JP4534845B2 - Steering control device - Google Patents

Description

  The present invention provides a steer-by-wire system in which a steering unit having a steering wheel and a steering reaction force actuator, and a steering unit having a steered wheel and a steering actuator can be mechanically separated and connected via a backup mechanism. It belongs to the technical field of steering control devices.

  A so-called steer-by-wire (hereinafter abbreviated as “SBW”) in which a mechanical connection between a steering member such as a steering wheel and a steered wheel is released and a part of a steering transmission system is configured by an electrical path. In the system, it is important to take a fail-safe measure when an abnormality occurs. For example, when an abnormality is detected in the reaction force actuator, reaction force control by the reaction force control unit is stopped, a mechanical backup mechanism that mechanically connects the steering member and the steering wheel is operated, and the steering control unit is activated. A configuration has been proposed in which the function as a normal electric power steering (hereinafter abbreviated as “EPS”) device is realized by switching to the control for steering assist control and controlling the steering actuator ( For example, see Patent Document 1).

In such a configuration having a mechanical backup mechanism, if the mechanical backup mechanism does not operate normally, there is a problem in terms of safety and performance, and therefore it is considered important to detect an abnormality of the mechanical backup mechanism. As a mechanical backup mechanism abnormality detection method, for example, a method for determining a sensor abnormality or a clutch abnormality when the motor rotation speed and the steering speed do not match based on the relationship between the motor rotation speed and the steering speed has been proposed ( For example, see Patent Document 2).
Japanese Patent Application Laid-Open No. 2004-090783 Japanese Patent Laid-Open No. 10-310067

  However, in a conventional steering control device, when there are multiple backup connection / disconnection control systems for fail-safe measures, it is necessary to execute SBW control after confirming whether the redundant control system is functioning. However, if the backup operation of all the control systems is confirmed by the above-mentioned conventional mechanical backup mechanism abnormality detection method, the time required for confirmation becomes longer and the start of SBW control is delayed. there were.

  The present invention has been made paying attention to the above-described problem. When there are a plurality of backup connection / disconnection control systems, the present invention is required for mechanical diagnosis and electrical diagnosis while ensuring reliable connection / disconnection operation of the backup mechanism. An object of the present invention is to provide a steering control device capable of reducing time.

In order to achieve the above object, in the present invention, a steering unit having a steering wheel and a steering reaction force actuator and a steering unit having a steered wheel and a steering actuator are mechanically separated and connected via a backup mechanism. Is possible,
In the steering control device comprising a plurality of control means for driving and controlling at least one of the steering reaction force actuator and the steering actuator and performing connection / disconnection control of the backup mechanism by a connection / disconnection signal,
The control means includes
An electrical diagnostic unit for performing an electrical diagnosis as to whether the backup mechanism is connected or disconnected when the connection / disconnection signal is output;
Whether or not driving force is transmitted between the steering unit and the steering unit when the backup mechanism mechanically connects the steering unit and the steering unit after outputting the connection / disconnection signal A mechanical diagnosis unit for performing such mechanical diagnosis,
A backup mechanism self-diagnosis unit in which the other control means executes the electrical diagnosis after at least one of the control means completes the mechanical diagnosis;
It is characterized by having.

  Therefore, in the steering control device of the present invention, after the backup mechanism self-diagnostic unit outputs at least one control means among the plurality of control means to output the connection / disconnection signal to the backup mechanism, the backup mechanism steers. When the steering part and the steered part are mechanically connected, a mechanical diagnosis is made as to whether or not the driving force is transmitted between the steering part and the steered part. Then, after completing this mechanical diagnosis, when other control means outputs a connection / disconnection signal to the backup mechanism, an electrical diagnosis is made as to whether or not the backup mechanism is connected / disconnected. For this reason, for example, if a normal diagnosis result is obtained by mechanical diagnosis for one control means, and a normal diagnosis result is obtained by electrical diagnosis for another control means, the backup mechanism is operable. I can confirm that. In this way, as long as both mechanical and electrical are normal, there is only one control means for performing mechanical diagnosis and electrical diagnosis. Therefore, when performing mechanical diagnosis for each of a plurality of control means. Compared with, the diagnosis time can be greatly shortened. As a result, when there are a plurality of backup connection / disconnection control systems, it is possible to reduce the time required for mechanical diagnosis and electrical diagnosis while guaranteeing reliable connection / disconnection operation of the backup mechanism.

  Hereinafter, the best mode for carrying out the steering control device of the present invention will be described based on Examples 1 to 3 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall configuration diagram illustrating an SBW system to which the steering control device according to the first embodiment is applied.
As shown in FIG. 1, the SBW system to which the steering control device of the first embodiment is applied includes a steering wheel 1 (steering wheel), a steering angle sensor 2 (vehicle traveling state detecting means), and a steering torque sensor 3 (vehicle traveling). State detecting means), steering reaction force actuator 4, backup clutch 5 (backup mechanism), backup cable 6 (backup mechanism), steering actuator 7, steering reaction force controller 8 (control means), A steering controller 9 (control means), a communication line 10, a clutch control signal line 11, and a steered wheel 12 are provided.

  The steering part having the steering wheel 1 and the steering reaction force actuator 4 and the steering part having the steering wheel 12 and the steering actuator 7 are mechanically separated and connected via the backup clutch 5 and the backup cable 6. It is possible. When mechanically separating the steering part and the steered part, the backup clutch 5 is opened, and when mechanically connecting the steering part and the steered part, the backup clutch 5 is fastened.

  The backup clutch 5 includes all the steering reaction force controllers 8 (two steering reaction force first controllers and two steering reaction force second controllers in the first embodiment) and all the steering devices that have a redundant configuration. From the controller 9 (three in the first embodiment, the first steering controller, the second steering controller, and the third steering controller) through the clutch control signal line 11 (five in the first embodiment) / It can be separated. In addition, each controller 8 and 9 transmits each signal through a communication line 10, and this communication line has a double system configuration. Furthermore, sensors (motor rotation angle sensors, etc.) that detect the operating states of the steering reaction force actuator 4 and the steering actuator 7 have a double system configuration, and the redundant configuration of each controller 8 and 9 together with the SBW system. As a result, a redundant configuration is realized.

  In SBW control with the backup clutch 5 disconnected, steering control by the steering controller 9 and steering reaction force control by the steering reaction force controller 8 are performed. That is, the rotation operation of the steering wheel 1 is detected by the steering angle sensor 2, and the drive command value of the steering actuator 7 is calculated by the steering controller 9 together with the output of the steering torque sensor 3, and the steering is performed based on this command value. The steering operation is performed by driving the actuator 7. The steering actuator 7 is constituted by an electric motor such as a brushless motor, and each steering controller 9 calculates a drive command value for each motor (three in the first embodiment). Similarly to the steering actuator 7, the steering reaction force actuator 4 for applying a steering reaction force to the steering wheel 1 is constituted by an electric motor such as a brushless motor. ) On the basis of command values calculated by the respective steering reaction force controllers 8. That is, the drive command value calculated by the steering reaction force controller 8 and the steering controller 9 is a current command value to the electric motors that constitute the steering reaction force actuator 4 and the steering actuator 7.

In the case of the SBW system including the backup cable 6, the steering wheel 12 can be directly moved according to the steering wheel 1 by connecting the backup clutch 5. If any abnormality occurs in the SBW system, safe traveling is possible by mechanically connecting the steering reaction force actuator 4 and the turning actuator 7 by the backup cable 6. Furthermore, it is also possible to perform electric power steering control (EPS control) that assists the steering force using the steering actuator 7.
However, if there is an abnormality in the backup clutch 5 and the backup cable 6, there is a problem in safety and performance, so diagnosis of these backup mechanisms is important. In the first embodiment, the backup clutch 5 can be connected / disconnected from five controllers, and a backup mechanism self-diagnosis method for each system is proposed.

  FIG. 2 is a control system circuit diagram to which the steering control device of the first embodiment is applied. The backup clutch 5 is configured to be disconnected when energized. Therefore, when the ignition is OFF, since the power is not supplied, the backup clutch 5 is connected, and the steering unit and the steered unit are mechanically connected. Upstream of the backup clutch 5 is a normally closed type clutch drive relay 13 that is connected to a contact point when no power is supplied. The clutch drive relay 13 can turn off the relay from all the controllers 8, 9 by turning on the transistor A, that is, the backup clutch 5 is engaged, and the steering unit and the steering unit are mechanically connected. It is possible to connect. There is a transistor B downstream of the backup clutch 5, and turning on the transistor B energizes the clutch coil. Thereby, it is possible to release the backup clutch 5 from all the controllers 8 and 9 and to mechanically separate the steering unit and the steered unit. In the mechanical diagnosis, when the backup clutch 5 is engaged and the steering unit and the steering unit are mechanically connected, it is confirmed whether or not the driving force is transmitted between the steering unit and the steering unit. . The electrical diagnosis confirms whether or not a current has flowed through the clutch coil when a connection / disconnection signal is output to the backup clutch 5, and includes confirmation of the operation of the clutch drive relay 13 and each transistor. Specifically, an electrical diagnosis is performed by monitoring the voltage at point C in FIG. 2 with a microcomputer.

Next, the operation will be described.
[Backup mechanism self-diagnosis processing]
FIG. 3 is a flowchart showing the flow of the backup mechanism self-diagnosis process executed by the steering reaction force controller 8 or the steering controller 9 of the first embodiment. Each step will be described below (backup mechanism self-diagnosis unit). . This process is simultaneously executed by each controller when the system is started (when the ignition is ON).

  In step S1, it is confirmed whether or not the calculating controller is a controller that performs mechanical diagnosis. If the controller number CNT_No being calculated matches the controller number MD_CNT for performing the mechanical diagnosis, the controller currently performing the calculation is a controller for performing the mechanical diagnosis, and the process proceeds to step S2. When the controller number CNT_No being calculated does not match the controller number MD_CNT for performing the mechanical diagnosis, the process proceeds to step S7. In the first embodiment, the controller selected when the ignition is ON is used as a controller for mechanical diagnosis.

  In step S2, following the determination that CNT_No = MD_CNT in step S1, mechanical diagnosis of the backup mechanism (the flowchart in FIG. 4 or the flowchart in FIG. 5) is performed, and the process proceeds to step S3.

  In step S3, following the mechanical diagnosis of the backup mechanism in step S2, a mechanical diagnosis end flag M_END_flag is set, and the process proceeds to step S4.

  In step S4, following the M_END_flag set in step S3, it is determined from the state of the M fail flag whether an abnormality has been detected by mechanical diagnosis. If the M fail flag is set, some abnormality has occurred in the backup mechanism, and the process proceeds to step S5. If the M fail flag is cleared, there is no abnormality in the mechanical diagnosis, and the process proceeds to step S13.

  In step S5, following the determination of the M fail flag set in step S4, since an abnormality is detected by mechanical diagnosis, the warning lamp is turned on, and the process proceeds to step S6.

  In step S6, following the warning lamp lighting in step S5, both SBW control and EPS control are stopped.

  In step S7, following the determination that CNT_No ≠ MD_CNT in step S1, it is checked whether the mechanical diagnosis end flag M_END_flag is set. If the mechanical diagnosis end flag M_END_flag is set, the process proceeds to step S8. If the mechanical diagnosis end flag M_END_flag is cleared, the mechanical diagnosis has not ended yet, and the process waits until M_END_flag is set. To do.

  In step S8, following the determination of the M_END_flag set in step S7, it is determined from the state of the M fail flag whether an abnormality has been detected by mechanical diagnosis. If the M fail flag is set, some abnormality has occurred in the backup mechanism, and the process proceeds to step S5. If the M fail flag is cleared, there is no abnormality in the mechanical diagnosis, and the process proceeds to step S9.

  In step S9, following the determination of clearing the M fail flag in step S8, a value obtained by adding 1 to the controller number MD_CNT subjected to the mechanical diagnosis is set as the electrical diagnosis target controller number ED_CNT, and the process proceeds to step S10. For example, when the mechanical diagnosis controller number MD_CNT = 2, the controller other than the controller that performs the mechanical diagnosis is set as the electrical diagnosis target controller so that the electrical diagnosis target controller number is ED_CNT = 3.

  In step S10, following the setting of the electrical diagnosis target controller in step S9, it is confirmed whether or not the currently calculated controller is a controller that performs electrical diagnosis. If ED_CNT matches CNT_No, the process proceeds to step S11. If the controller number CNT_No being calculated does not match ED_CNT, the electrical diagnosis is not performed and the process proceeds to step S13.

  In step S11, following the determination that CNT_No = ED_CNT in step S10, an electrical diagnosis of the backup mechanism (flowchart in FIG. 6) is performed, and the process proceeds to step S12.

  In step S12, following the electrical diagnosis in step S11, an electrical diagnosis end flag E_END_flag of the controller currently being calculated is set, and the process proceeds to step S13. The electrical diagnosis end flag E_END_flag is set separately for each controller.

  In step S13, the state of the electrical diagnosis end flag E_END_flag is checked after the clear determination of the M fail flag in step S4, the CNT_No ≠ ED_CNT determination in S10, or the E_END_flag set in step S12. If yes, the process proceeds to step S15. If clear, wait. In other words, after the mechanical diagnosis, each controller waits for a transition to the next operation until one electrical diagnosis is completed.

  In step S15, following the set determination of the electrical diagnosis end flag E_END_flag in step S13, the presence or absence of an abnormality in the electrical diagnosis is determined based on the state of the E fail flag. If the E fail flag is cleared, the process proceeds to step S16. In the case of the E-fail flag set, the process proceeds to step S18.

  If the E-fail flag is set in step S15, ED_CNT = ED_CNT + 1 etc. is executed again from step S10, electrical diagnosis of other controllers is performed, there is one normal controller, and a redundant configuration When the above can be realized, SBW control may be started.

  In step S16, SBW control (flowchart in FIG. 7) is started following the determination of clearing the E-fail flag in step S15, and the process proceeds to step S17.

  In step S17, following the SBW control in step S16, after the SBW control is started, the status of electrical diagnosis by the remaining controllers is determined based on the state of the E-fail flag of each controller. When the E-fail flag is set, since some abnormality is detected in the backup mechanism by the electrical diagnosis performed after the start of the SBW control, the process proceeds to step S18. Otherwise, the process returns to step S16 to continue the SBW control.

  In step S18, following the determination of the E-fail flag set in step S15 or step S17, the EPS control is subsequently executed.

  In the flowchart of FIG. 3, steps S2 to S4 indicate processing of the controller that performs mechanical diagnosis, and steps S7 to S12 indicate processing of the controller that performs electrical diagnosis. Step S13 and subsequent steps are common processing. With these operations, it is possible to start SBW control only after a normal system has been confirmed more than two systems.

[Mechanical diagnosis processing]
The mechanical diagnosis processing is performed according to the flowchart shown in FIG. 4 when the steering reaction force controller 8 (one of the two) is selected as the controller for performing the mechanical diagnosis in step S2 of the flowchart of FIG. When the steering controller 9 (any one of the three) is selected as the controller that performs the mechanical diagnosis, it is executed according to the flowchart shown in FIG.

  FIG. 4 is a flowchart showing the flow of the mechanical diagnosis process of the backup mechanism executed by the steering reaction force controller 8 according to the first embodiment. Each step will be described below (mechanical diagnosis unit).

  In step S2-1, the steering angle command value θcom is output, and the process proceeds to step S2-2. By this command value, a current flows to the electric motor of the steering reaction force actuator 4 and the steering wheel 1 is operated.

In step S2-2, it is determined whether or not a predetermined time T1 has elapsed since the steering angle command value θcom was output following the output of the steering angle command value θcom in step S2-1. -3, and in the case of No, the determination in step S2-2 is repeated.
That is, even if the steering angle command value θcom is output, it takes time for the steering wheel 1 to actually operate and reach a steady state, so the next time until the predetermined time T1 elapses in consideration of the operation delay. Don't go to the next step.

In step S2-3, following the determination that the predetermined time T1 has elapsed from the output of the steering angle command value θcom in step S2-2, the relationship between the actual steering angle θ and the steering angle command value θcom is checked. If the steering angle θ is in the range of the steering angle command value θcom ± β, it is determined that the steering angle θ is operating according to the steering angle command value θcom, and the process proceeds to step S2-4. If the steering angle θ is not within the range of the steering angle command value θcom ± β, the operation proceeds to step S2-12 because of an abnormal operation.
Here, β is set in consideration of the detection accuracy of the steering angle θ, the accuracy of reaction motor control, the friction of the steering wheel and the shaft, and the like.

In step S2-4, following the determination of θ = θcom ± β in step S2-3, the relationship between the actual turning angle δ and the turning angle command value δcom calculated from the steering angle command value θcom is checked. The turning angle command value Δcom is a value obtained by dividing the steering angle command value θcom by the steering gear ratio. As the value of the turning angle δ, a value estimated by a motor rotation angle, a rack shaft gear ratio, a knuckle arm length, or the like can be used. If the turning angle δ is within the range of the turning angle command value δcom ± α, it is determined that the turning angle δ operates according to the turning angle command value δcom, and the process proceeds to step S2-5. If the turning angle δ is not within the range of the turning angle command value δcom ± α, the operation proceeds to step S2-12 because of abnormal operation. Since the mechanical diagnosis of the backup mechanism is executed before the start of the SBW control, the backup clutch 5 is in the engaged state at the time of diagnosis (uncontrolled clutch engaged state). Therefore, when the steering wheel 1 is operated, the steered wheel 12 mechanically connected also operates. In steps S2-3 and S2-4, it is confirmed that the backup mechanism is mechanically connected.
Here, α is determined in consideration of the detection accuracy of the turning angle δ, the accuracy of the reaction force motor control, the torsion angle of the backup mechanism, and the like.

  In step S2-5, following the determination of δ = δcom ± α in step S2-4, the steering angle command value θcom is output as zero, and the process proceeds to step S2-6.

  In step S2-6, following the output of the steering angle command value θcom = 0 in step S2-5, it is checked whether a predetermined time T1 has elapsed since the steering angle command value θcom was output. Similar to step S2-2, even if the steering angle command value θcom is output, it takes time for the actual steering wheel 1 to operate and reach a steady state. It does not advance to the next step until it passes. When T1 has elapsed, the process proceeds to step S2-7.

  In step S2-7, following the determination of the elapse of the predetermined time T1 in step S2-6, a release signal is output to the backup clutch 5, the mechanical connection between the steering part and the steered part is disconnected, and the process proceeds to step S2-8. Transition.

  In step S2-8, following the clutch OFF command output in step S2-7, it is checked whether a predetermined time T2 has elapsed after the release signal is output to the backup clutch 5. That is, considering the delay in the release operation of the backup clutch 5, the process does not proceed to the next step until the predetermined time T2. When T2 has elapsed, the process proceeds to step S2-9.

  In step S2-9, following the determination of the elapse of the predetermined time T2 in step S2-8, the steering angle command value θcom is output as in step S2-1, and the process proceeds to step S2-10. Due to the output of the steering angle command value θcom, a current flows through the electric motor of the steering reaction force actuator 4 and the steering wheel 1 is operated.

  In step S2-10, following the output of the steering angle command value θcom in step S2-9, it is checked whether a predetermined time T1 has elapsed since the steering angle command value θcom was output. Similar to step S2-2 and step S2-6, even if the steering angle command value θcom is output, it takes time for the steering wheel 1 to actually operate and reach a steady state, so the operation delay is taken into account. Thus, the process does not proceed to the next step until the predetermined time T1 has elapsed. When T1 has elapsed, the process proceeds to step S2-11.

  In step S2-11, following the determination of the elapse of the predetermined time T1 in step S2-10, the actual state of the turning angle δ is checked. If the turning angle δ is in the range of the turning angle command value δ ± α, that is, if the turning angle δ does not move with respect to the movement of the steering angle, it is mechanically separated by the backup mechanism Judge and go to step S2-13. If the turning angle δ is not within the range of the turning angle command value δ ± α, it can be determined that the operation is abnormal, such as being not mechanically separated, and the process proceeds to step S2-12.

  In step S2-12, it is determined that the steering angle θ and the turning angle δ deviate from the normal range in steps S2-3, S2-4, and S2-11, that is, some mechanical abnormality relating to the backup mechanism. Therefore, M fail flag is set, and the process proceeds to step S2-13. Thereafter, the warning lamp is turned on according to the M fail flag to perform an operation such as notifying the driver of an abnormality.

  In step S2-13, following the determination of the turning angle δ = steering angle command value δ ± α in step S2-11, or the M-fail flag setting in step S2-12, the steering angle command value θcom is set to zero. The mechanical diagnosis is terminated as (return to neutral position).

  FIG. 5 is a flowchart showing the flow of the mechanical diagnosis process of the backup mechanism executed by the steering controller 9 of the first embodiment. Hereinafter, each step will be described (mechanical diagnosis unit).

  In step S2-21, the turning angle command value δcom is output, and the process proceeds to step S2-22. With this command value, a current flows to the electric motor of the steering actuator 7 and the steered wheel 12 is actuated.

In step S2-22, it is determined whether or not a predetermined time T1 has elapsed since the turning angle command value δcom was output, following the turning angle command value δcom output in step S2-21. The process proceeds to step S2-23, and in the case of No, the determination in step S2-22 is repeated.
That is, even if the steered angle command value δcom is output, it takes time for the steered wheels 12 to actually operate and reach a steady state. Therefore, until a predetermined time T1 elapses in consideration of the operation delay. Does not proceed to the next step.

In step S2-23, following the determination that the predetermined time T1 has elapsed from the output of the turning angle command value δcom in step S2-22, the relationship between the actual turning angle δ and the turning angle command value δcom is checked. As the value of the turning angle δ, a value estimated by a motor rotation angle, a rack shaft gear ratio, a knuckle arm length, or the like can be used. If the turning angle δ is within the range of the turning angle command value δcom ± α, it is determined that the turning angle δ operates according to the turning angle command value δcom, and the process proceeds to step S2-24. If the turning angle δ is not within the range of the turning angle command value δcom ± α, the operation proceeds to step S2-32 because of abnormal operation.
Here, α is determined in consideration of the detection accuracy of the turning angle δ, the accuracy of the turning motor control, and the mechanical reaction force of the steered wheels and the rack.

In step S2-24, following the determination of δ = δcom ± α in step S2-23, the relationship between the actual steering angle θ and the steering angle command value θcom calculated from the turning angle command value δcom is checked. The steering angle command value θcom is a value obtained by multiplying the steering angle command value Δcom by the steering gear ratio. If the steering angle θ is within the range of the steering angle command value θcom ± β, it is determined that the steering angle θ is operating according to the steering angle command value θcom, and the process proceeds to step S2-25. If the steering angle θ is not within the range of the steering angle command value θcom ± β, the process proceeds to step S2-32 because of an abnormal operation. Since the mechanical diagnosis of the backup mechanism is executed before the start of the SBW control, the backup clutch 5 is in the engaged state at the time of diagnosis (uncontrolled clutch engaged state). Therefore, when the steering wheel 12 operates, the mechanically connected steering wheel 1 also operates. In steps S2-23 and S2-24, it is confirmed that the backup mechanism is mechanically connected.
Here, β is set in consideration of the detection accuracy of the steering angle θ, the accuracy of the steering motor control, the mechanical reaction force of the steered wheels and the rack, the torsion angle of the backup mechanism, and the like.

  In step S2-25, following the determination of θ = θcom ± β in step S2-24, the turning angle command value δcom is output as zero, and the process proceeds to step S2-26.

  In step S2-26, following the output of the turning angle command value δcom = 0 in step S2-25, it is checked whether a predetermined time T1 has elapsed since the turning angle command value δcom was output. Similar to step S2-22, even if the steered angle command value δcom is output, it takes time for the steered wheels 12 to actually operate and reach a steady state. It does not proceed to the next step until time T1 has elapsed. When T1 has elapsed, the process proceeds to step S2-27.

  In step S2-27, following the determination of the elapse of the predetermined time T1 in step S2-26, an opening signal is output to the backup clutch 5, the mechanical connection between the steering part and the steered part is disconnected, and the process proceeds to step S2-28. Transition.

  In step S2-28, following the clutch OFF command output in step S2-27, it is checked whether a predetermined time T2 has elapsed since the release signal was output to the backup clutch 5. That is, considering the delay in the release operation of the backup clutch 5, the process does not proceed to the next step until the predetermined time T2. When T2 has elapsed, the process proceeds to step S2-29.

  In step S2-29, following the determination of the elapse of the predetermined time T2 in step S2-28, the steering angle command value θcom is output as in step S2-21, and the process proceeds to step S2-30. Due to the output of the turning angle command value δcom, a current flows through the electric motor of the turning actuator 7 and the steered wheel 12 is actuated.

  In step S2-30, following the output of the turning angle command value δcom in step S2-29, it is checked whether a predetermined time T1 has elapsed since the turning angle command value δcom was output. As in step S2-22 and step S2-26, even if the steered angle command value δcom is output, it takes time for the steered wheels 12 to actually operate and reach a steady state. Considering the above, it does not proceed to the next step until the predetermined time T1 has elapsed. When T1 has elapsed, the process proceeds to step S2-31.

  In step S2-31, following the determination of the elapse of the predetermined time T1 in step S2-30, the state of the actual steering angle (steering angle) θ is checked. If the steering angle θ is within the range of the steering angle command value θ ± β, that is, if the steering angle θ does not move with respect to the movement of the turning angle, it is determined that the steering mechanism is mechanically separated by the backup mechanism. The process proceeds to step S2-33. If the steering angle θ is not within the range of the steering angle command value θ ± β, it can be determined that the operation is abnormal, such as not being mechanically separated, and the process proceeds to step S2-32.

  In step S2-32, it is determined that the steering angle θ and the turning angle δ deviate from the normal range in steps S2-23, S2-24, and S2-31, that is, some mechanical abnormality relating to the backup mechanism. Therefore, M fail flag is set, and the process proceeds to step S2-33. Thereafter, the warning lamp is turned on according to the M fail flag to perform an operation such as notifying the driver of an abnormality.

  In step S2-33, following the determination of the steering angle θ = steering angle command value θ ± β in step S2-31 or the M-fail flag set in step S2-32, the turning angle command value δcom is set to zero ( Return to the neutral position) to finish the mechanical diagnosis.

  A time chart of the mechanical diagnosis of the backup mechanism by the steering controller 9 explained in the flowchart of FIG. 5 is shown in FIG. That is, in FIG. 6, the steering angle δ is detected corresponding to the steering angle command value δcom regardless of whether the backup clutch 5 is engaged or disengaged, and the steering angle command value δcom and the backup clutch 5 are engaged. The steering angle θ is detected, and the diagnosis result at the time of mechanical normality of the backup mechanism in which the steering angle θ is not detected corresponding to the turning angle command value δcom and the release of the backup clutch 5 is shown.

[Electrical diagnosis processing]
FIG. 7 is a flowchart showing the flow of the electrical diagnosis process executed by the steering reaction force controller 8 or the turning controller 9 of the first embodiment. Each step will be described below (electrical diagnosis unit). This process is executed in step S11 of the flowchart of FIG.

  In step S11-1, a check condition is set. Specifically, an ON signal is output to the transistor A and an OFF signal is output to the transistor B. This signal is a command for fastening the backup clutch 5.

  In step S11-2, following the check condition setting in step S11-1, it is checked whether a predetermined time T0 has elapsed since the signal was output to each of the transistors A and B. Considering the response delay until each transistor A, B operates, it does not proceed to the next step until a predetermined time T0 has elapsed. If the predetermined time T0 has elapsed, the process proceeds to step S11-3.

  In step S11-3, following the determination that the predetermined time T0 has elapsed in step S11-2, the voltage at point C in FIG. 2 is checked. If the voltage at the point C is within the range of 0V ± 0.2V, it is determined that it is operating normally, and the process proceeds to step S11-4. If the voltage at the point C is outside the range of 0V ± 0.2V, it is determined that the transistor A is abnormal and the clutch drive relay 13 has failed, and the process proceeds to step S11-7.

  In step S11-4, following the determination that the voltage at point C is in the range of 0V ± 0.2V in step S11-3, the check condition is changed. Specifically, an OFF signal is output to the transistor A and an ON signal is output to the transistor B. This signal is a command to release the backup clutch 5.

  In step S11-5, following the check condition change in step S11-4, it is checked whether or not a predetermined time T0 has elapsed since the signal was output to each of the transistors A and B. As in step S11-2, considering the response delay until the transistors A and B operate, the process does not proceed to the next step until a predetermined time T0 has elapsed. If the predetermined time T0 has elapsed, the process proceeds to step S11-6.

  In step S11-6, following the determination that the predetermined time T0 has elapsed in step S11-5, the voltage at point C in FIG. 2 is checked. When the voltage at the point C is in the range of 2V ± 0.2V, it is determined that the operation is normal, and the electrical diagnosis is terminated. If the voltage at the point C is outside the range of 2V ± 0.2V, it is determined that the transistor B is abnormal and the clutch drive relay 13 has failed, and the process proceeds to step S11-7.

  In step S11-7, following the determination that voltage ≠ 0V ± 0.2V in step S11-3 or the determination that voltage ≠ 2V ± 0.2V in step S11-6, some abnormality related to the backup mechanism has occurred. Therefore, E fail flag is set. Thereafter, an operation such as turning on a warning lamp and notifying the driver of an abnormality is performed according to the E-fail flag.

  In the first embodiment, the backup clutch 5 is released at the end of the electrical diagnosis. This is because it is possible to quickly shift to the SBW control, but the electrical diagnosis is possible even if the backup clutch 5 is engaged at the end of the electrical diagnosis.

[SBW control processing]
FIG. 8 is a flowchart showing the flow of the SBW control process executed by the steering reaction force controller 8 and the turning controller 9 of the first embodiment. Each step will be described below. This process is executed at a predetermined control cycle (for example, 5 msec) in step S15 of the flowchart of FIG.

  In step S15-1, normal SBW control calculation is performed. A steering reaction force controller 8 calculates a control command value for the steering reaction force actuator 4, and a steering controller 9 calculates a control command value for the steering actuator 9.

  In step S15-2, following the normal SBW control calculation in step S15-1, the electrical diagnosis end flag E_END_flag of the controller currently being calculated is checked to confirm whether or not the electrical diagnosis has ended. If the electrical diagnosis end flag E_END_flag is clear, the electrical diagnosis has not ended, and the process proceeds to step S15-3. When the electrical diagnosis end flag E_END_flag is set, since the electrical diagnosis has ended, the calculation of the current control cycle is ended.

  In step S15-3, following the determination of the E_END_flag set in step S15-2, 1 is added to the electrical diagnosis target controller number ED_CNT, and the next controller is set as the electrical diagnosis target controller.

  In step S15-4, following ED_CNT = ED_CNT + 1 in step S15-3, it is confirmed whether or not the controller that performs the electrical diagnosis is the controller that is currently calculating. If the controller number ED_CNT matches the controller number CNT_No, the controller that is currently operating is a controller that performs electrical diagnosis, and thus the process proceeds to step S15-5. If the controller number ED_CNT does not coincide with the controller number CNT_No, the calculation of the current control cycle is terminated because the controller currently being calculated is not a controller that performs electrical diagnosis.

  In step S15-5, following the determination that CNT_No = ED_CNT in step S15-4, the state of the vehicle speed VSP is checked. If the vehicle speed VSP is zero, the process proceeds to step S15-6. If it is not zero, it means that the vehicle is running, and thus the calculation of the current control cycle is terminated without performing an electrical diagnosis of the backup mechanism. A vehicle speed sensor (not shown) that detects the vehicle speed VSP corresponds to a vehicle running state detecting means.

  In step S15-6, following the determination of VSP = 0 in step S15-5, the state of the brake switch is checked. If the brake switch is ON (the brake is depressed), the process proceeds to step S15-7. If the brake switch is OFF, the process proceeds to step S15-7. A brake switch (not shown) corresponds to vehicle running state detecting means.

  In step S15-7, following the determination of turning off the brake switch in step S15-6, the state of the parking brake is checked. If the parking brake is ON, the process proceeds to step S15-8. When the parking brake is OFF, since the brake switch and the parking brake are both OFF, the calculation of the current control cycle is terminated without performing an electrical diagnosis of the backup mechanism. An inhibitor switch for detecting a parking brake operation not shown corresponds to a vehicle running state detecting means.

  In step S15-8, following the brake ON operation determination in step S15-6 or step S15-7, the state of the steering angle is checked. If the steering angle absolute value | STR | is within the predetermined value str0, the process proceeds to step S15-9. Here, the predetermined value str0 is a value near zero. If the steering angle absolute value | STR | exceeds the predetermined value str0, it is considered that the driver is steering, and thus the calculation of the current control cycle is terminated without performing an electrical diagnosis of the backup mechanism. The steering angle sensor 2 corresponds to a vehicle running state detection unit.

  In step S15-9, following the determination of | STR | ≦ str0 in step S15-8, the state of the steering angular velocity is checked. If the steering angular velocity absolute value | dSTR | is within the predetermined value dstr0, the process proceeds to step S15-11. Here, the predetermined value dstr0 is a value near zero. When the steering angular velocity absolute value | dSTR | exceeds the predetermined value dstr0, the process proceeds to step S15-10.

  In step S15-10, following the determination of | dSTR |> dstr0 in step S15-9, the output state of the steering torque sensor 3 (vehicle running state detecting means) is checked. The output S_TRQ of the steering torque sensor 3 is the difference between the steering torque by the driver and the reaction motor torque. When the steering torque sensor output S_TRQ is zero, the driver has released his hand from the steering wheel 1 or no force is applied. It can be judged that the hand is attached. If the absolute value | S_TRQ | of the steering torque sensor output is within the predetermined value trq0, the process proceeds to step S15-11. When the absolute value | S_TRQ | of the steering torque sensor output exceeds the predetermined value trq0, it is considered that the steering angle is changing, that is, the driver is performing the steering operation. The calculation of the current control cycle is terminated.

  In step S15-11, following the determination of | dSTR | ≦ dstr0 in step S15-9 or the determination of | S_TRQ | ≦ trq0 in step S15-10, the command value for variable gear control in SBW control is used as the gear. Let the ratio = 1 state. When performing electrical diagnosis of the backup mechanism during SBW control, control of the SBW control command value so that the gear ratio = 1 is performed, thereby minimizing the influence of the backup mechanism even when the backup clutch 5 is connected. Is possible. The command value calculated here is reflected in the SBW control in the next calculation cycle.

  In step S15-12, following the SBW command value gear ratio = 1 in step S15-11, an electrical diagnosis of the backup mechanism is performed based on the flowchart shown in FIG. 7, and the process proceeds to step S15-13.

  In step S15-13, following the electrical diagnosis in step S15-12, an electrical diagnosis end flag E_END_flag of the controller currently being calculated is set, and the process proceeds to step S15-14.

  In step S15-14, following the E_END_flag set in step S, the controller number ED_CNT to be electrically diagnosed is set to the controller number CNT_No currently being calculated, and the calculation of the current control cycle ends.

[Backup mechanism self-diagnosis function]
When there are multiple backup connection / disconnection control systems for fail-safe measures, it is necessary to execute SBW control after confirming whether the redundant control system is functioning. However, for example, in the case of five controllers, when the backup operation of all control systems is confirmed by the abnormality detection method of the mechanical backup mechanism, as shown in FIG. Controller 2 mechanical diagnostics → Controller 3 mechanical diagnostics → Controller 4 mechanical diagnostics → Controller 5 Mechanical diagnostics are completed and the diagnosis is completed, so the time required for the self-diagnosis of the mechanical backup mechanism is lengthened and the start of SBW control is delayed. End up.

  On the other hand, in the first embodiment, when there are five backup connection / disconnection control systems, one of the five controllers outputs a connection / disconnection signal to the backup mechanism, and then the backup mechanism steers. After mechanically connecting the steering part and the steered part, perform a mechanical diagnosis as to whether or not the driving force is transmitted between the steering part and the steered part. When the controller outputs a connection / disconnection signal to the backup mechanism, an electrical diagnosis is performed to determine whether the backup mechanism is connected / disconnected.

  That is, in the flowchart of FIG. 3, the controller that performs mechanical diagnosis after the ignition is turned on proceeds from step S1 to step S2, and mechanical diagnosis is executed in step S2. Then, when it is finished while outputting a diagnosis result that the mechanical diagnosis is normal, the process proceeds from step S2 to step S3 → step S4 → step S13, and the controller that performed the mechanical diagnosis is the controller that performs the electrical diagnosis. Wait for the end of diagnosis. On the other hand, controllers other than the controller that performs the mechanical diagnosis proceed to step S1, step S7, step S8, step S9, step S10, and step S11. In step S11, electrical diagnosis is performed using one controller. The Then, when outputting the diagnosis result indicating that the electrical diagnosis is normal, the process proceeds from step S11 to step S12 → step S13 → step S15 → step S16, and the SBW control is started. If the electrical diagnosis is abnormal, execute ED_CNT = ED_CNT + 1, etc., and execute again from step S10, perform electrical diagnosis with another controller, and start SBW control when there is a normal controller You may make it do.

  That is, in the first embodiment, when a self-diagnosis result of normality is obtained by mechanical diagnosis with respect to one controller, a self-diagnosis result of normality is obtained by electrical diagnosis with respect to another one controller, whereby the backup mechanism is We focused on the fact that it can be confirmed that the system can be operated by a normal system of a heavy system. Therefore, as long as the backup mechanism is mechanically and electrically normal, there is one controller for performing the mechanical diagnosis and the electrical diagnosis. Therefore, as shown in FIG. The self-diagnosis is completed only by passing 1 mechanical diagnosis → controller 2 electrical diagnosis. As a result, the time required for the self-diagnosis of the backup mechanism can be significantly reduced as compared with the case where the mechanical diagnosis is performed for all of the five controllers as in the prior art. By performing electrical diagnosis with at least two controllers that have a redundant configuration (mechanical diagnosis includes electrical diagnosis), the cause of the system abnormality is a failure of one of the diagnosed controllers. However, the backup mechanism can be reliably operated by another controller.

Further, in the first embodiment, as an initial diagnosis, mechanical diagnosis by one controller and electrical diagnosis by another controller are executed, and after starting SBW control, as shown in the flowchart of FIG. The electrical diagnosis (step S15-12) of the backup mechanism is performed by another controller remaining when the condition is satisfied (steps S15-5 to S15-10).
That is, since the mechanical diagnosis is completed at the time of the initial diagnosis, it can be confirmed that the backup mechanism can be operated only by the electrical diagnosis. As a result, as shown in FIG. 11, the self-diagnosis of the backup mechanism is completed in all other controllers that did not perform the initial diagnosis after the start of the SBW control without extending the initial diagnosis time for accelerating the start of the SBW control. be able to.

  If the vehicle is stopped and the brake is ON (steps S15-5 to S15-7) as a condition for performing the electrical diagnosis after the start of the SBW control, the vehicle is stopped while waiting for a signal or the like. In addition, an electrical diagnosis of the backup mechanism can be performed with another controller that has not performed the initial diagnosis.

  Further, as a condition for performing an electrical diagnosis after starting the SBW control, the steering angle absolute value | STR | is within a predetermined value str0 (near zero) and the absolute value of the steering angular velocity | dSTR | is within a predetermined value dstr0 ( In the case where the steering angle is not moving) (steps S15-8 to S15-9), when the steering angle is stopped near zero, that is, with other controllers that did not perform initial diagnosis during straight running It is possible to perform electrical diagnosis of the backup mechanism.

  Furthermore, if the absolute value | S_TRQ | of the steering torque sensor output is less than or equal to the predetermined value trq0 (near zero) as a condition for performing the electrical diagnosis after starting the SBW control (step S15-10), the electrical diagnosis Sometimes, the driver feels uncomfortable by temporarily connecting the backup mechanism. That is, the steering torque sensor output S_TRQ is the difference between the steering torque by the driver and the reaction force motor torque. When the steering torque sensor 3 is zero output, the driver has released his hand from the steering wheel 1 or applied no force. It can be determined that the hand is attached to. In such a state, by conducting an electrical diagnosis of the backup mechanism, it is possible to suppress a sense of incongruity to the driver by temporarily connecting the backup mechanism.

  In addition, during the electrical diagnosis of the backup mechanism after the start of SBW control, the gear ratio of variable gear control in SBW control is set to 1. Thus, even if the driver performs a steering operation during the electrical diagnosis, the SBW control is performed so that the gear ratio becomes 1, so that the driver does not feel uncomfortable due to the operation of the backup mechanism.

Next, the effect will be described.
In the steering control device of the first embodiment, the effects listed below can be obtained.

  (1) The steering part having the steering wheel 1 (steering wheel) and the steering reaction force actuator 4 and the steering part having the steering wheel 12 and the steering actuator 7 are mechanically separated and connected via a backup mechanism. A plurality of steering reaction force controllers 8 and a steerer that are capable of driving and controlling at least one of the steering reaction force actuator 4 and the steering actuator 7 and controlling connection / disconnection of the backup mechanism by a connection / disconnection signal. In the steering control device provided with the controller 9 (control means), the controller 8, 9, when the connection / disconnection signal is output, the electrical diagnosis unit for performing an electrical diagnosis as to whether the backup mechanism is connected / disconnected. And when the backup mechanism mechanically connects the steering unit and the steered unit after outputting the connection / disconnection signal, A mechanical diagnosis unit that performs a mechanical diagnosis as to whether or not a driving force is transmitted to and from the rudder unit, and after at least one of the controllers 8 and 9 completes the mechanical diagnosis, the other controller 8 , 9 has a backup mechanism self-diagnosis unit for executing the electrical diagnosis, and therefore, when there are a plurality of backup connection / disconnection control systems, the mechanical diagnosis is performed while ensuring the reliable connection / disconnection operation of the backup mechanism. In addition, the time required for electrical diagnosis can be reduced.

  (2) The backup mechanism self-diagnosis unit is configured to perform a mechanical operation since one of the controllers 8 and 9 completes the mechanical diagnosis and the other one of the controllers 8 and 9 executes the electrical diagnosis. One controller performs diagnosis, and the other controllers perform only electrical diagnosis, and the diagnosis time can be further shortened while confirming a normal system with two or more systems.

  (3) Vehicle running state detecting means for detecting the vehicle running state is provided, and the backup mechanism self-diagnostic unit is configured so that after one of the controllers 8, 9 completes the mechanical diagnosis, the other one of the controllers 8, If the diagnosis result is normal when 9 performs the electrical diagnosis, the controllers 8 and 9 start SBW control. When the vehicle running state is a predetermined condition, the mechanical diagnosis or the electrical diagnosis is performed. The controllers 8 and 9 not performing diagnosis complete the electrical diagnosis of the backup mechanism in all the controllers 8 and 9 without extending the initial diagnosis that delays the start of SBW control in order to execute the electrical diagnosis. Can be

  (4) Since the vehicle running state detecting means detects the stop state of the vehicle, the backup mechanism in the other controllers 8 and 9 that did not perform the initial diagnosis while the vehicle stopped due to a signal or the like. An electrical diagnosis can be made.

  (5) Since the vehicle running state detecting means detects the straight running state of the vehicle, it can perform an electrical diagnosis of the backup mechanism in the other controllers 8 and 9 that did not perform the initial diagnosis during the straight running. .

  (6) When the backup mechanism self-diagnosis unit completes the mechanical diagnosis and the diagnosis result is abnormal, the other controllers 8 and 9 do not execute the mechanical diagnosis and the electrical diagnosis. Therefore, it is possible to immediately cope with the abnormality of the backup mechanism without waiting for diagnosis by the other controllers 8 and 9 by turning on the warning lamp or stopping the control.

  (7) When the steering reaction force controller 8 drives the steering reaction force actuator 4 and the driving force is transmitted to the steered portion, the mechanical diagnosis unit (FIG. 4) mechanically In order to diagnose that it is normal, when the mechanical diagnosis target is the steering reaction force controller 8, it can be confirmed by the steered portion that the backup mechanism is mechanically connected.

  (8) The mechanical diagnosis unit (FIG. 5) is mechanically normal when the driving force is transmitted to the steering unit when the steering controller 9 drives the steering actuator 7. Therefore, when the mechanical diagnosis target is the steering controller 9, the steering unit can confirm that the backup mechanism is mechanically connected.

  (9) When the result of the mechanical diagnosis is normal and the result of the electrical diagnosis by at least one of the other controllers 8 and 9 is normal, the backup mechanism includes the steering unit and the steering unit. The controller 8 and 9 are mechanically separated from the steered portion, and the controllers 8 and 9 start driving control (SBW control) of the steered actuator 7 and the steering reaction force actuator 4, so that when the system is normal, one controller When the mechanical diagnosis and the electrical diagnosis by the other controller are completed, the SBW control can be started with good response without waiting for the diagnosis by the other controller.

  (10) When the result of the mechanical diagnosis is normal and the result of the electrical diagnosis by the other controllers 8 and 9 is abnormal, the backup mechanism includes the steering unit and the steering unit. And the controllers 8 and 9 start driving control (EPS control) of the steering actuator 7 or the steering reaction force actuator 4 and are thus diagnosed as abnormal only by electrical diagnosis. EPS control that obtains steering assist force by the steering actuator 7 or the steering reaction force actuator 4 based on the fact that the mechanical connection between the steering unit and the steering unit by the backup mechanism is guaranteed (mechanical diagnosis is normal). Power steering control) can be started immediately.

  The second embodiment is an example in which the electrical diagnosis of all the other controllers is sequentially executed successively after the mechanical diagnosis by one controller. Since the configuration is the same as that of the first embodiment shown in FIGS. 1 and 2, illustration and description thereof are omitted.

Next, the operation will be described.
[Backup mechanism self-diagnosis processing]
FIG. 12 is a flowchart showing the flow of the backup mechanism self-diagnosis process executed by the steering reaction force controller 8 or the steering controller 9 of the second embodiment. Each step will be described below (backup mechanism self-diagnosis unit). . This process is executed when the system is started (when the ignition is on). Steps S21 to S28 correspond to steps 1 to S8 in the flowchart of FIG.

  In step S29, following the determination of clearing the M fail flag in step S28, a controller having a value obtained by subtracting one from the currently calculated controller number CNT_No, that is, the previous controller when performing electrical diagnosis in order, Check if the electrical diagnosis is finished. If E_END_flag of the previous controller is set, the process proceeds to step S30. In the case of clear, since the electrical diagnosis of the previous controller has not been completed yet, it waits for E_END_flag to be set. When the controller having a value obtained by subtracting one from the controller number CNT_No being calculated is the controller number to be mechanically diagnosed, the process proceeds to step S30.

  In step S30, following the determination that E_END_flag of the previous controller in step S29 is set, an electrical diagnosis of the backup mechanism (flowchart in FIG. 6) is performed, and the process proceeds to step S31.

  In step S31, following the electrical diagnosis in step S30, an electrical diagnosis end flag E_END_flag of the controller currently being calculated is set, and the process proceeds to step S32. The electrical diagnosis end flag E_END_flag is set separately for each controller.

  In step S32, following the determination of clearing the M fail flag in step S24 or the E_END_flag set in S31, the state of all the electrical diagnosis end flags E_END_flag is checked, and the diagnosis of all the controllers is completed Proceeds to step S34. If all the controllers have not been diagnosed, wait. That is, it waits until all the diagnosis of the controllers other than the controller being calculated is completed.

  In step S34, following the determination that all the controllers have been diagnosed in step S32, the state of the E-fail flag is confirmed. Here, since the mechanical diagnosis is already OK, if at least one of the controllers other than the controller that performed the mechanical diagnosis has an electrical diagnosis OK, the backup system has a dual system. realizable.

  In Example 2, when all E fail flags of the four controllers except the controller that performed the mechanical diagnosis among the five controllers are set, the redundant configuration cannot be realized, so the process proceeds to step S35. Then, the process proceeds to step S36.

  In step S35, following the determination that there are four or more fail controllers in which the E fail flag is set in step S34, the backup mechanism is connected and EPS control is executed.

  In step S36, following the determination in step S34 that the number of fail controllers in which the E fail flag is set is three or less (one or more is OK), normal SBW control is started.

[Backup mechanism self-diagnosis function]
In the second embodiment, in the case where there are five backup connection / disconnection control systems, one of the five controllers is subjected to mechanical diagnosis, and after completion of this mechanical diagnosis, the other controllers are continued. Thus, the self-diagnosis by all the controllers is terminated at the initial diagnosis.

  That is, in the flowchart of FIG. 12, after the ignition is turned on, the controller that performs mechanical diagnosis proceeds from step S21 to step S22, and mechanical diagnosis is executed in step S22. Then, when the process ends while outputting a diagnosis result indicating that the mechanical diagnosis is normal, the process proceeds from step S22 to step S23 → step S24 → step S32, and the controller that performed the mechanical diagnosis ends the diagnosis of another controller. Wait for. On the other hand, the controller other than the controller that performs the mechanical diagnosis proceeds to step S21 → step S27 → step S28 → step S29, and waits for the previous No controller to finish the electrical diagnosis in step S29. The process proceeds to step S30. In step S30, an electrical diagnosis is performed. When the diagnosis of all the controllers is completed, the process proceeds from step S32 to step S34. If the result of the electrical diagnosis of at least one controller other than the controller used for the mechanical diagnosis is normal, the process proceeds from step S34 to step S36. The SBW control is started. Further, when the results of the electrical diagnosis of the four controllers other than the controller used for the mechanical diagnosis are all abnormal, the process proceeds from step S34 to step S35, and EPS control is started.

  That is, in the second embodiment, when a diagnosis result of normality is obtained by mechanical diagnosis with respect to one controller, the electrical diagnosis with respect to the other four controllers is terminated at the initial diagnosis time. Therefore, as shown in FIG. 13, the initial diagnosis is completed when the controller 1 mechanical diagnosis → the controller 2 electrical diagnosis → the controller 3 electrical diagnosis → the controller 4 electrical diagnosis → the controller 5 electrical diagnosis passes after the ignition is turned on. . As a result, the time required for the self-diagnosis of the backup mechanism can be shortened as compared with the case where mechanical diagnosis is performed for all of the five controllers, as in the prior art shown in FIG. Further, when the SBW control is started, unlike the first embodiment, the electrical diagnosis of the remaining controller is not performed after the predetermined condition is satisfied.

  Furthermore, if it is determined that the electrical diagnosis is normal for only one controller among the four controllers except for one controller that has performed the mechanical diagnosis, the SBW control can be started. In the second embodiment, the electrical diagnosis is performed for all controllers other than the controller that performed the mechanical diagnosis. Therefore, as long as a redundant configuration can be realized even if an abnormality occurs in some controllers, the SBW Maximum control can be ensured.

Next, the effect will be described.
In the steering control device of the second embodiment, in addition to the effects (1) and (2) of the first embodiment, the following effects can be obtained.

  (11) The backup mechanism self-diagnosis unit is configured so that after one of the controllers 8 and 9 completes the mechanical diagnosis, the other controllers 8 and 9 sequentially execute the electrical diagnosis. While shortening the time required for diagnosis compared with the prior art, diagnosis by all controllers is terminated at the initial diagnosis, and as long as a redundant configuration can be realized, SBW control can be ensured to the maximum extent.

  The third embodiment is an example in which the controller to be mechanically diagnosed is changed every time the system is started, and the self-diagnosis of the backup mechanism using not only a specific controller but also all the controllers is possible. Since the configuration is the same as that of the first embodiment shown in FIGS. 1 and 2, illustration and description thereof are omitted.

Next, the operation will be described.
[Backup mechanism self-diagnosis processing]
FIG. 14 is a flowchart showing the flow of the backup mechanism self-diagnosis process executed by the steering reaction force controller 8 or the steering controller 9 of the third embodiment. Each step will be described below (backup mechanism self-diagnosis unit). . This process is executed when the system is started (when the ignition is on). Steps S41 to S58 respectively correspond to Steps 1 to S18 in the flowchart of FIG.

  In step S40, a controller for diagnosis is set. Each controller has a number (CNT_No) of 1 to 5 (the number of controllers in this embodiment), and 1 is added to the controller number M_CNT that was mechanically diagnosed when the ignition was turned on the previous time, and this time the ignition is turned on. The controller number MD_CNT for the mechanical diagnosis at the time. If MD_CNT exceeds the number of controllers, MD_CNT = 1.

[Backup mechanism self-diagnosis function]
In the third embodiment, when there are five backup connection / disconnection control systems, the controller that performs the mechanical diagnosis and electrical diagnosis of the backup mechanism is the controller that performed the previous diagnosis every time the system is turned on. Different controllers are used to perform mechanical and electrical diagnostics.

  That is, in the flowchart of FIG. 14, the controller used for the self-diagnosis is changed every time the initial diagnosis of the backup mechanism is performed by the ignition ON operation (step S40). After the controller change is selected, as in the first embodiment, a mechanical diagnosis is performed for one changed controller, and after the mechanical diagnosis is completed, an electrical diagnosis for another controller is executed. Thus, the initial diagnosis is finished, and if the two initial diagnosis results are normal, the SBW control is started.

  Therefore, as shown in FIG. 15, the first initial diagnosis is completed when the controller 1 mechanical diagnosis → the controller 2 electrical diagnosis elapses from the time of the first ignition ON. Further, the second initial diagnosis is completed by passing the controller 2 mechanical diagnosis → the controller 3 electrical diagnosis from the time of the second ignition ON. Furthermore, the third initial diagnosis is completed by passing the controller 3 mechanical diagnosis → the controller 4 electrical diagnosis from the time of the third ignition ON. As a result, it is possible to perform self-diagnosis of the backup mechanism using not only a specific controller but all controllers. Further, as in the first embodiment, the self-diagnosis can be executed without extending the time for one self-diagnosis. Since other operations are the same as those in the first embodiment, description thereof is omitted.

Next, the effect will be described.
In the steering control device of the third embodiment, in addition to the effects (1) to (10) of the first embodiment, the following effects can be obtained.

  (12) The backup mechanism self-diagnosis unit, when one of the controllers 8 and 9 completes the mechanical diagnosis and then another one of the controllers 8 and 9 executes the electrical diagnosis, When normal, the controllers 8 and 9 start SBW control, and when the controllers 8 and 9 are stopped and then started up, the mechanical diagnosis or the electrical diagnosis is executed up to the previous time. Of the controllers 8, 9 that are not, a particular controller 8, 9 performs the electrical diagnosis after one of the controllers 8, 9 completes the mechanical diagnosis. The self-diagnosis of the back-up mechanism using all the controllers can be performed.

  As mentioned above, although the steering control apparatus of this invention has been demonstrated based on Example 1-3, it is not restricted to these Examples about a concrete structure, Each claim of a claim is a claim. Design changes and additions are allowed without departing from the gist of the invention.

  In the first embodiment, when the electrical diagnosis of the backup mechanism is performed by satisfying a predetermined condition after the SBW control is started, from the viewpoint of ensuring safety and minimizing the influence on the driver, (1) the vehicle stop state, In addition, an example of performing an electrical diagnosis of the backup mechanism when the three conditions (2) near the steering angle of zero and (3) the driver is not steering is shown. The electrical diagnosis of the backup mechanism may be performed when a single condition is satisfied, or the electrical diagnosis of the backup mechanism is performed when two conditions appropriately combined among the three conditions are satisfied. May be.

  In the first and third embodiments, as a backup mechanism self-diagnosis unit, after one control unit completes the mechanical diagnosis, another one control unit performs an electrical diagnosis. In the second embodiment, An example is shown in which, after one control means completes a mechanical diagnosis, the other control means sequentially executes an electrical diagnosis. However, the number of control means for performing the mechanical diagnosis and the number of control means for performing the electrical diagnosis are not limited to those in the first to third embodiments. In short, at least one control means is used as the backup mechanism self-diagnosis unit. Any other control means that performs electrical diagnosis after completing the mechanical diagnosis is included in the present invention.

  In the first to third embodiments, an example of a steering control device applied to a steer-by-wire system using a backup clutch and a backup cable as a backup mechanism has been shown. However, any system other than the first to third embodiments can be used as long as the system has a backup mechanism. It can also be applied to steer-by-wire systems.

1 is an overall configuration diagram illustrating a steer-by-wire system to which a steering control device according to a first embodiment is applied. It is a control system circuit diagram to which the steering control device of the first embodiment is applied. 3 is a flowchart showing a flow of a backup mechanism self-diagnosis process executed by the steering reaction force controller or the steering controller of the first embodiment. 3 is a flowchart illustrating a flow of a mechanical diagnosis process of a backup mechanism executed by the steering reaction force controller according to the first embodiment. 3 is a flowchart illustrating a flow of a mechanical diagnosis process of a backup mechanism executed by a steering controller according to the first embodiment. It is a figure which shows the time chart of the mechanical diagnosis of the backup mechanism by the controller for steering demonstrated with the flowchart of FIG. It is a flowchart which shows the flow of the electrical diagnostic process performed in the controller for steering reaction force of the Example 1, or the controller for turning. 3 is a flowchart illustrating a flow of SBW control processing executed by a steering reaction force controller and a steering controller according to the first embodiment. It is a time chart which shows the self-diagnosis process of the mechanical backup mechanism of a prior art example. 6 is a time chart showing a self-diagnosis process (initial diagnosis until the start of SBW control) of the backup mechanism in the first embodiment. 6 is a time chart showing self-diagnosis processing (including electrical diagnosis after starting SBW control) of the backup mechanism in the first embodiment. It is a flowchart which shows the flow of the backup mechanism self-diagnosis process performed in the controller for steering reaction force of the Example 2, or the controller for steering. 6 is a time chart showing a self-diagnosis process of a backup mechanism in Embodiment 2. 10 is a flowchart illustrating a flow of a backup mechanism self-diagnosis process executed by a steering reaction force controller or a steering controller according to a third embodiment. 10 is a time chart showing a self-diagnosis process of a backup mechanism in Embodiment 3.

Explanation of symbols

1 Steering wheel (handle)
2 Steering angle sensor (vehicle running state detection means)
3 Steering torque sensor (vehicle running state detection means)
4 Steering reaction force actuator 5 Backup clutch (backup mechanism)
6 Backup cable (backup mechanism)
7 Steering actuator 8 Steering reaction force controller (control means)
9 Steering controller (control means)
10 Communication Line 11 Clutch Control Signal Line 12 Steering Wheel 13 Clutch Drive Relay

Claims (13)

A steering part having a steering wheel and a steering reaction force actuator and a steering part having a steering wheel and a steering actuator can be mechanically separated and connected via a backup mechanism,
In the steering control device comprising a plurality of control means for controlling the connection / disconnection of the backup mechanism according to the connection / disconnection signal, while drivingly controlling at least one of the steering reaction force actuator and the steering actuator,
The control means includes
An electrical diagnostic unit for performing an electrical diagnosis as to whether the backup mechanism is connected or disconnected when the connection / disconnection signal is output;
After the connection / disconnection signal is output, whether the driving force is transmitted between the steering unit and the steered unit when the backup mechanism mechanically connects the steering unit and the steered unit. A mechanical diagnosis unit for performing such mechanical diagnosis,
A backup mechanism self-diagnosis unit in which the other control means executes the electrical diagnosis after at least one of the control means completes the mechanical diagnosis;
A steering control device comprising: In the steering control device according to claim 1,
The backup control device self-diagnosis unit is a steering control device in which, after one of the control units completes the mechanical diagnosis, the other one of the control units executes the electrical diagnosis. In the steering control device according to claim 1 or 2,
Vehicle running state detecting means for detecting the vehicle running state is provided;
The backup mechanism self-diagnosis unit, when one of the control means completes the mechanical diagnosis, and when the other one of the control means executes the electrical diagnosis, when the diagnosis result is normal, The control means starts drive control, and when the vehicle running state is a predetermined condition, the control means not performing the mechanical diagnosis or the electrical diagnosis executes the electrical diagnosis. Control device. In the steering control device according to claim 3,
The vehicle travel state detection means detects a stop state of the vehicle. In the steering control device according to claim 3,
The vehicle running state detecting means detects a straight running state of the vehicle. In the steering control device according to claim 1 or 2,
The backup control device self-diagnosis unit is characterized in that after one of the control means completes the mechanical diagnosis, the other control means sequentially executes the electrical diagnosis. In the steering control device according to claim 1 or 2,
The backup mechanism self-diagnosis unit, when one of the control means completes the mechanical diagnosis, and when the other one of the control means executes the electrical diagnosis, when the diagnosis result is normal, The control means starts the drive control, and when the control means is stopped and then started, one of the control means that has not executed the mechanical diagnosis or the electrical diagnosis up to the previous time. After the control means completes the mechanical diagnosis, another one of the control means executes the electrical diagnosis. The steering control device according to any one of claims 1 to 7,
When the backup mechanism self-diagnosis unit completes the mechanical diagnosis and the diagnosis result is abnormal, the other control means does not execute the mechanical diagnosis and the electrical diagnosis. Steering control device. The steering control device according to any one of claims 1 to 8,
The mechanical diagnosis unit diagnoses that the control unit is mechanically normal when the driving force is transmitted to the steering unit when the control unit drives the steering reaction force actuator. Control device. The steering control device according to any one of claims 1 to 9,
When the control means drives the steering actuator, the mechanical diagnosis unit diagnoses mechanically normal when the driving force is transmitted to the steering unit. . The steering control device according to any one of claims 1 to 10,
When the result of the mechanical diagnosis is normal and the result of the electrical diagnosis by at least one other control means is normal, the backup mechanism includes the steering unit and the steering unit. The steering control device characterized in that it is mechanically disconnected and the control means starts driving control of the steering actuator and the steering reaction force actuator. The steering control device according to any one of claims 1 to 11,
When the result of the mechanical diagnosis is normal and the result of the electrical diagnosis by the other control means is abnormal, the backup mechanism mechanically connects the steering unit and the steered unit. The steering control device is connected, and the control means starts driving control of the steering actuator or the steering reaction force actuator. A steering part having a steering wheel and a steering reaction force actuator and a steering part having a steering wheel and a steering actuator can be mechanically separated and connected via a backup mechanism,
In the steering control device comprising a plurality of control means for controlling the connection / disconnection of the backup mechanism according to the connection / disconnection signal, while drivingly controlling at least one of the steering reaction force actuator and the steering actuator,
When the control unit outputs the connection / disconnection signal, the control unit performs an electrical diagnosis as to whether or not the backup mechanism is connected / disconnected, and after outputting the connection / disconnection signal, the backup mechanism is connected to the steering unit and the steered wheel. A mechanical diagnosis is performed as to whether or not a driving force is transmitted between the steering unit and the steered unit, and at least one of the control means includes the mechanical unit. The steering control device, wherein after completion of the diagnosis, the other control means executes the electrical diagnosis.

Images