JP2020093704A - Angle calculation device and steering device - Google Patents

Abstract

To provide an angle calculation device that can propose the unprecedented use of an absolute angle calculated redundantly, and provide a steering device.SOLUTION: A steering control unit 47 includes a first count value arithmetic circuit 50, a second count value arithmetic circuit 60, a first absolute angle arithmetic circuit 70, a second absolute angle arithmetic circuit 80 and a control device 90. The control device 90 calculates a first integrating angle by using a first count value C1 calculated by the first count value arithmetic circuit 50, calculates a first absolute angle by using absolute angle information calculated by the first absolute angle arithmetic circuit 70, and calculates a second absolute angle by using the absolute angle information calculated by the second absolute angle arithmetic circuit 80. The control device 90 has a determination unit for determining the presence or absence of abnormality of the first absolute angle and the second absolute angle on the basis of the relationship between the first absolute angle and the first integrating angle, and the relationship between the second absolute angle and the first integrating angle.SELECTED DRAWING: Figure 2

Description

The present invention relates to an angle calculation device and a steering device.

Conventionally, a so-called steer-by-wire type steering device in which power transmission between a steering wheel and steered wheels is separated is known. For example, the steering device of Patent Document 1 has a clutch that intermittently transmits power between a steering wheel and steered wheels, a reaction force motor that is a source of a steering reaction force applied to a steering shaft, and a steering wheel that steers the steered wheels. It has a steering motor that is the source of the rudder force. Further, the steering device of Patent Document 1 has a control device that controls the operations of the clutch, the reaction force motor, and the steering motor.

When the vehicle is traveling, the control device releases the clutch to disconnect the power transmission between the steering wheel and the steered wheels. The control device controls the steering motor so that the actual steering angle of the steered wheels follows the target steering angle, and also the reaction motor to generate the steering reaction force according to the steered state of the steered wheels. Control. The target turning angle is calculated based on the steering angle detected by the steering angle sensor. The steered state is detected by a steered angle sensor. Both the steering angle sensor and the steering angle sensor are absolute angle sensors.

The control device controls the reaction force motor by using the rotation angle detected by the first rotation angle sensor provided in the reaction force motor, and detects it by the second rotation angle sensor provided in the steering motor. The steering angle is controlled to control the steering motor. Both the first rotation angle sensor and the second rotation angle sensor are relative angle sensors. The first rotation angle sensor acquires the midpoint of the steering angle, which is a reference point for sensing, through the steering angle sensor. The second rotation angle sensor acquires the midpoint of the turning angle, which is a reference point for sensing, through the turning angle sensor. The control device described above uses the midpoint of the turning angle acquired through the turning angle sensor, and based on the rotation angle detected through the second rotation angle sensor, the actual turning of the steered wheels indicated by the absolute angle. The angle is calculated. The control device controls the steered motor using the absolute angle obtained by the calculation.

JP, 2016-545, A

In the above control device, it is possible to configure the control device so as to calculate a plurality of absolute angles from the viewpoint of redundancy for enhancing system reliability. The present invention proposes an unprecedented new use of redundantly computed absolute angles.

An angle calculation device that can achieve the above object is a first calculation circuit that calculates a count value based on a detection result of a first sensor that detects a relative angle of a motor that is a power source of a mechanical device; A second arithmetic circuit that calculates the first absolute position information based on the detection result of the second sensor that detects the absolute position of the detection target that interlocks with the motor; and the absolute detection target that is the same as the detection target of the second sensor. A third arithmetic circuit which is provided for calculating a position and which calculates second absolute position information based on a detection result of a third sensor which detects the absolute position of the detection target; and the motor using the count value. Angle calculation unit for calculating an integrated angle obtained by integrating the relative angles of the first absolute angle calculation unit and a first absolute angle calculation unit for calculating a first absolute angle which is an absolute angle of a rotary shaft interlocked with the motor using the first absolute position information. Section, a second absolute angle calculating section for calculating a second absolute angle which is an absolute angle of the rotation axis using the second absolute position information, the first absolute angle, the second absolute angle and the integrated angle And a fourth arithmetic circuit having a judging unit for judging whether or not there is an abnormality in the first absolute angle and the second absolute angle on the basis of the relationship between the first absolute angle and the second absolute angle, and the count value is for calculating the integrated angle. The first absolute position information and the second absolute position information are values for calculating the absolute position of the detection target.

Since the motor and the detection target work together, there is a correlation between the relative angle of the motor detected by the first sensor and the absolute position of the detection target detected by the second sensor and the third sensor. Therefore, the relationship between the first absolute angle and the integrated angle and the relationship between the second absolute angle and the integrated angle should match. Therefore, according to the above configuration, the determination unit can determine whether there is an abnormality in the first absolute angle and the second absolute angle based on the relationship between the first absolute angle and the second absolute angle and the integrated angle. .. When the relationship between the first absolute angle and the integrated angle is different from the relationship between the second absolute angle and the integrated angle, the determination unit causes an abnormality in either the calculated first absolute angle or the second absolute angle. You can determine what you are doing. According to such an angle calculation device, it is possible to propose a new use of the redundantly calculated absolute angle, which has never been achieved.

In the angle calculation device described above, the determination unit is configured to correlate the relationship between the first absolute angle and the integrated angle between the motor and the rotating shaft on the assumption that there is no abnormality in the integrated angle. If the relationship is the same and the relationship between the second absolute angle and the integrated angle does not match the correlation that should be made between the motor and the rotation shaft, it is determined that the second absolute angle is abnormal, The relationship between the second absolute angle and the integrated angle coincides with the correlation that should be made between the motor and the rotary shaft, and the relationship between the first absolute angle and the integrated angle is the motor and the rotation. When the correlation with the axis does not match, it is preferable to determine that the first absolute angle is abnormal.

According to the above configuration, the determination unit is configured such that the relationship between the first absolute angle and the integrated angle is different from the correlation that should be made between the motor and the rotation shaft, on the assumption that the integrated angle is normal. When the relationship between the two absolute angles and the integrated angle matches the correlation that should be made between the motor and the rotary shaft, it can be determined that the first absolute angle calculated has an abnormality. In this case, it can be said that an abnormality has occurred in the second sensor or the second arithmetic circuit. Further, the relationship between the first absolute angle and the integrated angle coincides with the correlation that should be established between the motor and the rotary shaft, while the relationship between the second absolute angle and the integrated angle is established between the motor and the rotary shaft. If it is different from the power correlation, it can be determined that the second absolute angle calculated has an abnormality. In this case, it can be said that an abnormality has occurred in the third sensor or the third arithmetic circuit. Thus, by using the redundantly calculated absolute angle, it is possible to specify the location of the abnormality in the abnormality determination.

In a steering apparatus including the above angle calculation device and a steering unit as the mechanical device, the steering unit includes the second sensor and the third sensor, and the second sensor and the third sensor. And are constituted by separate sensors.

According to the above configuration, the second sensor and the third sensor are each configured as separate sensors. From this, even when an abnormality occurs in one of the second sensor and the third sensor, the detection result of the detection target can be obtained from the other sensor in which no abnormality has occurred. Therefore, for example, the fourth arithmetic circuit can continue the arithmetic operation of the absolute angle of the rotation axis using the detection result obtained from the sensor in which no abnormality has occurred.

In a steering apparatus including the above angle calculation device and a steering unit as the mechanical device, the steering unit includes the second sensor and the third sensor, and the second sensor and the third sensor. Is configured by the same sensor, and the output lines for outputting the detection result of the same sensor to the second arithmetic circuit and the third arithmetic circuit are different.

According to the above configuration, the second sensor and the third sensor are configured such that the output lines for outputting the detection results are separate from each other. Therefore, even if an abnormality occurs in either the output line for outputting the detection result from the second sensor or the output line for outputting the detection result from the third sensor, the abnormality does not occur. The detection result can be output through the other output line which is not provided. Therefore, the fourth arithmetic circuit can continue the arithmetic operation of the absolute angle of the rotation axis using the detection result obtained from the sensor in which no abnormality has occurred.

In the above steering apparatus, the steering unit is provided to the steering shaft, which steers the steered wheels by performing linear motion, a pinion shaft meshed with the steering shaft, and the steering shaft. A steering motor that is a power generation source, and a transmission mechanism that transmits the power generated by the steering motor to the steering shaft, and the detection target is provided so as to interlock with the steering motor. The above-mentioned pinion shaft may be used.

According to the above configuration, since the steered system includes the above-described angle calculation device, when it is necessary to obtain the absolute angle of the pinion shaft, the reliability of the calculated absolute angle of the pinion shaft can be improved. A steering device can be realized.

According to the angle calculation device and the steering device of the present invention, it is possible to propose a new use of the redundantly calculated absolute angle, which has never been achieved.

FIG. 3 is a schematic configuration diagram of a steering device equipped with an angle calculation device and a steering device. The block diagram which shows the steering control part of 1st Embodiment. (A) is a block diagram showing a first count value calculation circuit, and (b) is a block diagram showing a second count value calculation circuit. (A) is a block diagram showing a first absolute angle arithmetic circuit, and (b) is a block diagram showing a second absolute angle arithmetic circuit. The block diagram which shows a control apparatus. The graph which shows the relationship between the 1st absolute angle information, the 2nd absolute angle information, and the absolute angle of a 1st pinion shaft. 6 is a flowchart for determining whether or not there is an abnormality in the integrated angle, which is executed by the determination unit. 6 is a flowchart for determining whether or not there is an absolute angle abnormality, which is executed by a determination unit. The block diagram which shows the steering control part of 2nd Embodiment.

<First Embodiment>
A first embodiment in which a steering device of a steer-by-wire system is mounted with an angle calculation device and a steering device will be described.

As shown in FIG. 1, a vehicle steering system 10 has a steering shaft 12 connected to a steering wheel 11. A first pinion shaft 13 is provided at an end of the steering shaft 12 opposite to the steering wheel 11. The first pinion teeth 13 a of the first pinion shaft 13 are meshed with the first rack teeth 14 a of the steered shaft 14 extending in a direction intersecting with the first pinion shaft 13. Left and right steered wheels 16 and 16 are connected to both ends of the steered shaft 14 via tie rods 15 and 15, respectively.

The steering device 10 has a clutch 21 and a clutch control unit 22.
The clutch 21 is provided in the middle of the steering shaft 12. As the clutch 21, an electromagnetic clutch is used that connects and disconnects power by connecting and disconnecting power to the exciting coil. When the clutch 21 is disengaged, power transmission between the steering wheel 11 and the steered wheels 16, 16 is disengaged. When the clutch 21 is connected, power transmission between the steering wheel 11 and the steered wheels 16, 16 is connected.

The clutch control unit 22 controls engagement/disengagement of the clutch 21. The clutch control unit 22 switches the clutch 21 from the connected state to the disconnected state by energizing the exciting coil of the clutch 21. Further, the clutch control unit 22 switches the clutch 21 from the disengaged state to the connected state by stopping energization of the exciting coil of the clutch 21.

When the clutch 21 is engaged, the steering shaft 12, the first pinion shaft 13, and the steered shaft 14 function as a power transmission path between the steering wheel 11 and the steered wheels 16, 16. That is, the turning angle θt of the steered wheels 16 and 16 is changed by the linear movement of the steered shaft 14 in accordance with the rotation operation of the steering wheel 11.

The steering device 10 includes a reaction force motor 31, a first reduction mechanism 32, a reaction force rotation angle sensor 33, a torque sensor 34, and a reaction force control unit 35 as a configuration for generating a steering reaction force. The steering reaction force is a force acting in a direction opposite to the direction in which the driver operates the steering wheel 11. By applying the steering reaction force to the steering wheel 11, it is possible to give the driver an appropriate feeling of response.

The reaction force motor 31 is a source of a steering reaction force. As the reaction force motor 31, for example, a three-phase (U-phase, V-phase, W-phase) brushless motor is adopted. The rotation shaft of the reaction force motor 31 is connected to the steering shaft 12 via the first reduction mechanism 32. The first reduction gear mechanism 32 reduces the rotation of the reaction force motor 31, and transmits the reduced rotation force to the steering shaft 12. The first reduction gear mechanism 32 is provided on a portion of the steering shaft 12 closer to the steering wheel 11 than the clutch 21. The torque of the reaction force motor 31 is applied to the steering shaft 12 as a steering reaction force.

The reaction force rotation angle sensor 33 is provided in the reaction force motor 31. The reaction force rotation angle sensor 33 is a relative angle sensor that detects the rotation angle of the rotation shaft of the reaction force motor 31 in the range of 0 degrees to 360 degrees. The reaction force rotation angle sensor 33 generates an electric signal Sa according to the rotation angle θa of the rotation shaft of the reaction force motor 31. As the reaction force rotation angle sensor 33, for example, an MR sensor (magnetoresistive effect sensor) which is a kind of magnetic sensor is adopted. The MR sensor generates an electric signal Sa according to the magnetic field direction of a bias magnet having a pair of magnetic poles (N pole, S pole) provided at the end of the output shaft of the reaction force motor 31. The electrical signal Sa is a sine wave signal Ssin that changes sinusoidally with respect to the rotation angle θa of the rotation shaft of the reaction force motor 31, and a cosine wave that changes cosine wave with respect to the rotation angle θa of the rotation shaft of the reaction force motor 31. It contains the wave signal Scos. Each of the sine wave signal Ssin and the cosine wave signal Scos is a signal having one period in which the reaction force motor 31 rotates by an angle (360 degrees in this case) corresponding to one magnetic pole pair of the bias magnet.

The torque sensor 34 detects the steering torque Th applied to the steering shaft 12 through the rotating operation of the steering wheel 11. The torque sensor 34 is provided in a portion of the steering shaft 12 closer to the steering wheel 11 than the first reduction gear mechanism 32.

The reaction force control unit 35 executes reaction force control for generating a steering reaction force according to the steering torque Th through drive control of the reaction force motor 31. The reaction force control unit 35 calculates the target steering reaction force based on the steering torque Th detected by the torque sensor 34 and the vehicle speed V detected by the vehicle speed sensor 36, and based on the calculated target steering reaction force. The target steering angle θ* of the steering wheel 11 is calculated. The reaction force control unit 35 outputs the calculated target steering angle θ* to the steering control unit 47. The reaction force control unit 35 calculates the rotation angle θa of the reaction force motor 31 based on the electric signal Sa generated by the reaction force rotation angle sensor 33, and the actual steering of the steering wheel 11 based on the calculated rotation angle θa. The angle θs is calculated. The reaction motor 31 and the steering shaft 12 are interlocked with each other via the first reduction gear mechanism 32. Therefore, there is a correlation between the rotation angle θa of the rotation shaft of the reaction force motor 31 and the rotation angle of the steering shaft 12. There is also a correlation between the rotation angle of the steering shaft 12 and the steering angle θs that is the rotation angle of the steering wheel 11. Therefore, the steering angle θs can be obtained based on the rotation angle θa of the rotation shaft of the reaction force motor 31. The reaction force control unit 35 calculates the steering angle θs of the steering wheel 11 based on the electric signal Sa generated by the reaction force rotation angle sensor 33. Then, the reaction force control unit 35 obtains a deviation between the target steering angle θ* and the actual steering angle θs, and controls power supply to the reaction force motor 31 so as to eliminate the deviation.

The reaction force control unit 35 executes the connection/disconnection control for switching the connection/disconnection of the clutch 21 based on whether or not the clutch connection condition is satisfied. Examples of clutch connection conditions include the following (a) to (c).

a. The vehicle start switch is turned off. The start switch is a switch that switches between energization and interruption of electric power supplied from the vehicle drive source. A start signal Sig indicating the on/off state of the start switch is input to the reaction force control unit 35 and the steering control unit 47.

b. Abnormalities are detected in the components for generating the steering reaction force including the reaction force motor 31.
c. An abnormality is detected in the configuration for generating the steering force including the steering motor 41.

The reaction force control unit 35 generates a command signal to connect the clutch 21 when the clutch connection condition is satisfied. On the other hand, the reaction force control unit 35 generates a command signal to disconnect the clutch 21 when the clutch connection condition is not satisfied. The clutch control unit 22 controls the engagement/disengagement of the clutch 21 based on the command signal generated by the reaction force control unit 35.

The steering device 10 includes a steering motor 41, a second reduction mechanism 42, a second pinion shaft 43, and a first rotation as a configuration for generating a steering force that is power for steering the steered wheels 16, 16. It has a steering rotation angle sensor 44, a second steering rotation angle sensor 45, a torque angle sensor (hereinafter referred to as “TAS46”), and a steering control unit 47. The first sensors described in the claims are the first turning rotation angle sensor 44 and the second turning rotation angle sensor 45.

The second reduction mechanism 42 and the second pinion shaft 43 configure a transmission mechanism that transmits the power generated by the steering motor 41 to the steering shaft 14. The first pinion shaft 13, the steered shaft 14, the steered motor 41, the second reduction mechanism 42, the second pinion shaft 43, the first steered rotation angle sensor 44, and the second steered rotation angle sensor 45 are mechanical devices. U2 is configured as follows. Further, the steering unit U2, the TAS 46, and the steering control unit 47 form a steering device 10b.

The steered motor 41 is a source of a steered force. As the steering motor 41, for example, a three-phase (U-phase, V-phase, W-phase) brushless motor is adopted. The rotating shaft of the steered motor 41 is connected to the second pinion shaft 43 via the second reduction mechanism 42. The second reduction gear mechanism 42 reduces the rotation of the steered motor 41 and transmits the reduced rotation force to the steering shaft 12. The second pinion teeth 43 a of the second pinion shaft 43 are meshed with the second rack teeth 14 b of the steered shaft 14. The torque of the steered motor 41 is applied to the steered shaft 14 as a steered force via the second pinion shaft 43. The steered shaft 14 moves along the vehicle width direction according to the rotation of the steered motor 41. The vehicle width direction is the left-right direction in FIG. 1 and is the direction in which the steered shaft 14 extends.

The first turning rotation angle sensor 44 and the second turning rotation angle sensor 45 are provided in the turning motor 41. The first steering rotation angle sensor 44 and the second steering rotation angle sensor 45 are relative angle sensors that detect the rotation angle of the rotation shaft of the steering motor 41 in the range of 0 degrees to 360 degrees. The first steering rotation angle sensor 44 generates an electric signal Sb1 according to the rotation angle θb of the rotation shaft of the steering motor 41. The second turning rotation angle sensor 45 also generates an electric signal Sb2 according to the rotation angle θb of the rotation shaft of the turning motor 41. That is, the first turning rotation angle sensor 44 and the second turning rotation angle sensor 45 are sensors that individually detect the rotation angle θb of the rotation shaft of the turning motor 41 that is the same detection target. The signal line for outputting the electric signal Sb1 from the first turning rotation angle sensor 44 and the signal line for outputting the electric signal Sb2 from the second turning rotation angle sensor 45 are different. As the first turning rotation angle sensor 44 and the second turning rotation angle sensor 45, for example, an MR sensor is adopted. The electrical signals Sb1 and Sb2 change in a sine wave signal Ssin that changes sinusoidally with respect to the rotation angle θb of the rotation shaft of the steered motor 41, and with a cosine wave shape with respect to the rotation angle θb of the rotation shaft of the steered motor 41. It includes a cosine wave signal Scos that

The TAS 46 is an absolute angle sensor that detects the torque Tp that acts on the first pinion shaft 13 and detects the pinion angle θpa that is the absolute position of the first pinion shaft 13 over multiple rotations of more than 360 degrees. The TAS 46 is provided on the first pinion shaft 13. Specifically, the TAS 46 is provided in a housing that houses the first pinion shaft 13 together with the steered shaft 14. The TAS 46 includes a first pinion angle sensor 46a, a second pinion angle sensor 46b, a third pinion angle sensor 46c, a fourth pinion angle sensor 46d, and a first pinion for detecting the pinion angle θpa of the first pinion shaft 13. The pinion torque sensor 46e detects the torque Tp acting on the shaft 13. Two sets of gear parts are meshed with the outer circumference of the first pinion shaft 13. On the outer circumference of the first pinion shaft 13, a gear that meshes with two sets of gear units is provided. The gear unit group includes a first gear unit group having a first gear unit and a second gear unit, and a second gear unit group having a third gear unit and a fourth gear unit. .. The number of teeth of the first gear portion and the number of teeth of the second gear portion are different from each other. That is, the reduction gear ratio of the first gear portion and the reduction gear ratio of the second gear portion are different from each other. Further, the number of teeth of the third gear portion and the number of teeth of the fourth gear portion are different from each other. That is, the reduction gear ratio of the third gear portion and the reduction gear ratio of the fourth gear portion are different from each other. Further, the number of teeth of the first gear portion and the number of teeth of the third gear portion are the same, and the number of teeth of the second gear portion and the number of teeth of the fourth gear portion are the same.

The first pinion angle sensor 46a is a relative angle sensor that detects the rotation angle of the first gear portion that rotates in response to the rotation of the first pinion shaft 13 in the range of 0 degrees to 360 degrees. The first pinion angle sensor 46a generates an electric signal Sg1 according to the rotation angle of the first gear portion. The electric signal Sg1 includes a sine wave signal Ssin that changes sinusoidally with respect to the rotation angle of the first gear portion, and a cosine wave signal Scos that changes cosine wave with respect to the rotation angle of the first gear portion. The second pinion angle sensor 46b is a relative angle sensor that detects the rotation angle of the second gear portion that rotates in response to the rotation of the first pinion shaft 13 in the range of 0 degrees to 360 degrees. The second pinion angle sensor 46b generates an electric signal Sg2 according to the rotation angle of the second gear portion. The electrical signal Sg2 includes a sine wave signal Ssin that changes sinusoidally with respect to the rotation angle of the second gear portion, and a cosine wave signal Scos that changes cosine wave with respect to the rotation angle of the second gear portion. The third pinion angle sensor 46c is a relative angle sensor that detects the rotation angle of the third gear portion that rotates in response to the rotation of the first pinion shaft 13 in the range of 0 degrees to 360 degrees. The third pinion angle sensor 46c generates an electric signal Sg3 according to the rotation angle of the third gear portion. The electrical signal Sg3 includes a sine wave signal Ssin that changes sinusoidally with respect to the rotation angle of the third gear portion and a cosine wave signal Scos that changes cosine wave with respect to the rotation angle of the third gear portion. The fourth pinion angle sensor 46d is a relative angle sensor that detects the rotation angle of the fourth gear portion that rotates in accordance with the rotation of the first pinion shaft 13 in the range of 0 degrees to 360 degrees. The fourth pinion angle sensor 46d generates an electric signal Sg4 according to the rotation angle of the fourth gear portion. The electrical signal Sg4 is obtained by the fourth pinion angle sensor 46d, the sine wave signal Ssin changing sinusoidally with respect to the rotation angle of the fourth gear portion, and the cosine wave changing cosine wave with respect to the rotation angle of the fourth gear portion. It contains the wave signal Scos. As the first pinion angle sensor 46a, the second pinion angle sensor 46b, the third pinion angle sensor 46c, and the fourth pinion angle sensor 46d, for example, an MR sensor (magnetoresistive effect sensor) is adopted. The second sensors described in the claims are the first pinion angle sensor 46a and the second pinion angle sensor 46b. The third sensors described in the claims are the third pinion angle sensor 46c and the fourth pinion angle sensor 46d.

The steered control unit 47 executes steered control to steer the steered wheels 16 and 16 according to the steering state through control of the steered motor 41. The turning control unit 47 is the actual rotation angle of the first pinion shaft 13 based on the rotation angle θb of the turning motor 41 detected through the first turning rotation angle sensor 44 and the second turning rotation angle sensor 45. The pinion angle θpa is calculated as an absolute angle. The steering motor 41 and the second pinion shaft 43 are interlocked with each other via the second reduction gear mechanism 42. Therefore, there is a correlation between the rotation angle θb of the rotation shaft of the steered motor 41 and the rotation angle of the second pinion shaft 43. The second pinion teeth 43 a of the second pinion shaft 43 are meshed with the second rack teeth 14 b of the steered shaft 14, and the first pinion teeth 13 a of the first pinion shaft 13 are the first rack teeth 14 a of the steered shaft 14. Have been meshed with. From this, there is a correlation between the pinion angle θpb, which is the rotation angle of the second pinion shaft 43, and the pinion angle θpa of the first pinion shaft 13. Therefore, the pinion angle θpa can be obtained based on the rotation angle θb of the rotation shaft of the steering motor 41. The steering control unit 47, based on the electric signal Sb1 generated by the first steering rotation angle sensor 44 and the electric signal Sb2 generated by the second steering rotation angle sensor 45, the pinion angle θpa of the first pinion shaft 13. Is calculated. Further, the turning control unit 47 calculates the target pinion angle using the target steering angle θ* calculated by the reaction force control unit 35. Then, the steering control unit 47 obtains a deviation between the target pinion angle and the actual pinion angle θpa, and controls power supply to the steering motor 41 so as to eliminate the deviation.

As the communication standard between the steering control unit 47 and the TAS 46, for example, SPI (Serial Peripheral Interface) is adopted. SPI is a type of synchronous serial communication standard.

The steered control unit 47 also executes the connection/disconnection control for switching the connection/disconnection of the clutch 21 based on the success or failure of the previous clutch connection conditions (a) to (c). The steering control unit 47 generates a command signal for connecting the clutch 21 when the clutch connection condition is satisfied, and generates a command signal for disconnecting the clutch when the clutch connection condition is not satisfied. This command signal is for the clutch control unit 22. When the command signal cannot be acquired from the reaction force control unit 35, the clutch control unit 22 controls the engagement/disengagement of the clutch 21 based on the command signal generated by the steering control unit 47.

When the clutch 21 is in the connected state, the turning control unit 47 controls the operation of the turning motor 41 based on the torque Tp acting on the first pinion shaft 13 detected by the pinion torque sensor 46e of the TAS 46. You can In this case, the steering control unit 47 executes the assist control for assisting the rotation operation of the steering wheel 11 by the driver. An example of such a case where the steering control unit 47 executes the assist control is a case where the reaction force control unit 35 stops operating.

The steered control unit 47 also executes the connection/disconnection control for switching the connection/disconnection of the clutch 21 based on the success or failure of the previous clutch connection conditions (a) to (c). The steering control unit 47 generates a command signal for connecting the clutch 21 when the clutch connection condition is satisfied, and generates a command signal for disconnecting the clutch when the clutch connection condition is not satisfied. This command signal is for the clutch control unit 22. When the command signal cannot be acquired from the reaction force control unit 35, the clutch control unit 22 controls the engagement/disengagement of the clutch 21 based on the command signal generated by the steering control unit 47.

The function of the steering control unit 47 will be described.
As shown in FIG. 2, the steering control unit 47 as an angle calculation device includes a first count value calculation circuit 50, a second count value calculation circuit 60, a first absolute angle calculation circuit 70, and a second absolute angle. The arithmetic circuit 80, the control device 90, and the drive circuit 100 are provided. The first arithmetic circuit described in the claims is the first count value arithmetic circuit 50 and the second count value arithmetic circuit 60. The second arithmetic circuit described in the claims is the first absolute angle arithmetic circuit 70. The third arithmetic circuit described in the claims is the second absolute angle arithmetic circuit 80. The fourth arithmetic circuit described in the claims is the controller 90.

The first count value calculation circuit 50 is configured by packaging a logic circuit, which is a combination of electronic circuits and flip-flops, in a single chip. The first count value calculation circuit 50 is a so-called ASIC (application specific integrated circuit). The first count value calculation circuit 50 performs a predetermined output with respect to a specific input. The electric signal Sb1 generated by the first turning rotation angle sensor 44 is input to the first count value calculation circuit 50 as a specific input. The first count value calculation circuit 50 calculates the first count value C1 as rotation speed information indicating the number of multi-turns (multi-rotation speed) of the steered motor 41 based on the electric signal Sb1, as described later, and performs the calculation. The calculated first count value C1 is output to the control device 90.

The second count value calculation circuit 60 is configured by packaging a logic circuit, which is a combination of electronic circuits and flip-flops, in a single chip. The second count value calculation circuit 60 is a so-called ASIC. The second count value calculation circuit 60 performs a predetermined output with respect to a specific input. The electric signal Sb2 generated by the second steered rotation angle sensor 45 is input to the second count value calculation circuit 60 as a specific input. The second count value calculation circuit 60 calculates a second count value C2 as rotation speed information indicating the number of multi-turns of the steering motor 41 based on the electric signal Sb2, and calculates the second count value. C2 is output to the controller 90. As described above, in the first embodiment, the first count value calculation circuit 50 and the second count value calculation circuit 60 are provided, and the first count value C1 and the second count value C2 are redundantly obtained.

As shown in FIG. 2, FIG. 3A, and FIG. 3B, the first count value calculation circuit 50 reduces the power supply voltage of a battery (not shown) to a control voltage Vco within a predetermined voltage range. It has a circuit 51. A first absolute angle calculation circuit 70, a second absolute angle calculation circuit 80, and a control device 90 are connected to the first power supply circuit 51 via a connection line 51a, and the first count value calculation circuit 50 is connected to the first absolute angle calculation circuit 70. Each of the constituent circuits is connected. Note that, in FIG. 3A, a connecting line that connects the first power supply circuit 51 and each circuit forming the first count value calculation circuit 50 is omitted for convenience. The first power supply circuit 51 supplies the control voltage Vco to the first absolute angle calculation circuit 70, the second absolute angle calculation circuit 80, and the control device 90 only when the start switch is in the ON state, while the start switch The control voltage Vco is constantly supplied to each circuit that constitutes the first count value calculation circuit 50 regardless of the ON state and the OFF state. As a result, each circuit forming the first count value calculation circuit 50 operates not only when the start switch is in the on state but also when it is in the off state. In addition, the first power supply circuit 51 constantly supplies the operating voltage necessary for operating the first turning rotation angle sensor 44 to the first turning rotation angle sensor 44 regardless of the ON state and the OFF state of the start switch. To do.

The second count value calculation circuit 60 has a second power supply circuit 61 that lowers the power supply voltage of the battery (not shown) to the control voltage Vco within a predetermined voltage range. The first absolute angle calculation circuit 70, the second absolute angle calculation circuit 80, and the control device 90 are connected to the second power supply circuit 61 via a connection line 61a, and the second count value calculation circuit 60 is connected to the second count value calculation circuit 60. Each of the constituent circuits is connected. Note that, in FIG. 3, for convenience, a connecting line that connects the second power supply circuit 61 and each circuit forming the second count value calculation circuit 60 is omitted. The second power supply circuit 61 supplies the control voltage Vco to the first absolute angle calculation circuit 70, the second absolute angle calculation circuit 80, and the control device 90 only when the start switch is in the ON state, while The control voltage Vco is constantly supplied to each circuit that constitutes the second count value calculation circuit 60 regardless of the ON state and the OFF state. As a result, each circuit forming the second count value calculation circuit 60 operates not only when the start switch is in the on state but also when it is in the off state. Further, the second power supply circuit 61 constantly supplies the operating voltage necessary for operating the second turning rotation angle sensor 45 to the second turning rotation angle sensor 45 regardless of the ON state and the OFF state of the start switch. To do.

When the first count value calculation circuit 50 is functioning normally, the control voltage Vco is supplied from the first power supply circuit 51 to the first absolute angle calculation circuit 70, the second absolute angle calculation circuit 80, and the control device 90. On the other hand, when the first count value calculation circuit 50 is not functioning normally, the control voltage Vco is supplied from the second power supply circuit 61 to the first absolute angle calculation circuit 70, the second absolute angle calculation circuit 80, and the control device 90. To supply.

As shown in FIG. 2, the drive circuit 100 is connected to the battery via a drive relay (not shown). As the drive relay, a mechanical relay, FET (field effect transistor), etc. are adopted. The controller 90 controls ON/OFF of the drive relay.

The first absolute angle calculation circuit 70 is configured by packaging a logic circuit, which is a combination of electronic circuits and flip-flops, in a single chip. The first absolute angle calculation circuit 70 is a so-called ASIC. The first absolute angle calculation circuit 70 performs a predetermined output with respect to a specific input. The electric signal Sg1 of the first pinion angle sensor 46a and the electric signal Sg2 of the second pinion angle sensor 46b are input to the first absolute angle calculation circuit 70 as specific inputs. The first absolute angle calculation circuit 70 operates when the control voltage Vco within a predetermined voltage range is supplied from the first power supply circuit 51 or the second power supply circuit 61 when the start switch is in the ON state. The first absolute angle calculation circuit 70 calculates the pinion angle θpa of the first pinion shaft 13 based on the electric signal Sg1 and the electric signal Sg2, as will be described later. The second absolute angle information θg2 is calculated, and the first absolute angle information θg1 and the second absolute angle information θg2 are output to the control device 90.

The second absolute angle calculation circuit 80 is configured by packaging a logic circuit, which is a combination of electronic components and flip-flops, in a single chip. The second absolute angle calculation circuit 80 is a so-called ASIC. The second absolute angle calculation circuit 80 performs a predetermined output with respect to a specific input. The electric signal Sg3 of the third pinion angle sensor 46c and the electric signal Sg4 of the fourth pinion angle sensor 46d are input to the second absolute angle calculation circuit 80 as specific inputs. The second absolute angle calculation circuit 80 operates when the control voltage Vco within a predetermined voltage range is supplied from the first power supply circuit 51 or the second power supply circuit 61 when the start switch is in the ON state. The second absolute angle calculation circuit 80 calculates the pinion angle θpa of the first pinion shaft 13 based on the electric signal Sg3 and the electric signal Sg4, as will be described later. The fourth absolute angle information θg4 is calculated, and the third absolute angle information θg3 and the fourth absolute angle information θg4 are output to the control device 90.

The control device 90 operates by being supplied with the control voltage Vco within a predetermined voltage range from the first power supply circuit 51 or the second power supply circuit 61 when the start switch is in the ON state. When the control device 90 starts operation by being supplied with the control voltage Vco, the control device 90 controls opening/closing of a drive relay provided in a power supply path to the drive circuit 100. When the drive relay is closed, power is supplied to the drive circuit 100, and drive power can be supplied to the steering motor 41.

When the control voltage Vco is supplied, the control device 90 calculates the pinion angle θpa of the first pinion shaft 13 and controls the electric power supplied to the steered motor 41. The control device 90 includes, for example, a microprocessing unit (microcomputer). The controller 90 is connected to a first count value calculation circuit 50, a second count value calculation circuit 60, a first absolute angle calculation circuit 70, and a second absolute angle calculation circuit 80. The control device 90 operates by being supplied with the control voltage Vco within a predetermined voltage range from the first power supply circuit 51 or the second power supply circuit 61 when the start switch is in the ON state. The controller 90 receives the first count value C1 calculated by the first count value calculation circuit 50 and the second count value C2 calculated by the second count value calculation circuit 60. Further, the controller 90 includes the first absolute angle information θg1 and the second absolute angle information θg2 calculated by the first absolute angle calculation circuit 70, and the third absolute angle information calculated by the second absolute angle calculation circuit 80. θg3 and the fourth absolute angle information θg4 are input. The control device 90 also controls the electric signal Sb1 generated by the first turning rotation angle sensor 44, the electric signal Sb2 generated by the second turning rotation angle sensor 45, and the vehicle speed V detected by the vehicle speed sensor 36. The target steering angle θ* calculated by the reaction force control unit 35, the actual current value I detected by the current sensor 101, and the torque Tp detected by the pinion torque sensor 46e are input. The current sensor 101 is provided in the power feeding path between the steering motor 41 and the drive circuit 100. The control device 90 generates a motor control signal Sm necessary for driving the turning motor 41 based on these various input values. The control device 90 outputs the calculated motor control signal Sm to the drive circuit 100. ..

Functions of the first count value calculation circuit 50 and the second count value calculation circuit 60 will be described.
As shown in FIG. 3A, the first count value calculation circuit 50 includes a first power supply circuit 51, a first counter circuit 52, and a communication interface 53.

The electric signal Sb1 generated by the first turning rotation angle sensor 44 is input to the first counter circuit 52. The first counter circuit 52 calculates a first count value C1 used for calculating the rotation angle of the multi-turn of the turning motor 41 based on the electric signal Sb1. The first count value C1 is rotation speed information indicating the number of multi-turns of the steering motor 41. In the first embodiment, the first count value C1 is information indicating how many rotations the rotation position of the rotation shaft of the steered motor 41 rotates with respect to the reference position.

The first counter circuit 52 includes an amplifier 54, a comparator 55, a quadrant determination unit 56, and a first count value calculation unit 57.
The electric signal Sb1 generated by the first turning rotation angle sensor 44 is input to the amplifier 54. The amplifier 54 amplifies the electric signal Sb1 input from the first steered rotation angle sensor 44 and outputs it to the comparator 55.

The comparator 55 generates a Hi level signal when the electric signal Sb1 amplified by the amplifier 54 has a value equal to or larger than the set threshold value, and a Lo level signal when the electric signal Sb1 has a value smaller than the threshold value. This threshold is set to "0", for example.

The quadrant determination unit 56 generates quadrant information, which is information indicating the quadrant in which the rotational position of the rotating shaft of the steered motor 41 exists, based on the Hi-level signal and the Lo-level signal generated by the comparator 55. .. One rotation (360 degrees) of the rotating shaft of the steered motor 41 is divided into four quadrants every 90 degrees based on the positive/negative combination of the electric signal Sb1. The quadrant determination unit 56 generates the left rotation flag Fl or the right rotation flag Fr based on the change in the quadrant in which the rotation position of the rotation shaft of the steered motor 41 indicated by the quadrant information exists. It is assumed that the quadrant determination unit 56 rotates the unit rotation amount each time the quadrant in which the rotational position of the rotation shaft of the steered motor 41 exists changes to the adjacent quadrant. This unit rotation amount is, for example, 90 degrees. The quadrant determination unit 56 determines that the rotational position of the rotation shaft of the steering motor 41 is based on the relationship between the quadrant existing before the rotation of the steering motor 41 and the quadrant existing after the rotation of the steering motor 41. The rotation direction of the rotary shaft of the rudder motor 41 is specified.

The first count value calculation unit 57 calculates the first count value C1 based on the left rotation flag Fl or the right rotation flag Fr acquired from the quadrant determination unit 56. The first count value calculator 57 is a logic circuit that combines flip-flops and the like. The first count value C1 indicates the number of times the rotational position of the rotating shaft of the steered motor 41 has rotated by a unit rotational amount with respect to its reference position. The first count value calculation unit 57 increments each time the left rotation flag Fl is acquired from the quadrant determination unit 56, and decrements it every time the right rotation flag Fr is acquired from the quadrant determination unit 56. Here, the increment means to add 1 to the first count value C1, and the decrement means to subtract 1 from the first count value C1. As described above, the first count value calculator 57 calculates the first count value C1 every time the first steering rotation angle sensor 44 generates the electric signal Sb1, and stores the first count value C1. It is configured to be able to. The first count value C1 calculated by the first count value calculator 57 is output to the communication interface 53.

The communication interface 53 is configured to operate when the start switch is in the on state, and does not operate when the start switch is in the off state. When the first count value C1 is input, the communication interface 53 outputs the first count value C1 to the control device 90.

As shown in FIG. 3B, the second count value calculation circuit 60 has the same configuration as the first count value calculation circuit 50. That is, the second count value calculation circuit 60 includes a second power supply circuit 61, a second counter circuit 62, and a communication interface 63.

The electric signal Sb2 generated by the second steered rotation angle sensor 45 is input to the second counter circuit 62. The second counter circuit 62 calculates a second count value C2 used for calculating the rotation angle of the multi-turn of the turning motor 41 based on the electric signal Sb2. The second count value C2 is rotation speed information indicating the number of multi-turns of the steering motor 41. In the first embodiment, the second count value C2 is information indicating how many revolutions the rotational position of the rotation shaft of the steered motor 41 rotates with respect to its reference position.

The second counter circuit 62 includes an amplifier 64, a comparator 65, a quadrant determination unit 66, and a second count value calculation unit 67.
The electric signal Sb2 generated by the second steered rotation angle sensor 45 is input to the amplifier 64. The amplifier 64 amplifies the electric signal Sb2 input from the second steered rotation angle sensor 45 and outputs it to the comparator 65.

The comparator 65 generates a Hi level signal when the electric signal Sb2 amplified by the amplifier 64 has a value equal to or larger than the set threshold value, and a Lo level signal when the electric signal Sb2 has a value smaller than the threshold value. This threshold is set to "0", for example.

The quadrant determination unit 66 generates quadrant information, which is information indicating a quadrant in which the rotational position of the rotating shaft of the steered motor 41 exists, based on the Hi-level signal and the Lo-level signal generated by the comparator 65. .. The quadrant determination unit 66 generates the left rotation flag Fl or the right rotation flag Fr based on the change in the quadrant in which the rotational position of the rotation shaft of the steered motor 41 indicated by the quadrant information exists. It is assumed that the quadrant determination unit 66 rotates the unit rotation amount every time the quadrant in which the rotational position of the rotation shaft of the steering motor 41 exists changes to the adjacent quadrant. This unit rotation amount is, for example, 90 degrees. The quadrant determination unit 66 determines that the rotation position of the rotation shaft of the steered motor 41 changes from the relationship between the quadrant existing before the rotation of the steered motor 41 and the quadrant existing after the rotation of the steered motor 41. The rotation direction of the rotary shaft of the rudder motor 41 is specified.

The second count value calculation unit 67 calculates the second count value C2 based on the left rotation flag Fl or the right rotation flag Fr acquired from the quadrant determination unit 66. The second count value calculator 67 is a logic circuit that combines flip-flops and the like. The second count value C2 indicates the number of times the rotational position of the rotary shaft of the steered motor 41 has rotated by a unit rotational amount with respect to its reference position. The second count value calculation unit 67 increments each time it obtains the left rotation flag Fl from the quadrant determination unit 66, and decrements it every time it obtains the right rotation flag Fr from the quadrant determination unit 66. Here, the increment means to add 1 to the second count value C2, and the decrement means to subtract 1 from the second count value C2. In this way, the second count value calculator 67 calculates the second count value C2 each time the second steering rotation angle sensor 45 generates the electric signal Sb2, and stores the second count value C2. It is configured to be able to. The second count value C2 calculated by the second count value calculator 67 is output to the communication interface 63.

The communication interface 63 is configured to operate when the start switch is in the on state, and does not operate when the start switch is in the off state. When the second count value C2 is input, the communication interface 63 outputs the second count value C2 to the control device 90.

Functions of the first absolute angle calculation circuit 70 and the second absolute angle calculation circuit 80 will be described.
As shown in FIG. 4A, the first absolute angle calculation circuit 70 calculates a first absolute angle information calculation circuit 110 that calculates and outputs the first absolute angle information θg1 and second absolute angle information θg2. And a second absolute angle information calculation circuit 120 which outputs the information. The first absolute position information described in the claims is the first absolute angle information θg1 and the second absolute angle information θg2.

The first absolute angle information calculation circuit 110 has an amplifier 111, an A/D converter 112 (analog/digital converter), and a communication interface 113.
The electric signal Sg1 generated by the first pinion angle sensor 46a is input to the amplifier 111 as an analog signal. The amplifier 111 amplifies the electric signal Sg1 input from the first pinion angle sensor 46a and outputs it to the A/D converter 112.

The A/D converter 112 converts the electric signal Sg1 amplified by the amplifier 111 into a digital signal and outputs it as the first absolute angle information θg1.
The communication interface 113 is configured to operate when the start switch is in the on state, and does not operate when the start switch is in the off state. When the first absolute angle information θg1 is input, the communication interface 113 outputs the first absolute angle information θg1 to the control device 90.

The second absolute angle information calculation circuit 120 has an amplifier 121, an A/D converter 122 (analog/digital converter), and a communication interface 123.
The electric signal Sg2 generated by the second pinion angle sensor 46b is input to the amplifier 121 as an analog signal. The amplifier 121 amplifies the electric signal Sg2 input from the second pinion angle sensor 46b and outputs it to the A/D converter 122.

The A/D converter 122 converts the electric signal Sg2 amplified by the amplifier 121 into a digital signal, and outputs it as second absolute angle information θg2.
The communication interface 123 is configured to operate when the start switch is in the on state, and does not operate when the start switch is in the off state. When the second absolute angle information θg2 is input, the communication interface 123 outputs the second absolute angle information θg2 to the control device 90.

As shown in FIG. 4B, the second absolute angle calculation circuit 80 has the same configuration as the first absolute angle calculation circuit 70. That is, the second absolute angle calculation circuit 80 calculates the third absolute angle information θg3 and outputs the third absolute angle information calculation circuit 130 and the fourth absolute angle information θg4 calculates and outputs the fourth absolute angle information. And an arithmetic circuit 140. The second absolute position information described in the claims is the third absolute angle information θg3 and the fourth absolute angle information θg4.

The third absolute angle information calculation circuit 130 includes an amplifier 131, an A/D converter 132 (analog/digital converter), and a communication interface 133.
The electric signal Sg3 generated by the third pinion angle sensor 46c is input to the amplifier 131 as an analog signal. The amplifier 131 amplifies the electric signal Sg3 input from the third pinion angle sensor 46c and outputs the amplified electric signal Sg3 to the A/D converter 132.

The A/D converter 132 converts the electric signal Sg3 amplified by the amplifier 131 into a digital signal and outputs it as third absolute angle information θg3.
The communication interface 133 is configured to operate when the start switch is in the on state, and does not operate when the start switch is in the off state. When the third absolute angle information θg3 is input, the communication interface 133 outputs the third absolute angle information θg3 to the control device 90.

The fourth absolute angle information calculation circuit 140 includes an amplifier 141, an A/D converter 142 (analog/digital converter), and a communication interface 143.
The electric signal Sg4 generated by the fourth pinion angle sensor 46d is input to the amplifier 141 as an analog signal. The amplifier 141 amplifies the electric signal Sg4 input from the fourth pinion angle sensor 46d and outputs the amplified electric signal Sg4 to the A/D converter 142.

The A/D converter 142 converts the electric signal Sg4 amplified by the amplifier 141 into a digital signal and outputs the digital signal as fourth absolute angle information θg4.
The communication interface 143 is configured to operate when the start switch is in the on state, and does not operate when the start switch is in the off state. When the fourth absolute angle information θg4 is input, the communication interface 143 outputs the fourth absolute angle information θg4 to the control device 90.

In the first embodiment, the first absolute angle calculation circuit 70 and the second absolute angle calculation circuit 80 are provided, respectively, and the first absolute angle information θg1 and the second absolute angle information θg2, the third absolute angle information θg3, and the fourth absolute angle information. The angle information θg4 is redundantly obtained.

The function of the control device 90 will be described.
As shown in FIG. 5, the control device 90 includes a first integrated angle calculation unit 150, a second integrated angle calculation unit 151, a first absolute angle calculation unit 152, a second absolute angle calculation unit 153, a determination unit 154, and an absolute angle. An output unit 155, a steering angle command value calculation unit 156, and a current feedback control unit 157 are provided.

The first integrated angle calculation unit 150 acquires the first count value C1 calculated by the first count value calculation circuit 50 and the electric signal Sb1 generated by the first turning rotation angle sensor 44. In the first embodiment, the first integrated angle calculation unit 150 acquires the first count value C1 calculated by the first count value calculation circuit 50 every time the start switch is turned on. The first integrated angle calculation unit 150 uses the first count value C1 acquired when the start switch is in the ON state while the start switch is in the ON state as an electric signal generated by the first turning rotation angle sensor 44. It is updated at a predetermined calculation cycle based on the change in the quadrant of Sb1. The first integrated angle calculation unit 150 increments and updates the first count value C1 each time the quadrant of the electric signal Sb1 changes to the quadrant adjacent in the counterclockwise direction. The first integrated angle calculation unit 150 decrements and updates the first count value C1 each time the quadrant of the electric signal Sb1 changes to the adjacent quadrant in the clockwise direction. That is, in the first embodiment, the control device 90 updates the first count value C1 separately from the first count value calculation circuit 50 while the start switch is in the ON state.

The first integrated angle calculation unit 150 acquires the electric signal Sb1 generated by the first steered rotation angle sensor 44 at a predetermined calculation cycle. The first integrated angle calculation unit 150 calculates the first integrated angle θi1 as an absolute angle from a value obtained by integrating the rotation angles of the multi-turns of the steering motor 41 based on the acquired first count value C1 and the electric signal Sb1. .. The first integrated angle θi1 is a value obtained by integrating the rotation angle of the steering motor 41 with a relative angle. More specifically, the first integrated angle calculation unit 150 obtains the arc tangent from the electric signal Sb1 generated by the first turning rotation angle sensor 44 to obtain the rotation angle of the turning motor 41 as a relative angle. The obtained relative angle represents the rotation angle of the steering motor 41 within the range of 0 degrees to 360 degrees. The first integrated angle calculation unit 150 adds a value obtained by multiplying the calculated relative angle by a value obtained by multiplying the number of multi-turns of the rotation shaft of the steering motor 41 based on the first count value C1 by 360 degrees. The first integrated angle θi1 is obtained as a value obtained by integrating the rotation angle of the rudder motor 41.

The second integrated angle calculation unit 151 acquires the second count value C2 calculated by the second count value calculation circuit 60 and the electric signal Sb2 generated by the second steered rotation angle sensor 45. In the first embodiment, the second integrated angle calculation unit 151 acquires the second count value C2 calculated by the second count value calculation circuit 60 each time the start switch is turned on. The second integrated angle calculation unit 151 uses the second count value C2 acquired when the start switch is in the ON state while the start switch is in the ON state as an electric signal generated by the second steered rotation angle sensor 45. It is updated at a predetermined calculation cycle based on the change in the quadrant of Sb2. The second integrated angle calculation unit 151 increments and updates the second count value C2 each time the quadrant of the electric signal Sb2 changes to the adjacent quadrant in the counterclockwise direction. The second integrated angle calculation unit 151 decrements and updates the second count value C2 each time the quadrant of the electric signal Sb2 changes to the adjacent quadrant in the clockwise direction. That is, in the first embodiment, the control device 90 updates the second count value C2 separately from the second count value calculation circuit 60 while the start switch is in the ON state.

The second integrated angle calculation unit 151 acquires the electric signal Sb2 generated by the second steered rotation angle sensor 45 at a predetermined calculation cycle. The second integrated angle calculation unit 151 calculates the second integrated angle θi2 as an absolute angle from a value obtained by integrating the rotation angles of the multi-turns of the steering motor 41, based on the acquired second count value C2 and the electric signal Sb2. .. The second integrated angle θi2 is, like the first integrated angle θi1, a value obtained by integrating the rotation angle of the steering motor 41 with the relative angle. More specifically, the second integrated angle calculation unit 151 obtains the arc tangent from the electric signal Sb2 generated by the second turning rotation angle sensor 45 to obtain the rotation angle of the turning motor 41 as a relative angle. The second integrated angle calculation unit 151 adds a value obtained by multiplying the calculated relative angle by a value obtained by multiplying the multi-turn number of the rotating shaft of the steering motor 41 based on the second count value C2 by 360 degrees, and The second integrated angle θi2 is obtained as a value obtained by integrating the rotation angle of the rudder motor 41. As described above, in the first embodiment, the control device 90 determines the first integrated angle θi1 and the second integrated angle θi2, respectively.

The first absolute angle calculation unit 152 acquires the first absolute angle information θg1 and the second absolute angle information θg2 calculated by the first absolute angle calculation circuit 70. The first absolute angle calculation unit 152 calculates the first absolute angle θga1 of the first pinion shaft 13 based on the first absolute angle information θg1 and the second absolute angle information θg2. More specifically, the first absolute angle calculation unit 152 uses the value obtained by calculating the arc tangent from the first absolute angle information θg1 and the value obtained by calculating the arc tangent from the second absolute angle information θg2, to determine the first pinion shaft 13 The first absolute angle θga1 is calculated.

The second absolute angle calculation unit 153 acquires the third absolute angle information θg3 and the fourth absolute angle information θg4 calculated by the second absolute angle calculation circuit 80. The second absolute angle calculation unit 153 calculates the second absolute angle θga2 of the first pinion shaft 13 based on the third absolute angle information θg3 and the fourth absolute angle information θg4. More specifically, the second absolute angle calculation unit 153 uses the value obtained by calculating the arc tangent from the third absolute angle information θg3 and the value obtained by calculating the arc tangent from the fourth absolute angle information θg4, to determine the first pinion shaft 13 The second absolute angle θga2 is calculated. The calculation of the first absolute angle θga1 by the first absolute angle calculation unit 152 and the calculation of the second absolute angle θga2 by the second absolute angle calculation unit 153 will be described with reference to FIG. Since the first absolute angle calculation unit 152 calculates the first absolute angle θga1 and the second absolute angle calculation unit 153 calculates the second absolute angle θga2 by the same calculation, the first absolute angle θga1 is calculated here. Description will be given focusing on the calculation of the first absolute angle θga1 by the calculation unit 152. In the case of the calculation of the second absolute angle θga2 by the second absolute angle calculation unit 153, the first absolute angle information θg1 and the second absolute angle information θg2 may be replaced with the third absolute angle information θg3 and the fourth absolute angle information θg4. Good.

The vertical axis of the graph shown in FIG. 6 represents the first absolute angle information θg1 and the second absolute angle information θg2, and the horizontal axis represents the first absolute angle θga1 of the first pinion shaft 13. The broken line shows the transition of the first absolute angle information θg1, and the solid line shows the transition of the second absolute angle information θg2. The electric signal Sg1 of the first pinion angle sensor 46a and the electric signal Sg2 of the second pinion angle sensor 46b have the same axis multiplication angle. The axial multiplication angle of the electric signal Sg1 of the first pinion angle sensor 46a and the axial multiplication angle of the electric signal Sg2 of the second pinion angle sensor 46b are, for example, 1 time. Due to the difference between the reduction ratio of the first gear portion of the TAS 46 and the reduction ratio of the second gear portion of the TAS 46, the phase of the waveform of the first absolute angle information θg1 indicated by the broken line and the waveform of the second absolute angle information θg2 indicated by the solid line The phase shifts as the first pinion shaft 13 rotates. The first absolute angle information θg1 and the second absolute angle information θg2 are rotation angles (0 degrees to 360 degrees) in the detection ranges of the first pinion angle sensor 46a and the second pinion angle sensor 46b, respectively. Therefore, the first absolute angle θga1 that is the rotation angle of the multi-turn of the first pinion shaft 13 cannot be obtained only by the first absolute angle information θg1 or only the second absolute angle information θg2.

The first absolute angle calculation unit 152 calculates the absolute value of the angle difference between the first absolute angle information θg1 and the second absolute angle information θg2. The thick line in the graph of FIG. 6 indicates the absolute value of the angular difference between the first absolute angle information θg1 and the second absolute angle information θg2. As shown in FIG. 6, as the first absolute angle θga1 increases, the absolute value of the angle difference increases in proportion to the first absolute angle θga1. The first absolute angle calculation unit 152 stores a map showing the relationship between the first absolute angle θga1 and the absolute value of the angular difference between the first absolute angle information θg1 and the second absolute angle information θg2. Therefore, the first absolute angle calculation unit 152 can calculate the first absolute angle θga1 from the absolute value of the angle difference between the first absolute angle information θg1 and the second absolute angle information θg2.

The second absolute angle calculation unit 153 calculates the absolute value of the angle difference between the third absolute angle information θg3 and the fourth absolute angle information θg4. The thick line in the graph of FIG. 6 indicates the absolute value of the angular difference between the third absolute angle information θg3 and the fourth absolute angle information θg4. As shown in FIG. 6, as the second absolute angle θga2 increases, the absolute value of the angle difference increases in proportion to the second absolute angle θga2. The second absolute angle calculation unit 153 stores a map showing the relationship between the second absolute angle θga2 and the absolute value of the angular difference between the third absolute angle information θg3 and the fourth absolute angle information θg4. Therefore, the second absolute angle calculation unit 153 can calculate the second absolute angle θga2 from the absolute value of the angle difference between the third absolute angle information θg3 and the fourth absolute angle information θg4.

As shown in FIG. 5, the determination unit 154 includes a first integrated angle θi1 calculated by the first integrated angle calculation unit 150, a second integrated angle θi2 calculated by the second integrated angle calculation unit 151, and a first absolute angle. The first absolute angle θga1 calculated by the calculation unit 152 and the second absolute angle θga2 calculated by the second absolute angle calculation unit 153 are acquired. The first integrated angle θi1, the second integrated angle θi2, the first absolute angle θga1, and the second absolute angle θga2 have the same calculation cycle. The determination unit 154 determines the first integrated angle θi1, the second integrated angle θi2, and the second integrated angle θi2 based on the relationship between the first integrated angle θi1 and the second integrated angle θi2 and the relationship between the first absolute angle θga1 and the second absolute angle θga2. Whether or not there is an abnormality in the first absolute angle θga1 and the second absolute angle θga2 is determined, and integrated angle flags Fi0 to Fi2 and absolute angle flags Fga0 to Fga2 are generated.

The absolute angle output unit 155 includes a first integrated angle θi1, a second integrated angle θi2, a first absolute angle θga1, a second absolute angle θga2, integrated angle flags Fi0 to Fi2 generated by the determination unit 154, and a determination unit 154. The absolute angle flags Fga0 to Fga2 generated by are input. The absolute angle output unit 155 determines, based on the input absolute angle flags Fga0 to Fga2, which one of the first absolute angle θga1 and the second absolute angle θga2 has no abnormality and converts from the absolute angle. The motor midpoint of the rudder motor 41 is calculated. The motor midpoint refers to the rotation angle θb of the steering motor 41 corresponding to the steering neutral position of the steering wheel 11 or the steering neutral position of the steering shaft 14 in the straight traveling state of the vehicle. Further, the absolute angle output unit 155 determines, based on the input integrated angle flags Fi0 to Fi2, the integrated angle in which no abnormality has occurred among the first integrated angle θi1 and the second integrated angle θi2. The absolute angle output unit 155 calculates the pinion angle θpa of the first pinion shaft 13 as an absolute angle based on the integrated angle and the motor midpoint of the steering motor 41. That is, the absolute angle output unit 155 uses the motor midpoint of the steered motor 41 as a reference point, and steers the steered motor 41 based on the amount of change in the first integrated angle θi1 or the second integrated angle θi2 of the steered motor 41 from the reference point. The rotation angle θb of the motor 41 is calculated as an absolute angle in a range exceeding 360 degrees, and the pinion angle θpa is calculated as an absolute angle based on the calculated rotation angle θb. Since there is a correlation between the rotation angle θb of the steering motor 41 and the rotation angle of the first pinion shaft 13, the absolute angle output unit 155 determines that the first pinion shaft 13 of the first pinion shaft 13 based on the rotation angle of the steering motor 41. The pinion angle θpa can be obtained as an absolute angle. The absolute angle output unit 155 outputs this pinion angle θpa when either the first integrated angle θi1 or the second integrated angle θi2 is not abnormal. On the other hand, when there is an abnormality in both the first integrated angle θi1 and the second integrated angle θi2, the absolute angle output unit 155 outputs the first absolute angle θga1 or the second absolute angle θga2 as the pinion angle θpa.

The turning angle command value calculation unit 156 acquires the pinion angle θpa from the absolute angle output unit 155, the target steering angle θ* calculated by the reaction force control unit 35, and the vehicle speed V detected by the vehicle speed sensor 36. The steering angle command value calculation unit 156 sets a steering angle ratio which is a ratio of the steering angle θt to the steering angle θs according to the vehicle speed V. The turning angle command value calculation unit 156 calculates a correction angle for the target steering angle θ* calculated by the reaction force control unit 35 in order to realize the set steering angle ratio, and the calculated correction angle is set as a target. A target angle according to the steering angle ratio is calculated by adding it to the steering angle θ*. The turning angle command value calculation unit 156 converts this target angle into a target pinion angle that is a value corresponding to the rotation angle of the first pinion shaft 13. The steered angle command value calculation unit 156 performs angle feedback control so that the pinion angle θpa of the first pinion shaft 13 follows the target pinion angle calculated based on the target steering angle θ*, thereby performing a current command. Calculate the value I*. As the angle feedback control, for example, PID control is performed.

The current feedback control unit 157 acquires the actual current value I actually supplied to the steering motor 41 through the current sensor 101 provided in the power feeding path to the steering motor 41. The current feedback control unit 157 also acquires the electric signal Sb1 or the electric signal Sb2 through the first turning rotation angle sensor 44 or the second turning rotation angle sensor 45. The current feedback control unit 157 executes the current feedback control so that the actual current value I follows the current command value I* based on the electrical signal Sb1 or the electrical signal Sb2 and the actual current value I, thereby controlling the motor. The signal Sm is generated and output to the drive circuit 100 as a PWM signal.

The drive circuit 100 is a three-phase (U-phase, V-phase, W-phase) drive circuit. The drive circuit 100 converts DC power supplied from a battery (not shown) into three-phase AC power by turning on/off a switching element that constitutes the drive circuit 100 based on the motor control signal Sm. The drive circuit 100 supplies the three-phase AC power to the steering motor 41.

A procedure for determining whether or not there is an abnormality in the first integrated angle θi1 and the second integrated angle θi2, which is performed by the determination unit 154, will be described using a flowchart. The process of determining whether or not there is an abnormality in the first integrated angle θi1 and the second integrated angle θi2 is repeatedly executed every predetermined period. In the following description, the present embodiment is based on the premise that the first integrated angle θi1, the second integrated angle θi2, the first absolute angle θga1, and the second absolute angle θga2 do not become abnormal at the same time.

As shown in the flowchart of FIG. 7, the determination unit 154 determines whether or not the integrated angle flag Fi0 has been acquired (step S1). The integrated angle flag Fi0 is a flag indicating that the first integrated angle θi1 and the second integrated angle θi2 are normal. When the integrated angle flag Fi0 is generated in the previous cycle, it is determined whether or not there is an abnormality in the first integrated angle θi1 and the second integrated angle θi2, while the integrated angle flag Fi0 is generated in the previous cycle. If there is no abnormality, the first integrated angle θi1 or the second integrated angle θi2 is abnormal, and therefore the determination as to whether or not the first integrated angle θi1 and the second integrated angle θi2 are abnormal is not executed. When the integrated angle flag Fi0 is not generated, the integrated angle flag Fi1 indicating that the first integrated angle θi1 is abnormal or the integrated angle flag Fi2 indicating that the second integrated angle θi2 is abnormal is generated. Note that the determination unit 154 is set to acquire the integrated angle flag Fi0 in the first cycle of determining whether or not there is an abnormality in the first integrated angle θi1 and the second integrated angle θi2.

When the determination unit 154 acquires the integrated angle flag Fi0 (YES in step S1), the determination unit 154 determines whether or not the first integrated angle θi1 and the second integrated angle θi2 match (step S2). When the deviation between the first integrated angle θi1 and the second integrated angle θi2 is less than or equal to a predetermined threshold, the determination unit 154 determines that the first integrated angle θi1 and the second integrated angle θi2 match.

When the first integrated angle θi1 and the second integrated angle θi2 match (YES in step S2), the determination unit 154 determines that there is no abnormality in the first integrated angle θi1 and the second integrated angle θi2, and determines the first integrated angle. An integrated angle flag Fi0 indicating that there is no abnormality in θi1 and the second integrated angle θi2 is generated (step S3).

When the determination unit 154 does not acquire the integrated angle flag Fi0 (NO in step S1), the determination unit 154 ends the process of determining whether the first integrated angle θi1 and the second integrated angle θi2 are abnormal.
When the first integrated angle θi1 and the second integrated angle θi2 do not match (NO in step S2), the determination unit 154 determines whether or not the absolute angle flag Fga0 or the absolute angle flag Fga2 has been acquired (step S4). .. The absolute angle flag Fga0 is a flag indicating that the first absolute angle θga1 and the second absolute angle θga2 are normal. The absolute angle flag Fga1 is a flag indicating that the first absolute angle θga1 is abnormal. The absolute angle flag Fga2 is a flag indicating that the second absolute angle θga2 is abnormal. Note that the determination unit 154 is set to acquire the absolute angle flag Fga0 in the first cycle in which it is determined whether the first integrated angle θi1 and the second integrated angle θi2 are abnormal.

When the determination unit 154 acquires the absolute angle flag Fga0 or the absolute angle flag Fga2 (YES in step S4), the first integrated angle θi1 and the first absolute angle θi1 are assumed on the assumption that the first absolute angle θga1 is at least normal. It is determined whether the relationship of θga1 does not have a correct correlation and the relationship of the second integrated angle θi2 and the first absolute angle θga1 has a correct correlation (step S5). The correct correlation here means that the relationship between the first integrated angle θi1 and the first absolute angle θga1 and the relationship between the second integrated angle θi2 and the first absolute angle θga1 are the steering motor 41 and the first pinion shaft 13 It is in agreement with the correlation that should be made between and. Specifically, when the determination unit 154 can convert the first integrated angle θi1 into the first absolute angle θga1 by multiplying the first integrated angle θi1 by the predetermined conversion coefficient, the relationship between the first integrated angle θi1 and the first absolute angle θga1 is determined. It is determined that the steering motor 41 and the first pinion shaft 13 are in agreement with the correlation to be made. Further, when the determination unit 154 can convert the second integrated angle θi2 into the first absolute angle θga1 by multiplying the second integrated angle θi2 by a predetermined conversion coefficient, the relationship between the second integrated angle θi2 and the first absolute angle θga1 is the steering motor. 41 and the first pinion shaft 13 are determined to be in agreement with the correlation to be made.

The determination unit 154 determines that the relationship between the first integrated angle θi1 and the first absolute angle θga1 does not have a correct correlation, and the relationship between the second integrated angle θi2 and the first absolute angle θga1 has a correct correlation. (YES in step S5), it is determined that the first integrated angle θi1 is abnormal, and the integrated angle flag Fi1 is generated (step S6). If the first integrated angle θi1 is abnormal, it can be said that the first turning angle sensor 44, the first count value calculation circuit 50, or the first integrated angle calculation unit 150 is abnormal.

If NO in step S5, the determination unit 154 determines that the second integrated angle θi2 is abnormal, and generates the integrated angle flag Fi2 (step S7). If there is an abnormality in the second integrated angle θi2, it can be said that an abnormality has occurred in the second turning rotation angle sensor 45, the second count value calculation circuit 60, or the second integrated angle calculation unit 151.

When the determination unit 154 acquires the absolute angle flag Fga1 (NO in step S4), the relationship between the first integrated angle θi1 and the second absolute angle θga2 is correct on the assumption that there is at least no abnormality in the second absolute angle θga2. It is determined whether there is no correlation and the relationship between the second integrated angle θi2 and the second absolute angle θga2 has a correct correlation (step S8). When it is possible to convert the first integrated angle θi1 into the second absolute angle θga2 by multiplying the first integrated angle θi1 by a predetermined conversion coefficient, the determination unit 154 determines that the relationship between the first integrated angle θi1 and the second absolute angle θga2 is the same as that of the steered motor 41. It is determined that the correlation with the first pinion shaft 13 matches. Further, when the determination unit 154 can convert the second integrated angle θi2 into the second absolute angle θga2 by multiplying the second integrated angle θi2 by a predetermined conversion coefficient, the determination unit 154 determines that the relationship between the second integrated angle θi2 and the second absolute angle θga2 is the steering motor. 41 and the first pinion shaft 13 are determined to be in agreement with the correlation to be made.

The determination unit 154 determines that the relationship between the first integrated angle θi1 and the second absolute angle θga2 does not have a correct correlation, and the relationship between the second integrated angle θi2 and the second absolute angle θga2 has a correct correlation. (YES in step S8), it is determined that the first integrated angle θi1 is abnormal, and the integrated angle flag Fi1 is generated (step S9).

If NO in step S8, the determination unit 154 determines that the second integrated angle θi2 is abnormal, and generates the integrated angle flag Fi2 (step S10).
With the above, the process for determining whether or not there is an abnormality in the first integrated angle θi1 and the second integrated angle θi2 ends, and the process proceeds to the next process.

A procedure for determining whether or not there is an abnormality in the first absolute angle θga1 and the second absolute angle θga2, which is performed by the determination unit 154, will be described using a flowchart. The process of determining whether or not there is an abnormality in the first absolute angle θga1 and the second absolute angle θga2 is repeatedly executed every predetermined period.

As shown in FIG. 8, the determination unit 154 determines whether or not the absolute angle flag Fga0 has been acquired (step S11).
When the absolute angle flag Fga0 is acquired (YES in step S11), the determination unit 154 determines whether the first absolute angle θga1 and the second absolute angle θga2 match (step S12). When the deviation between the first absolute angle θga1 and the second absolute angle θga2 is less than or equal to a predetermined threshold, the determination unit 154 determines that the first absolute angle θga1 and the second absolute angle θga2 match.

When the first absolute angle θga1 and the second absolute angle θga2 match (YES in step S12), the determination unit 154 determines that the first absolute angle θga1 and the second absolute angle θga2 are normal, and the absolute angle flag Fga0. Is generated (step S13).

If the determination unit 154 does not acquire the absolute angle flag Fga0 (NO in step S11), the process ends.
When the first absolute angle θga1 and the second absolute angle θga2 do not match (step S13), the determination unit 154 determines whether or not the integrated angle flag Fi0 or the integrated angle flag Fi2 is acquired (step S14). Note that the determination unit 154 is set to acquire the integrated angle flag Fi0 in the first cycle of determining whether or not there is an abnormality in the first absolute angle θga1 and the second absolute angle θga2.

When the determination unit 154 acquires the integrated angle flag Fi0 or the integrated angle flag Fi2 (YES in step S14), the first absolute angle θga1 and the first integrated angle θga1 are determined on the assumption that there is at least no abnormality in the first integrated angle θi1. It is determined whether or not the relationship of θi1 does not have a correct correlation and the relationship of the second absolute angle θga2 and the first integrated angle θi1 has a correct correlation (step S15). When the determination unit 154 can convert the first absolute angle θga1 into a first integrated angle θi1 by multiplying the first absolute angle θga1 by a predetermined conversion coefficient, the determination unit 154 determines that the relationship between the first absolute angle θga1 and the first integrated angle θi1 is the steering motor 41. It is determined that the correlation with the first pinion shaft 13 matches. Further, when the determination unit 154 can convert the second absolute angle θga2 into the first integrated angle θi1 by multiplying the second absolute angle θga2 by a predetermined conversion coefficient, the determination unit 154 determines that the relationship between the second absolute angle θga2 and the first integrated angle θi1 is the steering motor. 41 and the first pinion shaft 13 are determined to be in agreement with the correlation to be made.

The determination unit 154 determines that the relationship between the first absolute angle θga1 and the first integrated angle θi1 does not have a correct correlation, but the relationship between the second absolute angle θga2 and the first integrated angle θi1 has a correct correlation. (YES in step S15), it is determined that the first absolute angle θga1 is abnormal, and the absolute angle flag Fga1 is generated (step S16). If the first absolute angle θga1 is abnormal, it can be said that the first pinion angle sensor 46a, the second pinion angle sensor 46b, or the first absolute angle calculation circuit 70 is abnormal.

If NO in step S15, the determination unit 154 determines that the second absolute angle θga2 is abnormal, and generates the absolute angle flag Fga2 (step S17). If the second absolute angle θga2 is abnormal, it can be said that the third pinion angle sensor 46c, the fourth pinion angle sensor 46d, or the second absolute angle calculation circuit 80 is abnormal.

When the determination unit 154 acquires the integrated angle flag Fi1 (NO in step S14), the relationship between the first absolute angle θga1 and the second integrated angle θi2 is correct on the assumption that there is at least no abnormality in the second integrated angle θi2. It is determined whether or not there is no correlation and the relationship between the second absolute angle θga2 and the second integrated angle θi2 has a correct correlation (step S18). When the determination unit 154 can convert the first absolute angle θga1 into the second integrated angle θi2 by multiplying the first absolute angle θga1 by a predetermined conversion coefficient, the relationship between the first absolute angle θga1 and the second integrated angle θi2 is determined by the steering motor 41. It is determined that the correlation with the first pinion shaft 13 matches. When the determination unit 154 can convert the second absolute angle θga2 into the second integrated angle θi2 by multiplying the second absolute angle θga2 by a predetermined conversion coefficient, the determination unit 154 determines that the relationship between the second absolute angle θga2 and the second integrated angle θi2 is the steering motor 41. It is determined that the correlation with the first pinion shaft 13 matches.

The determination unit 154 determines that the relationship between the first absolute angle θga1 and the second integrated angle θi2 does not have a correct correlation, and the relationship between the second absolute angle θga2 and the second integrated angle θi2 has a correct correlation. (YES in step S18), it is determined that the first absolute angle θga1 is abnormal, and the absolute angle flag Fga1 is generated (step S19).

If NO in step S18, the determination unit 154 determines that the second absolute angle θga2 is abnormal, and generates the absolute angle flag Fga2 (step S20).
With the above, the process for determining whether or not there is an abnormality in the first absolute angle θga1 and the second absolute angle θga2 ends, and the process proceeds to the next process.

When the integrated angle flag Fi0 and the absolute angle flag Fga0 are input, the absolute angle output unit 155 calculates the first integrated angle θi1 and the first absolute angle θi for calculating the motor midpoint and the pinion angle θpa of the first pinion shaft 13. θga1 is used. When the integrated angle flag Fi1 and the absolute angle flag Fga0 are input, the absolute angle output unit 155 uses the second integrated angle θi2 and the first absolute angle θga1 to calculate the motor midpoint and the pinion angle θpa of the first pinion shaft 13. To use. When the integrated angle flag Fi2 and the absolute angle flag Fga0 are input, the absolute angle output unit 155 uses the first integrated angle θi1 and the first absolute angle θga1 to calculate the motor midpoint and the pinion angle θpa of the first pinion shaft 13. To use. When the integrated angle flag Fi0 and the absolute angle flag Fga1 are input, the absolute angle output unit 155 uses the first integrated angle θi1 and the second absolute angle θga2 to calculate the motor midpoint and the pinion angle θpa of the first pinion shaft 13. To use. When the integrated angle flag Fi0 and the absolute angle flag Fga2 are input, the absolute angle output unit 155 uses the first integrated angle θi1 and the first absolute angle θga1 to calculate the motor midpoint and the pinion angle θpa of the first pinion shaft 13. To use.

The absolute angle output unit 155 inputs the integrated angle flag Fi1 and the absolute angle flag Fga1, the integrated angle flag Fi2 and the absolute angle flag Fga1, and the integrated angle flag Fi1 and the absolute angle flag Fga2. When the accumulated angle flag Fi2 and the absolute angle flag Fga2 are input, the fail-safe control according to the situation is executed. In this case, for example, the operation shifts to fail-safe control for stopping the operation of the steering control unit 47.

The operation and effect of the first embodiment will be described.
(1) Since the steering motor 41 and the first pinion shaft 13 are interlocked, the relative angle of the steering motor 41 detected through the first steering rotation angle sensor 44 and the second steering rotation angle sensor 45, There is a correlation between the first absolute angle θga1 and the second absolute angle θga2 of the first pinion shaft 13 detected by each pinion angle sensor. Therefore, on the assumption that there is no abnormality in each, the relationship between the first absolute angle θga1 and the first integrated angle θi1 and the relationship between the second absolute angle θga2 and the first integrated angle θi1 should match. Therefore, in the first embodiment, the determination unit 154 determines the first absolute angle θga1 based on the relationship between the first absolute angle θga1 and the second absolute angle θga2 and the first integrated angle θi1 (or the second integrated angle θi2). Also, it is possible to determine whether or not there is an abnormality in the second absolute angle θga2. According to such a steering control unit 47, it is possible to propose a new use of the redundantly calculated absolute angle, which has never been achieved.

(2) Specifically, the determination unit 154 assumes that there is no abnormality in the first integrated angle θi1 (or the second integrated angle θi2), and the first absolute angle θga1 and the first integrated angle θi1 (or the second integrated angle θi1). While the relationship with the integrated angle θi2) is different from the correlation that should be made between the steering motor 41 and the first pinion shaft 13, the second absolute angle θga2 and the first integrated angle θi1 (or the second integrated angle θi2) are obtained. If the above relationship matches the correlation to be made between the steered motor 41 and the first pinion shaft 13, it can be determined that the first absolute angle θga1 is abnormal. In this case, it can be said that an abnormality has occurred in the first pinion angle sensor 46a, the second pinion angle sensor 46b, or the first absolute angle calculation circuit 70. In addition, the determination unit 154 determines that the first absolute angle θga1 and the first integrated angle θi1 (or the second integrated angle θi2) on the assumption that the first integrated angle θi1 (or the second integrated angle θi2) is normal. While the relationship matches the correlation that should be made between the steering motor 41 and the first pinion shaft 13, the relationship between the second absolute angle θga2 and the first integrated angle θi1 (or the second integrated angle θi2) is turned. If the correlation between the motor 41 and the first pinion shaft 13 is different, it can be determined that the second absolute angle θga2 is abnormal. Thus, by using the redundantly calculated absolute angle, it is possible to specify the location of the abnormality in the abnormality determination.

(3) The first pinion angle sensor 46a and the second pinion angle sensor 46b, which generate the electric signals Sg1 and Sg2 used in the calculation in the first absolute angle calculation circuit 70, are used in the calculation in the second absolute angle calculation circuit 80. The third pinion angle sensor 46c and the fourth pinion angle sensor 46d that generate the electric signals Sg3 and Sg4 to be used are configured as separate sensors. From this, even if the first pinion angle sensor 46a and the second pinion angle sensor 46b, or the third pinion angle sensor 46c and the fourth pinion angle sensor 46d are abnormal, the person who has no abnormality It becomes possible to obtain the detection result from the sensor. Therefore, for example, the control device 90 can continue the calculation of the pinion angle θpa of the first pinion shaft 13 using the detection result obtained from the sensor in which no abnormality has occurred.

(4) In the steer-by-wire type steering device of the first embodiment, in order to generate the motor control signal Sm required to drive the steering motor 41, the steering shaft 12 and the steering wheel 11 when the clutch 21 is engaged. It is necessary to obtain the pinion angle θpa that is the absolute angle of the first pinion shaft 13 that rotates in conjunction with the rotation of the. That is, according to the first embodiment, it is possible to realize the steering apparatus 10b that can improve the reliability of the calculated pinion angle θpa of the first pinion shaft 13.

<Second Embodiment>
A second embodiment in which the angle calculation device and the steering device are mounted on a steer-by-wire type steering device will be described. Here, the difference from the first embodiment will be mainly described.

As shown in FIG. 9, the electric signal Sb1 generated by the first turning rotation angle sensor 44 is input to the second count value calculation circuit 60. The steering motor 41 is provided only with the first steering rotation angle sensor 44. That is, the sensor that outputs the detection result to the first count value calculation circuit 50 and the second count value calculation circuit 60 is the first steering rotation angle sensor 44 that is the same sensor. The output lines for outputting the detection result of the angle sensor 44 to the first count value calculation circuit 50 and the second count value calculation circuit 60 are different. The second count value calculation circuit 60 uses the electric signal Sb1 generated by the first turning rotation angle sensor 44 instead of the electric signal Sb2 generated by the second turning rotation angle sensor 45. The second count value calculation circuit 60 calculates the second count value C2 based on the electric signal Sb1, and outputs the calculated second count value C2 to the control device 90.

The electric signal Sg1 generated by the first pinion angle sensor 46a and the electric signal Sg2 generated by the second pinion angle sensor 46b are input to the second absolute angle calculation circuit 80. The TAS 46 includes a first pinion angle sensor 46a, a second pinion angle sensor 46b, and a pinion torque sensor 46e. That is, the sensors that output the detection results to the first absolute angle calculation circuit 70 and the second absolute angle calculation circuit 80 are the same sensor, that is, the first pinion angle sensor 46a and the second pinion angle sensor 46b. The output lines for outputting the detection results of the first pinion angle sensor 46a and the second pinion angle sensor 46b to the first absolute angle calculation circuit 70 and the second absolute angle calculation circuit 80 are different. .. The second absolute angle calculation circuit 80 uses the electric signal Sg1 generated by the first pinion angle sensor 46a instead of the electric signal Sg3 generated by the third pinion angle sensor 46c, and generates the electric signal Sg1 by the fourth pinion angle sensor 46d. The electric signal Sg2 generated by the second pinion angle sensor 46b is used instead of the electric signal Sg4. The second absolute angle calculation circuit 80 calculates the third absolute angle information θg3 and the fourth absolute angle information θg4 based on the electric signal Sg1 and the electric signal Sg2, and calculates the calculated third absolute angle information θg3 and the fourth absolute angle. The information θg4 is output to the control device 90.

The operation and effect of the second embodiment will be described.
(5) The first pinion angle sensor 46a and the second pinion angle sensor 46b that generate the electric signals Sg1 and Sg2 have an output line for outputting the detection result to the first absolute angle calculation circuit 70, and a second absolute value. The output line for outputting the detection result to the angle calculation circuit 80 is configured to be separate from each other. From this, an abnormality is detected in either the output line for outputting the detection result to the first absolute angle calculation circuit 70 or the output line for outputting the detection result to the second absolute angle calculation circuit 80. Even if occurs, the detection result can be output through the other output line in which no abnormality has occurred. Therefore, the control device 90 can continue the calculation of the pinion angle θpa of the first pinion shaft 13 using the detection result obtained from the sensor in which no abnormality has occurred.

The embodiments may be modified as follows. Further, the following other embodiments can be combined with each other within a technically consistent range.
The clutch control unit 22, the reaction force control unit 35, and the steering control unit 47 may be configured as a single control unit (ECU: electronic control unit).

The first count value calculation circuit 50, the second count value calculation circuit 60, the first absolute angle calculation circuit 70, and the second absolute angle calculation circuit 80 are ASICs that execute a predetermined calculation for a specific input. Yes, but not limited to this. For example, the first count value calculation circuit 50, the second count value calculation circuit 60, the first absolute angle calculation circuit 70, and the second absolute angle calculation circuit 80 may be realized by a microcomputer including a microprocessing unit or the like. In addition, the first count value calculation circuit 50, the second count value calculation circuit 60, the first absolute angle calculation circuit 70, and the second absolute angle calculation circuit 80 read the program stored in the storage unit and read the program. The calculation may be performed according to Further, the first count value calculation circuit 50, the second count value calculation circuit 60, the first absolute angle calculation circuit 70, and the second absolute angle calculation circuit 80 are realized by a low power consumption microcomputer specialized for a specific function. May be. Even in this case, the first count value calculation circuit 50, the second count value calculation circuit 60, the first absolute angle calculation circuit 70, and the second absolute angle calculation circuit 80 are specialized for a specific function. The configuration can be simpler than that of the control device 90.

-Reaction force rotation angle sensor 33, first turning rotation angle sensor 44, second turning rotation angle sensor 45, first pinion angle sensor 46a, second pinion angle sensor 46b, third pinion angle sensor 46c, and fourth The pinion angle sensor 46d may be, for example, a sensor that uses a Hall element or a sensor that uses a resolver.

The reaction force rotation angle sensor 33, the first turning rotation angle sensor 44, and the second turning rotation angle sensor 45 may detect the rotation angles of the steering shaft 12 and the first pinion shaft 13, for example. For example, the rotation angle of the first pinion shaft 13 can be converted into a multi-turn rotation angle of the steering motor 41 in consideration of the reduction ratio between the steering motor 41 and the first pinion shaft 13. ..

The reaction force rotation angle sensor 33 is provided in the reaction force motor 31, but may be provided in the steering shaft 12 that is the rotation axis of the steering wheel 11. Further, the first turning rotation angle sensor 44 and the second turning rotation angle sensor 45 are provided on the turning motor 41, but may be provided on the first pinion shaft 13 and the second pinion shaft 43. ..

The first count value calculation circuit 50 and the second count value calculation circuit 60 calculate the first count value C1 and the second count value C2 even when the start switch is in the ON state, but the start switch is in the ON state. In some cases, the first count value C1 and the second count value C2 may not be calculated.

The control device 90 transmits the electric signal Sb1 of the first turning rotation angle sensor 44 and the electric signal Sb2 of the second turning rotation angle sensor 45 via the first count value calculation circuit 50 and the second count value calculation circuit 60. May be imported.

-Instead of the first pinion angle sensor 46a, the second pinion angle sensor 46b, the third pinion angle sensor 46c, and the fourth pinion angle sensor 46d, the steering device 10 detects the absolute position in the axial direction of the steered shaft 14. At the same time, a stroke sensor may be provided to detect the amount of movement of the steered shaft 14 in the axial direction based on the change in the absolute position. Since there is a correlation between the amount of movement of the steered shaft 14 and the rotation angle θb of the steered motor 41, the absolute angle output unit 155 determines the motor midpoint of the steered motor 41 from the amount of movement of the steered shaft. You can ask. Therefore, the absolute angle output unit 155 sets the rotation angle θb of the steering motor 41 to 360 based on the change amount of the rotation angle θb of the steering motor 41 from the reference point with the motor middle point of the steering motor 41 as the reference point. It is possible to calculate with an absolute angle in a range exceeding degrees, and to calculate the pinion angle θpa with an absolute angle based on the calculated rotation angle θb.

A stroke sensor may be provided in addition to the first pinion angle sensor 46a, the second pinion angle sensor 46b, the third pinion angle sensor 46c, and the fourth pinion angle sensor 46d. For example, in the control device 90, the first absolute angle θga1 calculated by the first absolute angle calculation unit 152 and the second absolute angle θga2 calculated by the second absolute angle calculation unit 153, or the moving amount of the steered shaft 14 is calculated. A switching unit that outputs one of the rotation angles of the first pinion shaft 13 obtained based on the above to the absolute angle output unit 155 is provided. For example, when an abnormality occurs in the TAS 46, the switching unit replaces the first absolute angle θga1 and the second absolute angle θga2 with the first pinion shaft 13 of the first pinion shaft 13 obtained based on the moving amount of the steered shaft 14. The rotation angle is output to the absolute angle output unit 155.

Although the turning motor 41 is provided with two sensors, the first turning rotation angle sensor 44 and the second turning rotation angle sensor 45, three or more sensors may be provided.
The TAS 46 includes a first pinion angle sensor 46a and a second pinion angle sensor 46b for calculating the first absolute angle information θg1, a third pinion angle sensor 46c and a third pinion angle sensor 46c for calculating the second absolute angle information θg2. Although the 4-pinion angle sensor 46d is provided, the invention is not limited to this. A pinion angle sensor may be further provided to enable calculation of three or more pieces of absolute angle information.

The steering motor 41 is provided with the first steering rotation angle sensor 44 and the second steering rotation angle sensor 45, but only one of the sensors may be provided. For example, when only the first turning rotation angle sensor 44 is provided in the turning motor 41, only the first count value calculation circuit 50 of the first count value calculation circuit 50 and the second count value calculation circuit 60 is provided. You can In this case, the control device 90 is provided with only the first integrated angle calculation unit 150 of the first integrated angle calculation unit 150 and the second integrated angle calculation unit 151. The determination unit 154 determines the first absolute angle θga1 and the second absolute angle based on the comparison between the relationship between the first absolute angle θga1 and the first integrated angle θi1 and the relationship between the second absolute angle θga2 and the first integrated angle θi1. Only the determination of whether or not there is an abnormality in θga2 is executed.

The determination unit 154 determines that the relationship between the first absolute angle θga1 and the first integrated angle θi1 and the relationship between the second absolute angle θga2 and the first integrated angle θi1 are between the steering motor 41 and the first pinion shaft 13. The presence or absence of abnormality in the first absolute angle θga1 and the second absolute angle θga2 is determined based on whether or not the correlation is to be made, but it is not necessary to determine. For example, in the determination unit 154, the first integrated angle θi1 and the second integrated angle θi2 are determined based on the relationship between the first integrated angle θi1 and the first absolute angle θga1 and the relationship between the second integrated angle θi2 and the first absolute angle θga1. It is only necessary to determine the presence or absence of abnormalities. If the determination unit 154 determines that the first integrated angle θi1 or the second integrated angle θi2 is abnormal, the absolute angle output unit 155 sets the first absolute angle θga1 or the second absolute angle θga2 as the pinion angle θpa. Output.

The determination unit 154 outputs, to the absolute angle output unit 155, a flag indicating which of the first integrated angle θi1, the second integrated angle θi2, the first absolute angle θga1, and the second absolute angle θga2 is received as the input value. However, the absolute angle output unit 155 may calculate the pinion angle θpa using what is received as an input value based on the flag.

In the determination process of FIG. 7, the order of each process may be changed. For example, steps S4 to S10 may be performed before step S2. Further, the determination process of step S2 may be omitted. In this case, for example, the determination unit 154 determines that the relationship between the first integrated angle θi1 and the first absolute angle θga1 (or the second absolute angle θga2) has a correct correlation, and the second integrated angle θi2 and the first absolute angle. When the relationship of θga1 (or the second absolute angle θga2) has a correct correlation, the integrated angle flag Fi0 is generated.

In the determination process of FIG. 8, the order of each process may be changed. For example, the determination process of steps S14 to S10 may be performed before step S12. Further, the determination process of step S12 may be omitted. In this case, for example, the determination unit 154 determines that the relationship between the first absolute angle θga1 and the first integrated angle θi1 (or the second integrated angle θi2) has a correct correlation, and the second absolute angle θga2 and the first integrated angle. When the relationship of θi1 (or the second integrated angle θi2) has a correct correlation, the absolute angle flag Fga0 is generated.

When the determination unit 154 acquires the absolute angle flag Fga0 in step S4, the determination unit 154 performs the process of step S5 using the first absolute angle θga1, but performs the process of step S8 using the second absolute angle θga2. Good. That is, the determination unit 154 executes the process of step S8 when the absolute angle flag Fga0 is acquired in step S4.

When the determination unit 154 acquires the integrated angle flag Fi0 in step S14, the determination unit 154 performs the process of step S15 using the first integrated angle θi1, but performs the process of step S18 using the second integrated angle θi2. Good. That is, the determination unit 154 executes the process of step S18 when the integrated angle flag Fi0 is acquired in step S14.

When the integrated angle flag Fi0 is input, the absolute angle output unit 155 uses the first integrated angle θi1 but may perform the calculation using the second integrated angle θi2. When the absolute angle flag Fga0 is input, the absolute angle output unit 155 uses the first absolute angle θga1 but may perform the calculation using the second absolute angle θga2.

A belt transmission mechanism and a ball screw mechanism may be adopted as the transmission mechanism that transmits the power generated by the steering motor 41 to the steering shaft 14, instead of the second reduction gear mechanism 42 and the second pinion shaft 43.

The TAS 46 is provided with the pinion torque sensor 46e, but this configuration is omitted and only the first pinion angle sensor 46a, the second pinion angle sensor 46b, the third pinion angle sensor 46c, and the fourth pinion angle sensor 46d are provided. May be provided.

The TAS 46 is provided on the first pinion shaft 13 but may be provided on the steering shaft 12. In this case, the TAS 46 is an absolute angle sensor that detects the rotation angle of the steering shaft 12 as an absolute angle. The configuration of the above embodiment applied to the steering control unit 47 may be applied to the reaction force control unit 35.

The steering device 10 may have a configuration in which the clutch 21 and the clutch control unit 22 are omitted. In this case, the power transmission between the steering wheel 11 and the steered wheels 16, 16 is always maintained in a separated state. However, it is possible to construct a steering device and a steering unit capable of supporting both the first type having the clutch 21 and the second type not having the clutch 21 as the steering device 10.

The reaction force control unit 35 or the steering control unit 47 may be applied to a control device of an electric power steering device that applies a motor torque as an assist force to a steering mechanism of a vehicle. The electric power steering device may be a type that applies an assist force to the steering shaft or a type that applies an assist force to the steered shaft.

The vehicle on which the steering device 10 and the steering device 10b are mounted may be a vehicle having a so-called internal combustion engine that employs an engine as a vehicle drive source, or a so-called electric vehicle that employs a motor as a vehicle drive source. May be. The start switch in the case of an electric vehicle is a switch that starts a motor as a vehicle drive source.

The reaction force control unit 35 or the steering control unit 47 is not limited to the steering device 10, and may be embodied as a control device for a mechanical device using a motor as a power source.

10... Steering device, 10b... Steering device, 12... Steering shaft, 13... First pinion shaft, 14... Steering shaft, 16... Steering wheel, 21... Clutch, 31... Reaction force motor, 33... Reaction force rotation angle Sensor, 35... Reaction force control part, 41... Steering motor, 43... Second pinion shaft, 44... First steering rotation angle sensor, 45... Second steering rotation angle sensor, 46... TAS, 46a to 46d... 1st-4th pinion angle sensor, 46e... Pinion torque sensor, 47... Steering control part, 50... 1st count value calculation circuit, 52... 1st counter circuit, 57... 1st count value calculation part, 60... 2 count value calculation circuit, 62... 2nd counter circuit, 67... 2nd count value calculation part, 70... 1st absolute angle calculation circuit, 80... 2nd absolute angle calculation circuit, 90... Control device, 100... Drive circuit, 110, 120, 130, 140... First, second, third, fourth absolute angle information arithmetic circuit, 150... First integrated angle arithmetic unit, 151... Second integrated angle arithmetic unit, 152... First absolute angle arithmetic operation Section, 153... Second absolute angle calculation section, 154... Judgment section, 155... Absolute angle output section, 156... Steering angle command value calculation section, 157... Current feedback control section, .theta.g1 to .theta.g4... First to fourth absolute Angle information, θga1... First absolute angle, θga2... Second absolute angle, θi1, First integrated angle, θi2... Second integrated angle, θpa, θpb... Pinion angle, θ*... Target steering angle, θa, θb... Rotation Angle, θs... Steering angle, θt... Steering angle, I*... Current command value, Sa, Sb1, Sb2, Sg1, Sg2, Sg3, Sg4... Electric signal, Sm... Motor control signal, Tp... Torque, Th... Steering Torque, U2... Steering unit, V... Vehicle speed, Vco... Control voltage.

Claims (5)

A first arithmetic circuit that calculates a count value based on a detection result of a first sensor that detects a relative angle of a motor that is a power source of the mechanical device;
A second arithmetic circuit that calculates first absolute position information based on a detection result of a second sensor that detects an absolute position of a detection target that interlocks with the motor in the mechanical device;
The second absolute position information is calculated based on the detection result of the third sensor that is provided to calculate the absolute position of the same detection target as the detection target of the second sensor and that detects the absolute position of the detection target. A third arithmetic circuit for
An integrated angle calculation unit that calculates an integrated angle obtained by integrating the relative angle of the motor using the count value, and a first absolute angle that is an absolute angle of a rotating shaft that is interlocked with the motor using the first absolute position information. A first absolute angle calculation unit, a second absolute angle calculation unit that calculates a second absolute angle that is the absolute angle of the rotation axis using the second absolute position information, the first absolute angle and the second absolute angle calculation unit. A fourth arithmetic circuit having a determination unit that determines whether there is an abnormality in the first absolute angle and the second absolute angle based on the relationship between the second absolute angle and the integrated angle,
The count value is a value for calculating the integrated angle,
The angle calculation device, wherein the first absolute position information and the second absolute position information are values for calculating the absolute position of the detection target. The determination unit,
Assuming that there is no abnormality in the integrated angle,
The relationship between the first absolute angle and the integrated angle matches the correlation that should be made between the motor and the rotating shaft, and the relationship between the second absolute angle and the integrated angle is the motor and the rotation. If the correlation with the axis does not match, it is determined that the second absolute angle is abnormal,
The relationship between the second absolute angle and the integrated angle coincides with the correlation that should be made between the motor and the rotary shaft, and the relationship between the first absolute angle and the integrated angle is the motor and the rotation. The angle calculation device according to claim 1, wherein when the correlation with the axis does not match, it is determined that the first absolute angle is abnormal. A steering apparatus comprising the angle calculation device according to claim 1 or 2, and a steering unit as the mechanical device,
The steering unit includes the second sensor and the third sensor,
The steered system in which the second sensor and the third sensor are configured by separate sensors. A steering apparatus comprising the angle calculation device according to claim 1 or 2, and a steering unit as the mechanical device,
The steering unit has the second sensor and the third sensor,
The second sensor and the third sensor are configured by the same sensor, and an output line for outputting the detection result of the same sensor to the second arithmetic circuit and the third arithmetic circuit is provided. A steering device configured differently. The steering unit is
A steering shaft that steers the steered wheels by making a linear motion,
A pinion shaft meshed with the steering shaft,
A steering motor that is a generation source of power applied to the steering shaft,
A transmission mechanism that transmits the power generated by the steering motor to the steering shaft,
The steering apparatus according to claim 3 or 4, wherein the detection target is the pinion shaft provided so as to interlock with the steering motor.