Steering control system and steering control method

Abstract

To provide a steering control system capable of suppressing the occurrence of deviation in a utilization state set by each control device.SOLUTION: The PU grasps the presence or absence of an abnormality in each control device based on communication between the control devices (S14). When the PU itself is the transition master, the PU determines the utilization state that defines the control device to be utilized for operating the actuators according to the presence or absence of an abnormality (S18). Then, the PU of the transition master notifies the other control devices of the determined utilization state (S20). When the PU of the other control device receives the notified utilization state, the PU follows the utilization state.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a steering control system and a steering control method. [Background technology]

[0002] For example, Patent Document 1 listed below describes a steer-by-wire system in which power transmission between the steering shaft and the steered wheels is blocked. This system includes a reaction motor that applies a reaction force against the operation of the steering wheel, and a steering motor that steers the steered wheels. This system also has a redundant design with two control systems, each consisting of a control circuit for the reaction motor and a control circuit for the steering motor. This system is configured so that the control circuit used for control switches between specified operating modes depending on whether all control circuits are normal or whether an abnormality occurs in one of the control circuits. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-59527 Summary of the Invention [Problem to be solved by the invention]

[0004] However, after an abnormality occurs, the time it takes for each control circuit to detect the abnormality may vary, and this variation may result in discrepancies in the operating modes set by each control circuit. [Means for solving the problem]

[0005] The means for solving the above problems and their effects will be described below. 1. A steering control system comprising a reaction force actuator that applies a steering reaction force to the steering shaft and a steering actuator that steers the steered wheels when power transmission between the steering shaft and the steered wheels is interrupted, the system comprising two or more reaction force control devices whose operation targets are the reaction force actuators, and steering control devices whose operation targets are the reaction force control devices, respectively, and the system is configured to have a plurality of control systems including the reaction force control devices and the steering control devices, and to carry out the operation of the reaction force actuator and the steering actuator by the plurality of control systems, and each of the reaction force control devices and the steering control devices that constitute the plurality of control systems detects the presence or absence of an abnormality and then A steering control system configured to transmit detection results to other control devices and to be able to determine which of a plurality of utilization states should be set based on the detection results transmitted from the other control devices, the utilization state being a state identified by which control device contributes to the operation of the actuator, one of the reaction force control devices and the steering control devices that constitute a plurality of control systems being selectively set as a transition master, the transition master being configured to set the utilization state depending on which of the plurality of reaction force control devices and the plurality of steering control devices is abnormal, and control devices other than the transition master being configured to follow the utilization state set by the transition master.

[0006] In the above configuration, each control device is configured to be able to determine which of multiple utilization states it should set by obtaining the detection results of the other control devices for the presence or absence of an abnormality. In this case, if each control device sets the utilization state independently of the other control devices, differences in the utilization states set by each control device may occur due to differences in the execution timing of the process for setting the utilization state. Therefore, in the above configuration, one control device is set as the transition master and sets the utilization state. Then, control devices other than the transition master follow the utilization state set by the transition master. This makes it possible to prevent differences in the utilization states set by each control device.

[0007] 2. A steering control system as described in 1 above, wherein the plurality of control systems are comprised of one main control system and the remaining sub-control systems, and the sub-control systems are configured to operate the reaction force actuator and the steering actuator based on command values ​​calculated by the main control system as input variables, and the transition master belongs to the main control system.

[0008] In the above configuration, the sub-control system operates the actuator based on the command value calculated by the main control system. Since the transition master belongs to the main control system, it is possible to have a sense of unity in the control device that determines the control of the steering control system.

[0009] 3. A steering control system as described in 2 above, configured so that if an abnormality occurs in at least one of the reaction force control device and the steering control device in the main control system, one of the sub-control systems will switch over to the main control system.

[0010] In the above configuration, when an abnormality occurs in at least one of the reaction force control device and the steering control device of the main control system, the main control system is switched over, and thereby a control system in which both the reaction force control device and the steering control device are normal can be preferentially set as the main control system.

[0011] 4. A steering control system described in any one of 1 to 3 above, wherein in each of the plurality of control systems, the steering control device is configured to operate the steering actuator in accordance with a signal output by the reaction force control device, and the reaction force control device belonging to one of the plurality of control systems is configured to be set as the transition master.

[0012] In the above configuration, the steering control device operates the steering actuator in response to a signal output by the reaction force control device, so the reaction force control device has the initiative in determining the operation of the actuator. And because the reaction force control device is set as the transition master, it is possible to have a sense of unity among the control devices that have the initiative in control within the steering control system.

[0013] 5. A steering control system described in any one of 1 to 4 above, in which the reaction force control device and the steering control device belonging to the same control system are configured to be able to communicate with each other via a communication line, the reaction force control devices belonging to different control systems are configured to be able to communicate with each other via a communication line, and the steering control devices belonging to different control systems are configured to be able to communicate with each other via a communication line, and no communication line is provided to directly connect the reaction force control device belonging to one control system and the steering control device belonging to another control system.

[0014] In the above configuration, a reaction force control device belonging to one control system cannot directly communicate with a steering control device belonging to another control system. Therefore, a configuration such as that described above in 4, in which the steering control device operates the steering actuator based on a signal output by a reaction force control device in the same control system, is particularly suitable.

[0015] 6. A steering control method applied to a steering control system comprising a reaction force actuator that applies a steering reaction force to the steering shaft and a steering actuator that steers the steered wheels when power transmission between the steering shaft and the steered wheels is interrupted, wherein the steering control system comprises two or more reaction force control devices whose operation targets are the reaction force actuators, and steering control devices that correspond to each of the reaction force control devices and whose operation targets are the steering actuators, thereby comprising a plurality of control systems including the reaction force control devices and the steering control devices, and is configured to operate the reaction force actuator and the steering actuator using the plurality of control systems; Each of the reaction force control devices and the steering control devices that constitute a plurality of control systems is configured to detect the presence or absence of an abnormality and then transmit the detection result to other control devices, and is configured to be able to determine which of a plurality of utilization states to set based on the detection result transmitted from the other control devices, the utilization state being a state identified by which control device contributes to the operation of an actuator, and the steering control method includes selectively setting one of the reaction force control devices and the steering control devices that constitute a plurality of control systems as a transition master, having the transition master set the utilization state depending on which of the plurality of reaction force control devices and the plurality of steering control devices is abnormal, and having control devices other than the transition master follow the utilization state set by the transition master.

[0016] Each of the control devices is configured to determine which of multiple utilization states it should set by acquiring the results of detection of abnormalities by the other control devices. In this case, if each control device sets its utilization state independently of the other control devices, differences in the utilization states set by each control device may occur due to differences in the execution timing of the process for setting the utilization state. Therefore, in the above method, one control device is set as a transition master and the utilization state is set. Then, the control devices other than the transition master follow the utilization state set by the transition master. This prevents differences in the utilization states set by each control device. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a block diagram showing a configuration of a steering control system according to an embodiment. [Figure 2] 2 is a block diagram showing a process executed by the steering control system shown in FIG. 1. FIG. [Figure 3] FIG. 2 is a state transition diagram of the steering control system shown in FIG. [Figure 4] FIG. 2 is a state transition diagram of the steering control system shown in FIG. [Figure 5]FIG. 2 is a state transition diagram of the steering control system shown in FIG. [Figure 6] FIG. 2 is a state transition diagram of the steering control system shown in FIG. [Figure 7] FIG. 2 is a state transition diagram of the steering control system shown in FIG. [Figure 8] 2 is a flowchart showing the procedure of processing executed by each control device of the steering control system shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment will be described below with reference to the drawings. "Prerequisite configuration" FIG. 1 shows the configuration of a steering control system according to this embodiment. A steering wheel 10 is an operating unit through which a driver expresses his or her steering intention. A reaction force actuator Ar is configured to apply a reaction force that resists the driver's operation of the steering wheel 10. The reaction force actuator Ar includes a reaction force motor 12. The reaction force motor 12 includes a rotor 14, a stator coil 16(1) of a first control system, and a stator coil 16(2) of a second control system. As an example, the stator coils 16(1) and 16(2) have the same specifications. Furthermore, as an example, the stator coils 16(1) and 16(2) are symmetrical. Therefore, the magnetic flux of the magnet included in the rotor 14 equally interlinks both the stator coils 16(1) and 16(2). If the current flowing through stator coil 16(1) is equal to the current flowing through stator coil 16(2), the torque generated by energizing stator coil 16(1) is equal to the torque generated by energizing stator coil 16(2).

[0019] The numbers in parentheses for the stator coil 16(1) and the stator coil 16(2) are numbers for identifying the control systems. In the following, when referring to components of both the first control system and the second control system, the parentheses and the numbers in the parentheses will be omitted.

[0020] The configuration is such that the output voltage of inverter 18(i) is applied to stator coil 16(i) where "i=1, 2." Reaction force control device 20(i) includes PU 22 and storage device 24. Reaction force control device 20(i) is configured to control the control amount of the controlled object by having PU 22 execute a program stored in storage device 24.

[0021] The control target of the reaction force control device 20(i) is the steering wheel 10. The reaction force control device 20(i) operates the inverter 18(i) to control the reaction force applied to the steering wheel 10 as a control amount. To control the control amount, the reaction force control device 20(i) refers to the rotation angle θa(i) of the rotor 14 of the reaction force motor 12 detected by the rotation angle sensor 30(i). To control the control amount, the reaction force control device 20(i) also refers to the steering torque Th detected by the torque sensor 32. The steering torque Th is the torque applied to the steering wheel 10.

[0022] Power transmission between steerable wheels 40 and steering wheel 10 is cut off. Steerable wheels 40 are configured to be steered by steering actuator At. Steering actuator At includes steering motor 42. Steering motor 42 includes rotor 44, stator coil 46(1) of a first control system, and stator coil 46(2) of a second control system. Stator coil 46(1) and stator coil 46(2) are, for example, of the same specifications. Furthermore, stator coil 46(1) and stator coil 46(2) are, for example, symmetrical. Therefore, the magnetic flux of the magnet included in rotor 44 equally interlinks both stator coil 46(1) and stator coil 46(2). If the current flowing through stator coil 46(1) and the current flowing through stator coil 46(2) are equal, the torque generated by energizing stator coil 46(1) and the torque generated by energizing stator coil 46(2) are equal to each other.

[0023] The output voltage of inverter 48(i) is applied to stator coil 46(i). Steering control device 50(i) includes PU 52 and storage device 54. Steering control device 50(i) is configured to control the control amount of the controlled object by causing PU 52 to execute a program stored in storage device 54.

[0024] The control object of steering control device 50(i) is steered wheels 40. Steering control device 50(i) operates inverter 48(i) to control the steering angle of steered wheels 40 as a control variable. To control the control variable, steering control device 50(i) refers to rotation angle θb(i) of rotor 44 of steering motor 42 detected by rotation angle sensor 60(i). Steering control device 50(i) also refers to steering angle θs detected by steering sensor 62.

[0025] The reaction force control device 20(i) and the steering control device 50(i) of the i-th control system are capable of communicating with each other via an intra-system communication line Lc(i). Furthermore, the reaction force control device 20(1) of the first control system and the reaction force control device 20(2) of the second control system are capable of communicating with each other via a reaction force-side communication line Lms. Furthermore, the steering control device 50(1) of the first control system and the steering control device 50(2) of the second control system are capable of communicating with each other via a steering-side communication line Lmt.

[0026] "Steering control" Figure 2 shows some of the processes executed by the steering control system shown in Figure 1. Among the processes shown in Figure 2, the processes with the number (i) in parentheses are processes executed in the i-th control system.

[0027] "Processing Executed by the Reaction Force Control Device" Steering angle calculation process M10(i) is a process for calculating steering angle θh(i) based on rotation angle θa(i) as an input variable. Note that the steering angle θh calculated from the rotation angle θa(i) and the steering angle θs detected by steering sensor 62 are the same physical quantity. Target steering equivalent angle setting process M12(i) is a process for setting target steering equivalent angle θp*(i) based on steering angle θh(i) as an input variable. Target steering equivalent angle θp* is a target value of steering equivalent angle θp. Steering equivalent angle θp is a variable that indicates the steering angle of steered wheels 40. Target steering equivalent angle setting process M12(i) is a process for changing target steering equivalent angle θp*(i) in accordance with steering angle θh under the following conditions, for example: The condition is that the absolute value of the target equivalent steering angle θp* when the absolute value of the steering angle θh is large is equal to or greater than the absolute value of the target equivalent steering angle θp* when the absolute value of the steering angle θh is small.

[0028] In the description "changing B according to A while satisfying the condition that when A is large, B is equal to or greater than B when A is small," the case where A is large and the case where A is small refer to the relative relationship of magnitude when comparing the two. For example, "when A is large" corresponds to the case where "A is a first value," and "when A is small" corresponds to the case where "A is a second value smaller than the first value." Furthermore, the above description means that, depending on the settings of the first and second values, B when A is the first value may be larger than B when A is the second value. Furthermore, the above description means that B is changed according to A so that when B is large, A is larger than A when B is small.

[0029] The target steering torque setting process M14(i) is a process for setting a target steering torque Th*, which is a target value of the steering torque Th. The steering operation amount calculation process M16(i) is a process for calculating a target reaction torque Ts*(i) according to the operation amount of feedback control, in which the steering torque Th is the control amount. The selector M18(i) is a process for selectively outputting either the target reaction torque Ts*(1) or the target reaction torque Ts*(2).

[0030] The reaction force operation process M20(i) is a process for generating an operation signal MSs(i) for the inverter 18(i) so that the torque generated by the reaction force motor 12 by energizing the stator coil 16(i) approaches "1 / 2" of the target reaction force torque Ts*. As a result, the reaction force control device 20(1) operates the inverter 18(1) and the reaction force control device 20(2) operates the inverter 18(2), so that the torque of the reaction force motor 12 is controlled to be equivalent to the target reaction force torque Ts*.

[0031] "Processing Executed by the Steering Control Device" The steering equivalent angle calculation process M30(i) is a process for calculating a steering equivalent angle θp(i) based on the rotation angle θb(i) as an input variable.

[0032] The failure target value setting process M32(i) is a process that sets a target steering equivalent angle θp*(i) based on the steering angle θs as an input variable. The failure target value setting process M32(i) is a process that changes the target steering equivalent angle θp* in accordance with the steering angle θs, for example, under the following condition: The condition is that the absolute value of the target steering equivalent angle θp* when the absolute value of the steering angle θs is large is equal to or greater than the absolute value of the target steering equivalent angle θp* when the absolute value of the steering angle θs is small. Note that even if the values ​​of the input variables are equal to each other, the target steering equivalent angle θp* output by the failure target value setting process M32(i) does not have to be equal to the target steering equivalent angle θp* set by the target steering equivalent angle setting process M12(i).

[0033] The selector M34(i) is a process that selectively outputs either the target steering equivalent angle θp*(i) set by the target steering equivalent angle setting process M12(i) or the target steering equivalent angle θp*(i) set by the fail target value setting process M32(i). The value of the output variable of the selector M34(i) is, in principle, the target steering equivalent angle θp*(i) set by the target steering equivalent angle setting process M12(i).

[0034] Steering operation amount calculation process M36(i) is a process for calculating target steering torque Tt*(i) in accordance with the operation amount of feedback control in which the steering equivalent angle θp(i) is the control amount. Selector M38(i) is a process for selectively outputting either target steering torque Tt*(1) output by steering operation amount calculation process M36(1) or target steering torque Tt*(2) output by steering operation amount calculation process M36(2).

[0035] Steering operation process M40(i) is a process for generating operation signal MSt(i) for inverter 48(i) so that the torque generated in steering motor 42 by energizing stator coil 46(i) approaches "1 / 2" of target steering torque Tt*. As a result, steering control device 50(1) operates inverter 48(1) and steering control device 50(2) operates inverter 48(2), so that the torque of steering motor 42 is controlled to be equivalent to target steering torque Tt*.

[0036] "Main control system, sub-control system" In this embodiment, the first control system is generally set as the main control system. The main control system operates the actuator in accordance with a command value set by the main control system. On the other hand, the sub-control system operates the actuator in accordance with a command value set by the main control system. That is, when the first control system is the main control system, selector M18(i) outputs target reaction torque Ts*(1). Furthermore, reaction force control device 20(i) controls the torque generated by reaction motor 12 to approach "1 / 2" of target reaction torque Ts*(1) by energizing stator coil 16(i). Furthermore, when the first control system is the main control system, selector M38(i) outputs target turning torque Tt*(1). Furthermore, steering control device 50(i) controls the torque generated by turning motor 42 to approach "1 / 2" of target turning torque Tt*(1).

[0037] "Handling Abnormalities" The following describes the processing to be performed when an abnormality occurs in the steering control system. When an abnormality occurs, the operation of the actuator by the control device related to the abnormality is stopped. In other words, the control device used to operate the actuator is changed. Figures 3 to 7 show the transition of the utilization state of each control device depending on the abnormality. In Figures 3 to 7, the control system surrounded by a two-dot chain line is the main control system.

[0038] State 1 State 1 shown in Figure 3 is a state where no abnormality occurs. In state 1, reaction force control device 20(1) and steering control device 50(1) are surrounded by a two-dot chain line. That is, in state 1, the first control system is the main control system. Therefore, reaction force control device 20(2) operates inverter 18(2) in accordance with target reaction force torque Ts*(1) calculated by reaction force control device 20(1). Also, steering control device 50(2) operates inverter 48(2) in accordance with target turning torque Tt*(1) calculated by steering control device 50(1).

[0039] State 2 State 2 shown in FIG. 3 is a state in which the operation of steering actuator At by steering control device 50(2) of the second control system is stopped. State 2 is a state to which state 1 transitions when an abnormality occurs in the control by steering control device 50(2) of the second control system. Here, an abnormality in the control by reaction force control device 20 or steering control device 50 includes an abnormality in the control object, such as an inverter, as well as an abnormality in the control device itself. That is, the control device executes self-diagnosis processing, etc. Therefore, if the self-diagnosis result indicates an abnormality, it means that an abnormality has occurred in the control by the control device. Furthermore, the control device executes abnormality diagnosis processing for the control object, such as a broken wire in the inverter. Then, if an abnormality occurs in the control object, it determines that there is an abnormality in the control by the control device. Note that abnormalities in the control device also include abnormalities that the control device cannot recognize. For example, if an abnormality occurs in the power supply to steering control device 50(2), steering control device 50(2) itself may not be able to detect the abnormality. However, even in that case, the utilization state is set to state 2 in which the operation of steering actuator At is stopped.

[0040] In the second state, the first control system is the main control system. Therefore, reaction force control device 20(2) operates inverter 18(2) in accordance with target reaction force torque Ts*(1) calculated by reaction force control device 20(1). However, the operation of steering actuator At is performed solely by steering control device 50(1) of the first control system.

[0041] State 3 State 3 shown in Fig. 3 is a state in which the operation of the reaction force actuator Ar by the reaction force control device 20(2) of the second control system is stopped. State 3 is a state to which the system transitions when an abnormality occurs in the control by the reaction force control device 20(2) of the second control system or a communication abnormality occurs in the second control system in State 1. The communication abnormality may be, for example, a break in the intra-system communication line Lc(2) or a short circuit in the intra-system communication line Lc(2).

[0042] In the third state, the first control system is the main control system. Therefore, steering control device 50(2) operates inverter 48(2) in accordance with target steering torque Tt*(1) calculated by steering control device 50(2). However, operation of reaction force actuator Ar is performed solely by reaction force control device 20(1) of the first control system.

[0043] State 4 3 is a state in which the operation of the reaction force actuator Ar by the reaction force control device 20(1) of the first control system is stopped. The fourth state is a state to which the vehicle transitions when an abnormality occurs in the control by the reaction force control device 20(1) of the first control system or a communication abnormality occurs in the first control system in the first state.

[0044] In the fourth state, the second control system is the main control system. Therefore, steering control device 50(1) operates inverter 48(1) in accordance with target steering torque Tt*(2) calculated by steering control device 50(2). However, operation of reaction force actuator Ar is performed solely by reaction force control device 20(2) of the second control system.

[0045] State 5 State 5 shown in Fig. 3 is a state in which the operation of steering actuator At by steering control device 50(1) of the first control system is stopped. State 5 is a state to which the system transitions when an abnormality occurs in the control by steering control device 50(1) of the first control system in State 1.

[0046] In the fifth state, the second control system is the main control system. Therefore, reaction force control device 20(1) operates inverter 18(1) in accordance with target reaction force torque Ts*(2) calculated by reaction force control device 20(2). However, the operation of steering actuator At is performed solely by steering control device 50(2) of the second control system.

[0047] State 6 State 6 shown in Fig. 4 is a state in which the operation of the actuator by the second control system is stopped. State 6 can be a state to which a transition occurs when a further abnormality occurs in State 2 or State 3. That is, State 6 is a state to which a transition occurs when an abnormality occurs in the control by reaction force control device 20(2) in State 2. State 6 is also a state to which a transition occurs when an abnormality occurs in the control by steering control device 50(2) in State 3.

[0048] In the sixth state, the first control system is the main control system. However, the operation of reaction force actuator Ar is performed solely by reaction force control device 20(1) of the first control system. Also, the operation of steering actuator At is performed solely by steering control device 50(1) of the first control system.

[0049] State 7 State 7 shown in Fig. 5 is a state in which the operation of the actuator by the first control system is stopped. State 7 can be a state to which a transition occurs when a further abnormality occurs in State 4 or State 5. That is, State 7 is a state to which a transition occurs when an abnormality occurs in the control by steering control device 50(1) in State 4. State 7 is also a state to which a transition occurs when an abnormality occurs in the control by reaction force control device 20(1) in State 5.

[0050] In the seventh state, the second control system is the main control system. However, the operation of reaction force actuator Ar is performed solely by reaction force control device 20(2) of the second control system. Also, the operation of steering actuator At is performed solely by steering control device 50(2) of the second control system.

[0051] State 8 State 8 shown in FIG. 6 is a state in which the operation of reaction force actuator Ar and the operation of steering actuator At by steering control device 50(2) are stopped. State 8 can be a state to which a transition occurs when a further abnormality occurs in State 2 or State 4. That is, State 8 is a state to which a transition occurs when an abnormality occurs in the control by reaction force control device 20(1) or the communication of the first control system in State 2. State 8 is also a state to which a transition occurs when an abnormality occurs in at least one of the three, namely, the control by reaction force control device 20(2), the communication of the second control system, and the control by steering control device 50(2), in State 4.

[0052] In state 8, the first control system is the main control system. However, in state 8, operation of reaction force actuator Ar is stopped. Meanwhile, operation of steering actuator At is carried out solely by steering control device 50(1) of the first control system. At this time, steering control device 50(1) calculates target steering torque Tt*(1) in accordance with target steering equivalent angle θp* set by fail-time target value setting process M32(1).

[0053] State 9 State 9 shown in FIG. 7 is a state in which the operation of reaction force actuator Ar and the operation of steering actuator At by steering control device 50(1) are stopped. State 9 can be a state to which a transition occurs when a further abnormality occurs in State 3 or State 5. That is, State 9 is a state to which a transition occurs when an abnormality occurs in at least one of the three, namely, the control by reaction force control device 20(1), the communication of the first control system, and the control by steering control device 50(1), in State 3. State 9 is also a state to which a transition occurs when an abnormality occurs in at least one of the two, namely, the control by reaction force control device 20(2) and the communication of the second control system, in State 5.

[0054] In the ninth state, the second control system is the main control system. However, in state 9, operation of reaction force actuator Ar is stopped. Meanwhile, operation of steering actuator At is carried out solely by steering control device 50(2) of the second control system. At this time, steering control device 50(2) calculates target steering torque Tt*(2) in accordance with target steering equivalent angle θp* set by fail-time target value setting process M32(2).

[0055] "Determining utilization status" In this embodiment, each control device constituting the steering control system can grasp, through communication, whether or not there is an abnormality in the other control devices, and execute processing to determine which utilization state to transition to. In other words, reaction force control devices 20(1), 20(2) and turning control devices 50(1), 50(2) can grasp, through communication, whether or not there is an abnormality in the other control devices, and execute processing to determine which utilization state to transition to. However, the steering control system is configured so that the other control devices follow the utilization state determined by the control device that is the transition master.

[0056] In this embodiment, in principle, reaction force control device 20 of the main control system is set as the transition master. However, for states 8 and 9, steering control device 50 that operates steering actuator At is set as the transition master. Each control device is configured to determine whether or not it is the transition master in accordance with this rule.

[0057] "Utilization state transition processing" Figure 8 shows the procedure for the transition process of the utilization state. The series of processes shown in Figure 8 is realized by the PU 22 repeatedly executing a program stored in the storage device 24 at a predetermined cycle. The series of processes shown in Figure 8 is also realized by the PU 54 repeatedly executing a program stored in the storage device 54 at a predetermined cycle. In Figure 8, the step number of each process is represented by a number preceded by an S. Hereinafter, the subject of the process will be referred to as PU 22, 52.

[0058] In the series of processes shown in Fig. 8, PUs 22, 54 acquire the results of diagnosis of the presence or absence of an abnormality by other control devices in the system via intra-system communication line Lc(i) (S10). That is, for example, PU 22 of reaction force control device 20(i) acquires the results of diagnosis of the presence or absence of an abnormality in turning control device 50(i). Also, for example, PU 52 of turning control device 50(i) acquires the results of diagnosis of the presence or absence of an abnormality in reaction force control device 20(i). The process of S10 includes a process of acquiring the results of diagnosis of the presence or absence of an abnormality in communication by each control device via intra-system communication line Lc(i). That is, the process of S10 includes, for example, a process by PU 22 of reaction force control device 20(i) to acquire the results of diagnosis of the presence or absence of an abnormality in its own intra-system communication line Lc(i).

[0059] Furthermore, the PUs 22 and 52 acquire the diagnosis results of the presence or absence of abnormalities in the other control systems via the reaction force side communication line Lms or the turning side communication line Lmt (S12). That is, for example, the reaction force control device 20(1) acquires the self-diagnosis results of the reaction force control device 20(2) and the self-diagnosis results of the turning control device 50(2) acquired by the reaction force control device 20(2) through the processing of S10.

[0060] Next, the PU 22, 54 determines whether or not there is an abnormality in the steering control system based on the results obtained by the processing of S10 and S12 (S14). Then, the PU 22, 52 determines whether or not it is the transition master based on the result of the processing of S14 (S16). If it determines that it is the transition master (S16: YES), the PU 22, 52 sets the utilization state to the determined state by determining which of states 1 to 9 the utilization state should be (S18). More specifically, the PU 22, 52 updates the data indicating the utilization state stored in a predetermined storage area of ​​the storage device 24, 54. Then, the PU 22, 52 notifies the other control devices of the utilization state set in the processing of S18 (S20).

[0061] On the other hand, if the PU 22, 52 determines that it is not the transition master (S16: NO), it receives the utilization state notified by the transition master executing the process of S20 (S22). Then, the PU 22, 52 sets the utilization state to the state received by the process of S22 (S24). Specifically, the PU 22, 52 updates the data indicating the utilization state stored in a predetermined storage area of ​​the storage device 24, 54.

[0062] When the processes of S20 and S24 are completed, the PUs 22 and 52 temporarily end the series of processes shown in FIG. "Actions and Effects of the Present Embodiment" Each of the four control devices, reaction force control devices 20(1), 20(2) and steering control devices 50(1), 50(2), communicates with one another and detects abnormalities. Each control device is configured to be able to determine, based on the abnormality detection results, what utilization state should be in which to define the control device to be utilized for operating reaction force actuator Ar and steering actuator At. However, one of the four control devices is set as a transition master, and the transition master determines the utilization state. The control devices other than the transition master are configured to follow the utilization state set by the transition master. This makes it possible to prevent discrepancies between the utilization states set by each of the control devices.

[0063] According to the present embodiment described above, the following actions and effects can be further obtained. (1) The control device belonging to the main control system is set as the transition master. This allows for a sense of unity among the control devices that determine the control of the steering control system. In particular, commands generated by the control device of the main control system are used in the sub-control system. Therefore, by setting the control device of the main control system as the transition master, it is easier to quickly output command values ​​from the control device of the main control system to the control device of the sub-control system, compared to when the control device of the sub-control system is set as the transition master.

[0064] (2) When an abnormality occurs in at least one of the reaction force control device 20(1) and the turning control device 50(1) in the main control system, the sub-control system and the main control system are switched over. This allows the control system in which both the reaction force control device 20 and the turning control device 50 are normal to be preferentially set as the main control system.

[0065] (3) Reaction force control device 20 is configured to be set as the transition master. Steering control device 50 operates steering actuator At based on target steering equivalent angle θp* output by reaction force control device. Therefore, by setting reaction force control device 20 as the transition master, it is possible to provide a sense of unity to the control devices that have the initiative in control within the steering control system.

[0066] (4) Although the intra-system communication line Lc(i), reaction force side communication line Lms, and steering side communication line Lmt are provided, the system is configured not to include communication lines for direct communication between the reaction force control device 20 and the steering control device 50 of different control systems. In this case, the reaction force control device 20 belonging to one control system cannot communicate directly with the steering control device 50 belonging to another control system. For this reason, a configuration in which the reaction force control device 20(i) transmits the target steering equivalent angle θp*(i) to the steering control device 50(i) of the same system is particularly effective.

[0067] <Correspondence> The correspondence between the matters in the above embodiment and the matters described in the "Means for solving the problem" column is as follows. Below, the correspondence is shown for each number of the means for solving the problem described in the "Means for solving the problem" column. [1,6] The utilization state corresponds to states 1 to 9. The processing of the control devices other than the transition master corresponds to the processing of S10 to S16, S22, and S24. [2] The main control system corresponds to the control system surrounded by the dashed line in Figures 3 to 7. [3] Switching to the main control system corresponds to the transition from state 1 to state 4, from state 1 to state 5, etc. [4] Corresponds to the setting of the transition master in states 1 to 7. [5] Corresponds to the fact that the communication lines connecting the control devices are the intra-system communication line Lc(i), the reaction force side communication line Lms, and the steering side communication line Lmt.

[0068] <Other embodiments> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0069] "About Transition Masters" The transition master does not necessarily have to be the reaction force control device 20 of the main control system. For example, the transition master may be the turning control device 50 of the main control system. Furthermore, for example, the transition master may be set to appropriately switch between the reaction force control device 20 and the turning control device 50 in the main control system, whichever takes the shortest time to transmit the activation state to the other control devices. This can be achieved by setting the reaction force control device 20 as the transition master in states 2 and 5, and setting the turning control device 50 as the transition master in states 3 and 4. That is, for example, when the reaction force control device 20(1) executes the process of S20 in state 2, the signal indicating the activation state is transmitted directly to the reaction force control device 20(2) and the turning control device 50(1) without passing through the other control devices. On the other hand, when the reaction force control device 20(1) executes the process of S20 in state 3, the signal indicating the activation state is transmitted to the turning control device 50(2) via the turning control device 50(1). Therefore, it takes a long time for this signal to be transmitted to steering control device 50(2). Therefore, a configuration is made in which steering control device 50(1) is set as the transition master in state 3. As a result, when steering control device 50(1) executes the processing of S20, the signal indicating the utilization state is transmitted directly to reaction force control device 20(1) and steering control device 50(2) without passing through other control devices. Therefore, it is possible to shorten as much as possible the time required for the signal output by the processing of S20 to be transmitted to each control device.

[0070] "About the condition" If an abnormality occurs in reaction force control device 20(1) or a communication abnormality occurs in the first control system in state 3, it is not essential to transition to state 9. In that case, for example, the state may transition to state 8. Also, for example, the state may transition to a state in which steering actuator At is operated by both steering control devices 50(1), 50(2).

[0071] If an abnormality occurs in reaction force control device 20(2) or a communication abnormality occurs in the second control system in state 4, it is not essential to transition to state 8. In that case, for example, the state may transition to state 9. Also, for example, the state may transition to a state in which both steering control device 50(1) and steering control device 50(2) operate steering actuator At.

[0072] In state 2, if an abnormality occurs in the control by reaction force control device 20(1), it is not essential to transition to state 8. For example, a transition may be made to a state in which steering control device 50(1) operates steering actuator At and reaction force control device 20(2) operates reaction force actuator Ar. Also, in state 2, if an abnormality occurs in the communication of the first control system, it is not essential to transition to state 8. For example, a transition may be made to a state in which steering control device 50(1) operates steering actuator At and reaction force control device 20(2) operates reaction force actuator Ar. Also, for example, a transition may be made to a state in which steering control device 50(1) operates steering actuator At and reaction force control device 20(1) operates reaction force actuator Ar. In these cases, steering control device 50(i) operates steering actuator At in accordance with target steering equivalent angle θp*(i) set in fail-time target value setting process M32(i).

[0073] In state 5, if an abnormality occurs in the control by reaction force control device 20(2), it is not essential to transition to state 9. For example, a transition may be made to a state in which steering control device 50(2) operates steering actuator At and reaction force control device 20(1) operates reaction force actuator Ar. Also, in state 5, if an abnormality occurs in the communication of the second control system, it is not essential to transition to state 9. For example, a transition may be made to a state in which steering control device 50(2) operates steering actuator At and reaction force control device 20(1) operates reaction force actuator Ar. Also, for example, a transition may be made to a state in which steering control device 50(2) operates steering actuator At and reaction force control device 20(2) operates reaction force actuator Ar. In these cases, steering control device 50(i) operates steering actuator At in accordance with target steering equivalent angle θp*(i) set in fail-time target value setting process M32(i).

[0074] "About communication errors" For example, if an abnormality occurs in the intra-system communication line Lc(1) of the first control system, in addition to the operation of the reaction force actuator Ar by the reaction force control device 20(1), the operation of the turning actuator At by the turning control device 50(1) may be stopped. In other words, if an abnormality occurs in the intra-system communication line Lc(1) of the first control system in State 1, a transition to State 7 may be made.

[0075] If an abnormality occurs in communication with the main control system, the main control system may be switched and operation of the reaction force actuator Ar by the reaction force control device 20(i) of the main control system before the switch may be continued. That is, for example, if an abnormality occurs in communication with the first control system in state 1, the second control system may be set as the main control system without transitioning to state 4, and operation of the reaction force actuator Ar by the reaction force control device 20(1) may be continued.

[0076] For example, if an abnormality occurs in the intra-system communication line Lc(2) of the second control system, in addition to the operation of the reaction force actuator Ar by the reaction force control device 20(2), the operation of the turning actuator At by the turning control device 50(2) may be stopped. In other words, if an abnormality occurs in the intra-system communication line Lc(2) of the second control system in State 1, a transition to State 6 may be made.

[0077] If an abnormality occurs in the communication of the sub-control system, the operation of the reaction force actuator Ar by the reaction force control device 20(i) of the sub-control system may continue. That is, for example, if an abnormality occurs in the communication of the second control system in State 1, the operation of the reaction force actuator Ar by the reaction force control device 20(2) may continue without transitioning to State 3.

[0078] "About communication lines" The installation of the communication lines is not limited to that shown in Fig. 1. For example, a communication line may be provided that connects the reaction force control device 20 in one control system with the steering control device 50 in another control system.

[0079] "About the control system" The number of control systems is not limited to two. The number of control systems may be three or more. Specifically, for example, reaction force control devices 20(1) to 20(3) and turning control devices 50(1) to 50(3) may be provided. In that case, for example, if an abnormality occurs in reaction force control device 20(1), reaction force actuator Ar may be operated by reaction force control devices 20(2) and 20(3), and turning actuator At may be operated by turning control devices 50(1) to 50(3).

[0080] "Regarding the process for setting the target steering angle" It is not essential that reaction force control device 20(1) executes target steering equivalent angle setting process M12(1). For example, steering control device 50(1) may execute target steering equivalent angle setting process M12(1). In that case, reaction force control device 20(1) simply transmits steering angle θh(i) to steering control device 50(1).

[0081] It is not essential that the reaction force control device 20(2) executes the target steering equivalent angle setting process M12(2). For example, the steering control device 50(2) may execute the target steering equivalent angle setting process M12(2). In that case, the reaction force control device 20(2) only needs to transmit the steering angle θh(2) to the steering control device 50(2).

[0082] "About the steering operation amount calculation process" The steering operation amount calculation process does not necessarily have to be a process of calculating the target reaction torque Ts* based on the operation amount of feedback control in which the steering torque Th is the control amount. For example, it may be a process of calculating the target reaction torque Ts* in accordance with the assist torque calculated in accordance with the steering torque Th as an input variable.

[0083] "Input variables for the steering operation amount calculation process" It is not essential that the input variable of steering operation amount calculation process M36(i) when control by reaction force control device 20(i) is normal include a signal output by reaction force control device 20(i). The input variable of steering operation amount calculation process M36(i) may be, for example, the target steering equivalent angle θp*(i) set by failure target value setting process M32(i).

[0084] "About sensors" In the above embodiment, the first control system and the second control system are provided with separate rotation angle sensors 30(1), 30(2) for detecting the rotation angle of the reaction force motor 12, but this is not limiting. For example, a rotation angle sensor may be shared between the systems.

[0085] In the above embodiment, the first control system and the second control system are provided with separate rotation angle sensors 60(1), 60(2) that detect the rotation angle of the steering motor 42, but this is not limiting. For example, a rotation angle sensor may be shared between the systems.

[0086] In the above embodiment, the torque sensor 32 is shared between the first control system and the second control system, but this is not limitative. For example, a separate torque sensor may be provided for each control system. In the above embodiment, the steering sensor 62 is shared between the first control system and the second control system, but this is not limitative. For example, a separate steering sensor may be provided for each control system.

[0087] "About the reaction force actuator Ar" It is not essential that the reaction motor 12 provided in the reaction actuator Ar includes a stator coil 16 for each of the multiple control systems. For example, a separate reaction motor may be provided for each control system. Also, for example, one reaction motor may be configured for each of the multiple control systems. Specifically, for example, in the case of four control systems, one reaction motor may be shared between the first and second control systems, and another reaction motor may be shared between the third and fourth control systems. In this case, one reaction motor will include stator coils for two control systems.

[0088] It is not essential that the reaction force actuator Ar is configured so that the outputs controlled by each control system are equal to each other. For example, the rated output of the inverter 18(1) may be K (>1) times the rated output of the inverter 18(2). In that case, for example, the reaction force control device 20(1) may operate the inverter 18(2) in accordance with a value that is "K / (1+K)" times the target reaction force torque Ts*(1). Furthermore, the reaction force control device 20(2) may operate the inverter 18(2) in accordance with a value that is "1 / (1+K)" times the target reaction force torque Ts*(1).

[0089] "About the steering actuator At" It is not essential that steering motor 42 provided in steering actuator At be provided with stator coils 46 for each of the multiple control systems. For example, a separate steering motor may be provided for each control system. Also, for example, one steering motor may be configured for each of the multiple control systems. Specifically, for example, in the case of four control systems, one steering motor may be shared by the first control system and the second control system, and another steering motor may be shared by the third control system and the fourth control system. In that case, one steering motor will be provided with stator coils for the two control systems.

[0090] It is not essential that steering actuator At is configured so that the outputs controlled by each control system are equal to each other. For example, the rated output of inverter 48(1) may be K (>1) times the rated output of inverter 48(2). In that case, for example, steering control device 50(1) may operate inverter 48(2) in accordance with a value that is K / (1+K) times target steering torque Tt*(1). Also, steering control device 50(2) may operate inverter 48(2) in accordance with a value that is 1 / (1+K) times target steering torque Tt*(1). [Explanation of symbols]

[0091] 10...Steering wheel 12...Reaction motor 14...Rotor 16...Stator coil 18...Inverter 20...Reaction force control device 40...Steering wheel 42...Steering motor 44...Rotor 46...Stator coil 48...Inverter 50...Steering control device

Claims

1. A steering control system including a reaction force actuator that applies a steering reaction force to a steering shaft in a state where power transmission between a steering shaft and steered wheels is interrupted, and a steering actuator that steers the steered wheels, by providing two or more reaction force control devices, the reaction force actuator of which is an object to be operated, and a steering control device corresponding to each of the reaction force control devices and the steering actuator of which is an object to be operated, the vehicle is provided with a plurality of control systems, each including the reaction force control device and the steering control device; a plurality of control systems are configured to operate the reaction force actuator and the steering actuator; each of the reaction force control device and the steering control device constituting a plurality of control systems is configured to detect the presence or absence of an abnormality and then transmit the detection result to another control device, and is configured to be able to determine which of a plurality of utilization states should be set based on the detection result transmitted from the other control device; The utilization state is a state that is specified by which control device contributes to the operation of the actuator, one of the reaction force control device and the steering control device constituting a plurality of control systems is selectively set as a transition master, the transition master is configured to set the utilization state depending on which of the plurality of reaction force control devices and which of the plurality of steering control devices is abnormal, A steering control system in which control devices other than the transition master are configured to follow the utilization state set by the transition master.

2. The plurality of control systems include one main control system and the remaining sub-control systems, the sub-control system is configured to operate the reaction force actuator and the steering actuator based on a command value calculated by the main control system as an input variable, The steering control system according to claim 1 , wherein the transition master belongs to the main control system.

3. 3. A steering control system according to claim 2, wherein when an abnormality occurs in at least one of the reaction force control device and the steering control device in the main control system, one of the sub-control systems is switched to the main control system.

4. In each of the plurality of control systems, the turning control device is configured to operate the turning actuator in response to a signal output by the reaction force control device, 2. The steering control system according to claim 1, wherein the reaction force control device belonging to one of the plurality of control systems is set as the transition master.

5. the reaction force control device and the steering control device belonging to the same control system are configured to be able to communicate with each other via a communication line, the reaction force control devices belonging to different control systems are configured to be able to communicate with each other via a communication line, the steering control devices belonging to different control systems are configured to be able to communicate with each other via a communication line, 2. The steering control system according to claim 1, wherein there is no communication line directly connecting the reaction force control device belonging to one of the control systems and the turning control device belonging to another of the control systems.

6. A steering control method applied to a steering control system including a reaction force actuator that applies a steering reaction force to a steering shaft and a steering actuator that steers the steered wheels in a state where power transmission between the steering shaft and the steered wheels is interrupted, the method comprising: The steering control system includes: by providing two or more reaction force control devices, the reaction force actuator of which is an object to be operated, and a steering control device corresponding to each of the reaction force control devices and the steering actuator of which is an object to be operated, the vehicle is provided with a plurality of control systems, each including the reaction force control device and the steering control device; a plurality of control systems are configured to operate the reaction force actuator and the steering actuator; each of the reaction force control device and the steering control device constituting a plurality of control systems is configured to detect the presence or absence of an abnormality and then transmit the detection result to another control device, and is configured to be able to determine which of a plurality of utilization states should be set based on the detection result transmitted from the other control device; The utilization state is a state that is specified by which control device contributes to the operation of the actuator, The steering control method includes: Selectively setting one of the reaction force control device and the steering control device constituting a plurality of control systems as a transition master; causing the transition master to set the utilization state depending on which of the plurality of reaction force control devices and the plurality of steering control devices is abnormal; causing a control device other than the transition master to follow the utilization state set by the transition master.

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