Drive control device, drive control method, and program

Abstract

To provide a drive control device, a drive control method, and a program for controlling a position of a pitman arm with high accuracy.SOLUTION: A drive control device includes a plurality of drive instruction systems. Each of the plurality of drive instruction systems includes a communication unit, an angle detection unit, a calculation unit, a distribution unit, and a drive control unit. The communication unit receives an instruction regarding a position of a pitman arm from a high-level device. The angle detection unit detects an angle of the pitman arm. The calculation unit calculates drive torque for the pitman arm based on the instruction and the angle of the pitman arm. The distribution unit distributes the drive torque according to a preset ratio. The drive control unit controls a drive unit. One drive instruction system of the plurality of drive instruction systems performs a series of torque distribution processing including calculation processing by the calculation unit and distribution processing by the distribution unit. Each drive control unit synchronously controls the drive unit by the torque distributed by the torque distribution processing.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a drive control device, a drive control method, and a program. [Background technology]

[0002] Conventionally, vehicles have adopted electric power steering systems (EPS) using a motor as a drive source. For example, in order to improve the reliability of the steering system, an EPS is known in which, in a redundant configuration with a drive motor and two microcomputers (systems), each system independently calculates an assist control amount for the pitman arm based on a command related to the position of the pitman arm, and each system independently controls the current of the drive motor (see, for example, Patent Document 1). Also, in a redundant configuration, an EPS is known that performs cooperative control by using multiple signals with different control periods as a control signal (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP2011-195089 Public Relations [Patent Document 2] JP2018-130007 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, there is a problem that the control of the drive motor may be inconsistent in the redundant configuration, and the position control of the pitman arm cannot be performed with high accuracy. To be more specific, regarding the cooperative control between the systems, if the synchronization between the systems is controlled independently, the calculation results related to the position control are likely to be inconsistent between the systems, especially in the case of a by-wire type EPS. In addition, as in Patent Document 2, when the torque amount output by each system is adjusted using the total drive command of all systems and the state variable (measured current) of each system as the control signal, the adjustment becomes complicated, making it difficult to calculate and control the drive torque for each system according to the system state (for example, the operation mode, heat generation limit, etc.), and further, it becomes difficult to verify the validity of the drive torque in each system. In addition, there is a risk of inconsistency occurring due to mutual errors of the position sensors.

[0005] Regarding failure, if one system fails or if the same system of another system fails, unintended control is performed in the failed system, resulting in unintended drive torque being output. Also, if an unintended position command value is received from the failed system, unintended drive torque is output. Furthermore, if a brake torque is generated due to a failure, it affects the normal system. Also, if an unintended drive torque is output due to a sensor failure, inconsistency occurs between the systems, making it impossible to perform high-precision position control. Thus, the conventional technology has a problem in that it is not possible to perform high-precision position control of the pitman arm.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a technique that can control the position of a pitman arm with high accuracy. [Means for solving the problem]

[0007] A drive control device according to one embodiment of the present invention includes a plurality of drive command systems each having a communication unit that receives a command related to the position of a pitman arm from a higher-level device, an angle detection unit that detects the angle of the pitman arm, a calculation unit that calculates a drive torque for the pitman arm based on the command and the angle of the pitman arm, a distribution unit that distributes the drive torque according to a preset ratio, and a drive control unit that controls a drive unit, wherein one of the plurality of drive command systems performs a series of torque distribution processing including calculation processing by the calculation unit and distribution processing by the distribution unit, and each of the drive control units synchronously controls the drive unit with the torque distributed by the torque distribution processing.

[0008] According to the above configuration, the position of the pitman arm can be controlled with high accuracy using a simple configuration and control.

[0009] In the above configuration, each of the plurality of drive instruction systems may have a setting unit that sets either a master mode in which the torque distribution process is performed or a slave mode in which the torque distribution process is not performed.

[0010] According to the above configuration, even if one of the drive control systems fails, inconsistencies in the control of the drive motors between the drive control systems can be prevented, and the position of the pitman arm can be controlled with high precision.

[0011] In the above configuration, each of the plurality of drive instruction systems has a calculation abnormality detection unit that detects a calculation abnormality that indicates an abnormality in which the torque distribution process cannot be performed, The setting unit may set the slave mode when the calculation abnormality is detected by the calculation abnormality detection unit.

[0012] According to the above configuration, it is possible to prevent inconsistencies in the control of the drive units between the drive instruction systems.

[0013] In the above configuration, each of the plurality of drive instruction systems has a calculation abnormality acquisition unit that acquires calculation abnormality information indicating that the calculation abnormality has been detected in another system other than the own system, The setting unit may set the master mode when the calculation abnormality information is acquired by the calculation abnormality acquisition unit.

[0014] According to the above configuration, even if a calculation abnormality is detected in another drive instruction system, the drive torque is not degenerated and the drive parts can be controlled in a synchronous manner.

[0015] In the above configuration, each of the multiple drive instruction systems has a drive control abnormality detection unit that detects a drive control abnormality that indicates an abnormality in the drive control unit, and the slave mode includes a termination mode that terminates operation of its own system, and the setting unit may be configured to set the termination mode when the drive control abnormality is detected by the drive control abnormality detection unit.

[0016] According to the above configuration, it is possible to prevent inconsistencies in the control of the drive motors between the drive command systems.

[0017] In the above configuration, each of the multiple drive instruction systems has a drive control abnormality acquisition unit that acquires drive control abnormality information indicating that the drive control abnormality has been detected in other systems other than the own system, and a degeneration unit that degenerates the drive torque calculated by the calculation unit, and the master mode includes a degenerate mode, and when the drive control abnormality information is acquired by the drive control abnormality acquisition unit, the setting unit sets the degenerate mode, and in the degenerate mode, the degenerate unit prohibits the allocation process by the allocation unit and degenerates the drive torque to a third torque, and in the degenerate mode, the drive control unit controls the drive unit with the third torque.

[0018] According to the above configuration, even if one drive command system cannot perform drive control, the other drive command system can control the drive unit by reducing the drive torque.

[0019] In the above configuration, each of the drive instruction systems may include a rotation angle detection unit that detects a rotation angle of the drive unit, and an abnormality detection unit that detects the occurrence of at least one of an abnormality in the rotation angle detection unit and an abnormality in the angle detection unit based on the rotation angle detected by the rotation angle detection unit and the angle detected by the angle detection unit.

[0020] According to the above configuration, the sensor abnormality can be detected with high accuracy by the parts related to the position control of the pitman arm without adding any additional components.

[0021] In the above configuration, the rotation angle detection unit may be arranged concentrically with an output shaft of the drive unit, the drive unit may have a plurality of motor windings provided corresponding to each of the drive control units and arranged at a predetermined angle different from each other, and each of the drive control units may generate a control signal corresponding to the difference in the predetermined angle to control the drive unit.

[0022] According to the above configuration, the error in the motor angle between the systems is reduced, so that the relative detection accuracy is improved and the position of the pitman arm can be controlled with high accuracy.

[0023] In the aforementioned configuration, when the abnormality is detected by the abnormality detection section, the setting section may change the mode at a timing before the abnormality is confirmed.

[0024] According to the above configuration, the mode can be switched quickly, so that the drive motor 320 can be prevented from being controlled with an inappropriate value.

[0025] In the above configuration, the drive unit has a coil unit, and each of the multiple drive instruction systems may have a disconnection unit that, when a termination mode is set, stops the supply of power to the drive unit and cuts off the connection of the wiring unit to which the end of the coil unit is connected.

[0026] According to the above configuration, the drive motor 320 can be controlled with an appropriate torque.

[0027] In the above configuration, the communication unit may receive a mode command corresponding to a mode to be set in the higher-level device from the higher-level device, and the setting unit may set the mode indicated by the mode command.

[0028] According to the above configuration, simple control through coordination among multiple axles can be realized.

[0029] A drive control method according to one aspect of the present invention is a drive control method for a drive control device with multiple drive instruction systems, each of which includes a communication unit that receives a command related to the position of a pitman arm from a higher-level device, an angle detection unit that detects the angle of the pitman arm, a calculation unit that calculates a drive torque for the pitman arm based on the command and the angle of the pitman arm, a distribution unit that distributes the drive torque according to a preset ratio, and a drive control unit that controls a drive unit, wherein one of the multiple drive instruction systems performs a series of torque distribution processing including a calculation process by the calculation unit and a distribution process by the distribution unit, and each of the drive control units provided in the multiple drive instruction systems synchronously controls the drive unit with the torque distributed by the torque distribution process.

[0030] According to the above configuration, the position of the pitman arm can be controlled with high accuracy using a simple configuration and control.

[0031] A program according to one aspect of the present invention causes a computer to function as a drive control device with multiple drive instruction systems, each of which includes a communication unit that receives a command related to the position of a pitman arm from a higher-level device, an angle detection unit that detects the angle of the pitman arm, a calculation unit that calculates a drive torque for the pitman arm based on the command and the angle of the pitman arm, a distribution unit that distributes the drive torque according to a preset ratio, and a drive control unit that controls a drive unit. The program is characterized in that it causes one of the multiple drive instruction systems to perform a series of torque distribution processes including calculation processing by the calculation unit and distribution processing by the distribution unit, and causes each of the drive control units provided in the multiple drive instruction systems to synchronously control the drive unit with the torque distributed by the torque distribution process.

[0032] According to the above configuration, the position of the pitman arm can be controlled with high accuracy using a simple configuration and control. Effect of the Invention

[0033] According to the present invention, the position of the pitman arm can be controlled with high precision. [Brief description of the drawings]

[0034] [Figure 1] 1 is a diagram showing an example of a vehicle 100 according to an embodiment of the present invention. [Diagram 2] 1 is a diagram showing an example of the configuration of a drive control system 200 around a steering wheel of a vehicle 100. [Diagram 3] FIG. 2 is a diagram showing an example of a configuration related to drive control of a drive motor. [Figure 4] FIG. 3 shows an example of the configuration of a control unit 310. [Diagram 5] FIG. 4 is a diagram showing an example of an operation example of a control unit 310. [Figure 6A] FIG. 4 is a diagram showing an example of a motor winding of a drive motor 320. [Figure 6B] FIG. 4 is a diagram showing an example of a waveform of a phase current. [Figure 7] FIG. 2 is a diagram showing an example of the layout of an ECU board which is a drive command system 300. [Figure 8] FIG. 2 is a diagram showing an example of the configuration of a drive instruction system 300 and a drive motor 320. [Figure 9] FIG. 2 is a diagram illustrating a schematic circuit configuration of a drive control system 300. [Figure 10] 11A and 11B are diagrams showing a comparative example between mode switching timing according to the present embodiment and conventional mode switching timing. [Figure 11] 11 is a flowchart showing an example of a process related to a fail-operation mode. [Figure 12] 11 is a flowchart showing an example of a process related to a fail-safe operation mode. [Figure 13] 10 is a flowchart showing an example of a process when another drive control system 300 mounted on another axle 120 changes modes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Next, an embodiment of the present invention will be described with reference to the drawings.

[0036] (Embodiment) (An example of vehicle 100) FIG. 1 is a diagram showing an example of a vehicle 100 according to an embodiment of the present invention. The vehicle 100 is a truck, a bus, a passenger car, or the like. The vehicle 100 has n (e.g., two) axles 120 (120-1, 120-n) and a number (e.g., four) of tires 130 (130-1, 130-n) corresponding to the number (n) of the axles 120. Specifically, the front wheels have a tire 130a connected to the axle 120a. The rear wheels have a tire 130b connected to the axle 120b. Note that the number (n) of the axles 120 is not limited to "2" and may be "three or more" in the case of a vehicle 100 such as a trailer or a large bus.

[0037] The axle 120 is equipped with an electric power steering system (EPS). The EPS is of a by-wire type. The EPS includes a drive motor, a reduction gear, and a pitman arm 330 (FIG. 3). The drive motor 320 (FIG. 3) generates a drive torque for steering. The reduction gear transmits the drive torque from the drive motor 320 to the steering mechanism below the pitman arm 330. The pitman arm 330 is an output arm that is connected to the reduction gear and rotates by the drive torque output from the reduction gear.

[0038] (An example of the configuration around the steering wheel of the vehicle 100) 2 is a diagram showing an example of the configuration of a drive control system 200 around a steering wheel of the vehicle 100. As shown in FIG.

[0039] The handle actuator 230 (reaction force generating device) includes an angle control device 250. The angle control device 250 is a higher-level device of the drive control device 240. The angle control device 250 calculates an optimal travel trajectory based on the detection results of various sensors, and issues a command (hereinafter referred to as a "position command") to each drive control device 240 regarding the position of the pitman arm 330. The drive control device 240 (240a to 240n) is provided corresponding to each axle 120 (120a to 120n). The drive control device 240 controls the drive motor 320 with a predetermined torque based on the position command from the angle control device 250.

[0040] (Configuration Related to Drive Control of Drive Motor 320) Fig. 3 is a diagram showing an example of a configuration related to drive control of the drive motor 320. As shown in Fig. 3, the drive control device 240 includes a plurality of drive instruction systems 300 (a first drive instruction system 300a and a second drive instruction system 300b). The plurality of drive instruction systems 300 each have a similar configuration and are configured to be redundant. Each of the plurality of drive instruction systems 300 is realized by an ECU (Electronic Control Unit).

[0041] Moreover, the angle control device 250 includes a plurality of angle control systems 251 (a first angle control system 251a and a second angle control system 251b). The plurality of angle control systems 251 each have a similar configuration and are redundant. Each of the plurality of angle control systems 251 is realized by an ECU.

[0042] (About Channel 1) The first angle control system 251a has a channel 1 connected to the drive control device 240. The control unit 310 controls the entire drive instruction system 300. The first control unit 310a has a channel 1 and is connected to the channel 1 of the first angle control system 251a. The channel 1 of the first control unit 310a receives a position command for the pitman arm 330 from the channel 1 of the first angle control system 251a.

[0043] (About Channel 2) The second angle control system 251 b has a channel 2 connected to the drive control device 240 . The second control unit 310b includes a channel 2, which is connected to the channel 2 of the second angle control system 251b. The channel 2 of the second control unit 310b receives a position command from the channel 2 of the second angle control system 251b.

[0044] (Drive control system 300) Each of the multiple drive instruction systems 300 has the following configuration. Control unit 310: a first control unit 310a, a second control unit 310b. ·Power supply circuit 311: first power supply circuit 311a, second power supply circuit 311b. Inverter circuit 312: a first inverter circuit 312a, a second inverter circuit 312b. Current sensors 313: a first current sensor 313a, a second current sensor 313b. Motor angle sensors 314: first motor angle sensor 314a, second motor angle sensor 314b. Pitman arm (PA) angle sensors 315: first pitman arm angle sensor 315a, second pitman arm angle sensor 315b.

[0045] Power supply circuit 311 generates a supply current and sends it to inverter circuit 312. Inverter circuit 312 operates drive motor 320 with the current value supplied from power supply circuit 311. Current sensor 313 detects the current value when drive motor 320 is operating. Motor angle sensor 314 detects the angle (number of rotations) of drive motor 320. Motor angle sensor 314 is an example of a rotation angle detection unit. Pitman arm angle sensor 315 detects the angle (position) of pitman arm 330. Pitman arm angle sensor 315 is an example of an angle detection unit.

[0046] (Regarding the drive motor 320) The driving motor 320 has a channel 1 and a channel 2. The channel 1 of the driving motor 320 is connected to each part of the first driving instruction system 300a (the first inverter circuit 312a, the first motor angle sensor 314a, and the first current sensor 313a). For example, the first inverter circuit 312a supplies a current to the driving motor 320 via the channel 1 of the driving motor 320. Similarly, the channel 2 of the driving motor 320 is connected to each part of the second driving instruction system 300b (the second inverter circuit 312b, the second motor angle sensor 314b, and the second current sensor 313b). For example, the second inverter circuit 312b supplies a current to the driving motor 320 via the channel 2 of the driving motor 320.

[0047] (Configuration of control unit 310) Next, the control unit 310 will be described with reference to FIGS. FIG. 4 is a diagram showing an example of the configuration of control unit 310. As shown in FIG. Fig. 5 is a diagram showing an example of an operation example of the control unit 310. Note that Fig. 5 shows only some of the functional units shown in Fig. 4.

[0048] In FIG. 4, the control unit 310 (first control unit 310a and second control unit 310b) each includes the following functional units: a communication unit 400, a calculation unit 401, an allocation unit 402, a drive control unit 403, a setting unit 404, a calculation anomaly detection unit 405, a calculation anomaly acquisition unit 406, a drive control anomaly detection unit 407, a drive control anomaly acquisition unit 408, a disconnection unit 409, a degeneration unit 410, and an anomaly detection unit 411.

[0049] The control unit 310 is realized by a central processing unit (CPU) provided in the ECU executing a drive control program stored in a memory such as a random access memory (RAM) or a read only memory (ROM). The control unit 310 may be realized by hardware (including a circuit unit; circuitry) such as a large scale integration (LSI), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a graphics processing unit (GPU), or may be realized by cooperation between software and hardware. The drive control program may be stored in advance in the memory of the control unit 310, or may be stored in a memory such as a removable storage medium, and may be installed in the memory of the control unit 310 by mounting the memory in the drive device. In addition, various information stored in the memory may be stored in an external server accessible by the control unit 310.

[0050] (Regarding receiving position commands) The communication unit 400 receives a position command from the angle control system 251 (host device) of the corresponding channel. The communication unit 400 also communicates with other drive instruction systems 300 forming a redundant configuration.

[0051] (Calculating driving torque) The calculation unit 401 calculates the drive torque for the pitman arm 330. Specifically, the calculation unit 401 acquires a position command transmitted from the angle control device 250 via the communication unit 400. The calculation unit 401 also acquires the angle (position) of the pitman arm 330 detected by the pitman arm angle sensor 315. The calculation unit 401 calculates the drive torque based on the acquired position command and the angle of the pitman arm 330.

[0052] (Regarding distribution of driving torque) The distribution unit 402 distributes the drive torque calculated by the calculation unit 401 to the first torque and the second torque according to a preset ratio. The ratio is, for example, 1:1. Here, to explain by way of example, the capacity (maximum torque) of each of the first drive control unit 403a and the second drive control unit 403b according to this embodiment is set to "80" (total "160"). The drive torque calculated by the calculation unit 401 is set to "100". In this case, the distribution unit 402 distributes the drive torque of "100" to the first torque of "50 / 80" and the second torque of "50 / 80". The ratio can be changed as appropriate according to, for example, limitations on functions due to heat generation.

[0053] (About mode settings) The setting unit 404 sets the drive control system 300 to a master mode or a slave mode. The drive control system 300 set to the master mode performs a series of torque distribution processes. The torque distribution process includes a drive torque calculation process by the calculation unit 401 and a drive torque distribution process by the distribution unit 402. The drive control system 300 set to the slave mode does not perform torque distribution processes. In the drive control system 300 in the slave mode, the communication unit 400 receives the second torque distributed by the distribution unit 402 of the drive control system 300 in the master mode from the communication unit 400 in the master mode.

[0054] In the following, it is assumed that the first drive instruction system 300a is set to the master mode, and the second drive instruction system 300b is set to the slave mode.

[0055] As shown in Fig. 5, the first drive instruction system 300a performs torque distribution processing. Specifically, the first calculation unit 401a calculates a drive torque based on the position command received by the first communication unit 400a and the angle of the pitman arm 330 detected by the first pitman arm angle sensor 315a. Then, the first distribution unit 402a distributes the drive torque "100" calculated by the first calculation unit 401a to a first torque "50" and a second torque "50" at a ratio of 1:1. The first distribution unit 402a outputs a first assist command indicating the first torque to the first drive control unit 403a, and outputs a second assist command indicating the second torque to the second drive control unit 403b via the first communication unit 400a.

[0056] The drive control section 403 performs drive control processing to control the drive of the drive motor 320. The drive control processing is, for example, converting the torque indicated by the assist command into a current command value, performing current control, and outputting a motor drive signal. The first drive control section 403a drives and controls the drive motor 320 with a first torque indicated by the first assist command. The second drive control section 403b drives and controls the drive motor 320 with a second torque indicated by the second assist command.

[0057] The first drive control unit 403a and the second drive instruction system 300b each control the drive of the drive motor 320 at the timing when the assist command is acquired from the first distribution unit 402a. Therefore, the first drive control unit 403a and the second drive control unit 403b can synchronously control the drive of the drive motor 320. This allows the drive of the drive motor 320 to be controlled without inconsistency between the drive instruction systems 300, and therefore allows the position of the pitman arm 330 to be controlled with high accuracy.

[0058] (About changing modes) In this embodiment, the drive control device 240 can be applied to a system in which the master mode and the slave mode are unified for all systems. When the mode is changed (switched) in the drive control system 300 mounted on one axle 120 among the drive control systems 300 mounted on n (e.g., two) axles 120, the mode is also changed in the drive control systems 300 mounted on the other axles 120.

[0059] (Fail-safe operation mode: 100% output continues) Next, a description will be given of switching of the master mode in the case where an abnormality (calculation abnormality) occurs in which torque distribution processing cannot be performed in the drive instruction system 300 in the master mode. Note that the switching of the master mode described below may be referred to as a "fail-safe operation mode."

[0060] The calculation abnormality detection unit 405 detects a calculation abnormality that indicates an abnormality that makes it impossible to perform the torque distribution process. The calculation abnormality is, for example, an abnormality (failure) of the pitman arm angle sensor 315 or an abnormality (failure) that makes it impossible for the communication unit 400 to receive a position command from the angle control system 251. An example of detection of an abnormality of the pitman arm angle sensor 315 will be described later.

[0061] The calculation abnormality detection unit 405 detects a calculation abnormality, for example, when the driving instruction system is in master mode. Although the calculation abnormality is not suitable for calculating the driving torque, the driving control by the driving control unit 403 is in a normal state. Therefore, when a calculation abnormality is detected by the calculation abnormality detection unit 405, the driving instruction system 300 switches between the master mode and the slave mode.

[0062] (First drive command system 300a → slave mode) When the calculation abnormality detection unit 405 detects a calculation abnormality, the first setting unit 404a sets the slave mode.

[0063] (Second drive command system 300b → master mode) In addition, when the calculation anomaly detection unit 405 of the first drive instruction system 300a detects a calculation anomaly, it outputs calculation anomaly information indicating that a calculation anomaly has been detected to the second drive instruction system 300b via the first communication unit 400a.

[0064] The calculation abnormality acquisition unit 406 of the second drive instruction system 300b acquires the calculation abnormality information transmitted from the first communication unit 400a via the second communication unit 400b. The calculation abnormality information acquired by the calculation abnormality acquisition unit 406 is information indicating that a calculation abnormality has been detected in the other drive instruction system (first drive instruction system 300a) other than the self drive instruction system (second drive instruction system 300b). The second setting unit 404b sets the master mode when the calculation abnormality acquisition unit 406 acquires the calculation abnormality information.

[0065] In this way, in the fail-safe operation mode, when a calculation abnormality is detected in the first drive instruction system 300a in the master mode, the first drive instruction system 300a is changed to the slave mode, and the second drive instruction system 300b in the slave mode is changed to the master mode. Therefore, in the fail-safe operation mode, the drive motor 320 can be driven and controlled with the same drive torque as before the calculation abnormality occurred. Specifically, even in a scene where the drive torque is insufficient and position control is not possible (for example, when turning the steering wheel while the vehicle is stopped), position control can be continuously performed with high accuracy.

[0066] (Fail operation mode: Degenerate to 50%) Next, a description will be given of switching of the master mode when an abnormality (drive control abnormality) occurs in which drive control cannot be performed in the master mode drive instruction system 300. The switching of the master mode described below may be referred to as a "fail operation mode."

[0067] The drive control abnormality detection unit 407 detects a drive control abnormality indicating an abnormality in the drive control unit 403. The drive control abnormality is, for example, an abnormality in the power supply circuit 311, the inverter circuit 312, the current sensor 313, or the motor angle sensor 314. An example of detecting an abnormality in the motor angle sensor 314 will be described later.

[0068] The drive control abnormality detection unit 407 makes it possible to detect drive control abnormalities regardless of whether the drive control is set to the master mode or the slave mode. The slave mode includes a termination mode in which the operation of the drive instruction system itself is terminated. The master mode includes a degeneration mode in which the drive torque is degenerated. When the drive control abnormality detection unit 407 detects a drive control abnormality, the setting unit 404 sets the termination mode.

[0069] For example, if a drive control abnormality is detected in the first drive instruction system 300a, the first setting unit 404a sets the end mode.

[0070] (First drive command system 300a -> end mode) For example, if a drive control abnormality is detected in the first drive instruction system 300a, when the first drive instruction system 300a detects the drive control abnormality, it outputs drive control abnormality information indicating that a drive control abnormality has been detected to the second drive instruction system 300b via the first communication unit 400a.

[0071] (Second drive command system 300b -> degenerate mode) The drive control abnormality acquisition unit 408 of the second drive instruction system 300b acquires drive control abnormality information from the first drive instruction system 300a. The drive control abnormality information acquired by the drive control abnormality acquisition unit 408 is information indicating that a drive abnormality has been detected in the other drive instruction system (first drive instruction system 300a) other than the drive instruction system itself (second drive instruction system 300b). The second setting unit 404b sets the degenerate mode when the drive control abnormality acquisition unit 408 acquires drive control abnormality information.

[0072] In the degenerate mode, the second calculation unit 401b of the second drive instruction system 300b calculates the drive torque. Furthermore, the degenerate unit 410 of the second drive instruction system 300b prohibits the allocation process by the second allocation unit 402b and degenerates (reduces) the drive torque to a third torque. For example, the degenerate unit 410 degenerates the drive torque to 50% of the third torque. Degenerating to 50% of the third torque means, for example, that if the drive torque calculated by the calculation unit 401 is "100", the third torque is degenerated to "50".

[0073] Note that the degeneration unit 410 is not limited to degenerating the drive torque of "100" to the third torque of "50". For example, since the capacity (maximum torque) of each of the first drive control unit 403a and the second drive control unit 403b is "80", the degeneration unit 410 can degenerate the drive torque of "100" to a third torque within a range up to "80" depending on the setting. When the drive torque is degenerated to the third torque by the degeneration unit 410, the second drive control unit 403b controls the drive motor 320 with the degenerated third torque.

[0074] In this way, the fail-operation mode is a mode in which, when a drive control abnormality is detected in one of the drive instruction systems 300, the one of the drive instruction systems 300 is changed to the end mode, and the other drive instruction system 300 is changed to the master mode (degenerate mode). Therefore, in the fail-operation mode, even if one of the drive instruction systems 300 cannot perform drive control, the other drive instruction system 300 can degenerate the drive torque and drive control the drive motor 320.

[0075] When a drive control abnormality is detected in both the first drive instruction system 300a and the second drive instruction system 300b, both systems enter the end mode, and the position control of the pitman arm 330 is no longer performed.

[0076] (Regarding motor windings) FIG. 6A is a diagram showing an example of the motor windings of the drive motor 320. As shown in FIG. FIG. 6B is a diagram showing an example of a waveform of a phase current. 6A, the drive motor 320 includes a first motor winding 600a (channel 1) and a second motor winding 600b (channel 2). The first motor winding 600a includes a U1 coil 601a, a V1 coil 602a, and a W1 coil 603a. The second motor winding 600b includes a U2 coil 601b, a V2 coil 602b, and a W2 coil 603b.

[0077] The first motor winding 600a (channel 1) and the second motor winding 600b (channel 2) have equivalent electrical characteristics and are wound in a cancel manner around a common stator (not shown) with a predetermined electrical angle θ (e.g., 30°) shifted from each other. For this reason, as shown in FIG. 6B, the motor winding 600 is controlled so that a phase current whose phase φ is shifted by an electrical angle θ (30°) flows through it. This makes it possible to optimize the energization phase difference and improve the output torque. Furthermore, by setting the energization phase difference to an electrical angle of 30°, it is possible to reduce torque ripple.

[0078] (ECU board layout) FIG. 7 is a diagram showing an example of the arrangement of the ECU boards which are the drive instruction system 300. In FIG. 7, the first ECU board 700a has the first drive instruction system 300a. The second ECU board 700b has the second drive instruction system 300b. The first ECU board 700a and the second ECU board 700b are provided in an inverted manner (rotated 180°). The first ECU board 700a and the second ECU board 700b are provided concentrically with the output shaft (Z direction in the figure) of the drive motor 320 via the mounting parts 701 (701a, 701b). In addition, the first motor angle sensor 314a and the second motor angle sensor 314b are each provided on the output shaft of the drive motor 320, and detect the rotation angle of the drive motor 320 on the output shaft. Thus, in this embodiment, the first ECU board 700a and the second ECU board 700b are arranged inverted and the electrical angle θ is shifted by 30°, so that the detection results of each motor angle sensor 314 differ by 180°+30° (or 180°-30°).

[0079] Therefore, the first drive control section 403a and the second drive control section 403b each generate a control signal according to the difference in a predetermined electrical angle θ (30°) to control the drive motor 320. Specifically, in current control, each drive control section 403 outputs a PWM (Pulse Width Modulation) signal shifted by the phase of the motor windings 600 to shift the timing of switching the switching element. The PWM signal is calculated based on the detection result (RPS value) of the motor angle sensor 314 in each drive instruction system 300.

[0080] Each drive command system 300 is offset (calibrated) at the time of production to account for the phase shift of the motor windings 600. Therefore, current control (FOC: Field Oriented Control) is performed based on a common current command value and an RPS value calibrated for each drive command system 300, making it possible to output PWM signals with phase shifts between the drive command systems 300. With this configuration, it is possible to perform current control by using common software for the drive command systems 300, in which only the calibration value of the RPS value is different.

[0081] As a result, even in a configuration using multiple ECU boards 700, the rotation directions of the outputs are aligned, allowing for simple control. Also, since the motor angle sensors 314 are coaxial, the phase difference between the channels is clear, making it easy to detect failures related to the motor angle sensors 314 and the drive motor 320. Furthermore, since the channels of the drive instruction systems 300 and the central axis of the drive motor 320 are aligned, errors between the drive instruction systems 300 can be reduced. This improves the detection accuracy of the motor angle, allowing for highly accurate position control of the pitman arm 330.

[0082] (Example of abnormality detection: Guarantee of the angle of the Pitman arm 330) When an abnormality occurs in at least one of the motor angle sensor 314 and the pitman arm angle sensor 315, and it is not possible to identify which sensor is abnormal, it is unclear whether the torque distribution process or the drive control process should be performed. For this reason, in this embodiment, in such a case, the system is operated in a fail-safe operation mode. This will be described below.

[0083] Abnormality detection unit 411 detects that at least one of an abnormality in motor angle sensor 314 and an abnormality in pitman arm angle sensor 315 (hereinafter referred to as a "sensor abnormality") has occurred. Note that although abnormality detection unit 411 detects a sensor abnormality, it cannot specify which sensor is abnormal.

[0084] Anomaly detection unit 411 detects a sensor anomaly based on the rotation angle detected by motor angle sensor 314 and the angle detected by pitman arm angle sensor 315. For example, when motor angle sensor 314 and pitman arm angle sensor 315 are both normal, the value obtained from the rotation angle detected by motor angle sensor 314 and the value obtained from the angle detected by pitman arm angle sensor 315 are within a predetermined range. On the other hand, when an abnormality occurs in one of the sensors, a difference occurs between these values, that is, these values ​​are not within the predetermined range.

[0085] The detection of sensor abnormality will be specifically described below. Since an absolute value cannot be obtained from the motor angle sensor 314, the abnormality detection unit 411 virtually defines an absolute value of the motor angle sensor 314 from the detection result of the pitman arm angle sensor 315 when the drive control system 200 is started. When the abnormality detection unit 411 acquires the detection result (RPS value) from the motor angle sensor 314, it calculates a conversion value by multiplying the RPS value by a predetermined reduction ratio (for example, 1 / 500). Furthermore, the abnormality detection unit 411 determines whether or not the difference between this conversion value (angle) and the value (angle) detected by the pitman arm angle sensor 315 is within a certain value. In this determination, if it is determined that the difference is within the certain value, the abnormality detection unit 411 determines that the sensor is normal. On the other hand, in this determination, if it is determined that the difference is outside the certain value, the abnormality detection unit 411 detects a sensor abnormality.

[0086] In this manner, in this embodiment, the drive instruction system 300 that detects a sensor abnormality sets the end mode. On the other hand, the normal drive instruction system 300 sets the master mode. As a result, even if a sensor abnormality occurs in one of the drive instruction systems 300, the other drive instruction system 300 can reduce the drive torque and drive control the drive motor 320.

[0087] (Identifying the sensor involved in the sensor abnormality) Next, a method for identifying the sensor that is the subject of an abnormality when a sensor abnormality is detected will be described. In this embodiment, the phase difference of the motor angle sensor 314 is clear. Therefore, if the phase difference is a predetermined difference, it can be determined that the motor angle sensor 314 is normal (the pitman arm angle sensor 315 is abnormal), and on the other hand, if the phase difference is not the predetermined difference, it can be determined that the motor angle sensor 314 is abnormal (the pitman arm angle sensor 315 is normal).

[0088] Specifically, for example, it is assumed that the first drive instruction system 300a has a sensor abnormality, while the second drive instruction system 300b is normal. In this case, the abnormality detection unit 411 of either the first drive instruction system 300a or the second drive instruction system 300b compares the rotation angle detected by the first motor angle sensor 314a with the rotation angle detected by the second motor angle sensor 314b. If the comparison result is a predetermined difference (for example, 180°+30°), the abnormality detection unit 411 can determine that the first motor angle sensor 314a is normal, that is, the first pitman arm angle sensor 315a is abnormal. Also, even if the pitman arm angle sensor 315 is abnormal, if it is determined that the motor angle sensor 314 is normal, the motor angle sensor 314 can be used instead to continue position control.

[0089] On the other hand, if the comparison result is not the predetermined difference, the abnormality detection unit 411 can determine that the first motor angle sensor 314a is abnormal. The abnormality of the first pitman arm angle sensor 315a is included in the calculation abnormality. The calculation abnormality is a normal state with respect to the drive control by the drive control unit 403. Therefore, when it is determined that the pitman arm angle sensor 315 is abnormal, the setting unit 404 sets the slave mode without setting the end mode. This allows operation in a fail-safe operation mode.

[0090] (If a foreign object adheres to the pitman arm 330) Here, if a foreign object or the like adheres to pitman arm 330, abnormality detection unit 411 may erroneously detect a sensor abnormality. Specifically, since first pitman arm angle sensor 315a and second pitman arm angle sensor 315b are disposed in the same position, if a foreign object or the like adheres to pitman arm 330, abnormality detection units 411 of both drive instruction systems 300 may simultaneously detect a sensor abnormality.

[0091] In this case, the abnormality detection unit 411 determines that there is an abnormality in the pitman arm angle sensor 315. Also, the motor angle sensor 314 may be used to continue performing position control.

[0092] If it is determined that there is no sensor abnormality, each drive command system 300 may maintain the previous mode. In this case, the drive command system 300 may notify the user that a foreign object may be attached to the pitman arm 330.

[0093] (Regarding control of the drive motor 320 by each drive instruction system 300) Next, the motor stop process in the event of a failure (end mode) will be described together with the configuration around the drive motor 320. FIG. 8 is a diagram showing an example of the configuration of the drive instruction system 300 and the drive motor 320. As shown in FIG. FIG. 9 is a diagram showing a schematic circuit configuration of the drive instruction system 300. As shown in FIG. 8 and 9, the driving motor 320 is controlled by a first control unit 310a and a second control unit 310b based on instructions from the angle control device 250. The first control unit 310a and the second control unit 310b control the supply of electricity to the coil unit 810 of the driving motor 320 to adjust the rotation of the rotor.

[0094] The coil unit 810 includes a first three-phase coil unit 811 and a second three-phase coil unit 812. The first three-phase coil unit 811 has a three-phase coil, and is controlled by the first control unit 310a. The second three-phase coil unit 812 has a three-phase coil, and is controlled by the second control unit 310b. In the coil units 811 and 812, the first three-phase coil unit 811 and the second three-phase coil unit 812 may be provided separately, or may be a single unit of three-phase coils.

[0095] The first inverter circuit 312a energizes the first three-phase coil unit 811. The first inverter circuit 312a is composed of, for example, a plurality of power transistor elements 902. The first switching unit 800a controls the connection of a first connection unit 901a to which the end of the first three-phase coil unit 811 is connected. The first switching unit 800a is composed of, for example, a plurality of power transistor elements (not shown). The first control unit 310a controls the first inverter circuit 312a and the first switching unit 800a.

[0096] The first control unit 310a, for example, performs PWM control of the on / off timing of each power transistor element 902 of the first inverter circuit 312a to generate a pulse current and control the first three-phase coil unit 811. The first control unit 310a may control the first three-phase coil unit 811 by a control method other than PWM control. For example, when the first drive instruction system 300a fails (in the termination mode), the first control unit 310a opens the first switching unit 800a to cut off the power supply to the first three-phase coil unit 811. This ensures the safety of the drive control device 240 when a failure occurs.

[0097] The second inverter circuit 312b energizes the second three-phase coil unit 812. The second inverter circuit 312b is configured, for example, by a plurality of power transistor elements 902. The second switching unit 800b controls the connection of the second wiring unit 901b to which the end of the second three-phase coil unit 812 is connected. The second switching unit 800b is configured, for example, by a plurality of power transistor elements (not shown). The second control unit 310b controls the second inverter circuit 312b and the second switching unit 800b.

[0098] The second control unit 310b, for example, performs PWM control of the on / off timing of each power transistor element 902 of the second inverter circuit 312b to generate a pulse current and control the second three-phase coil unit 812. The second control unit 310b may control the second three-phase coil unit 812 by a control method other than PWM control. For example, when the second drive instruction system 300b fails (in the termination mode), the second control unit 310b opens the second switching unit 800b to cut off the current to the second three-phase coil unit 812. This ensures the safety of the drive control device 240 when a failure occurs.

[0099] The first control unit 310a controls 50% of the output of the drive motor 320 by controlling the first three-phase coil unit 811. The second control unit 310b controls 50% of the output of the drive motor 320 by controlling the second three-phase coil unit 812. With this configuration, the drive control device 240 can ensure at least half of the output even if either the first drive instruction system 300a or the second drive instruction system 300b fails.

[0100] The first control unit 310a may control the first three-phase coil unit 811 to control the 100% output of the drive motor 320. In this case, the second control unit 310b does not control the drive motor 320. The second control unit 310b may control the second three-phase coil unit 812 to control the 100% output of the drive motor 320. In this case, the first control unit 310a does not control the drive motor 320. In this way, when either the first drive instruction system 300a or the second drive instruction system 300b fails, the drive control device 240 can switch to the other drive instruction system 300 to ensure 100% output.

[0101] In addition, when either the first control unit 310a or the second control unit 310b controls the drive motor 320, the first control unit 310a and the second control unit 310b may be switched to control the drive motor 320 at a predetermined timing such as a predetermined period or every number of operations, to distribute the burden of controlling the drive motor 320. The balance of the control of the drive motor 320 between the first control unit 310a and the second control unit 310b may be adjusted to an arbitrary ratio. In this way, redundancy in the control of the drive motor 320 can be ensured. Also, an efficient power balance in the control of the drive motor 320 can be selected arbitrarily.

[0102] (Motor stop processing in case of failure) The switching unit 800 switches between connection and disconnection of the connection unit 901 to which the end of the coil unit 810 is connected. Here, if one drive instruction system 300 operates the drive motor 320 (if the degenerate mode is started) in a state in which the drive instruction system 300 stops the drive motor 320 (end mode), a brake torque is generated due to the generation of counter electromotive force, and it may not be possible to generate an appropriate drive torque. In order to prevent the generation of such a brake torque, in this embodiment, when the end mode is set by the setting unit 404, the disconnection unit 409 performs a motor stop process. The motor stop process is a process of stopping the supply of power to the drive motor 320 and switching the switching unit 800 to disconnection. This makes it possible to suppress the generation of counter electromotive force.

[0103] (Regarding the timing of mode switching by the setting unit 404) Next, the timing of switching the mode by the setting unit 404 will be described. First, the abnormality confirmation timing will be described. The control unit 310 confirms the abnormality at the abnormality confirmation timing when the abnormality continues for a certain period of time or more after the abnormality is detected, and stops the drive motor 320. In other words, the abnormality confirmation timing is the timing to start processing for transitioning to a safe state, for example, the timing to start motor stop processing. On the other hand, if the detection of the abnormality does not continue for a certain period of time or more, the control unit 310 does not confirm the abnormality, that is, does not stop the drive motor 320. Note that the abnormality includes at least one of the sensor abnormality detected by the abnormality detection unit 411, the calculation abnormality detected by the calculation abnormality detection unit 405, and the drive control abnormality detected by the drive control abnormality detection unit 407.

[0104] When an abnormality is detected, the setting unit 404 changes the mode at a timing before the abnormality is confirmed. In other words, even if the detection of an abnormality does not continue for a certain period of time or more, the setting unit 404 changes the mode at a stage where an abnormality is suspected.

[0105] FIG. 10 is a diagram showing a comparison example between the mode switching timing according to this embodiment and the conventional mode switching timing. The conventional mode switching is, for example, mode switching related to a general master-slave redundant system. In the conventional mode switching, as a system failure process, the failure is usually confirmed after an arbitrary time has elapsed after the failure is detected. Also, when the master side drive instruction system 300 detects a failure, the motor drive control of the master side drive instruction system 300 is stopped once as a normal process, and then the slave side is switched to the master. Note that, in FIG. 10, the explanation is given by taking the fail operation mode as an example, but the same applies to the fail-safe operation mode.

[0106] In FIG. 10, a time chart 1010 shows the conventional mode switching timing. Timing t1 is the timing when an abnormality is detected in the first drive instruction system 300a. Timing t2 is the abnormality confirmation timing when the abnormality is confirmed in the first drive instruction system 300a. Conventionally, the first drive instruction system 300a switches from the master mode to the slave mode at the abnormality confirmation timing t2. Also, the second drive instruction system 300b switches from the slave mode to the master mode at a timing t3 after the abnormality confirmation timing t2. For this reason, the drive motor 320 may be controlled with an inappropriate value until the mode is switched.

[0107] On the other hand, in Fig. 10, a time chart 1000 shows the timing of mode switching according to this embodiment. As shown in the time chart 1000, at timing t1, the first drive instruction system 300a switches from the master mode to the slave mode, and the second drive instruction system 300b switches from the slave mode to the master mode. This allows for rapid mode switching, making it possible to prevent the drive motor 320 from being controlled with an inappropriate value. If no abnormality is detected at abnormality determination timing t2 after the mode is switched, the switched mode may be returned to the original mode.

[0108] (Processing performed by the drive control device 240) Next, the processing performed by the drive control device 240 will be described with reference to FIGS.

[0109] (Fail operation mode processing) First, the process related to the fail-operation mode will be described with reference to FIG. Fig. 11 is a flowchart showing an example of processing related to the fail-operation mode. The processing in steps S1201 to S1207 in Fig. 11 will be described assuming that it is performed by the drive control system 300 set to the master mode at the start of this flowchart, and the processing in steps S1208 to S1214 will be described assuming that it is performed by the drive control system 300 set to the slave mode at the start of this flowchart.

[0110] 11, the drive instruction system 300 in the master mode judges whether or not a drive control abnormality has been detected by the drive control abnormality detection unit 407 (step S1201). If no drive control abnormality has been detected (step S1201: NO), the calculation unit 401 calculates the drive torque, and the distribution unit 402 distributes the drive torque to a first torque and a second torque (step S1202).

[0111] Then, the drive control unit 403 drives and controls the drive motor 320 with the first torque (step S1203). Moreover, the drive instruction system 300 in the master mode transmits the second torque to the other drive instruction systems 300 (step S1204). Furthermore, the communication unit 400 transmits the current mode of its own drive instruction system to the other drive instruction systems 300 and the angle control system 251 of the same channel (step S1205). Note that if there is no change in mode, the process of step S1205 may be omitted.

[0112] In step S1201, if a drive control abnormality is detected (step S1201: YES), the setting unit 404 sets the end mode (step S1206). Then, when the abnormality determination timing arrives, the drive control unit 403 stops the drive control of the drive motor 320 (step S1207), and proceeds to step S1205.

[0113] The drive instruction system 300 in the slave mode determines whether the other drive instruction systems 300 are set to the end mode (step S1208). If the other drive instruction systems 300 are not set to the end mode (step S1208: NO), the communication unit 400 receives the second torque from the other drive instruction systems 300 (step S1209). Then, the drive control unit 403 controls the drive of the drive motor 320 with the second torque (step S1210), and proceeds to step S1214.

[0114] In step S1208, if the other drive instruction systems 300 are set to the end mode (step S1208: YES), the setting unit 404 sets the master mode (step S1211). Then, the calculation unit 401 calculates the drive torque, and the reduction unit 410 reduces the drive torque to a third torque (step S1212).

[0115] Then, the drive control unit controls the drive of the drive motor 320 with the third torque degenerated by the degeneration unit 410 (step S1213). Next, the communication unit 400 transmits the current mode of its own system to the other drive instruction systems 300 and the angle control system 251 of the same channel (step S1214), and ends the series of processes. Note that if there is no change in mode, the process of step S1214 may be omitted.

[0116] (Fail-safe operation process) Next, the process related to the fail-safe operation mode will be described with reference to FIG. Fig. 12 is a flowchart showing an example of processing related to the fail-safe operation mode. The processing in steps S1301 to S1306 and the processing in steps S1314 to S1317 in Fig. 12 will be described assuming that they are performed by the drive control system 300 set to the master mode at the start of this flowchart, and the processing in steps S1307 to S1313 will be described assuming that they are performed by the drive control system 300 set to the slave mode at the start of this flowchart.

[0117] 12, the drive instruction system 300 in the master mode judges whether or not a calculation abnormality has been detected by the calculation abnormality detection unit 405 (step S1301). If a calculation abnormality is detected (step S1301: YES), the setting unit 404 sets the slave mode (step S1302) and proceeds to step S1306. Note that the setting of the slave mode is performed before the timing at which the calculation abnormality is confirmed.

[0118] On the other hand, if no calculation abnormality is detected in step S1301 (step S1301: NO), the calculation unit 401 calculates the driving torque, and the distribution unit 402 distributes the driving torque into a first torque and a second torque (step S1303).

[0119] Then, the drive control unit 403 drives and controls the drive motor 320 with the first torque (step S1304). The first drive instruction system 300a also transmits the second torque to the second drive instruction system 300b (step S1305). Furthermore, the communication unit 400 transmits the current mode of its own drive instruction system to the other drive instruction systems 300 and the angle control system 251 of the same channel (step S1306). Note that if there is no change in mode, the process of step S1306 may be omitted.

[0120] The drive instruction system 300 in the slave mode determines whether the other drive instruction systems 300 are set to the slave mode (step S1307). If the other drive instruction systems 300 are not set to the slave mode (step S1307: NO), the communication unit 400 receives the second torque from the other drive instruction systems 300 (step S1308). Then, the drive control unit 403 controls the drive of the drive motor 320 with the second torque (step S1309), and proceeds to step S1313.

[0121] In step S1307, if the other driving instruction system 300 is set to the slave mode (step S1307: YES), the setting unit 404 included in the driving instruction system sets the master mode (step S1310). Then, the calculation unit 401 included in the driving instruction system calculates the driving torque, and the distribution unit 402 distributes the driving torque to a first torque and a second torque (step S1311).

[0122] Then, the drive control unit 403 drives and controls the drive motor 320 with the first torque distributed by the distribution unit 402 of the drive instruction system (step S1312a). The drive instruction system 300 in the master mode transmits the second torque to the other drive instruction systems 300 (step S1312b). Next, the communication unit 400 transmits the current mode of the drive instruction system to the other drive instruction systems 300 and the angle control system 251 of the same channel (step S1313). Note that if there is no change in mode, the process of step S1313 may be omitted.

[0123] The driving instruction system 300 in the initial master mode judges whether the other driving instruction system 300 is set to the master mode (step S1314). If the other driving instruction system 300 is not set to the master mode (step S1314: NO), the driving instruction system 300 ends the process as it is. On the other hand, if the other driving instruction system 300 is set to the master mode (step S1314: YES), the driving instruction system 300 stops the calculation of the driving torque by the calculation unit 401 of the driving instruction system itself (step S1315). Then, the communication unit 400 receives the second torque calculated by the other driving instruction system 300 from the other driving instruction system 300 (step S1316). Next, the drive control unit 403 drives and controls the drive motor 320 with the second torque (step S1317), and ends the series of processes.

[0124] (Processing when another drive control system 300 mounted on another axle 120 changes mode) Fig. 13 is a flowchart showing an example of processing when another drive control system 300 mounted on another axle 120 changes modes. The processing of steps S1401 to S1407 in Fig. 13 will be described assuming that it is performed by the drive control system 300 set to the master mode at the start of this flowchart, and the processing of steps S1408 to S1414 will be described assuming that it is performed by the drive control system 300 set to the slave mode at the start of this flowchart. Also, in Fig. 13, processing related to the fail-safe operation mode will be described.

[0125] 13, the drive instruction system 300 in the master mode determines whether or not the mode command transmitted from the angle control device 250 is a slave mode command (step S1401). If the mode command is not a slave mode command (step S1401: NO), the calculation unit 401 calculates a drive torque, and the allocation unit 402 allocates the drive torque to a first torque and a second torque (step S1402).

[0126] Then, the drive control unit 403 drives and controls the drive motor 320 with the first torque (step S1403). Moreover, the drive instruction system 300 transmits the second torque to the other drive instruction systems 300 (step S1404). Furthermore, the communication unit 400 transmits the mode of its own drive instruction system to the other drive instruction systems 300 and the angle control system 251 of the same channel (step S1405).

[0127] In step S1401, if the mode command is a slave mode command (step S1401: YES), the setting unit 404 sets the slave mode (step S1406), and proceeds to step S1405. Note that the setting of the slave mode is performed before the timing of determining the abnormality of the calculation abnormality.

[0128] The drive instruction system 300 in the slave mode determines whether the conditions that the other drive instruction system 300 is set to the slave mode and the mode command is a master mode command are satisfied (step S1408). If the conditions are not satisfied (step S1408: NO), the communication unit 400 receives the second torque from the other drive instruction system 300 (step S1409). Then, the drive control unit 403 controls the drive of the drive motor 320 with the second torque (step S1410) and proceeds to step S1414.

[0129] In step S1408, if the condition is met (step S1408: YES), the setting unit 404 included in the self-driving command system sets the master mode (step S1411). Then, the calculation unit 401 included in the self-driving command system calculates the driving torque, and the degeneration unit 410 distributes the driving torque (step S1412).

[0130] Then, the drive control unit 403 drives and controls the drive motor 320 with the first torque (step S1413a). Furthermore, the drive instruction system 300 in the master mode transmits the second torque to the other drive instruction systems 300 (step S1413b). Next, the drive instruction system 300 transmits the mode of its own drive instruction system to the other drive instruction systems 300 and the angle control system 251 of the same channel (step S1414), and proceeds to step S1314 (steps S1314 to 1317) in FIG. 12, ending the series of processes.

[0131] As described above, the drive control device 240 according to this embodiment has a redundant configuration of the drive instruction systems 300, one drive instruction system 300 performs torque distribution processing, and each drive control unit 403 synchronously controls the drive motor 320 with the distributed torque. This prevents inconsistency in the control of the drive motor 320 between the drive instruction systems 300, and therefore the position control of the pitman arm 330 can be performed with high accuracy with a simple configuration and control. In addition, in this embodiment, the drive torque is distributed at a preset ratio, so that when the drive is operated with the torque, the torque estimated from the current value measured by the current sensor 313 of each drive instruction system 300 is compared with the drive torque after distribution, thereby making it possible to determine whether appropriate drive control is being performed. Therefore, the position control of the pitman arm 330 can be performed with high accuracy.

[0132] In the drive control device 240 according to this embodiment, the drive instruction system 300 is set to a master mode or a slave mode, and performs torque distribution processing in the master mode and does not perform torque distribution processing in the slave mode. As a result, even if the drive instruction system 300 in the master mode breaks down, the drive motor 320 can be synchronously controlled with the same drive torque as before by setting the drive instruction system 300 in the slave mode to the master mode. Therefore, even if one of the drive instruction systems 300 breaks down, inconsistencies in the control of the drive motor 320 between the drive instruction systems 300 can be suppressed, and the position control of the pitman arm 330 can be performed with high accuracy.

[0133] Furthermore, in the drive control device 240, each of the drive instruction systems 300 sets the slave mode when a calculation abnormality is detected by the calculation abnormality detection unit 405. This allows the drive instruction system 300 to not perform torque distribution processing when a calculation abnormality is detected. Therefore, it is possible to prevent erroneous calculation of drive torque or erroneous distribution of drive torque when a calculation abnormality is detected. Therefore, it is possible to prevent inconsistencies in the control of the drive motor 320 between the drive instruction systems 300.

[0134] Furthermore, in the drive control device 240, when each of the drive instruction systems 300 acquires calculation abnormality information, the master mode is set. This allows the drive instruction systems 300 without calculation abnormalities to perform torque distribution processing. Therefore, even if a calculation abnormality is detected in another drive instruction system 300, the drive motor 320 can be synchronously controlled with the same drive torque as before.

[0135] Furthermore, in the drive control device 240, each of the drive instruction systems 300 is set to an end mode when a drive control abnormality is detected. This allows the drive instruction system 300 to not control the drive of the drive motor 320 when a drive control abnormality is detected. This makes it possible to prevent erroneous drive control from being performed when a drive control abnormality is detected. This makes it possible to prevent inconsistencies in the control of the drive motor 320 between the drive instruction systems 300.

[0136] Furthermore, in the drive control device 240, when each of the drive instruction systems 300 acquires drive control abnormality information, it sets a degenerate mode, and in the degenerate mode, the allocation process by the allocation unit 402 is prohibited and the drive motor 320 is controlled with a third torque obtained by degenerating the drive torque. As a result, even if one drive instruction system 300 cannot perform drive control, the other drive instruction system 300 can control the drive motor 320 within a range of 50% to 80% of the drive torque.

[0137] Furthermore, in drive control device 240, each of drive instruction systems 300 detects a sensor abnormality based on the detection result of motor angle sensor 314 and the detection result of pitman arm angle sensor 315. This makes it possible to accurately detect a sensor abnormality using parts related to the position control of pitman arm 330 without adding additional components or the like.

[0138] In this embodiment, the motor angle sensor 314 is disposed concentrically with the output shaft of the drive motor 320. The drive motor 320 has a plurality of motor windings that are provided corresponding to the drive control unit 403 and are provided at a predetermined angle (30°) different from each other. The drive control unit 403 generates a control signal according to the difference in the predetermined angle (30°) to control the drive motor 320. This allows the output rotation directions to be aligned even in a configuration using a plurality of ECU boards 700, making it possible to perform simple control. Since the motor angle sensors 314 are on the same axis, the phase difference in each channel becomes clear, making it easy to detect failures related to the motor angle sensor 314 and the drive motor 320. Furthermore, since the channels of each drive instruction system 300 and the central axis of the drive motor 320 are aligned, it is possible to reduce errors between each drive instruction system 300. This improves the detection accuracy of the rotation angle of the drive motor 320, and allows the position control of the pitman arm 330 to be performed with high accuracy.

[0139] Furthermore, in the drive control device 240, when an abnormality is detected by the abnormality detection unit 411, the drive instruction system 300 changes the mode at a timing before the abnormality is confirmed. This allows for rapid mode switching, making it possible to prevent the drive motor 320 from being controlled with an inappropriate value.

[0140] Furthermore, in this embodiment, when the end mode is set, the drive control device 240 stops the supply of power to the drive motor 320 and disconnects the connection part 901 (FIG. 9) to which the end of the coil unit 810 (FIGS. 8 and 9) of the drive motor 320 is connected. This makes it possible to suppress the generation of back electromotive force at the start of the degenerate mode, thereby suppressing the generation of brake torque, and therefore making it possible to control the drive motor 320 with an appropriate torque.

[0141] In this embodiment, the drive control device 240 receives a mode command from the angle control device 250 according to the mode set in the angle control device 250, and sets the mode indicated by the mode command. This makes it possible to set a unified mode throughout the drive control system 200, thereby realizing simple control through cooperation.

[0142] In the above-described embodiments, the control units (angle control system 251, drive instruction system 300) and the functional units (communication unit 400, calculation unit 401, allocation unit 402, drive control unit 403, setting unit 404, calculation abnormality detection unit 405, calculation abnormality acquisition unit 406, drive control abnormality detection unit 407, drive control abnormality acquisition unit 408, disconnection unit 409, degeneration unit 410, abnormality detection unit 411) included in one computer device have been described. However, these may be included in other computer devices. For example, these may be included in an external server. Furthermore, the computer device in which these are included is not limited to one, and may be multiple. Specifically, for example, some of these functional units may be included in one computer device, and other functional units may be included in other computer devices.

[0143] The program for implementing the drive control device 240 described above may be stored in a computer-readable storage medium, and the program may be read into a computer system and executed. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. The term "computer-readable storage medium" refers to a portable medium such as a Universal Serial Bus (USB) flash memory, a solid state drive (SSD), a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, and a storage device such as a hard disk built into a computer system. The term "computer-readable storage medium" also refers to a storage device that holds a program for a certain period of time, such as a volatile memory (RAM) inside a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. The program may be transmitted from a computer system that stores the program in a storage device, etc., to another computer system via a transmission medium or by a transmission wave in the transmission medium. The "transmission medium" that transmits the program refers to a medium that has a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for implementing some of the functions described above, or may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already stored in the computer system.

[0144] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included.

[0145] In the embodiments disclosed in this specification, a device in which multiple functions are provided in a distributed manner may have some or all of the multiple functions integrated together, and conversely, a device in which multiple functions are provided in a distributed manner may have some or all of the multiple functions integrated together. Regardless of whether the functions are integrated or distributed, it is sufficient that the device is configured to achieve the object of the invention. [Explanation of symbols]

[0146] 100...vehicle, 120...axle, 200...drive control system, 230...steering actuator, 240...drive control device, 250...angle control device, 251a...first angle control system, 251b...second angle control system, 300a...first drive command system, 300b...second drive command system, 311a...first power supply circuit, 311b...second power supply circuit, 312a...first inverter circuit, 312b...second inverter circuit, 313a...first current sensor, 313b...second current sensor, 314a...first motor angle sensor, 314b...second motor angle sensor, 315a...first Pitman arm angle sensor, 315b...second pitman arm angle sensor, 320...drive motor, 330...pitman arm, 400a...first communication unit, 400b...second communication unit, 401a...first calculation unit, 401b...second calculation unit, 402a...first distribution unit, 402b...second distribution unit, 403a...first drive control unit, 403b...second drive control unit, 404a...first setting unit, 404b...second setting unit, 405...calculation abnormality detection unit, 406...calculation abnormality acquisition unit, 407...drive control abnormality detection unit, 408...drive control abnormality acquisition unit, 409...disconnection unit, 410...degeneration unit.

Claims

1. a communication unit for receiving a command relating to the position of the pitman arm from a higher-level device; an angle detection unit that detects an angle of the pitman arm; a calculation unit that calculates a drive torque for the pitman arm based on the command and an angle of the pitman arm; A distribution unit that distributes the driving torque according to a preset ratio; A drive control unit that controls the drive unit; A plurality of drive control systems each having One of the plurality of drive instruction systems performs a series of torque distribution processes including a calculation process by the calculation unit and a distribution process by the distribution unit, Each of the drive control units synchronously controls the drive units with the torque distributed by the torque distribution process. A drive control device comprising:

2. Each of the plurality of drive instruction systems has a setting unit that sets either a master mode in which the torque distribution process is performed or a slave mode in which the torque distribution process is not performed.

2. The drive control device according to claim 1 .

3. Each of the plurality of drive instruction systems has a calculation abnormality detection unit that detects a calculation abnormality indicating an abnormality that makes it impossible to perform the torque distribution process, the setting unit sets the slave mode when the calculation abnormality is detected by the calculation abnormality detection unit.

3. The drive control device according to claim 2.

4. Each of the plurality of drive instruction systems has a calculation abnormality acquisition unit that acquires calculation abnormality information indicating that the calculation abnormality has been detected in another system other than the own system, the setting unit sets the master mode when the calculation abnormality information is acquired by the calculation abnormality acquisition unit.

4. The drive control device according to claim 3.

5. Each of the plurality of drive instruction systems has a drive control abnormality detection unit that detects a drive control abnormality that indicates an abnormality in the drive control unit, The slave mode includes a termination mode in which the operation of the own system is terminated, the setting unit sets the mode to a termination mode when the drive control abnormality detection unit detects the drive control abnormality.

4. The drive control device according to claim 2 or 3.

6. Each of the plurality of drive instruction systems includes a drive control abnormality acquisition unit that acquires drive control abnormality information indicating that the drive control abnormality has been detected in another system other than the own system; a reduction unit that reduces the drive torque calculated by the calculation unit; having The master mode includes a degenerate mode. the setting unit sets a degenerate mode when the drive control abnormality acquisition unit acquires the drive control abnormality information; the degeneration unit, in a degeneration mode, prohibits the distribution process by the distribution unit and degenerates the drive torque to a third torque; In a degenerate mode, the drive control unit controls the drive unit with the third torque.

6. The drive control device according to claim 5.

7. Each of the drive instruction systems includes a rotation angle detection unit that detects a rotation angle of the drive unit; an abnormality detection unit that detects the occurrence of at least one of an abnormality in the rotation angle detection unit and an abnormality in the angle detection unit, based on the rotation angle detected by the rotation angle detection unit and the angle detected by the angle detection unit; The drive control device according to claim 5, further comprising:

8. the rotation angle detection unit is disposed concentrically with an output shaft of the drive unit, The drive unit has a plurality of motor windings provided corresponding to the drive control unit, respectively, and disposed at predetermined angles different from each other, Each of the drive control units generates a control signal according to the difference in the predetermined angle to control the drive unit.

8. The drive control device according to claim 7.

9. When the abnormality is detected by the abnormality detection unit, the setting unit changes the mode at a timing before the abnormality is determined. The drive control device according to claim 7.

10. The driving unit has a coil unit, Each of the plurality of drive instruction systems has a disconnection unit that stops the supply of power to the drive unit and disconnects a connection unit to which an end of the coil unit is connected when a termination mode is set. The drive control device according to claim 5.

11. the communication unit receives a mode command from the host device according to a mode set in the host device, The setting unit sets the mode indicated by the mode command.

4. The drive control device according to claim 2 or 3.

12. a communication unit for receiving a command relating to the position of the pitman arm from a higher-level device; an angle detection unit that detects an angle of the pitman arm; a calculation unit that calculates a drive torque for the pitman arm based on the command and an angle of the pitman arm; A distribution unit that distributes the driving torque according to a preset ratio; A drive control unit that controls the drive unit; A drive control method for a drive control device having a plurality of drive instruction systems each having One of the plurality of drive instruction systems performs a series of torque distribution processes including a calculation process by the calculation unit and a distribution process by the distribution unit, Each of the drive control units provided in the plurality of drive instruction systems synchronously controls the drive units with the torque distributed by the torque distribution process. A drive control method comprising:

13. a communication unit for receiving a command relating to the position of the pitman arm from a higher-level device; an angle detection unit that detects an angle of the pitman arm; a calculation unit that calculates a drive torque for the pitman arm based on the command and an angle of the pitman arm; A distribution unit that distributes the driving torque according to a preset ratio; A drive control unit that controls the drive unit; A program for causing a computer to function as a drive control device having a plurality of drive instruction systems each having causing one of the plurality of drive instruction systems to perform a series of torque distribution processes including a calculation process by the calculation unit and a distribution process by the distribution unit; causing each of the drive control units provided in the plurality of drive instruction systems to synchronously control the drive units with the torque distributed by the torque distribution process; A program characterized by:

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