected by each detecting unit of one of the rotation angle detecting units, First rotation angle calculation means for individually calculating the rotation angles of the rotation shafts, and second rotation angle calculation means for individually calculating the rotation angles of the rotation shafts based on the parts detected by the respective detection units of the other rotation angle detection units. Rotation angle calculation means A plurality of calculation units respectively provided; first determination means for determining whether the rotation angles respectively calculated by the first rotation angle calculation means coincide with each other; and rotation angles respectively calculated by the second rotation angle calculation means And a second determining means for determining whether or not the two are equal to each other, wherein the rotational torque is calculated based on a difference between the rotational angles respectively calculated by the first rotational angle calculating means and the second rotational angle calculating means. A torque detecting device, comprising: 3. The rotating shaft is a connected body of a first shaft and a second shaft coaxially connected via a torsion bar,
3. The torque detection device according to claim 2, wherein the rotation angle detection unit is disposed near a connection between the first shaft and the second shaft. 4. The rotation calculated by each of the first rotation angle calculation means and each of the second rotation angle calculation means when the first determination means or the second determination means determines that the rotation angles do not match. The torque detection device according to claim 2, further comprising a specification unit that specifies a damaged target, a detection unit in which a failure has occurred, or an operation unit in which a failure has occurred, based on the angle. 5. The rotation angle detection device according to claim 1, wherein a steering shaft that connects a steering wheel and a steering mechanism is configured as the rotation shaft, and the torque detection device according to any one of claims 2 to 4. A steering device comprising one or both of the following.