JP5239245B2 - Vehicle steering control device - Google Patents

Description

  The present invention relates to a vehicle steering control device employing a so-called steer-by-wire system in which a steering mechanism and a handle are mechanically separated.

  In a conventional steer-by-wire (SBW) system, when the system is operating normally, steering torque is applied to the front wheels according to the steering state of the steering wheel, and to the steering wheel according to the steering state of the front wheels. SBW control that applies steering reaction torque is performed.

If a system abnormality is diagnosed during this SBW control, the system switches from SBW control to backup control that engages the backup clutch and mechanically connects the steering mechanism and the steering wheel. The driver can steer. When it is diagnosed as normal during the backup control, the backup clutch is released to return to the SBW control (see, for example, Patent Document 1).
JP 2002-145098 A

  However, in the above prior art, even if the system abnormality is not temporary but continuous, it can return to SBW control if it is misdiagnosed as normal during backup control. There was sex. Therefore, once a system abnormality is diagnosed, the temporary abnormality has been resolved if the system is configured to prohibit the return to SBW control regardless of the diagnosis result. Even in this case, it is not possible to return to SBW control.

  The present invention has been made paying attention to the above-mentioned problem, and the object of the present invention is from backup control to steer-by-wire due to a misdiagnosis as normal even though a continuous abnormality has occurred. An object of the present invention is to provide a vehicle steering control device capable of returning to steer-by-wire control when a temporary abnormality is solved while preventing return to control.

In order to achieve the above-described object, the present invention diagnoses a temporary failure that is a temporary failure of the system and a definite failure that is a continuous failure of the system, and performs steer-by-wire control. When it is diagnosed as a temporary failure, it shifts to the backup control . When it is diagnosed that the temporary failure has been resolved during the backup control, it returns to the steer-by-wire control, while the steer-by-wire control. When a confirmed failure is diagnosed during execution of control, the system shifts to backup control, and backup control is continued even if it is diagnosed that the confirmed failure has been resolved during backup control. And

In the present invention, when it is diagnosed that there is a temporary failure, the process shifts to the backup control, and when it is diagnosed that the temporary failure has been resolved during the backup control, the backup control performs the steer-by-wire. Return to control. On the other hand, if it is diagnosed as a definite failure, it shifts to backup control, and even if it is determined that the definite failure has been resolved during backup control, it shifts to steer-by-wire control. However, backup control is continued.
As a result, even though a definite failure, which is a continuous abnormality, has occurred, a temporary abnormality is prevented while preventing a return from backup control to steer-by-wire control due to a false diagnosis of normality. If the transient faults has been eliminated is can and Turkey improve the reliability of the system as possible to return to steer-by-wire control.

  Hereinafter, the best mode for carrying out the present invention will be described based on Examples 1 to 3.

First, the configuration will be described.
FIG. 1 is a configuration diagram of a steer-by-wire (SBW) system according to a first embodiment to which the vehicle steering control device of the present invention is applied.

In the SBW system of the first embodiment, the steering mechanism 2 that steers the left and right front wheels 1a and 1b, which are steered wheels, and the handle 3 that is operated by the driver are mechanically separated.
The pinion shaft 4 of the steering mechanism 2 detects a steering actuator (steering motor) 5 that applies a steering torque to the steering mechanism 2 and a rack axial force that acts on the rack shaft 2 a of the steering mechanism 2. Axial force sensors 6a and 6b are provided.

  A column shaft 7 to which the handle 3 is attached is provided with a reaction force actuator (reaction motor) 8 for applying a reaction force torque to the handle 3 and a torque sensor 9 for detecting a steering torque. Further, a backup clutch (hereinafter referred to as a clutch) 10 is interposed between the column shaft 7 and the pinion shaft 4 as backup means that enables mechanical separation / connection of the two by opening and fastening.

  The turning motor 5 is controlled by a turning control controller (steering control means) 11, and the reaction force motor 8 is controlled by a reaction force control controller (reaction force control means) 12. Both controllers 11 and 12 perform mutual transmission of information through the mutual communication line 13.

FIG. 2 is a control block diagram of the first embodiment.
The turning control controller 11 includes a turning control unit 11a and a failure diagnosis unit (abnormality diagnosis unit) 11b. The steered control unit 11 a sets a target steered angle based on the steering angle of the steering wheel 3, the vehicle speed, and the like obtained from the rotational angle of the reaction force motor 8, and the actual wheels 1 a and 1 b obtained from the rotational angle of the steered motor 5. Steering control for servo-controlling the steered motor 5 is performed so that the steered angle becomes the target steered angle.

  The failure diagnosis unit 11b diagnoses a temporary failure that is a temporary failure of the steering control system and a fixed failure that is a permanent failure with respect to the temporary failure. The turning control unit 11a stops the turning control when the failure diagnosis unit 11b diagnoses that a failure has occurred in the turning control system.

  The reaction force control controller 12 includes a reaction force control unit 12a, a failure diagnosis unit (abnormality diagnosis unit) 12b, and a clutch control unit 12c. The reaction force control unit 12a sets a target steering reaction force torque based on the actual turning angle of the front wheels 1a and 1b, the rack axial force detected by the axial force sensors 6a and 6b, the vehicle speed, and the like, and is detected by the torque sensor 9. Reaction force control is performed to servo-control the reaction force motor 8 so that the steering torque thus obtained becomes the target steering reaction force torque.

  The failure diagnosis unit 12b diagnoses a temporary failure that is a temporary failure of the reaction force control system and a definite failure that is a permanent failure with respect to the temporary failure. The reaction force control unit 12a stops the reaction force control when the failure diagnosis unit 12b diagnoses that a failure has occurred in the reaction force control system. When it is diagnosed by the failure diagnosis units 11b and 12b that a failure has occurred in the steering control system or the reaction force control system, the clutch control unit 12c outputs an engagement command (connection command) to the clutch 12, and the failure is detected. When it is diagnosed that no occurrence has occurred, a release command is output to the clutch 12.

  Here, examples of the temporary failure in the steering control system include a failure of the mutual communication line 13, a failure of the rotation angle sensor of the steering motor, a failure of the current sensor, a failure of the temperature sensor, a voltage drop, and the like. Alternatively, as a concept of temporary failure, depending on the time from the occurrence of the failure, it is possible to treat less than a certain time as a temporary failure and treat as a definite failure when a certain time is exceeded.

  As an example of a temporary failure in the reaction force control system, a failure in the axial force sensors 6a and 6b for measuring the axial force of the tire, a failure in the mutual communication line 13, a failure in the rotation angle sensor in the reaction force motor, a current sensor Failure, temperature sensor failure, voltage drop, etc. Alternatively, as a concept of temporary failure, depending on the time from the occurrence of the failure, it is possible to treat less than a certain time as a temporary failure and treat as a definite failure when a certain time is exceeded.

  In the first embodiment, the steering mechanism 2 and the handle 3 are mechanically separated from each other by the steering control controller 11 and the reaction force controller 12 when the abnormality diagnosis units 11b and 12b diagnose the system as normal. The steering motor 5 is driven so that the front wheels 1 a and 1 b are steered according to the steering state 3, and the reaction force motor 8 is adapted so as to be a steering reaction force according to the steered state of the steering mechanism 2. SBW control (steering control + reaction force control) for driving the steering wheel, and when the system is diagnosed as abnormal, a steering control means for performing backup control for mechanically connecting the steering mechanism 2 and the handle 3 is configured. The

Next, the operation when each failure occurs in the SBW system of the first embodiment will be described.
[When a failure occurs in the steering control system]
(a) Temporary failure When a temporary failure occurs in the steering control system, the steering control is stopped, the clutch 10 is engaged, the reaction force control is stopped, and the backup mode (the mode in which backup control is executed). To manual steer. Thereafter, when the failure diagnosis result of the steering control system returns to normal, the steering control and the reaction force control are resumed, and the clutch 10 is released to return to the SBW mode (mode for executing SBW control). .

(b) Fixed failure When a fixed failure occurs in the steering control system, the steering control is stopped, the clutch 10 is engaged, and the reaction force control is stopped to shift to manual steering as the backup mode. Here, manual steering refers to turning the front wheels 1a and 1b only with the steering force of the driver. Thereafter, even when the failure diagnosis result of the steering control system returns to normal, the manual steer backup mode is maintained.

[When a failure occurs in the reaction force control system]
(a) Temporary failure When a temporary failure occurs in the reaction force control system, the clutch 10 is engaged and the reaction force control is stopped, whereby power assist control by the steered motor 5 is performed as a backup mode. Here, the power assist control refers to control that assists the driver's steering force by driving the actuator in accordance with the steering load of the front wheels 1a and 1b. Thereafter, when the failure diagnosis result of the reaction force control system returns to normal, the reaction force control is resumed and the clutch 10 is released to return to the SBW mode.

(b) Definite failure When a definite failure occurs in the reaction force control system, the clutch 10 is engaged and the reaction force control is stopped, so that the power assist control by the steered motor 5 is performed as a backup mode. Thereafter, even when the failure diagnosis result of the reaction force control system returns to normal, the backup mode of the power assist control by the steered motor 5 is maintained.

  Here, it is configured so that an engagement command for the clutch 10 is output in conjunction with an abnormality when the reaction force controller 12 is turned off. As a result, even when the clutch control unit 12c of the reaction force control controller 12 cannot issue an engagement command, such as when the power of the reaction force control controller 12 is turned off during the control in the SBW mode, The clutch 10 can be engaged to shift to the backup mode.

  As described above, in the SBW system according to the first embodiment, when it is diagnosed that a temporary failure has occurred, if it is subsequently diagnosed that the temporary failure has been resolved, it is possible to return from backup control to SBW control. Therefore, even when the temporary failure has actually been solved, or when it is erroneously diagnosed as a temporary failure, it is possible to prevent the steering performance from being deteriorated by continuing the backup control.

  On the other hand, if it is diagnosed that a confirmed failure has occurred, then even if it is determined that the confirmed failure has been resolved, SBW control will not be entered and backup control will continue. The possibility that the backup control is canceled due to an erroneous determination of normality despite the occurrence of a continuous abnormality that cannot be resolved can be suppressed.

  In the first embodiment, the clutch 10 connects the steering mechanism 2 and the handle 3 in response to a connection command from the reaction force controller 12. In other words, when it is determined that the reaction force control system has failed, it is necessary to stop the reaction force control and shift to the backup mode. 10 can be fastened to shift to the backup mode.

Next, the effect will be described.
The SBW system according to the first embodiment has the following effects.

  (1) The failure diagnosis units 11b and 12b diagnose a temporary failure that is a temporary failure of the system and a definite failure that is a continuous failure of the system, respectively, and steering control means (the steering control controller 11 and the counter failure). The force controller 12) shifts to backup control when it is diagnosed as a temporary failure during execution of SBW control, and then returns to SBW control when it is diagnosed that the temporary failure has been resolved. On the other hand, if a confirmed failure is diagnosed during execution of the SBW control, then the backup control is continued even if it is diagnosed that the confirmed failure has been resolved. This prevents a temporary failure that is a temporary abnormality while preventing a return from the backup control to the SBW control due to a misdiagnosis that is normal even though a definite failure that is a continuous abnormality has occurred. When this is resolved, it is possible to return to SBW control.

  (2) Since the clutch 10 is engaged when the power supply to the reaction force controller 12 is stopped, the backup mode is activated even when the reaction force controller 12 cannot output an engagement command to the clutch 10. Can be moved to.

  (3) Since the clutch 10 connects the steering mechanism 2 and the handle 3 in accordance with an engagement command from the reaction force control controller 12, the clutch 10 can be reliably and immediately engaged and shifted to the backup mode. .

The second embodiment is an example in which the steering control system is a dual system.
FIG. 3 is a configuration diagram of the SBW system according to the second embodiment. In the second embodiment, the steering motor 5A includes two steering motors 5A and 5B and two steering control controllers 11A and 11B. The steered motor 5B is controlled by the steered control controller 11B.

  In the second embodiment, the control blocks of the two steering control controllers 11A and 11B and the reaction force control controller 12 are the same as those in the first embodiment shown in FIG. 11B and the reaction force control controller 12 perform mutual monitoring. For example, the failure diagnosis units 11b and 11b of the steering control controllers 11A and 11B monitor the calculation results of the reaction force control unit 12a of the reaction force control controller 12. When the reaction force control unit 12a is diagnosed as abnormal, a stop signal is sent by the mutual diagnosis execution lines (signal lines) 14A and 14B connected from the steering control controllers 11A and 11B to the reaction force control controller 12 to diagnose the failure. When both parts 11b and 11b diagnose an abnormality, the control of the reaction force controller 12 is forcibly stopped and the clutch 10 is engaged. To.

  The results of the mutual diagnosis execution lines 14A and 14B are held as a definite fault. For example, a diagnosis result can be held by providing a latch circuit (holding means) (not shown) at the input part of the mutual diagnosis execution line 14.

  In FIG. 3, only the example in which the mutual diagnosis execution lines 14A and 14B are provided from the steering control controllers 11A and 11B to the reaction force controller 12 is shown for the sake of simplicity. 14A and 14B are respectively arranged from the other two controllers toward one control controller. In addition, a latch circuit that holds a definite failure is also provided for each controller.

  In the second embodiment, unlike the first embodiment, during the normal SBW control, the two steering motors 5A and 5B are driven to perform the steering control, and the reaction force motor 8 is driven to generate the road surface reaction force. If one of the steering control systems fails, the clutch 10 is engaged and the SBW mode is continued with one normal steering control system and reaction force control system without shifting to the backup mode. Is possible.

[Control mode switching process]
4 to 6 are flowcharts showing the flow of the control motor switching process executed by the steering control controllers 11A and 11B and the reaction force control controller 12 according to the second embodiment. Each step will be described below.

  First, in step S1, the SBW mode is executed by the two steered motors 11A and 11B and the reaction force motor 8, and the process proceeds to step S2.

  In step S2, abnormality of the reaction force control system is diagnosed. When it is diagnosed as normal, the process proceeds to step S3, and when it is diagnosed as abnormal, the process proceeds to step S21.

  In step S3, abnormality of the steering control system 1 is diagnosed. When it is diagnosed as normal, the process proceeds to step S1, when it is diagnosed as a temporary failure, the process proceeds to step S4, and when it is diagnosed as a definite abnormality, the process proceeds to step S12.

  In step S4, the steered motor 11A is stopped, SBW control is executed by the steered motor 11B and the reaction force motor 8, and the process proceeds to step S5.

  In step S5, it is determined whether or not the diagnosis of the steering control system 1 has returned to normal from the abnormality. If YES, the process proceeds to step S1, and if NO, the process proceeds to step S6.

  In step S6, an abnormality in the reaction force control system is diagnosed. When it is diagnosed as normal, the process proceeds to step S7, and when it is diagnosed as abnormal, the process proceeds to step S41.

  In step S7, abnormality of the steering control system 2 is diagnosed. When it is diagnosed as normal, the process proceeds to step S4. When it is diagnosed as a temporary failure, the process proceeds to step S8. When it is diagnosed as a definite failure, the process proceeds to step S10.

  In step S8, the steering control and the reaction force control are stopped, the clutch 10 is engaged, manual steering is executed as the backup mode, and the process proceeds to step S9.

  In step S9, it is determined whether or not the diagnosis of the steering control system 2 has returned to normal from the abnormality. If YES, the process proceeds to step S4. If NO, the process proceeds to step S8.

  In step S10, the definite failure of the steering control system 2 is held in the latch circuit in the steering control controller 11B, and the process proceeds to step S11.

  In step S11, the steering control and the reaction force control are stopped, the clutch 10 is engaged, manual steering is executed as a backup mode, and the process returns to return.

  In step S12, the definite failure of the steering control system 1 is held in the latch circuit in the steering control controller 11A, and the process proceeds to step S13.

  In step S13, the steered motor 11A is stopped, SBW control is executed by the steered motor 11B and the reaction force motor 8, and the process proceeds to step S14.

  In step S14, an abnormality in the reaction force control system is diagnosed. When it is diagnosed as normal, the process proceeds to step S15, and when it is diagnosed as abnormal, the process proceeds to step S41.

  In step S15, abnormality of the steering control system 2 is diagnosed. When it is diagnosed as normal, the process proceeds to step S13, when it is diagnosed as a temporary failure, the process proceeds to step S16, and when it is diagnosed as a definite failure, the process proceeds to step S18.

  In step S16, the steering control and the reaction force control are stopped, the clutch 10 is engaged, manual steering is executed as the backup mode, and the process proceeds to step S17.

  In step S17, it is determined whether or not the diagnosis of the steering control system 2 has returned to normal from the abnormality. If YES, the process proceeds to step S13. If NO, the process proceeds to step S16.

  In step S18, the definite failure of the steering control system 2 is held in the latch circuit in the steering control controller 11B, and the process proceeds to step S19.

  In step S19, the steering control and the reaction force control are stopped, the clutch 10 is engaged, the manual steer is executed as the backup mode, and the process returns to the return.

  In step S21, it is determined whether the abnormality in the reaction force control system is a temporary failure or a definite failure. If it is diagnosed that it is a temporary failure, the process proceeds to step S22, and if it is diagnosed that it is a definite failure, the process proceeds to step S29.

  In step S22, the reaction force motor 8 is stopped, the clutch 10 is engaged, power assist control is executed as a backup mode by the two steered motors 5A and 5B, and the process proceeds to step S23.

  In step S23, it is determined whether the diagnosis of the reaction force control system has returned to normal from the abnormality. If YES, the process proceeds to step S1, and if NO, the process proceeds to step S24.

  In step S24, abnormality of the steering control system 1 is diagnosed. When it is diagnosed as normal, the process proceeds to step S22, when it is diagnosed as a temporary failure, the process proceeds to step S25, and when it is diagnosed as a definite failure, the process proceeds to step S27.

  In step S25, the steering motor 5A is stopped, the power assist control is continued by the steering motor 5B, and the process proceeds to step S26.

  In step S26, it is determined whether or not the diagnosis of the steering control system 1 has returned to normal from the abnormality. If YES, the process proceeds to step S22. If NO, the process proceeds to step S23.

  In step S27, the definite failure of the steering control system 1 is held in the latch circuit in the steering control controller 11A, and the process proceeds to step S28.

  In step S28, the steering motor 5A is stopped, the power assist control is continued by the steering motor 5B, and the process proceeds to step S23.

  In step S29, the reaction force control controller 12 holds the confirmed failure of the reaction force control system in the latch circuit, and the process proceeds to step S30.

  In step S30, the reaction force motor 8 is stopped, the clutch 10 is engaged, power assist control is executed as a backup mode by the two steered motors 5A and 5B, and the process proceeds to step S31.

  In step S31, abnormality of the steering control system 1 is diagnosed. If it is diagnosed as normal, the process proceeds to step S30. If it is diagnosed as a temporary failure, the process proceeds to step S32. If it is diagnosed as a confirmed failure, the process proceeds to step S34.

  In step S32, the steering motor 5A is stopped, the power assist control is continued by the steering motor 5B, and the process proceeds to step S33.

  In step S33, it is determined whether or not the diagnosis of the steering control system 1 has returned to normal from the abnormality. If yes, then continue with step S30, otherwise continue with return.

  In step S34, the definite failure of the steering control system 1 is held in the latch circuit in the steering controller 11A, and the process proceeds to step S35.

  In step S35, the steered motor 5A is stopped, the power assist control is continued by the steered motor 5B, and a return is made.

  In step S41, it is determined whether the abnormality in the reaction force control system is a temporary failure or a definite failure. If it is diagnosed as a temporary failure, the process proceeds to step S42, and if it is diagnosed as a definite failure, the process proceeds to step S49.

  In step S42, the steered motor 5A and the reaction force motor 8 are stopped and the clutch 10 is engaged. The power assist control is executed as a backup mode by the steered motor 5B, and the process proceeds to step S43.

  In step S43, it is determined whether or not the reaction force control system diagnosis has returned to normal from the abnormality. If YES, the process proceeds to step S4 (or step S13), and if NO, the process proceeds to step S44.

  In step S44, abnormality of the steering control system 2 is diagnosed. When it is diagnosed as normal, the process proceeds to step S42, when it is diagnosed as a temporary failure, the process proceeds to step S45, and when it is diagnosed as a definite failure, the process proceeds to step S47.

  In step S45, the steering motor 5B is stopped, manual steering is performed, and the process proceeds to step S46.

  In step S46, it is determined whether or not the diagnosis of the steering control system 1 has returned to normal from the abnormality. If YES, the process proceeds to step S42, and if NO, the process proceeds to step S43.

  In step S47, the definite failure of the steered control system 2 is held in the latch circuit in the steered control controller 11B, and the process proceeds to step S48.

  In step S48, the steering motor 5B is stopped, manual steering is performed, and the process proceeds to step S43.

  In step S49, the reaction force control controller 12 holds the confirmed failure of the reaction force control system in the latch circuit, and the process proceeds to step S50.

  In step S50, the steering motor 5A and the reaction force motor 8 are stopped, the clutch 10 is engaged, power assist control is executed as a backup mode by the steering motor 5B, and the process proceeds to step S51.

  In step S51, abnormality of the steering control system 2 is diagnosed. When it is diagnosed as normal, the process proceeds to step S50, when it is diagnosed as a temporary failure, the process proceeds to step S52, and when it is diagnosed as a definite failure, the process proceeds to step S54.

  In step S52, the steering motor 5B is stopped, manual steering is performed, and the process proceeds to step S53.

  In step S53, it is determined whether or not the diagnosis of the steering control system 1 has returned to normal from the abnormality. If YES, the process proceeds to step S50, and if NO, the process proceeds to return.

  In step S54, the definite failure of the steering control system 2 is held in the latch circuit in the steering control controller 11B, and the process proceeds to step S55.

  In step S55, the steering motor 5B is stopped, manual steering is performed, and the process proceeds to return.

Next, the operation at the time of failure occurrence in the SBW system of the second embodiment will be described.
[When a failure occurs in the reaction force control system]
(a) Temporary failure When a temporary failure occurs in the reaction force control system, the flow proceeds to step S1, step S2, step S21, step S22 in the flowcharts of FIGS. 10 is fastened, and a transition is made to a backup mode in which power assist control is performed by the steering control system 1 (control system related to the steering control controller 11A) and the steering control system 2 (control system related to the steering control controller 11B). Thereafter, when the failure diagnosis result of the reaction force control system returns to normal, the process proceeds from step S23 to step S1, the reaction force control is resumed, and the clutch 10 is released to return to the SBW mode.

(b) Deterministic failure When a definite failure occurs in the reaction force control system, the process proceeds from step S1, step S2, step S21, step S29, step S30, and the reaction force control is stopped and the clutch 10 is engaged at the same time. At the same time as the shift to the backup mode in which the power assist control is performed by the rudder control system 1 and the steering control system 2, the abnormality diagnosis result is latched in the latch circuit of the reaction force control controller 12. Thereafter, since the diagnosis result of the reaction force control system is maintained as a definite failure, the backup mode is maintained.

[When a failure occurs in the steering control system]
(First failure)
(a) Temporary failure If a temporary failure occurs in the steering control system, proceed to step S1, step S2, step S3, step S4, stop the steering control system where the abnormality occurred, and an abnormality has occurred. Continue the SBW mode with one steering control system and reaction force control system. After that, when the failure diagnosis result of the steering control system returns to normal, the process proceeds from step S5 to step S1, the steering control system that has been stopped is restarted, and the two steering control systems and reaction force are restarted. Return to SBW mode by the control system.

(b) Fixed failure If a fixed failure occurs in the steering control system, proceed to step S1, step S2, step S3, step S12, step S13, stop the steering control system where the abnormality occurred, In the steering control system and the reaction force control system that have not occurred, the SBW mode is continued, and at the same time, the abnormality diagnosis result is held in the latch circuit in the steering control controller in which the definite failure has occurred. Thereafter, even when the failure diagnosis result of the steering control system returns to normal, the SBW mode in one steering control system is maintained.

(Secondary failure)
(a) Temporary failure → Temporary failure If a temporary failure occurs in the steering control system, proceed to Step S1 → Step S2 → Step S3 → Step S4, stop the steering control system where the abnormality occurred, The SBW mode is continued with one steering control system and reaction force control system that have not occurred. Thereafter, if a temporary failure occurs in the steering control system that is normally controlled, the process proceeds from step S7 to step S8 to stop the steering control, engage the clutch 10, and stop the reaction force control. To shift to manual steer as the backup mode. After that, when the failure diagnosis result of the steering control system returns to normal, the process proceeds from step S9 to step S4, the steering control and the reaction force control are resumed, and the clutch 10 is released to return to the SBW mode. To do.

(b) Temporary failure → definite failure If a temporary failure occurs in the steering control system, proceed to step S1 → step S2 → step S3 → step S4 to stop the abnormal steering control system and The SBW mode is continued with one steering control system and reaction force control system that have not occurred. Thereafter, when a definite failure occurs in the steering control system that is normally controlled, the process proceeds from step S7 to step S10 to step S11 to stop the steering control, engage the clutch 10, and perform the reaction force control. By stopping, it shifts to manual steering as the backup mode, and at the same time, the abnormality diagnosis result is held in the latch circuit in the steering control controller in which the definite failure has occurred. Thereafter, even when the failure diagnosis result of the steering control system returns to normal, the manual steer backup mode is maintained.

(c) Final failure → Temporary failure If a final failure occurs in the steering control system, proceed to step S1, step S2, step S3, step S12, step S13, and stop the steering control system where the abnormality occurred. The SBW mode is continued in the steering control system and the reaction force control system in which no abnormality has occurred, and at the same time, the abnormality diagnosis result is held in the latch circuit in the steering control controller in which the definite failure has occurred. After that, if a temporary failure occurs in the steering control system that is normally under control, the process proceeds from step S15 to step S16 to step S17 to stop the steering control, engage the clutch 10, and control the reaction force. Is stopped, and the mode shifts to manual steer as the backup mode. After that, when the failure diagnosis result of the steering control system returns to normal, the process proceeds from step S17 to step S13, the steering control and the reaction force control are resumed, and the clutch 10 is released to return to the SBW mode. To do.

(d) Definite failure → Definite failure If a definite failure occurs in the steering control system, proceed to step S1, step S2, step S3, step S12, step S13, and stop the steering control system where the abnormality occurred. The SBW mode is continued in the steering control system and the reaction force control system in which no abnormality has occurred, and at the same time, the abnormality diagnosis result is held in the latch circuit in the steering control controller in which the definite failure has occurred. After that, if a definite failure occurs in the steering control system that is normally controlled, the process proceeds from step S15 to step S18 to step S19 to stop the steering control, engage the clutch 10, and control the reaction force. Is stopped, the operation shifts to the manual steer as the backup mode, and at the same time, the abnormality diagnosis result is held in the latch circuit in the steering control controller in which the definite failure has occurred. Thereafter, even when the failure diagnosis result of the steering control system returns to normal, the manual steer backup mode is maintained.

[When a failure occurs in the reaction force control system after a failure in the steering control system]
(Secondary failure)
(a) Temporary turning failure → Reaction force temporary failure If a temporary failure occurs in the turning control system, proceed to Step S1, Step S2, Step S3, Step S4, and stop the turning control system where the abnormality occurred. Then, the SBW mode is continued with one steering control system and reaction force control system in which no abnormality has occurred. Thereafter, when a temporary failure occurs in the reaction force control system, the process proceeds from step S6 to step S41 to step S42, and the clutch 10 is engaged and the reaction force control is stopped. Shift to power assist control by the motor. Thereafter, when the failure diagnosis result of the reaction force control system returns to normal, the process proceeds from step S43 to step S4 to resume the steering control and reaction force control, and return to the SBW mode by releasing the clutch 10. To do.

(b) Temporary steering failure → Reaction force determination failure If a temporary failure occurs in the steering control system, proceed to step S1, step S2, step S3, step S4, and stop the abnormal steering control system. Then, the SBW mode is continued with one steering control system and reaction force control system in which no abnormality has occurred. Thereafter, when a definite failure occurs in the reaction force control system, the process proceeds from step S6 to step S49 to step S50, the clutch 10 is engaged, and the reaction force control is stopped. At the same time as the transition to the power assist control by the motor, the failure diagnosis result is held in the latch circuit in the reaction force controller 12 in which the definite failure has occurred. Thereafter, even when the failure diagnosis result of the reaction force control system returns to normal, the backup mode of the power assist control by one steering motor is maintained.

(c) Steering fixed failure → Reaction force temporary failure When a definite failure occurs in the steering control system, proceed to Step S1 → Step S2 → Step S3 → Step S12 → Step S13 The system is stopped and the SBW mode is continued in the steering control system and the reaction force control system in which no abnormality has occurred, and at the same time, the abnormality diagnosis result is held in the steering control controller in which a definite failure has occurred. Thereafter, when a temporary failure occurs in the reaction force control system, the process proceeds from step S14 to step S41 to step S42, the clutch 10 is engaged, and the reaction force control is stopped, so that one steering is performed as a backup mode. Shift to power assist control by the motor. After that, when the failure diagnosis result of the reaction force control system returns to normal, the process proceeds from step S43 to step S13, the steering control and the reaction force control are resumed, and the clutch 10 is released to return to the SBW mode. To do.

(d) Steering fixed failure → Reaction force deterministic failure If a definite failure occurs in the steering control system, proceed to Step S1 → Step S2 → Step S3 → Step S12 → Step S13. The system is stopped and the SBW mode is continued in the steering control system and reaction force control system in which no abnormality has occurred, and at the same time, the abnormality diagnosis result is held in the latch circuit in the steering control controller in which the definite failure has occurred . Thereafter, when a temporary failure occurs in the reaction force control system, the process proceeds from step S14 to step S41 to step S49 to step S50, the clutch 10 is engaged, and the reaction force control is stopped, so that 1 is set as the backup mode. At the same time, the reaction force control controller 12 holds the failure diagnosis result in the latch circuit. Thereafter, even when the result of turning failure diagnosis returns to normal, the backup mode of power assist control by one turning motor is maintained.

[If a failure occurs in the steering control system after a failure in the reaction force control system]
(Secondary failure)
(a) Reaction force temporary failure → Steering temporary failure When a temporary failure occurs in the reaction force control system, the process proceeds from step S1 to step S2 to step S21 to step 22, and the clutch 10 is engaged and the reaction force control is performed. By stopping, power assist control by two steered motors is performed as a backup mode. Thereafter, when a temporary failure occurs in the steering control system, the process proceeds from step S24 to step S25, the steering control system in which the failure has occurred is stopped, and power assist control is performed with one steering motor. Thereafter, when the steering failure diagnosis result returns to normal, the process proceeds from step S26 to step S22 to resume the steering control and return to the backup mode by the two steering motors.

(b) Reaction force temporary failure → Steering fixed failure If a temporary failure occurs in the reaction force control system, the process proceeds from step S1 to step S2 to step S21 to step 22, the clutch 10 is engaged, and reaction force control is performed. By stopping, power assist control by two steered motors is performed as a backup mode. After that, if a definite failure occurs in the steering control system, the process proceeds from step S24 to step S27 to step S28 to stop the steering control system in which the failure has occurred, and power assist control with one steering motor At the same time, the abnormality diagnosis result is held in the latch circuit in the steering control controller in which the definite failure has occurred. Thereafter, even when the result of turning failure diagnosis returns to normal, the backup mode of power assist control with one turning motor is maintained.

(c) Reaction force fixed failure → Steering temporary failure When a fixed failure occurs in the reaction force control system, the process proceeds from step S1 → step S2 → step S21 → step S29, the clutch 10 is engaged, and the reaction force control is performed. By stopping, power assist control by two steered motors is performed as a backup mode, and at the same time, an abnormality diagnosis result is held in the latch circuit in the reaction force controller 12. Thereafter, when a temporary failure occurs in the steering control system, the process proceeds from step S31 to step S32, the steering control system in which the failure has occurred is stopped, and power assist control is performed with one steering motor. Thereafter, when the steering failure diagnosis result returns to normal, the process proceeds from step S33 to step S30 to resume the steering control and return to the backup mode in which the power assist control by the two steering motors is performed.

(d) Reaction force fixed failure → steering determined failure If a fixed failure occurs in the reaction force control system, the process proceeds from step S1, step S2, step S21, step S29, the clutch 10 is engaged, and the reaction force control is performed. By stopping, power assist control by two steered motors is performed as a backup mode, and at the same time, an abnormality diagnosis result is held in the latch circuit in the reaction force controller 12. After that, if a definite failure occurs in the steering control system, the process proceeds from step S31 to step S34 to step S35 to stop the steering control system in which the failure has occurred, and power assist control with one steering motor At the same time, the abnormality diagnosis result is held in the latch circuit in the steering control controller in which the definite failure has occurred. Thereafter, even when the result of turning failure diagnosis returns to normal, the backup mode with one turning motor is maintained.

  In the second embodiment, the mutual diagnosis execution lines 14A and 14B for transmitting the results of mutual diagnosis to other control controllers and the input units of the mutual diagnosis execution lines 14A and 14B of each control controller are provided. A latch circuit that holds a mutual diagnosis result, and when all of the other control controllers have diagnosed an abnormality with respect to one control controller, a definite failure of the control controller is diagnosed.

  For example, when an abnormality is diagnosed with only one control controller, there is a possibility that if an abnormality occurs in the control controller, an abnormality is diagnosed even though the other controller is normal. On the other hand, in the second embodiment, even if all the control controllers that perform diagnosis by performing mutual diagnosis do not diagnose an abnormality, even if an abnormality occurs in one control controller and another controller is diagnosed as an abnormality, The diagnosis result is not executed.

  In addition, when an abnormality occurs in one controller, it is judged as an abnormality by mutual diagnosis, and the mode shifts to the backup mode. If a double fault occurs in this state, the abnormality diagnosis is performed. May be canceled and the backup mode may change to SBW mode. Therefore, in the second embodiment, the mutual diagnosis result is held as a definite failure in the latch circuit of the control controller in which the definite failure has occurred, and the backup mode is maintained, so that even if a double failure has occurred, the backup mode Can be maintained.

  In the second embodiment, the clutch 10 outputs an engagement command from the reaction force controller 12 to the clutch 10 when the diagnosis results of the other steering control controllers 11A and 11B with respect to the reaction force controller 12 are all abnormal. The steering mechanism 2 and the handle 3 are connected regardless of whether or not they are present. That is, when an abnormality occurs in the reaction force controller 12, the clutch engagement command output from the reaction force controller 12 is low in reliability, so the mutual diagnosis result for the reaction force controller 12 is used as the clutch engagement command. Thus, the control of the reaction force controller 12 in which the abnormality has occurred can be stopped, and the clutch 10 can be engaged and shifted to the backup mode regardless of the command of the reaction force controller 12 in which the abnormality has occurred. .

Next, the effect will be described.
The SBW system according to the second embodiment has the following effects in addition to the effects (1) to (3) of the first embodiment.

  (4) Each failure diagnosis unit 11b, 11b, 12b performs a mutual diagnosis for diagnosing an abnormality of another control controller, and when all other control controllers are diagnosed as abnormal for one control controller, the control concerned Diagnose a confirmed failure of the controller. Thus, even when an abnormality occurs in one control controller, other normal control controllers are not erroneously diagnosed as abnormal.

  (5) Since each abnormality diagnosis unit 11b, 11b, 12b diagnoses an abnormality based on the calculation result of the other controller, the abnormality of the control controller can be reliably detected without being affected by a sensor failure or the like. Diagnosis can be made immediately.

  (6) Whether or not the clutch 10 has received an engagement command from the reaction force controller 12 to the clutch 10 when the diagnosis results of the other steering control controllers 11A and 11B with respect to the reaction force controller 12 are all abnormal. Regardless, the steering mechanism 2 and the handle 3 are connected. As a result, even if an abnormality occurs in the reaction force controller 12, the clutch 10 can be engaged and the mode can be shifted to the backup mode.

  (7) The mutual diagnosis execution lines 14A and 14B for transmitting the results of mutual diagnosis to other control controllers and the mutual diagnosis execution lines 14A and 14B of the respective control controllers are provided at the input unit, and the mutual diagnosis of the other control controllers is performed. And a latch circuit for holding the result. As a result, the backup mode can be maintained even in the case where a double failure that causes an abnormality occurs in a normal controller performing abnormality diagnosis.

The third embodiment is an example in which both the steering control system and the reaction force control system are dual systems.
FIG. 7 is a configuration diagram of the SBW system according to the third embodiment. In the third embodiment, the reaction force motor 8A includes two reaction force motors 8A and 8B and two reaction force control controllers 12A and 12B. Controlled by the force control controller 12A, the reaction force control motor 12B is controlled by the reaction force control controller 12B.
Since other configurations are the same as those of the second embodiment, illustration and description thereof are omitted.

  In the third embodiment, since both the steering control system and the reaction force control system are dual systems, the failure pattern includes the following examples in addition to the examples given in the second embodiment.

[If the reaction force control system fails after the reaction force control system failure]
(Secondary failure)
(a) Reaction force temporary failure → Reaction force temporary failure When a temporary failure occurs in the reaction force control system, stop the reaction force control where the failure occurred and use the normal reaction force control system to turn the two steering motors. SBW mode is performed by 5A, 5B and one reaction force motor. Thereafter, if a temporary failure occurs in the normal reaction force control system, the reaction force control is stopped, the clutch 10 is engaged, and power assist control is performed with the two steered motors 5A and 5B. Thereafter, when the reaction force failure diagnosis result returns to normal, the reaction force control is resumed, and the SBW mode is resumed with the two steered motors 5A and 5B and one reaction force motor.

(b) Reaction force temporary failure → Reaction force fixed failure If a reaction force control system has a temporary failure, stop the reaction force control where the failure occurred and use the normal reaction force control system to turn the two steering motors. SBW mode is performed by 5A, 5B and one reaction force motor. Thereafter, when a definite failure occurs in the normal reaction force control system, the reaction force control is stopped, the clutch 10 is engaged, and power assist control is performed with the two steered motors 5A and 5B. In the reaction force control controller in which the definite failure has occurred, the abnormality diagnosis result is held in the latch circuit. Thereafter, even when the reaction force failure diagnosis result returns to normal, the backup mode of the two steered motors 5A and 5B is maintained.

(c) Reaction force fixed failure → Reaction force temporary failure If a reaction force control system has a temporary failure, stop the reaction force control where the failure occurred and use the normal reaction force control system to turn the two steering motors. The SBW mode with one reaction force motor is performed, and at the same time, the abnormality diagnosis result is held in the latch circuit in the reaction force controller in which a definite failure has occurred. Thereafter, when a temporary failure occurs in the normal reaction force control system, the reaction force control is stopped, the clutch 10 is engaged, and power assist control is performed with the two steered motors. Thereafter, when the reaction force failure diagnosis result returns to normal, the reaction force control is resumed, and the SBW mode is resumed with the two steered motors 5A and 5B and one reaction force motor.

(d) Reaction force deterministic failure → Reaction force definitive failure If a temporary failure occurs in the reaction force control system, the reaction force control in which the failure occurred is stopped and two steering motors are used using the normal reaction force control system. The SBW mode with one reaction force motor is performed, and at the same time, the abnormality diagnosis result is held in the latch circuit in the reaction force controller in which a definite failure has occurred. After that, when a definite failure occurs in the normal reaction force control system, the reaction force control is stopped, the clutch 10 is engaged, power assist control is performed with two steered motors, and at the same time a definite failure occurs. In the generated reaction force controller, the abnormality diagnosis result is held in the latch circuit. Thereafter, even when the reaction force failure diagnosis result returns to normal, the backup mode of the two steered motors 5A and 5B is maintained.

  As described above, in the SBW system according to the third embodiment, the same operational effects as those of the first and second embodiments can be obtained.

(Other examples)
The best mode for carrying out the present invention has been described based on the first to third embodiments. However, the specific configuration of the present invention is not limited to the first to third embodiments. Design changes and the like within a range that does not depart from the gist are also included in the present invention.

  In the second embodiment, only the steering control system is a dual system, and in the third embodiment, the steering control system and the reaction force control system are dual systems. For example, a configuration in which only the reaction force control system is a dual system or a configuration in which the steering control system is a triple system may be used.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of the steer-by-wire system of Example 1 to which the steering control apparatus for vehicles of this invention is applied. FIG. 3 is a control block diagram according to the first embodiment. It is a block diagram of the steer-by-wire system of Example 2. It is a flowchart which shows the flow of the control mode switching process performed with steering control controller 11A, 11B and reaction force controller 12 of Example 2. FIG. It is a flowchart which shows the flow of the control mode switching process performed with steering control controller 11A, 11B and reaction force controller 12 of Example 2. FIG. It is a flowchart which shows the flow of the control mode switching process performed with steering control controller 11A, 11B and reaction force controller 12 of Example 2. FIG. It is a block diagram of the steer-by-wire system of Example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Left front wheel 1b Right front wheel 2 Steering mechanism 2a Rack shaft 3 Handle 4 Pinion shaft 5 Steering motor 6a, 6b Axial force sensor 7 Column shaft 8 Reaction force motor 9 Torque sensor 10 Backup clutch 11 Steering control controller 12 Reaction force control Controller 13 Mutual communication line 14A, 14B Mutual diagnosis execution line

Claims (7)

A handle operated by the driver;
A steering mechanism that steers steering wheels;
A steering actuator for applying a steering torque to the steering mechanism;
A reaction force actuator for applying a steering reaction force to the handle;
Backup means provided between the steering mechanism and the handle, and capable of mechanical separation and connection of both;
An abnormality diagnosis unit for diagnosing a system abnormality, and when the abnormality diagnosis unit diagnoses that the system is normal, a disconnection command for mechanically separating the steering mechanism and the handle is provided to the backup unit; The steering actuator is driven so that the steering wheel is steered according to the steering state of the steering wheel, and the steering reaction force according to the steered state of the steering mechanism is obtained. When steer-by-wire control for driving the reaction force actuator is executed and the system is diagnosed as abnormal, a connection command for mechanically connecting the steering mechanism and the handle is output to the backup means. Steering control means for executing backup control;
In a vehicle steering control device comprising:
The abnormality diagnosis unit diagnoses a temporary failure that is a temporary failure of the system and a definite failure that is a continuous failure of the system,
When the steering control unit is diagnosed as the temporary failure during the execution of the steer-by-wire control, the steering control unit shifts to the backup control, and is diagnosed that the temporary failure is resolved during the backup control. When the steering failure is diagnosed while the steer-by-wire control is being executed, the process proceeds to the backup control, and the backup control is being performed. The vehicle steering control device is characterized in that the backup control is continued even when it is diagnosed that the confirmed failure has been resolved. The vehicle steering control device according to claim 1,
One or a plurality of steering control means for controlling the steering actuator and reaction force control means for controlling the reaction force actuator are set as the steering control means,
Each abnormality diagnosing unit performs a mutual diagnosis for diagnosing an abnormality of another control unit, and diagnoses a definite failure of the control unit when all other control units diagnose an abnormality for one control unit. A vehicle steering control device. The vehicle steering control device according to claim 2,
Each abnormality diagnosis part diagnoses abnormality based on the calculation result of another control means, The steering control apparatus for vehicles characterized by the above-mentioned. In the vehicle steering control device according to claim 2 or 3,
The vehicle steering control device, wherein the backup means connects the steering mechanism and the steering wheel in accordance with the connection command from the reaction force control means. The vehicle steering control device according to any one of claims 2 to 4,
The vehicle steering control device, wherein the backup means connects the steering mechanism and the steering wheel when power supply to the reaction force control means is stopped. The vehicle steering control device according to any one of claims 2 to 5,
The backup unit is configured so that when all the diagnosis results of the other control units for one reaction force control unit are abnormal, the steering mechanism is output regardless of whether the connection command is output from the reaction force control unit. And a steering control device for a vehicle. The vehicle steering control device according to any one of claims 2 to 6,
A signal line for transmitting the results of mutual diagnosis to other control means;
A holding unit that is provided in the signal line input unit of each control unit and holds a mutual diagnosis result of other control units;
A vehicle steering control device comprising:

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