JP2007333658A - Rotation angle detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect an absolute angle, even when one resolver sensor has broken down, using a normal resolver sensor. <P>SOLUTION: The rotation angle detector comprises a first resolver sensor for outputting the periodic waveform signals n times and a second resolver sensor for outputting m (m≠n) times the periodic waveform signals when a rotating member is rotated over a rotatable range. On the basis of the relative angle difference θab between relative angles θa and θb detected by the both resolver sensors, the absolute angle θ of the rotating member is calculated. From among a plurality of divided regions obtained by dividing the rotatable range of the rotating member by a division number according to the signal output period of each resolver sensor, an affiliation divided region to which a rotational position of the rotating member belongs is derived, on the basis of the progress of the signal output of each resolver sensor. When one resolver sensor is broken down, the absolute angle of the rotating member is calculated from the output value and affiliation divided region of the normal resolver sensor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation angle detection device that detects a rotation angle of a rotary member using a resolver sensor.

Conventionally, a technique for detecting an absolute angle of a rotating member using a resolver sensor is known. For example, in the absolute rotation angle detection device proposed in Patent Document 1, a sensor A and a sensor B are provided on a rotor as a rotating member, and the absolute rotation of the rotor is determined based on the phase difference between the output signals of the two sensors A and B. The turning angle of the wheel is obtained by calculating the rotation angle.
Each sensor A and B outputs a sawtooth-shaped periodic waveform signal in accordance with the rotation of the rotor, but the period is set to be different. For example, while the rotor rotates 15 times (steering range), the sensor A is set to output a signal for 12 cycles, and the sensor B is set to output a signal for 13 cycles. For this reason, the phase difference between the signal of the sensor A and the signal of the sensor B increases monotonously without having a periodicity from 0 degree to 360 degrees in electrical angle while the rotor rotates 15 times.
Therefore, the absolute rotation angle of the rotor can be detected by obtaining the phase difference between the signal from the sensor A and the signal from the sensor B.
JP 2004-325182 A

  However, in the configuration in which the absolute angle of the rotating member is detected based on the phase difference between the periodic waveform signals of the two sensors, when one of the sensors fails, the phase difference cannot be calculated, and the absolute angle is detected. Becomes impossible.

  The present invention has been made to cope with the above problem, and an object of the present invention is to detect an absolute angle using a normal sensor even when one of the sensors fails.

  To achieve the above object, the present invention is characterized in that a first resolver sensor that outputs a periodic waveform signal n times when a rotating member to be detected is rotated within a predetermined angular range, and the rotating member A second resolver sensor that outputs m (m ≠ n) number of periodic waveform signals when rotated within the predetermined angle range; a signal output value of the first resolver sensor; and a signal output value of the second resolver sensor; And a rotation angle detector that calculates an absolute rotation angle of the rotating member based on the output difference between the predetermined angle range and the number of divisions corresponding to the signal output period of the first resolver sensor. Of the plurality of divided areas obtained by the division, a first assigned divided area derivation method for deriving the belonging divided area to which the rotational position of the rotating member belongs based on the transition of the signal output of the first resolver sensor. And among the plurality of divided regions obtained by dividing the predetermined angle range by the number of divisions according to the signal output period of the second resolver sensor, the belonging divided region to which the rotational position of the rotating member belongs is A second belonging divided region deriving unit that derives based on a signal output transition of the two resolver sensor; an abnormality detecting unit that detects an abnormality of the first resolver sensor and the second resolver sensor; the first resolver sensor; When an abnormality in any one of the second resolver sensors is detected, the rotating member is based on the assigned divided region and the signal output value derived based on the signal output transition of the resolver in which the abnormality is not detected. And an abnormal time absolute angle calculating means for calculating the absolute rotation angle.

According to this invention, when the rotating member is rotated by a predetermined range, the first resolver sensor outputs n times of the periodic waveform signal, and the second resolver sensor outputs m times of the waveform signal. When the difference (phase difference) between the signal output values of the two resolver sensors is obtained, the output difference becomes a value corresponding to the rotation position (rotation angle) of the rotation member on a one-to-one basis in a wide rotation range of the rotation member. The absolute angle calculation means calculates the absolute rotation angle of the rotating member using this principle.
Since each resolver sensor outputs a periodic waveform signal when the rotating member is rotated by a predetermined range, if one of the resolver sensors can recognize the period of this signal output relative to the reference position, one resolver sensor will fail. In addition, the absolute rotation angle of the rotating member can be detected only by the normal resolver sensor.

Therefore, in the present invention, in order to cope with the failure of one of the resolver sensors, the first belonging divided area deriving means and the second belonging divided area deriving means are provided. When the rotating member is rotated by a predetermined range, the first resolver sensor outputs n periodic waveform signals. Therefore, the first assigned divided region deriving unit divides the predetermined angular range by the number of divisions corresponding to the cycle n. A belonging divided region to which the rotational position of the rotating member belongs is derived from the plurality of divided regions obtained as described above.
This belonging division is obtained from the absolute rotation angle calculated from the output difference if both resolver sensors are normal, but is not obtained if one resolver sensor fails. Therefore, the derivation of the divisional area is performed based on the transition of the signal output of the first resolver sensor. For example, a point at which a feature point appears in the signal output waveform is set as a boundary of the divided region, and the assigned divided region is changed every time this feature point is detected. In this case, when both resolver sensors are normal, the assigned divided area to which the rotation position of the rotating member belongs is obtained as an initial value, and the assigned divided area is changed with respect to the initial value.

  Similarly, the second belonging divided region deriving means also includes the rotational position of the rotating member among a plurality of divided regions obtained by dividing the predetermined angle range by the number of divisions corresponding to the period m of the second resolver sensor. The assigned division area is derived based on the transition of the signal output of the second resolver sensor.

  When either abnormality of the first resolver sensor or the second resolver sensor is detected by the abnormality detection means, the abnormality absolute angle calculation means changes the signal output of the resolver sensor whose abnormality is not detected. The absolute rotation angle (rotation position) of the rotating member is calculated based on the divisional area derived based on the above and the signal output value.

  As a result, even if one of the pair of resolver sensors fails, the absolute rotation angle of the rotating member can be calculated.

  Another configuration of the present invention is that the relationship between n and m is n = m + 1.

  According to this invention, the signal output of the first resolver sensor and the signal output of the second resolver sensor are in phase only after the rotating member has rotated by a predetermined angle. Therefore, the signal output difference between the two resolver sensors changes monotonously without having periodicity within a predetermined angle range, and corresponds to the rotation angle on a one-to-one basis. As a result, the absolute angle in the predetermined angle range can be detected well.

Another feature of the present invention is that the first resolver sensor and the second resolver sensor output a sawtooth signal as a periodic waveform signal corresponding to the rotational position of the rotating member, and the first belonging divided region deriving means. And the second belonging divided region deriving means detects passage of a triangular vertex in the sawtooth signal, and belongs to the rotation position of the rotating member as moving to an adjacent divided region every time the passage of the triangular vertex is detected. It is to change the divided area.
In this case, the belonging division range of the rotating member may be determined based on the passing direction of the triangular vertex in the sawtooth signal.

According to this invention, when the rotating member is rotated by a predetermined angle, the first resolver sensor outputs n times of sawtooth shape signals, and similarly, the second resolver sensor outputs m times of sawtooth shape signals. Each of the first belonging divided area deriving means and the second belonging divided area deriving means is a divided area in which the rotation position of the rotating member is adjacent each time the passage of the triangular vertex in the sawtooth signal output from the resolver sensor is detected. Recognize that you have moved to.
The output of the resolver sensor greatly fluctuates when the sawtooth signal passes through the triangle vertex. Therefore, it is easy to detect the passing point of the triangle vertex.
Further, from the transition of the signal of the resolver sensor, it is possible to easily grasp the passing direction of the triangular vertex in the sawtooth signal. That is, since the change in the output value of the sawtooth shape signal varies depending on the rotation direction of the rotating member, the rotating direction of the rotating member can be identified.
As a result, it is possible to properly detect the belonging divided area of the rotating member.

  Another feature of the present invention is that the rotating member is a steering shaft that rotates integrally with a steering handle of a vehicle, and the predetermined angle range is a rotatable range of the steering handle.

  According to the present invention, even if one of the pair of resolver sensors breaks down, the steering angle of the steering wheel can be detected appropriately, so that the safety and reliability of the vehicle are improved.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a vehicle steering apparatus provided with a rotation angle detection device as one embodiment.

  This vehicle steering device mechanically includes a steering operation device 10 that is steered by a driver, and a steering device 20 that steers left and right front wheels FW1 and FW2 as steered wheels according to the steering operation of the driver. A separate steer-by-wire system is used. The steering operation device 10 includes a steering handle 11 as an operation unit that is rotated by a driver. The steering handle 11 is fixed to the upper end of the steering input shaft 12, and a steering reaction force electric motor 13 is assembled to the lower portion of the steering input shaft 12. The steering reaction force electric motor 13 drives the steering input shaft 12 to rotate about the axis via the speed reduction mechanism 14.

  The steered device 20 includes a rack bar 21 that extends in the left-right direction of the vehicle. The left and right front wheels FW1, FW2 as steered wheels are connected to both ends of the rack bar 21 via a tie rod and a knuckle arm (not shown) so as to be steerable. The left and right front wheels FW1, FW2 are steered to the left and right by the displacement of the rack bar 21 in the axial direction. On the outer periphery of the rack bar 21, a steering electric motor 22 assembled in a housing (not shown) is provided. The rotation of the steered electric motor 22 is decelerated by the screw feed mechanism 23 and is converted into an axial displacement of the rack bar 21. The steering device 20 also has a steering output shaft 24 that can rotate around the axis. A pinion gear 25 is fixed to the lower end of the steering output shaft 24. The pinion gear 25 meshes with rack teeth 21a provided on the rack bar 21, and the rack bar 21 is axially rotated by rotation around the axis of the steering output shaft 24. It is displaced to.

  A cable 31 as an intermediate member is disposed between the steering input shaft 12 and the steering output shaft 24. The cable 31 transmits the rotation around the axis of the steering input shaft 12 to the steering output shaft 24. A first electromagnetic clutch 32 is disposed between the fixing member 31 a at the upper end of the cable 31 and the lower end of the steering input shaft 12. The first electromagnetic clutch 32 is set in a disconnected state in an energized state to disconnect the cable 31 and the steering input shaft 12 so that power cannot be transmitted, and is set in a connected state in a non-energized state to set the cable 31 and the steering input shaft 12. And are connected so that power can be transmitted. A second electromagnetic clutch 33 is disposed between the fixing member 31 b at the lower end of the cable 31 and the upper end of the steering output shaft 24. The second electromagnetic clutch 33 is set in a disconnected state in an energized state to disconnect the cable 31 and the steering output shaft 24 so that power cannot be transmitted, and is set in a connected state in a non-energized state to set the cable 31 and the steering output shaft 24. And are connected so that power can be transmitted.

Next, the electric control device 40 that controls the steering reaction force electric motor 13, the steering electric motor 22, and the electromagnetic clutches 32 and 33 will be described.
The electric control device 40 includes a steering angle detection device 50 for detecting the steering angle θ of the steering handle 11, a steering reaction force electronic control unit (hereinafter referred to as a steering reaction force ECU) 60, and front wheel steering electronics. And a control unit (hereinafter referred to as front wheel steering ECU) 70.

The steering angle detection device 50 corresponds to the rotation angle detection device of the present invention, and includes a first resolver sensor 51, a second resolver sensor 52, an absolute angle detection arithmetic device (hereinafter referred to as an absolute angle detection ECU). 53).
The first resolver sensor 51 includes a first resolver 51s provided at an intermediate portion of the steering input shaft 12, and a first relative angle detection circuit 51c that detects a relative angle θa from an output signal of the first resolver 51s.
The second resolver sensor 52 includes a second resolver 52s provided at an intermediate portion of the steering input shaft 12 along with the first resolver 51s, and a second relative angle detection circuit that detects a relative angle θb from an output signal of the second resolver 52s. 52c.

The first resolver 51s and the second resolver 52s include annular resolver rotors 51sr and 52sr and resolver stators 51ss and 52ss, respectively. In each resolver 51s, 52s, the resolver rotor 51sr, 52sr is fixed on the outer peripheral surface of the steering input shaft 12, and the resolver stator 51ss, 52ss is opposed to the outer peripheral surface of the resolver rotor 51sr, 52sr. Thus, it is fixed on the vehicle body side.
In the first resolver 51s and the second resolver 52s, primary windings (not shown) that are excitation coils are provided in the respective resolver rotors 51sr and 52sr, and secondary windings that are detection coils in the respective resolver stators 51ss and 52ss ( A plurality of (not shown) are provided.

  The first relative angle detection circuit 51c and the second relative angle detection circuit 52c excite the primary windings of the first resolver 51s and the second resolver 52s with a sine wave signal, respectively, and generate a plurality of induced voltage signals based on the excitation signal. From the secondary winding. When the steering input shaft 12 rotates and the positional relationship between the resolver stators 51ss and 52ss and the resolver rotors 51sr and 52sr of the resolvers 51s and 52s changes, the magnetic flux passing through the secondary winding changes. Therefore, by comparing the phase difference between the sinusoidal voltage applied to the primary winding and the induced voltage acting on the secondary winding, the relative angle between the resolver stators 51ss and 52ss and the resolver rotors 51sr and 52sr. The position can be detected.

The steering input shaft 12 is restricted from rotating about its axis by a stroke end (not shown). The rotatable range of the steering input shaft 12 is the same as the rotatable range of the steering handle 11. Hereinafter, this range is referred to as a steerable range.
In the present embodiment, the steerable range is set such that the neutral position of the steering handle 11 is “0” and the steering limit angle −θmax in the left direction to the steering limit angle + θmax in the right direction.

The first relative angle detection circuit 51c outputs a periodic waveform signal n times (13 times in the present embodiment) in the process in which the steering handle 11 rotates from the left steering limit angle −θmax to the right steering limit angle + θmax. Configured as follows.
On the other hand, the second relative angle detection circuit 52c outputs a periodic waveform signal m times (12 times in the present embodiment) in the process in which the steering handle 11 rotates from the left steering limit angle −θmax to the right steering limit angle + θmax. Configured as follows. In other words, the first relative angle detection circuit 51c and the second relative angle detection circuit 52c only output the periodic waveform signal once in the process of rotating the steering handle 11 from the left steering limit angle −θmax to the right steering limit angle + θmax. Different (n = m + 1) phase differences are provided.

FIG. 9 shows periodic waveform signals output from the first relative angle detection circuit 51c and the second relative angle detection circuit 52c. The horizontal axis represents the steering angle θ (absolute steering angle θ) of the steering handle 11, and the vertical axis represents the electrical angle. In the figure, a signal waveform represented by a one-dot chain line is output from the first relative angle detection circuit 51c, and a signal waveform represented by a two-dot chain line is output from the second relative angle detection circuit 52c. Represents the relative angle θb.
The relative angle θa is an electrical angle with an angle (2 · θmax / n) obtained by subtracting the steerable range by the value n as one cycle (2π), and the relative angle of the resolver rotor 51sr to the resolver stator 51ss of the first resolver 51s. Represents a specific position. Similarly, the relative angle θb is an electrical angle with an angle (2 · θmax / m) obtained by subtracting the steerable range by the value m as one cycle (2π), and the resolver rotor of the second resolver 52s with respect to the resolver stator 52ss. Represents the relative position of 52 sr.
On the other hand, the absolute steering angle θ represents a mechanical rotation angle (rotation position) of the steering handle 11 with the neutral position of the steering handle 11 as “0” with reference to the neutral position.
In the following description, the output signal of the first relative angle detection circuit 51c representing the relative angle θa is called the output signal θa of the first resolver sensor 51, and the output signal of the second relative angle detection circuit 52c representing the relative angle θb is the first output signal. This is called an output signal θb of the two resolver sensor 52.

As shown in FIG. 9, the periodic waveform signals θa and θb output from the first resolver sensor 51 and the second resolver sensor 52 are sawtooth-shaped signals obtained by connecting a plurality of right-angled triangles having sides perpendicular to the horizontal axis. appear. One peak of the sawtooth signal waveform is one cycle.
The first resolver sensor 51 and the second resolver sensor 52 are set so that their outputs are 0 radians in electrical angle when the steering handle 11 is turned to the left steering limit angle -θmax position. The first resolver sensor 51 and the second resolver sensor 52 are set so that the number of output of the periodic waveform signal is different only once in the process of rotating the steering handle 11 from the left steering limit angle −θmax to the right steering limit angle + θmax. Therefore, when the steering handle 11 is turned to the right steering limit angle + θmax position, the phase difference disappears and the output becomes the same value (2π radians in electrical angle). Therefore, the output values (relative angles θa and θb) of the first resolver sensor 51 and the second resolver sensor 52 are always different values within the steerable range that is between the left and right steering limits.

  Output signals θa and θb of the first resolver sensor 51 and the second resolver sensor 52 are input to the absolute angle detection ECU 53. The absolute angle detection ECU 53 includes a microcomputer as a main part, and calculates the steering angle θ (absolute steering angle) of the steering handle 11 using the relative angles θa and θb. The steering angle calculation process performed by the absolute angle detection ECU 53 will be described later.

The steering reaction force ECU 60 includes a microcomputer as a main part, and is a control device that generates an appropriate steering reaction force in response to a driver's steering operation, and connects the absolute angle detection ECU 53 and the vehicle speed sensor 41. . The vehicle speed sensor 41 outputs a detection signal indicating the vehicle speed V. The steering reaction force ECU 60 calculates a target steering reaction force based on the steering angle θ calculated by the absolute angle detection ECU 53 and the vehicle speed V detected by the vehicle speed sensor 41. In calculating the target steering reaction force, the steering reaction force table shown in FIG. 7 is referred to. This steering reaction force table is stored in the ROM of the steering reaction force ECU 60, and for each of a plurality of representative vehicle speed values, a plurality of target steering reaction force values that increase nonlinearly as the steering wheel steering angle θ increases. Is set.
Instead of using this steering reaction force table, a target steering reaction force value that changes according to the steering angle θ and the vehicle speed V is defined in advance by a function, and the target steering reaction force is calculated using the function. A value may be calculated.

The steering reaction force ECU 60 supplies a drive current corresponding to the calculated target steering reaction force to the steering reaction force electric motor 13 via a drive circuit (not shown). Thus, the target steering reaction force by the steering reaction force electric motor 13 is applied to the rotation operation of the steering handle 11, and the driver rotates the steering handle 11 while feeling an appropriate steering reaction force. it can.
The steering reaction force electric motor 13 uses a three-phase synchronous permanent magnet motor and is rotationally controlled by vector control described in a two-phase rotating magnetic flux coordinate system. In this case, it is necessary to input a signal synchronized with the motor rotation angle in order to perform the two-phase / three-phase conversion process. Therefore, the steering reaction force ECU 60 inputs a signal of the relative angle θa or the relative angle θb from the absolute angle detection ECU 53.

The front-wheel steering ECU 70 is configured by a microcomputer as a main part, and is a control device that steers the front wheels (steered wheels) at a steering angle corresponding to a driver's steering operation. The absolute-angle detection ECU 53 and the vehicle speed sensor 41 The turning angle sensor 43 is connected.
The turning angle sensor 43 is assembled to the rack bar 21 and measures the axial displacement of the rack bar 21 to detect and output the actual turning angle δ of the left and right front wheels FW1 and FW2. Note that the actual turning angle δ represents the rightward turning angle of the left and right front wheels FW1, FW2 as a positive value with the neutral position of the left and right front wheels FW1, FW2 being “0”, and the left direction of the left and right front wheels FW1, FW2 The steering angle of is expressed as a negative value. Further, the turning angle sensor 43 may be configured to detect the actual turning angle δ by detecting the rotation angle of the steering output shaft 24.

  The front wheel steering ECU 70 calculates a target front wheel steering angle based on the steering wheel steering angle θ calculated by the absolute angle detection ECU 53 and the vehicle speed V detected by the vehicle speed sensor 41. In calculating the target front wheel turning angle, the turning angle table shown in FIG. 8 is referred to. This steering angle table is stored in the ROM of the front wheel steering ECU 70, and for each of a plurality of representative vehicle speed values, the target front wheel rotation for the standby wire that increases nonlinearly as the steering wheel steering angle θ increases. The rudder angle is set. The rate of change of the target front wheel turning angle with respect to the steering wheel steering angle θ is small within a small range of the absolute value | θ | of the steering wheel steering angle θ, and increases as the absolute value | θ | of the steering wheel steering angle θ increases. Is set. Instead of using this turning angle table, a function indicating the relationship between the steering wheel steering angle θ and the target front wheel turning angle is prepared in advance. The wheel turning angle may be calculated.

  The front wheel turning ECU 70 turns the vehicle through a drive circuit (not shown) using the steering angle difference so that the actual turning angle δ detected by the turning angle sensor 43 becomes equal to the final target front wheel turning angle. The rotation of the rudder electric motor 22 is controlled. As a result, the steering electric motor 22 is rotationally driven, drives the rack bar 21 in the axial direction via the screw feed mechanism 23, and steers the left and right front wheels FW1, FW2 to the target turning angle.

  Next, the steering angle detection process of the steering handle 11 performed by the steering angle detection device 50 will be described. FIG. 2 is a flowchart showing an initial setting process performed by the absolute angle detection ECU 53 when the steering angle is detected. This process is stored as a control program in the ROM of the absolute angle detection ECU 53 and executed when the ignition switch of the vehicle is turned on.

  When the ignition switch of the vehicle is turned on and the initial setting routine is started, the absolute angle detection ECU 53 reads the output signals θa and θb of the first resolver sensor 51 and the second resolver sensor 52 in step S11. Subsequently, it is determined whether or not the read relative angle θa is equal to or greater than the relative angle θb (S12). If θa ≧ θb (S12: YES), the value obtained by subtracting θb from θa is used as the relative angle difference. It is calculated as θab (= θa−θb) (S13). On the other hand, if θa <θb (S12: NO), a value obtained by subtracting θb from θa and adding 2π is calculated as a relative angle difference θab (= θa−θb + 2π) (S14).

  As shown in FIG. 9, in the process of rotating the steering handle 11 from the left steering limit angle −θmax to the right steering limit angle + θmax, the first resolver sensor 51 outputs the sawtooth shape signal θa n times (13 times), The second resolver sensor 52 outputs m (12) sawtooth shape signals θb. Accordingly, in the steerable range (−θmax to + θmax), a phase difference is always generated between the two output signals θa and θb except for the steering limit end. The steering angle θ (absolute steering angle) can be calculated based on this phase difference.

  Here, consider a case where the steering handle 11 is steered rightward from the position of the left steering limit angle −θmax. As for the phase difference between the output signal θa of the first resolver sensor 51 and the output signal θb of the second resolver sensor 52, the position of the left steering limit angle −θmax is used as a reference (phase difference = 0), and the phase difference progresses in the right steering direction. It increases to the maximum “2π” at the position of the right steering limit angle + θmax and returns to the same phase. Therefore, if the phase difference in the steerable range is known, the steering angle θ can be obtained.

The processing in steps S13 and S14 calculates this phase difference, but the relative relationship between the relative angle θa and the relative angle θb is reversed in the middle. Therefore, when the magnitude relationship between the relative angle θa and the relative angle θb is reversed (θa <θb), 2π is added to the relative angle difference θab.
Therefore, as shown by a broken line in FIG. 9, the relative angle difference θab becomes the steering angle θ without periodicity in the process in which the steering handle 11 rotates from the left steering limit angle −θmax to the right steering limit angle + θmax. It increases linearly from “0” to “2π” in proportion. Thus, the steering angle θ of the steering handle 11 can be detected by obtaining the relative angle difference θab.

Subsequently, the steering angle θ (absolute steering angle) is calculated from the relative angle difference θab obtained in step S13 or step S14 (S15). The calculation of the steering angle θ is performed with reference to the steering angle table shown in FIG. This steering angle table is stored in the ROM of the absolute angle detection ECU 53, and associates the steering angle θ of the steering wheel 11 with the relative angle difference θab.
The steering angle θ may be calculated using a function. For example, if the rotation angle at which the steering handle 11 rotates from the left steering limit angle −θmax to the right steering limit angle + θmax is 2 · θmax, the relative angle difference θab is an electrical angle while the steering handle 11 rotates 2 · θmax. It changes by 2π. Therefore, the steering angle θ can be calculated as follows:
θ = θmax · θcb / π

Next, the absolute angle detection ECU 53 determines in which cycle the steering angle θ calculated in the previous step S15 is present in the sawtooth signal θa output from the first resolver sensor 51, and the second resolver sensor 52. The count values Na and Nb for determining the number of cycles in the saw-tooth shape signal θb output from (1) are determined (S16).
That is, as shown in FIG. 9, the count value Na is the first resolver in the process in which the steering handle 11 rotates from the left steering limit angle −θmax to the right steering limit angle + θmax within the steerable range (−θmax to + θmax). A range that is equally divided by the number of times n (= 13) at which the periodic waveform signal θa is output from the sensor 51 is defined as a divided area, and a value that specifies a belonging divided area to which the rotational position (steering angle θ) of the steering wheel 11 belongs. Become. In this case, the mechanical angle of each divided area is 2 · θmax / 13.
This count value Na is set to a value “0” when the rotational position (steering angle θ) of the steering wheel 11 is present in the divided region closest to the left steering limit angle −θmax, and becomes “1” as the steering proceeds in the right steering direction. "Is set to a larger value. Therefore, there are 13 count values Na from the value “0” to the value “12”.

Similarly, the count value Nb falls within a steerable range (−θmax to + θmax), and a periodic waveform signal is output from the second resolver sensor 52 in the process in which the steering handle 11 rotates from the left steering limit angle −θmax to the right steering limit angle + θmax. A range that is equally divided by the number of times of output m (= 12) is set as a divided region, and this value is used to specify the divided region. In this case, the mechanical angle of each divided area is 2 · θmax / 12.
This count value Nb is set to a value “0” when the rotational position (steering angle θ) of the steering wheel 11 is in the divided region closest to the left steering limit angle −θmax, and becomes “1” as the steering proceeds in the right steering direction. "Is set to a larger value. Therefore, there are 12 count values Nb from the value “0” to the value “11”.
Hereinafter, the count values Na and Nb are referred to as cycle count values Na and Nb.

In this step S16, since the steering angle θ is calculated in the previous step S15, the cycle count values Na and Nb are determined based on the steering angle θ. The cycle count values Na and Nb are stored in the RAM of the absolute angle detection ECU 53.
Subsequently, the absolute angle detection ECU 53 outputs the steering angle θ (absolute steering angle θ) calculated in the previous step S15 to the steering reaction force ECU 60 and the front wheel steering ECU 70 in step S17. In step S18, the relative angle θb is output to the steering reaction force ECU 60.

This relative angle θb is determined by the motor for performing the two-phase / three-phase conversion process when the steering reaction force ECU 60 drives the steering reaction force electric motor 13 by vector control described in the two-phase rotating magnetic flux coordinate system. Used as a signal synchronized with the rotation angle. Therefore, it is preferable that the signal output cycle of the second resolver sensor 52 that outputs the relative angle θb corresponds to the number of poles of the steering reaction force electric motor 13. The relative angle θa may be output instead of the relative angle θb.
When the process of step S18 is completed in this way, this control routine is ended.

  Next, the steering angle calculation process after the initial setting process is completed will be described. FIG. 3 is a flowchart showing a steering angle calculation routine executed by the absolute angle detection ECU 53. This process is stored as a control program in the ROM of the absolute angle detection ECU 53, and is repeatedly performed at a predetermined cycle after the initial setting process is completed.

  When the present steering angle calculation routine is started, the absolute angle detection ECU 53 determines whether or not both the first resolver sensor 51 and the second resolver sensor 52 are normal in step S21. This determination is made by checking the terminal voltages of the windings provided in the resolvers 51s and 52s. When a wire breakage, short circuit, insulation failure, or the like occurs in the windings provided in the resolvers 51s and 52s, the winding terminal voltage deviates from the reference range. Therefore, in this step S21, the winding terminal voltage is detected by the first relative angle detection circuit 51c and the second relative angle detection circuit 52c, and the resolvers 51s and 52s are abnormal when the detected voltage is out of the reference range. Judge that there is.

  In detecting the abnormality of the resolver sensors 51 and 52, the absolute angle detection ECU 53 may detect the abnormality including the abnormality of the relative angle detection circuits 51c and 52c itself. For example, the voltage value of the periodic waveform signal output from the relative angle detection circuits 51c and 52c may be checked by the absolute angle detection ECU 53, and it may be determined that the circuit is abnormal when the voltage value is out of the reference range. Further, the circuit abnormality may be determined from the waveforms of the output signals of the relative angle detection circuits 51c and 52cc.

When the absolute angle detection ECU 53 determines that the first resolver sensor 51 and the second resolver sensor 52 are normal (S21: YES), the process proceeds to step S22, where the first resolver sensor 51 and the second resolver sensor 51 are processed. Relative angles θa and θb are input from the sensor 52, respectively.
Subsequently, it is determined whether or not the relative angle θa is greater than or equal to the relative angle θb (S23). If θa ≧ θb (S23: YES), the value obtained by subtracting θb from θa is used as the relative angle difference θab ( = Θa−θb) (S24). If θa <θb (S23: NO), a value obtained by subtracting θb from θa and adding 2π is calculated as a relative angular difference θab (= θa−θb + 2π). (S25).

When the relative angle difference θab is calculated, a steering angle θ (absolute steering angle θ) is calculated from the relative angle difference θab (S26), and the calculated steering angle θ is used as the steering reaction force ECU 60 and the front wheel steering. To the ECU 70 (S27). Further, the relative angle θb is output to the steering reaction force ECU 60 (S28).
The processes in steps S22 to S28 are the same as steps S12 to S18 (except for step S16) in the initial setting process described above.

On the other hand, if it is determined in step S21 that at least one of the first resolver sensor 51 and the second resolver sensor 52 is abnormal, it is further determined whether or not the first resolver sensor 51 is normal ( S29) When the first resolver sensor 51 is normal (S29: YES), that is, when only the second resolver sensor 52 is abnormal, a first abnormality routine described later is executed (S30).
If it is determined in step S29 that the first resolver sensor 51 is not normal, it is determined in step S31 whether the second resolver sensor 52 is normal. When the second resolver sensor 52 is normal (S31: YES), that is, when only the first resolver sensor 51 is abnormal, a second abnormality routine described later is executed (S32).

  If it is determined in step S31 that the second resolver sensor 52 is not normal, both the first resolver sensor 51 and the second resolver sensor 52 are abnormal, so in step S33, the first electromagnetic clutch 32 and A connection command is output to the second electromagnetic clutch 33. In response to this connection command, the first electromagnetic clutch 32 connects the cable 31 and the steering input shaft 12 so that power can be transmitted. The second electromagnetic clutch 33 connects the cable 31 and the steering output shaft 24 so that power can be transmitted. As a result, the steering input shaft 12 and the steering output shaft 24 are coupled via the cable 31 so that power can be transmitted. Accordingly, the left and right front wheels FW1 and FW2 are set to be directly steered by the turning operation of the steering handle 11 performed by the driver.

  This control routine is repeatedly executed at a predetermined short cycle. Therefore, while both the first resolver sensor 51 and the second resolver sensor 52 are normal, the processes of steps S22 to S28 are repeated, and the calculated steering angle θ of the steering wheel 11 is changed to the steering reaction force ECU 60 and the front. It is output to the wheel steering ECU 70. The first abnormality routine is repeated while only the first resolver sensor 51 is normal, and the second abnormality routine is repeated while only the second resolver sensor 52 is normal. Further, while the abnormality of both the first resolver sensor 51 and the second resolver sensor 52 is detected, the first electromagnetic clutch 32 and the second electromagnetic clutch 33 are connected, and the left and right front wheels FW1 are operated by the driver's steering operation. , FW2 is set to be directly steered.

  Next, a relative angular period counting process performed in parallel with the above-described steering angle calculation routine will be described. FIG. 4 is a flowchart showing a relative angular period counting routine performed by the absolute angle detection ECU 53. This process is stored as a control program in the ROM of the absolute angle detection ECU 53, and is repeatedly performed at a predetermined cycle in parallel with the steering angle calculation routine after the initial setting process is completed.

When the initial setting process is completed and the relative angular period counting routine is started, the absolute angle detection ECU 53 inputs the relative angles θa and θb from the first resolver sensor 51 and the second resolver sensor 52 in step S41.
Subsequently, in step S42, it is determined whether or not the value of the relative angle θa has changed from “2π” to “0”. That is, it is determined whether or not the sawtooth-shaped output signal representing the relative angle θa output from the first resolver sensor 51 has changed from the value “2π” at the top of the waveform to the value “0” at the bottom of the waveform. To do. For example, in the signal waveform of FIG. 9, the point A is the waveform vertex and the point B is the waveform trough. In this case, the passage of the waveform apex is determined from the relationship between the relative angle θa (n−1) detected immediately before and the relative angle θan detected this time.

  When the steering wheel is rotated in the right direction, the relative angle θa decreases by 2π when passing through the waveform apex A as indicated by an arrow a1 in FIG. Therefore, in this embodiment, for example, when the value of the relative angle θan detected this time has decreased by a predetermined value (for example, π) or more with respect to the relative angle θa (n−1) detected immediately before, the relative angle is determined. It is determined that the value of θa has changed from “2π” to “0”. In this case, in step S43, the cycle count value Na is incremented by 1 (Na = Na + 1).

As described above, the cycle count value Na belongs to the rotation position (steering angle θ) of the steering wheel 11 in the divided region obtained by dividing the steerable range (−θmax to + θmax) into n equal parts (13 equal parts). It is a value that specifies the division area. Therefore, if “YES” is determined in step S42, it means that the belonging divided area to which the rotational position (steering angle θ) of the steering handle 11 belongs has shifted to the divided area adjacent to the right rotation direction. .
If it is determined in step S42 that the value of the relative angle θa has not changed from “2π” to “0” (S42: NO), the process of step S43 is skipped.

Subsequently, the absolute angle detection ECU 53 advances the process to step S44. In this step S44, it is determined whether or not the value of the relative angle θa has changed from “0” to “2π”. That is, whether or not the sawtooth-shaped output signal representing the relative angle θa output from the first resolver sensor 51 has changed from the value “0” corresponding to the waveform valley B to the value “2π” corresponding to the waveform vertex A. Judging.
Also in this case, the passage of the waveform apex A is determined from the relationship between the relative angle θa (n−1) detected immediately before and the relative angle θan detected this time.
When the steering handle 11 rotates to the left, the relative angle θa increases by 2π when passing through the corrugated valley B as indicated by an arrow a2 in FIG. Therefore, in this embodiment, for example, when the value of the relative angle θan detected this time has increased by a predetermined value (for example, π) or more with respect to the relative angle θa (n−1) detected immediately before, the relative angle is increased. It is determined that the value of θa has changed from “0” to “2π”. In this case, the cycle count value Na is decremented by 1 in step S45 (Na = Na-1).
On the other hand, if it is determined in step S44 that the value of the relative angle θa has not changed from “0” to “2π” (S44: NO), the process of step S45 is skipped.

Subsequently, the absolute angle detection ECU 53 advances the process to step S46. In step S46, it is determined whether or not the value of the relative angle θb has changed from “2π” to “0”. That is, it is determined whether or not the sawtooth-shaped output signal representing the relative angle θb output from the second resolver sensor 52 has changed from the value “2π” as the waveform apex to the value “0” as the waveform valley. To do.
As in step S42, this determination is made when the value of the relative angle θbn detected this time has decreased by a predetermined value (for example, π) or more with respect to the relative angle θb (n−1) detected immediately before. It is determined that the value of θb has changed from “2π” to “0”.

For example, as shown in FIG. 9, when the output signal representing the relative angle θb changes from the waveform vertex C to the waveform valley portion D along the arrow b1, the determination in step S46 is “YES”.
In this case, it is determined that the assigned divided area to which the rotational position (steering angle θ) of the steering wheel 11 belongs has shifted to a divided area adjacent to the right rotation direction, and the cycle count value Nb is incremented by 1 in step S47. (Nb = Nb + 1).
On the other hand, if it is determined in step S46 that the value of the relative angle θb has not changed from “2π” to “0” (S46: NO), the process of step S47 is skipped.

Subsequently, the absolute angle detection ECU 53 advances the process to step S48. In this step S48, it is determined whether or not the value of the relative angle θb has changed from “0” to “2π”. That is, it is determined whether or not the sawtooth-shaped output signal representing the relative angle θb output from the second resolver sensor 52 has changed from the value “0” as the waveform valley to the value “2π” as the waveform vertex. To do.
Similar to step S44, this determination is made when the value of the relative angle θbn detected this time has increased by a predetermined value (for example, π) or more with respect to the relative angle θb (n−1) detected immediately before. It is determined that the value of θb has changed from “0” to “2π”.

For example, as shown in FIG. 9, when the output signal representing the relative angle θb changes from the waveform valley D to the waveform vertex C along the arrow b2, the determination in step S48 is “YES”.
In this case, it is determined that the assigned divided area to which the rotational position (steering angle θ) of the steering wheel 11 belongs has shifted to a divided area adjacent in the left rotation direction, and the cycle count value Nb is reduced by 1 in step S49. Increment (Nb = Nb-1).
On the other hand, if it is determined in step S48 that the value of the relative angle θb has not changed from “0” to “2π” (S48: NO), the process of step S49 is skipped.

  Subsequently, in step S50, the absolute angle detection ECU 53 stores and updates the relative angles θa and θb input in step S41 as previous values. Therefore, the stored and updated relative angles θa and θb are used as the previous relative angles θa (n−1) and θb (n−1) in the next processing.

  When the process of step S50 ends, this control routine is temporarily ended. Since this control routine is repeatedly executed, based on the output signals of the first resolver sensor 51 and the second resolver sensor 52, the belonging divided region to which the rotational position (steering angle θ) of the steering handle 11 belongs is periodically counted. This is always grasped by the values Na and Nb. When the first resolver sensor 51 or the second resolver sensor 52 breaks down, the steering angle θ is detected using the cycle count value Na or the cycle count value Nb, as will be described later.

  Next, the first abnormality routine incorporated in the above-described steering angle calculation routine will be described. The first abnormality routine is a control routine executed when an abnormality of the second resolver sensor 52 is detected, and is processed according to the flowchart shown in FIG.

When the first abnormality routine is started, the absolute angle detection ECU 53 inputs the relative angle θa from the first resolver sensor 51 in step S61. Subsequently, in step S62, an absolute angle equivalent amount Δθ of the relative angle θa is calculated.
The first resolver sensor 51 outputs the periodic wave signal θa n times (n = 13) in the process in which the steering handle 11 rotates from the left steering limit angle −θmax to the right steering limit angle + θmax. Therefore, an angle corresponding to one cycle of the output signal θa of the first resolver sensor 51 (an angle corresponding to 2π in the relative angle θa) corresponds to the mechanical steering angle 2 · θmax / n of the steering handle 11. Therefore, the absolute angle equivalent amount Δθ in the relative angle θa can be expressed as the following equation.
Δθ = (2 · θmax / n) × (θa / 2π) = (θmax · θa) / (n · π)
In calculating the absolute angle equivalent amount Δθ, a table for associating the relative angle θa and the absolute angle equivalent amount Δθ may be prepared and obtained with reference to this table.

Subsequently, the absolute angle detection ECU 53 advances the process to step S63. In step S63, the steering wheel is obtained by the following equation (1) using the cycle count value Na obtained in the previous relative angular cycle count routine and the absolute angle equivalent amount Δθ of the relative angle θa calculated in step S62. 11 steering angle θ (absolute steering angle θ) is calculated.
θ = −θmax + (2 · θmax / n) · Na + Δθ (1)

Since the periodic waveform signal θa output from the first resolver sensor 51 does not have periodicity and increases monotonously within the same divided region, the same value is not output for different steering angles θ. Therefore, if the belonging divided area to which the rotational position (steering angle θ) of the steering wheel 11 belongs is known, the absolute angle of the relative angle θa is set to the origin of the belonging divided area (the absolute steering angle at the left end of each divided area in FIG. 9). The absolute steering angle θ can be calculated by adding the angle equivalent amount Δθ. Further, since the divided area is specified by the count value Na, the absolute angle of the origin of the belonging divided area is expressed as −θmax + (2 · θmax / n) · Na.
Therefore, the steering angle θ of the steering wheel can be calculated by the above formula (1).

Next, in step S64, the absolute angle detection ECU 53 outputs the calculated steering angle θ to the steering reaction force ECU 60 and the front wheel steering ECU 70. In step S65, the relative angle θa is output to the steering reaction force ECU 60. This relative angle θa is determined by the motor for performing the two-phase / three-phase conversion process when the steering reaction force ECU 60 drives the steering reaction force electric motor 13 by vector control described in the two-phase rotating magnetic flux coordinate system. Used as a signal synchronized with the rotation angle.
Since the steering reaction force electric motor 13 is controlled with the relative angle θb as a rotation angle signal, in this step S65, a signal obtained by converting the relative angle θa into a rotation angle corresponding to the relative angle θb is output.

  When the process of step S65 is finished in this way, the first abnormality routine is once ended. Since the first abnormality routine is incorporated in the steering angle calculation control routine shown in FIG. 3, it is repeatedly executed. Therefore, even when the second resolver sensor 52 fails in the middle, the steering angle θ of the steering handle 11 can be detected based on the first resolver sensor 51.

Next, the second abnormality routine will be described. This second abnormality routine is a control routine that is incorporated in the steering angle calculation routine and executed when an abnormality of the first resolver sensor 51 is detected, and is processed according to the flowchart shown in FIG.
Note that the second abnormality routine is the same as the above-described first abnormality routine except that the signal to be handled is the same and the calculation method of the steering angle θ is the same.

When the second abnormality routine is started, first, the relative angle θb is input from the second resolver sensor 52 in step S71. Subsequently, in step S72, an absolute angle equivalent amount Δθ of the relative angle θb is calculated.
The second resolver sensor 52 outputs m (m = 12) periodic wave signals in the process in which the steering handle 11 rotates from the left steering limit angle −θmax to the right steering limit angle + θmax. Therefore, the absolute angle equivalent amount Δθ in the relative angle θb can be expressed as the following equation.
Δθ = (2 · θmax / m) × (θb / 2π) = (θmax · θb) / (m · π)
In calculating the absolute angle equivalent amount Δθ, a table for associating the relative angle θb and the absolute angle equivalent amount Δθ may be prepared and obtained by referring to this table.

Subsequently, in step S73, the absolute angle detection ECU 53 uses the count value Nb obtained in the previous relative angular period counting routine and the absolute angle equivalent amount Δθ of the relative angle θb calculated in step S72. The steering angle θ of the steering wheel 11 is calculated from the equation.
θ = −θmax + (2 · θmax / m) · Nb + Δθ (2)
Subsequently, in step S74, the absolute angle detection ECU 53 outputs the calculated steering angle θ to the steering reaction force ECU 60 and the front wheel steering ECU 70. In step S75, the relative angle θb is output to the steering reaction force ECU 60. This relative angle θb is determined by the motor for performing the two-phase / three-phase conversion process when the steering reaction force ECU 60 drives the steering reaction force electric motor 13 by vector control described in the two-phase rotating magnetic flux coordinate system. Used as a signal synchronized with the rotation angle.

  When the process of step S75 is finished in this way, the second abnormality routine is once finished. Since this second abnormality routine is incorporated in the steering angle calculation control routine shown in FIG. 3, it is repeatedly executed. Therefore, even when the first resolver sensor 51 fails in the middle, the steering angle θ of the steering handle 11 can be detected based on the second resolver sensor 52.

As described above, according to the vehicle steering apparatus of the present embodiment, the divided region is set by dividing the steerable range (−θmax to + θmax) by the number of divisions corresponding to the signal output periods of the first resolver sensor 51 and the second resolver sensor 52. At the time of starting the vehicle, it is determined to which divided region the rotational position of the steering handle 11 belongs based on the steering angle θ calculated from the relative angle difference θab.
Then, every time the assigned divided area is changed by the rotation operation of the steering handle 11, the cycle count values Na and Nb storing the assigned divided area are increased or decreased. Therefore, even if one resolver sensor 51 (52) fails during traveling, the absolute value of the steering wheel 11 can be determined from the relative angle θa (θb) of the normal resolver sensor 51 (52) and the cycle count value Na (Nb). The steering angle θ can be calculated.

When both resolver sensors 51 and 52 fail, the steering input shaft 12 and the steering output shaft 24 are connected by the operation of the electromagnetic clutches 32 and 33, so that the left and right front wheels FW1 are operated by turning the steering handle 11. , FW2 can be steered directly.
As a result, the reliability of the steer-by-wire steering device can be improved, and the safety of the vehicle can be improved.

The steering device has been described as an embodiment of the rotation angle detection device of the present invention. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention. .
For example, in the present embodiment, the present invention is applied to the detection of the rotation angle of the vehicle steering device, but the application target is not limited at all. For example, the present invention may be applied to a rotation angle detection device for an electric motor.

  Further, in the present embodiment, the belonging divided areas are stored and updated using the count values Na and Nb from the time of starting the vehicle. For example, when a failure of one resolver sensor is detected, the relative angles θa and θb are changed. The divided area corresponding to the rotational position of the steering wheel is detected from the relative angle difference θab, and then the assigned divided area is updated based on the transition of the relative angle output from the normal resolver sensor (the cycle count value is increased or decreased). You may make it go. In other words, when the two resolver sensors are normal, the divided areas are detected, and the divided areas may be detected and updated after a failure of the resolver sensor is detected.

  Note that the processing in steps S21 to S27 in the steering angle calculation routine performed by the absolute angle detection ECU 53 in the present embodiment corresponds to the absolute angle calculation means of the present invention, and the steps in the relative angle cycle counting routine performed by the absolute angle detection ECU 53. The processing of S42 to S45 corresponds to the first belonging divided region deriving means of the present invention, and the processing of steps S46 to S49 in the relative angular period counting routine performed by the absolute angle detection ECU 53 is the second belonging divided region deriving means of the present invention. The steps S21, S29, and S31 in the steering angle calculation routine performed by the absolute angle detection ECU 53 correspond to the abnormality detection means of the present invention, and the first abnormality routine and the second abnormality performed by the absolute angle detection ECU 53. The routine corresponds to the abnormal absolute angle calculation means of the present invention.

1 is an overall schematic diagram of a vehicle steering apparatus including a rotation angle detection device as one embodiment of the present invention. It is a flowchart showing an initial setting routine. It is a flowchart showing a steering angle calculation routine. It is a flowchart showing a relative angular period count routine. It is a flowchart showing a 1st abnormality routine. It is a flowchart showing a 2nd abnormality routine. It is explanatory drawing showing the table for calculating a target steering reaction force from a steering angle. It is explanatory drawing showing the table for calculating a target front wheel turning angle from a steering angle. It is explanatory drawing showing a relative angle, an absolute steering angle, a relative angle difference, and a division area. It is explanatory drawing showing the steering angle table for calculating a steering angle from a relative angle difference.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Steering operation device, 11 ... Steering handle, 12 ... Steering input shaft, 13 ... Electric motor for steering reaction force, 20 ... Steering device, 22 ... Electric motor for steering, 24 ... Steering output shaft, 40 ... Electricity Control device, 50 ... steering angle detection device, 51 ... first resolver sensor, 51s ... first resolver, 51c ... first relative angle detection circuit, 52 ... second resolver sensor, 52s ... second resolver, 52c ... second relative Angle detection circuit, 53: ECU for absolute angle detection, θ: Steering angle (absolute steering angle), θa, θb: Relative angle, θab: Relative angle difference, Na, Nb: Period count value.

Claims (5)

A first resolver sensor that outputs a periodic waveform signal of n times when the rotation member to be detected is rotated within a predetermined angle range;
A second resolver sensor that outputs a periodic waveform signal m times (m ≠ n) when the rotating member is rotated within the predetermined angle range;
A rotation angle detecting device comprising: absolute angle calculating means for calculating an absolute rotation angle of the rotating member based on an output difference between a signal output value of the first resolver sensor and a signal output value of the second resolver sensor;
Of the plurality of divided regions obtained by dividing the predetermined angle range by the number of divisions corresponding to the signal output period of the first resolver sensor, the assigned divided region to which the rotational position of the rotating member belongs is defined as the first resolver. First affiliation divided region deriving means for deriving based on a change in signal output of the sensor;
Of the plurality of divided regions obtained by dividing the predetermined angle range by the number of divisions corresponding to the signal output period of the second resolver sensor, the belonging divided region to which the rotational position of the rotating member belongs is defined as the second resolver. A second belonging divided region deriving means for deriving based on the transition of the signal output of the sensor;
An abnormality detecting means for detecting an abnormality of the first resolver sensor and the second resolver sensor;
When an abnormality in one of the first resolver sensor and the second resolver sensor is detected, the assigned divided region and the signal output value derived based on the signal output transition of the resolver in which the abnormality is not detected A rotation angle detecting device comprising: an abnormal angle calculating means for calculating an absolute rotation angle of the rotating member based on   2. The rotation angle detecting device according to claim 1, wherein the relationship between n and m is n = m + 1. The first resolver sensor and the second resolver sensor output a sawtooth signal as a periodic waveform signal corresponding to the rotational position of the rotating member,
The first belonging divided region deriving unit and the second belonging divided region deriving unit detect the passage of a triangular vertex in the sawtooth signal, and the rotation position of the rotating member is adjacent each time the passage of the triangular vertex is detected. The rotation angle detecting device according to claim 1 or 2, wherein the belonging divided area is changed as having moved to the divided area.   4. The rotation angle detecting device according to claim 3, wherein a belonging divided region of the rotating member is determined based on a passing direction of a triangular vertex in the sawtooth shape signal. 5. The rotating member is a steering shaft that rotates integrally with a steering handle of a vehicle, and the predetermined angle range is a rotatable range of the steering handle. Rotation angle detector.

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