JP2006335209A - Abnormality detecting device for steering device in vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect an abnormality in a connection/disconnection device for selectively and mechanically connect a steering wheel and a turning wheel without affecting a driving state in a steering device for a vehicle in a steer-by-wire method. <P>SOLUTION: In the steering device for a vehicle in a steer-by-wire method, first and second electromagnetic clutches 32 and 33 are provided between a steering input shaft 12 and a steering output shaft 24, so that the steering input shaft 12 and the steering output shaft 24 can be selectively connected and disconnected. By controlling to disconnect one of the first and the second electromagnetic clutches 32 and 33, and controlling to connect the other, an electric motor 22 for turning is drive-controlled, so that a disconnection abnormality of the first or the second electromagnetic clutch 32 or 33 (an abnormality that they are not disconnected) depending on if the steering input shaft 12 is rotated or not. In this case, the electric motor 22 for turning is rotated to reciprocate right and left, so that a turning angle of right and left front wheels FW1 and FW2 returns to an initial value when the detection of the first and the second electromagnetic clutches 32 and 33 is completed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an abnormality detection device for a steering device for a steer-by-wire vehicle.

Conventionally, the steering wheel and the steered wheel are mechanically separated, and the steered wheel is steered at the same time as the steered wheel is steered by controlling the steering electric motor provided on the steered wheel side according to the steering operation of the steering handle. 2. Description of the Related Art A steering apparatus for a vehicle adopting a steer-by-wire system in which a steering reaction force is applied by controlling an operation of a steering reaction force electric motor provided on the steering handle side in accordance with the steering operation is well known. In this type of steering device, for example, as shown in Patent Document 1 below, in order to ensure the turning of the steered wheels according to the steering operation of the steering handle even when the steering electric motor is abnormal. An interrupter is placed between the input member connected to the steering wheel side and the output member connected to the steered wheel side, and the input member and the output member are normally disconnected by setting the interrupter in a disconnected state. When the steering electric motor is abnormal, the interrupter is set to the connected state to connect the input member and the output member.
JP 2001-213335 A

  The above-mentioned Patent Document 1 mentions detection of an abnormality of the electric motor for steering, but does not mention abnormality of the interrupter.

  The present invention has been made to address the above-described problems, and an object of the present invention is to selectively select an input member on the steering wheel side and an output member on the steered wheel side without affecting the driving operation of the vehicle. It is an object of the present invention to provide an abnormality detection device for a vehicle steering device that can detect an abnormality of an intermittent device that is disconnected and connected.

  In order to achieve the above object, the features of the present invention include an input member connected to a steering handle and displaced in conjunction with the steering handle, an output member connected to a steered wheel and displaced in conjunction with the steered wheel, It is interposed between the input member and the output member and is selectively switched between the disconnected state and the connected state. In the disconnected state, the input member and the output member are disconnected so that power cannot be transmitted. An intermittent device for connecting the output member so as to be able to transmit power, an electric motor for steering reaction force connected to the input member for applying a reaction force to the steering operation of the steering handle, and a steering handle connected to the output member In a steer-by-wire vehicle steering apparatus having a steering electric motor for steering the steered wheels by displacing the output member according to the steering operation of the steering wheel, the steering angle of the steering handle is detected. Steering detected by the steering angle sensor during rotation of the turning electric motor by rotating the turning electric motor by a predetermined amount in opposite directions with the angle sensor and the intermittent device set to the disconnected state. An abnormality detecting means for detecting a disconnection abnormality of the interrupting device when the angle changes is provided.

  In this case, for example, the abnormality detection means is configured to rotate the electric motor for steering by a predetermined amount in one direction and the electric motor for steering by a predetermined amount in the one direction by the first driving means. After that, the steering angle detected by the steering angle sensor is changed when the second driving means for rotating the electric motor for turning by a predetermined amount in the direction opposite to the one direction and the electric motor for turning are changed. It is good to comprise with the 1st abnormality detection means which detects the cutting | disconnection abnormality of an intermittent device on condition.

  In the present invention configured as described above, even when the intermittent device is set to the disconnected state, when the steering angle detected by the steering angle sensor is changed by rotating the steering electric motor, That is, when the input member and the steering wheel are displaced, the interrupting device is erroneously connected, and thus the disconnection device disconnection abnormality (abnormality that is not disconnected) is detected. In this abnormality detection, since the steering electric motor is rotated by a predetermined amount in opposite directions, the steered wheels after the abnormality detection are always returned to the steered position at the start of the abnormality detection. Therefore, it is possible to prevent the positional deviation between the steering angle of the steering wheel and the turning angle of the steered wheels, and the driving operation of the vehicle is not affected.

  Another feature of the present invention is that when the abnormality detecting means is constituted by the first driving means, the second driving means, and the first abnormality detecting means, the first driving means is the first electric motor for turning. First direction drive control means for driving and controlling the electric motor for turning in order to rotate the steering electric motor by a predetermined amount, non-rotation detecting means for detecting non-rotation of the electric motor for turning, and first direction drive control means When the non-rotation of the steered electric motor is detected by the non-rotation detecting means during the drive control of the steered electric motor, the steered electric motor is rotated in the second direction opposite to the first direction. And the second direction drive control means for driving and controlling the steering electric motor.

  According to this, even when the side of the steered wheel is in contact with the road shoulder or the like and the steered wheel cannot be steered in one direction corresponding to the rotation in the first direction, the steered wheel is moved in the other direction. When the turning electric motor corresponding to the turning of the steering wheel can be rotated in the second direction, the rotation of the turning electric motor is secured and the disconnection abnormality in the intermittent device can be detected as described above. It becomes. In this case, the second drive means rotates the electric motor for steering by a predetermined amount in the first direction opposite to the second direction, so that the steered wheel after the abnormality is detected always rotates at the start of the abnormality detection. It is returned to the rudder position and does not affect the driving operation of the vehicle.

  Another feature of the present invention is that the abnormality detection means further detects non-rotation of the steering electric motor by the non-rotation detection means during drive control of the steering electric motor by the second direction drive control means. In this case, the second abnormality detecting means for detecting an abnormality of the steering electric motor is provided. According to this, an abnormality of the electric motor for turning is also detected.

  Another feature of the present invention resides in that the first and second driving means gradually change the rotation angle of the steering electric motor with time. Thus, there is a case where the change of the steering angle detected by the steering angle sensor can be detected, that is, the disconnection abnormality of the intermittent device can be detected without increasing the rotation angle of the electric motor for steering. As a result, it is possible to minimize the change in the turning angle of the steered wheels and the change in the steering angle of the steering wheel in order to detect the abnormality of the interrupting device, and it is possible to minimize the change in the state of the vehicle accompanying the detection of the abnormality. It becomes.

  Another feature of the present invention is that the output torque of the electric motor for turning is set to be larger than the output torque of the electric motor for steering reaction force, and further, the turning is performed to detect disconnection abnormality of the intermittent device. There is provided a stationary control means for controlling the steering reaction force electric motor so that the steering reaction force electric motor does not rotate when the electric motor for rotation is rotated.

  In another feature of the present invention configured as described above, if a disconnection abnormality occurs in the interrupting device, that is, if the interrupting device is erroneously connected, the output torque of the steering electric motor is for the steering reaction force. Since it is larger than the output torque of the electric motor, the input member and the steering handle are driven by the steering electric motor, the steering angle of the steering handle changes, and the disconnection abnormality of the intermittent device can be detected. Also, since the steering handle is controlled to be stationary with an appropriate force by the stationary control means, the steering angle of the steering handle does not change if the interrupting device is cut without any abnormality, and the abnormality of the interrupting device is accurately detected. Will be detected. This also makes it possible to accurately detect the disconnection abnormality of the interrupting device with a small change in the steering angle.

  Another feature of the present invention is that the interrupting device is composed of first and second interrupters that are connected in series via a cable and selectively switched to a connected state and a disconnected state, respectively. , One of the first and second interrupters is set to a disconnected state, and the other of the first and second interrupters is set to a connected state, This is because a cutting abnormality is detected.

  According to this, the cable is driven by the rotation of the electric motor for turning when the disconnection abnormality of the interrupting device constituted by the first and second interrupters is detected. Therefore, even if the cable is fixed to a covering member such as a pipe that accommodates the cable, the fixing of the cable is canceled by the driving, and the subsequent operation becomes accurate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall schematic diagram of a vehicle steering apparatus according to the embodiment.

  This vehicle steering device mechanically includes a steering operation device 10 that is steered by a driver and a steering device 20 that steers left and right front wheels FW1 and FW2 as steered wheels according to the steering operation of the driver. The steer-by-wire method is used. The steering operation device 10 includes a steering handle 11 as an operation unit that is rotated by a driver. The steering handle 11 is fixed to the upper end of the steering input shaft 12, and a steering reaction force electric motor 13 is assembled to the lower portion of the steering input shaft 12. The steering reaction force electric motor 13 drives the steering input shaft 12 to rotate about the axis via the speed reduction mechanism 14.

  The steered device 20 includes a rack bar 21 that extends in the left-right direction of the vehicle. The left and right front wheels FW1, FW2 as steered wheels are connected to both ends of the rack bar 21 via a tie rod and a knuckle arm (not shown) so as to be steerable. The left and right front wheels FW1, FW2 are steered to the left and right by the displacement of the rack bar 21 in the axial direction. On the outer periphery of the rack bar 21, a steering electric motor 22 assembled in a housing (not shown) is provided. The rotation of the steered electric motor 22 is decelerated by the screw feed mechanism 23 and is converted into an axial displacement of the rack bar 21. The steering device 20 also has a steering output shaft 24 that can rotate around an axis. A pinion gear 25 is fixed to the lower end of the steering output shaft 24. The pinion gear 25 meshes with rack teeth 21a provided on the rack bar 21, and the rack bar 21 is axially rotated by rotation around the axis of the steering output shaft 24. It is displaced to.

  A cable 31 as an intermediate member is disposed between the steering input shaft 12 and the steering output shaft 24. The cable 31 transmits the rotation around the axis of the steering input shaft 12 to the steering output shaft 24. A first electromagnetic clutch 32 is disposed between the fixing member 31 a at the upper end of the cable 31 and the lower end of the steering input shaft 12. The first electromagnetic clutch 32 is set in a disconnected state in an energized state to disconnect the cable 31 and the steering input shaft 12 so that power cannot be transmitted, and is set in a connected state in a non-energized state to set the cable 31 and the steering input shaft 12. And are connected so that power can be transmitted. A second electromagnetic clutch 33 is disposed between the fixing member 31 b at the lower end of the cable 31 and the upper end of the steering output shaft 24. The second electromagnetic clutch 33 is set in a disconnected state in an energized state to disconnect the cable 31 and the steering output shaft 24 so that power cannot be transmitted, and is set in a connected state in a non-energized state to set the cable 31 and the steering output shaft 24. And are connected so that power can be transmitted.

  The first and second electromagnetic clutches 32 and 33 constitute an interrupter of the present invention, and the first electromagnetic clutch 32, the second electromagnetic clutch 33 and the cable 31 constitute an interrupting device of the present invention. Further, the steering input shaft 12, the steering output shaft 24, the pinion gear 25, the rack bar 21, and the like constitute a steering force transmission mechanism that transmits the steering operation of the steering handle 11 to the left and right front wheels FW1, FW2. And the said interruption device is interposed in this steering force transmission mechanism.

  Next, the electric control device 40 that inspects and controls the steering reaction force electric motor 13, the steering electric motor 22, and the electromagnetic clutches 32 and 33 will be described. The electric control device 40 includes a steering angle sensor 41, a steering torque sensor 42, a turning angle sensor 43, and a vehicle speed sensor 44. The steering angle sensor 41 is assembled to the steering input shaft 12 and measures the rotation angle around the axis of the steering input shaft 12 to detect the rotation angle from the neutral position of the steering handle 11 and output it as the steering angle θ of the steering wheel. To do. Note that the steering angle θ of the steering wheel 11 is “0” as the neutral position of the steering wheel 11, the steering angle in the right direction is represented by a positive value, and the steering angle in the left direction is represented by a negative value. The steering torque sensor 42 detects torque acting on the steering input shaft 12 and outputs it as steering torque T. The steering torque T represents positive torque when the steering handle 11 is steered in the right direction, and represents negative torque when steered in the left direction. The turning angle sensor 43 is assembled to the rack bar 21 and measures the axial displacement of the rack bar 21 to detect and output the actual turning angle δ of the left and right front wheels FW1 and FW2. The actual turning angle δ is represented by a positive value for the rightward turning angle of the left and right front wheels FW1 and FW2, with the neutral position of the left and right front wheels FW1 and FW2 being “0”, and the leftward direction of the left and right front wheels FW1 and FW2. The steering angle of is expressed as a negative value. Further, the turning angle sensor 43 may be configured to detect the actual turning angle δ by detecting the rotation angle of the steering output shaft 24. The vehicle speed sensor 44 detects and outputs the vehicle speed V.

  The electric control device 40 includes an inspection electronic control unit (hereinafter referred to as an inspection ECU) 46, a steering reaction force electronic control unit (hereinafter referred to as an steering reaction force ECU) 47, and a steering device that are connected to each other. An electronic control unit (hereinafter referred to as a steering ECU) 48 is provided. A steering angle sensor 41, a steering torque sensor 42, a turning angle sensor 43, and a vehicle speed sensor 44 are connected to the inspection ECU 46. A steering angle sensor 41 and a vehicle speed sensor 44 are connected to the steering reaction force ECU 47. A steering angle sensor 41, a steering angle sensor 43, and a vehicle speed sensor 44 are connected to the steering ECU 48.

  These ECUs 46 to 48 each have a microcomputer composed of a CPU, a ROM, a RAM and the like as main components. The inspection ECU 46 detects an abnormality in the steering electric motor 22 and the electromagnetic clutches 32 and 33 by executing the fail inspection program of FIG. 2 (including the first to third inspection routines of FIGS. 3 to 5). To do. During the execution of this fail inspection program, the inspection ECU 46 switches and controls the first and second electromagnetic clutches 32 and 33 via the drive circuit 51, and the steering reaction force electric motor 13 via the drive circuits 52 and 53. And the drive electric motor 22 for steering is controlled. Further, an alarm device 54 is connected to the inspection ECU 46, and when the abnormality is detected in the steering electric motor 22 and the first or second electromagnetic clutch 32, 33, the alarm device 54 generates an alarm. A transmission 55 is also connected to the inspection ECU 46, and a shift position signal indicating a shift position is also input from the transmission 55. The steering reaction force ECU 47 executes the steering reaction force control program shown in FIG. 6 and drives and controls the steering reaction force electric motor 13 via the drive circuit 52. The steering ECU 48 executes the steering control program shown in FIG. 7 to drive and control the steering electric motor 22 via the drive circuit 53.

  Next, the operation of the embodiment configured as described above will be described. By turning on the ignition switch, the inspection ECU 46 starts to repeatedly execute the fail inspection program every predetermined short time immediately after turning on the ignition switch. In addition, when the ignition switch is turned on, the steering reaction force ECU 47 and the steering ECU 48 start to repeatedly execute the steering reaction force control program and the steering control program every predetermined short time.

  The execution of the inspection program is started in step S10 in FIG. The outline of this inspection program will be described. In this inspection program, the first to third inspections are sequentially executed. The first inspection detects an operation abnormality of the steering electric motor 22 and a disconnection abnormality (abnormality that is not disconnected) of the second electromagnetic clutch 33. In the second inspection, a disconnection abnormality of the first electromagnetic clutch 32 is detected. In the third inspection, a connection abnormality (abnormality that is not connected) of the first electromagnetic clutch 32 or the second electromagnetic clutch 33 is detected.

  After starting the execution of the inspection program, the inspection ECU 46 determines whether or not the inspection end flag CEall is “1” in step S11. The inspection end flag CEall indicates that all inspections including the first to third inspections are not completed by “0”, and all inspections are completed by “1”. The inspection end flag CEall is initially set to “0”. Initially, since the inspection end flag CEall is set to “0”, the inspection ECU 46 makes a “No” determination at step S11, and the vehicle is stopped and the steering handle 11 is steered at step S12. Judge that it is not.

  In the determination process of step S12, the inspection ECU 46 inputs the shift position signal from the transmission 55, the vehicle speed V detected by the vehicle speed sensor 44, and the steering torque T detected by the steering torque sensor 42. When the shift position signal represents the parking position P or the neutral position N, the vehicle speed V is equal to or less than a predetermined minimum value Vo, and the steering torque T is equal to or less than a predetermined minimum value To, “Yes” And proceed to step S14 and subsequent steps. The condition that the vehicle speed V is less than or equal to the value Vo is a condition for determining that the vehicle is stopped, and the condition that the steering torque T is less than or equal to the value To is that the steering handle 11 is not turned. It is a condition for judging.

  If the vehicle is not stopped or the steering handle 11 is steered, the inspection ECU 46 determines “No” in step S12 and includes the above-described inspection end flag CEall in step S13. Specifically, various flags FL1 to FL3, CF1 to CF3, CF11, and CE1 to CE3 described later are set to “0”, and the execution of the fail inspection program is terminated in step S31.

  In steps S14, S15, and S16, it is determined in this order whether the third, second, and first inspection flags CF3, CF2, and CF1 are “1”. The first, second, and third inspection flags CF1, CF2, and CF3 indicate “0” before the first, second, and third inspection, respectively, and “1” indicates the first, second, and third inspection flags. Indicate the end of inspection or the end of the first, second and third inspections, respectively, and initially set to “0”.

  If the first, second, and third inspection flags CF1, CF2, and CF3 are respectively set to “0”, the inspection ECU 46 determines “No” in steps S14 to S16, and first Steps S17 and S18 corresponding to the initial setting of the inspection are executed. In step S17, the current steering angle θ is input and set as the initial steering angle θo, the actual actual steering angle δ is input and set as the initial steering angle δo, and the first inspection flag CF1 is set. Set to “1”. In step S17, the inspection ECU 46 cooperates with the drive circuit 52 to control the position of the steering reaction force electric motor 13 so as to stop at the current rotational position. Note that the output torque of the steering reaction force electric motor 13 is smaller than the output torque of the steering electric motor 22. More specifically, the driving torque for rotationally driving the steering input shaft 12 by the steering reaction force electric motor 13 is smaller than the driving torque for rotationally driving the steering input shaft 12 by the steering electric motor 22. Is set. In step S <b> 18, the inspection ECU 46 controls the drive circuit 51 to release the energization of the first electromagnetic clutch 32 to set the first electromagnetic clutch 32 to the connected state, and to the second electromagnetic clutch 33. By energizing, the second electromagnetic clutch 32 is set to a disconnected state.

  Next, the inspection ECU 46 determines whether or not the first inspection end flag CE1 is “1” in step S19. The first inspection end flag CE1 is set to “0” to indicate the end of the first inspection, “1” to indicate the end of the first inspection, and is initially set to “0”. Since the first inspection end flag CE1 is set to “0”, “No” is determined in step S19, and the first inspection routine is executed in step S20.

  The first inspection routine is shown in detail in FIG. 3, and its execution is started in step S40. After starting the execution of the first inspection routine, the inspection ECU 46 inputs the current actual turning angle δ detected by the turning angle sensor 43 in step S41, and from the input actual turning angle δ. It is determined whether the state where the absolute value | δ−δo | of the value δ−δo obtained by subtracting the set initial turning angle δo is less than the predetermined angle δ1 continues for a predetermined time or more. The predetermined angle δ1 is a small value (for example, about 1 degree). The predetermined time condition excludes the case where the left and right front wheels FW1, FW2 are steered for a moment due to a disturbance, and is set to a value that is not affected by the disturbance (for example, about 0.3 seconds). Has been. This determination is to determine whether the steering electric motor 22 is abnormal by determining whether the left and right front wheels FW1, FW2 are steered. Further, as will be described in detail later, one side surface of the left and right front wheels FW1 and FW2 may be in contact with a road shoulder or the like, and the left and right front wheels FW1 and FW2 may be steered only to the other.

  First, the case where the left and right front wheels FW1, FW2 are in a steerable state and the steering electric motor 22 is normal will be described. In this case, since the left and right front wheels FW1 and FW2 are steered by the steered electric motor 22, the state where the absolute value | δ−δo | is less than the predetermined angle δ1 does not continue for a predetermined time or longer. Accordingly, the inspection ECU 46 determines “No” in step S41, and inputs the current steering wheel angle θ detected by the steering wheel angle sensor 41 in step S44, and from the input steering wheel angle θ. It is determined whether the absolute value | θ−θo | of the value θ−θo obtained by subtracting the set initial steering angle θo is equal to or larger than a predetermined angle θ1. The predetermined angle θ1 is set to a somewhat large value (for example, about 5 degrees). This determination is based on the condition that the steering handle 11 is rotated when the steering electric motor 22 is rotated with the second electromagnetic clutch 33 disconnected. ). Also in this case, first, the case where the second electromagnetic clutch 33 is normal will be described.

  In this case, as described above, since the second electromagnetic clutch 33 is disengaged, the steering handle 11 is not rotated by the drive of the steering electric motor 22, and the inspection ECU 46 determines that “ No, that is, the absolute value | θ−θo | is determined to be less than the predetermined angle θ1, and the process proceeds to step S45. In step S45, the inspection ECU 46 inputs the actual turning angle δ detected by the turning angle sensor 43, and subtracts the set initial turning angle δo from the inputted actual turning angle δ. It is determined whether the absolute value | δ−δo | of δ−δo is equal to or greater than a predetermined angle δ2. The predetermined angle δ2 corresponds to the maximum turning angle of the left and right front wheels FW1 and FW2, and is set to a value (for example, about 2 degrees) larger than the predetermined angle δ1. This determination is a determination for confirming that the left and right front wheels FW1, FW2 are steered to a predetermined angle δ2 for the first inspection.

  Initially, the absolute value | δ−δo | is less than the predetermined angle δ2, and the inspection ECU 46 determines “No” in step S45, and proceeds to step S46. In step S46, it is determined whether the motor abnormality inspection flag CF11 is "0". The motor abnormality check flag CF11 is more specifically described when the left and right front wheels FW1 and FW2 are not steered in one direction (right direction in the present embodiment) even by driving of the steered electric motor 22 described later. Is set to “1” in order to detect an abnormality, and is initially set to “0”. Therefore, immediately after the start of the processing of the first inspection routine, the motor abnormality inspection flag CF11 is set to “0”, and the inspection ECU 46 determines “Yes” in step S46, and in step S47. A target turning angle δ * (= δ + Δδ) is calculated by adding a predetermined small turning angle Δδ to the input actual turning angle δ. Next, in cooperation with the drive circuit 53, the inspection ECU 46 controls the steering electric motor 22 to control the left and right front wheels FW1, FW2 to the target turning angle δ *. Then, the inspection ECU 46 ends the execution of the first inspection routine in step S55. After the end of the execution of the first inspection routine, in the fail inspection program of FIG. 2, the inspection ECU 46 ends the execution of the fail inspection program in step S31.

  When the execution of the fail inspection program is started again after a lapse of a predetermined short time, the inspection ECU 46 starts the execution of the fail inspection program again in step S10 as described above. In this case, the inspection end flag CEall, the third inspection flag CF3, and the second inspection flag CF2 are set to “0”, and the first inspection flag CF1 is set to “1” by the process of the above-described step S17. As long as the vehicle stop and the non-steering condition of the steering wheel 11 are satisfied, “No”, “Yes”, “No”, and “No” are determined in steps S11, S12, S14, and S15, respectively, and in step S16 Since it determines with "Yes", the determination process of step S19 is performed.

  In the determination process of step S19, the inspection ECU 46 determines again whether the first inspection end flag CE1 is “1”. Also in this case, the inspection ECU 46 determines “No” in step S19, and executes the first inspection routine in step S20 again. After the first inspection flag CF1 is set to “1” as described above, the inspection ECU 46 performs steps S11, S12, S14, S15, as long as the vehicle stop and the non-steering condition of the steering handle 11 are satisfied. In S16 and S19, “No”, “Yes”, “No”, “No”, “Yes”, and “No” are determined, respectively, and the first inspection routine of Step S20 is repeatedly executed every predetermined short time. .

  In the first inspection routine, as long as the absolute value | δ−δo | is less than the predetermined angle δ2, the processes of steps S47 and S49 described above are repeatedly executed. As a result, the actual turning angle δ of the left and right front wheels FW1, FW2 is reduced by minute turning every predetermined short time when the fail inspection program is repeatedly executed as shown in FIG. The angle Δδ gradually increases in one direction (right direction in the present embodiment) (that is, in a ramp shape).

  Then, when the left and right front wheels FW1, FW2 are steered by a predetermined angle δ2 or more by the processing of steps S47, S49, it is determined as “Yes” in step S45, and the processing of steps S53, S54 is executed. In step S55, the execution of the first inspection routine (step S20 in FIG. 2) is completed, and in step S31, the execution of the fail inspection program is also temporarily ended. In step S53, the first inspection end flag CE1 is set to “1”. In step S54, the drive circuits 52 and 53 are controlled to release the energization of the steering reaction force electric motor 14 and the steering electric motor 22.

  By executing this first inspection routine, the left and right front wheels FW1, FW2 are steered in one direction (that is, in the right direction) with the second electromagnetic clutch 33 controlled to be disconnected, and it is confirmed that the steering handle 11 does not rotate. Thus, it is determined that no disconnection abnormality has occurred in the second electromagnetic clutch 33.

  When the fail inspection program is executed again, the inspection end flag CEall, the third inspection flag CF3, and the second inspection flag CF2 are set to “0” as described above, and the first inspection flag CF1 is set to “0”. The first inspection end flag CE1 is set to “1” by the process of step S53 in FIG. Accordingly, the inspection ECU 46 determines “No”, “Yes”, “No” in steps S11, S12, S14, S15, S16, and S19, respectively, as long as the vehicle stop and the non-steering condition of the steering wheel 11 are satisfied. , “No”, “Yes”, and “Yes” are determined, and the processes of steps S21 and S22 are executed.

  In step S21, the inspection ECU 46 inputs the current steering wheel angle θ and sets it as the initial steering wheel angle θo, and inputs the current actual steering angle δ, as in step S17. The turning angle δo is set, and the position of the steering reaction force electric motor 13 is controlled so as to stop at the current rotational position. In step S21, the second inspection flag CF2 is set to “1”. In step S22, the inspection ECU 46 controls the drive circuit 51 to energize the first electromagnetic clutch 32, thereby setting the first electromagnetic clutch 32 to a disconnected state and energizing the second electromagnetic clutch 33. By releasing, the second electromagnetic clutch 33 is set to the connected state.

  Next, the inspection ECU 46 determines whether or not the second inspection end flag CE2 is “1” in step S23. The second inspection end flag CE2 indicates 0 before the end of the second inspection, “1” indicates the end of the second inspection, and is initially set to “0.” Now, the second inspection ends. Since the second inspection end flag CE2 is set to “0”, “No” is determined in step S23, and the second inspection routine is executed in step S24.

  The second inspection routine is shown in detail in FIG. 4, and its execution is started in step S60. After starting the execution of the second inspection routine, in step S61, the inspection ECU 46 inputs the current steering angle θ detected by the steering angle sensor 41, and sets the setting based on the input steering angle θ. It is determined whether the absolute value | θ−θo | of the value θ−θo obtained by subtracting the initial steering angle θo is equal to or greater than the predetermined angle θ1. This determination is based on the condition that the steering handle 11 is rotated when the steering electric motor 22 is rotated with the first electromagnetic clutch 32 disconnected, and the first electromagnetic clutch 32 is disconnected abnormally (not disconnected). ). Also in this case, the case where the 1st electromagnetic clutch 32 is normal is demonstrated first. Therefore, the absolute value | θ−θo | is kept less than the predetermined angle θ1, the inspection ECU 46 determines “No” in step S61, and proceeds to step S62.

  In step S62, the inspection ECU 46 receives the actual turning angle δ detected by the turning angle sensor 43, and subtracts the set initial turning angle δo from the inputted actual turning angle δ. It is determined whether the absolute value | δ−δo | of δ−δo is equal to or larger than the predetermined angle δ2. Also in this case, the absolute value | δ−δo | is initially less than the predetermined angle δ2, and the inspection ECU 46 determines “No” in step S62 and proceeds to step S63. In step S63, it is determined whether the above-described motor abnormality inspection flag CF11 is “0”. Also in this case, since the motor abnormality inspection flag CF11 is set to “0”, the inspection ECU 46 determines “Yes” in step S63, and the current actual turning angle input in step S64. The target turning angle δ * (= δ−Δδ) is calculated by subtracting the above-mentioned minute turning angle Δδ from δ. Next, in cooperation with the drive circuit 53, the inspection ECU 46 controls the steering electric motor 22 to control the steering to the target turning angle δ * of the left and right front wheels FW1, FW2. Then, the inspection ECU 46 ends the execution of the second inspection routine in step S71. After the end of the execution of the second inspection routine, in the fail inspection program of FIG. 2, the inspection ECU 46 ends the execution of the fail inspection program in step S31.

  When the execution of the fail inspection program is started again after a lapse of a predetermined short time, the inspection ECU 46 starts the execution of the fail inspection program again in step S10 as described above. In this case, the inspection end flag CEall and the third inspection flag CF3 are set to “0”, and the second inspection flag CF2 is set to “1” by the process of step S21 described above. As long as the 11 non-steering conditions are satisfied, “No”, “Yes”, and “No” are determined in steps S11, S12, and S14, respectively, and “Yes” is determined in step S15. Execute the judgment process.

  In the determination process of step S23, the inspection ECU 46 determines whether or not the second inspection end flag CE2 is “1”. Also in this case, the inspection ECU 46 determines “No” in step S23, and executes the second inspection routine in step S24 again. After the second inspection flag CF2 is set to “1” as described above, the inspection ECU 46 performs steps S11, S12, S14, S15, as long as the vehicle stop and the non-steering condition of the steering handle 11 are satisfied. In S23, “No”, “Yes”, “No”, “Yes”, and “No” are determined, respectively, and the second inspection routine of Step S24 is repeatedly executed every predetermined short time.

  In the second inspection routine, as long as the absolute value | δ−δo | is less than the predetermined angle δ2, the processes of steps S64 and S66 described above are repeatedly executed. As a result of the processing in steps S64 and S66, the actual turning angle δ of the left and right front wheels FW1 and FW2 is minutely changed every predetermined short time in which the fail inspection program is repeatedly executed, as in the case of the first inspection routine. The vehicle is steered by the steering angle Δδ. However, in this case, the rotation direction of the steering electric motor 22 is opposite to that in the first inspection routine, and the actual turning angle δ of the left and right front wheels FW1, FW2 is the same as that in the first inspection routine. Decreases gradually (that is, in a ramp shape) in the opposite direction (left direction in the present embodiment).

  Then, when the left and right front wheels FW1, FW2 are steered by a predetermined angle δ2 or more by the processing in steps S64, S66, it is determined as “Yes” in step S62, and the processing in steps S69, S70 is performed. In step S71, the execution of the second inspection routine (step S24 in FIG. 2) is terminated, and in step S31, the execution of the fail inspection program is also temporarily terminated. In step S69, the second inspection end flag CE2 is set to “1”. In step S70, the drive circuits 52 and 53 are controlled to release the energization of the steering reaction force electric motor 14 and the steering electric motor 22.

  By executing the second inspection routine, the left and right front wheels FW1 and FW2 are steered in the opposite direction to the first inspection routine (that is, the left direction) with the first electromagnetic clutch 32 being controlled to be disengaged. By confirming that 11 does not rotate, it is determined that no disconnection abnormality has occurred in the first electromagnetic clutch 32. In this case, the left and right front wheels FW1 and FW2 are steered leftward by the predetermined angle δ2 from the state steered rightward by the predetermined angle δ2 in the first inspection routine described above. The actual turning angle δ of FW2 is returned to the initial turning angle δo before the first inspection routine and corresponds to the steering state of the steering handle 11, so that the operation is performed by executing the first and second inspection routines. There is no adverse effect.

  Further, in the second inspection process, since the second electromagnetic clutch 33 is set to the connected state by the process of step S22 in FIG. 2, the cable 31 rotates when the electric motor 22 for turning is driven to rotate. As a result, even if the cable 31 is fixed to a covering member such as a pipe that accommodates it, the fixing of the cable 31 is eliminated, and the subsequent operation becomes accurate.

  When the fail inspection program is executed again, the inspection end flag CEall and the third inspection flag CF3 are set to “0” and the second inspection flag CF2 is set to “1” as described above. Further, the second inspection end flag CE2 is set to “1” by the process of step S69 of FIG. Therefore, as long as the vehicle stop and the non-steering condition of the steering handle 11 are satisfied, the inspection ECU 46 determines “No”, “Yes”, “No”, “No” in steps S11, S12, S14, S15, and S23, respectively. It determines with "Yes" and "Yes", and performs the process of step S25, S26.

  In step S25, the inspection ECU 46 inputs the current steering wheel steering angle θ, sets it as the initial steering wheel steering angle θo, and initially sets a driving voltage value E representing the driving voltage applied to the steering reaction force electric motor 13. The value is set to “0”, the third inspection flag CF3 is set to “1”, and the position of the steering electric motor 22 is controlled so as to stop at the current rotational position. In step S26, the inspection ECU 46 controls the drive circuit 51 to release the energization of the first and second electromagnetic clutches 32 and 33, thereby bringing the first and second electromagnetic clutches 32 and 33 into the connected state. Set.

  Next, the inspection ECU 46 determines whether or not the third inspection end flag CE3 is “1” in step S27. The third inspection end flag CE3 indicates that the third inspection has ended before “0”, indicates that the third inspection has ended by “1”, and is initially set to “0.” Now, the third inspection ends. Since the third inspection end flag CE3 is set to “0”, “No” is determined in step S27, and the third inspection routine is executed in step S28.

  The third inspection routine is shown in detail in FIG. 5, and its execution is started in step S80. After starting the execution of the third inspection routine, the inspection ECU 46 inputs the current steering angle θ detected by the steering angle sensor 41 in step S81, and sets the setting based on the input steering angle θ. It is determined whether the absolute value | θ−θo | of the value θ−θo obtained by subtracting the initial steering angle θo is equal to or greater than a predetermined angle θ2 (for example, about 5 degrees). This determination is made by connecting the first and second electromagnetic clutches 32 and 33 and restraining the steering of the left and right front wheels FW1 and FW2 by position control of the steering electric motor 22 and controlling the steering reaction force electric motor 13. If the steering handle 11 is rotated by driving the rotation, it is determined that one of the first and second electromagnetic clutches 32 and 33 is abnormal in connection (abnormality that is not connected). Also in this case, first, the case where the first and second electromagnetic clutches 32 and 33 are normal will be described. Initially, the absolute value | θ−θo | is kept below a predetermined angle θ2, and the inspection ECU 46 makes a “No” determination at step S81 to proceed to step S62.

  In step S82, the inspection ECU 46 determines whether the drive voltage value E is equal to or greater than the predetermined voltage value E1. The predetermined voltage value E1 is a voltage value sufficient to rotate the steering reaction force electric motor 13 by the predetermined angle θ2 or more by being applied to the steering reaction force electric motor 13 via the drive circuit 52. . Since the drive voltage value E is initially set to “0” by the process of step S25 of FIG. 2, the inspection ECU 46 determines “No” in step S82 and proceeds to steps S83 and S84. In step S83, the predetermined voltage value ΔE is added to the drive voltage value E to update the drive voltage value E. In step S84, in cooperation with the drive circuit 52, the drive voltage E is applied to the steering reaction force electric motor 13 to attempt to drive the steering reaction force electric motor 13. Then, the inspection ECU 46 ends the execution of the third inspection routine in step S71. After completion of the execution of the third inspection routine, in the fail inspection program of FIG. 2, the inspection ECU 46 ends the execution of the fail inspection program in step S31.

  When the execution of the fail inspection program is started after a lapse of a predetermined short time, the inspection ECU 46 again starts executing the fail inspection program in step S10 as described above. In this case, since the inspection end flag CEall is set to “0” and the third inspection flag CF3 is set to “1” by the process of step S25 described above, the vehicle stop and the non-steering condition of the steering handle 11 are As long as it is established, “No” and “Yes” are determined in steps S11 and S12, respectively, and “Yes” is determined in step S14. Therefore, the determination process of step S27 is executed.

  In the determination process of step S27, the inspection ECU 46 determines whether or not the third inspection end flag CE3 is “1”. Also in this case, the inspection ECU 46 determines “No” in step S27, and executes the third inspection routine in step S28 again. After the third inspection flag CF3 is set to “1” as described above, the inspection ECU 46 proceeds to steps S11, S12, S14, and S27 as long as the vehicle stop and the non-steering condition of the steering handle 11 are satisfied. Are determined as “No”, “Yes”, “Yes”, and “No”, respectively, and the third inspection routine of Step S28 is repeatedly executed every predetermined short time.

  In the third inspection routine, as long as the drive voltage value E is less than the predetermined voltage value E1, the processes of steps S83 and S84 described above are repeated. By the processing in steps S83 and S84, the drive voltage value E gradually increases (ie, in a ramp shape) by a minute voltage value ΔE every predetermined short time during which the fail inspection program is repeatedly executed.

  When the drive voltage value E becomes equal to or higher than the predetermined voltage value E1 by the processes in steps S83 and S84, it is determined “Yes” in step S82, the processes in steps S87 to S89 are executed, and the process proceeds to step S90. Then, the execution of the third inspection routine (step S28 in FIG. 2) is completed, and the execution of the fail inspection program is also temporarily ended in step S31. In step S87, the third inspection end flag CE3 is set to “1”. In step S88, the drive circuits 52 and 53 are controlled to release the energization of the steering reaction force electric motor 14 and the steered electric motor 22. In step S89, the drive circuit 51 is controlled to energize the first and second electromagnetic clutches 32 and 33, thereby setting the first and second electromagnetic clutches 32 and 33 to the disconnected state.

  The steering reaction force electric motor 13 is driven in a state in which the steering of the left and right front wheels FW1 and FW2 is prohibited by executing the third inspection routine in a state where the first and second electromagnetic clutches 32 and 33 are connected and controlled. Then, by confirming that the steering handle 11 does not rotate, it is determined that no connection abnormality has occurred in the first and second electromagnetic clutches 32 and 33.

  When the fail inspection program is executed again, as described above, the inspection end flag CEall is set to “0”, the third inspection flag CF3 is set to “1”, and the third inspection is performed. The end flag CE3 is set to “1” by the process of step S87 in FIG. Accordingly, the inspection ECU 46 determines “No”, “Yes”, “Yes”, “Yes” in steps S11, S12, S14, and S27, respectively, as long as the vehicle stop and the non-steering condition of the steering wheel 11 are satisfied. And the processes of steps S29 and S30 are executed.

  In step S29, the inspection end flag CEall is set to “1”. In step S30, the first to third abnormality detection flags FL1 to FL3 and the inspection end flag CEall are output to the steering reaction force ECU 47 and the steering ECU 48, respectively. The first to third abnormality detection flags FL1 to FL3 indicate that no abnormality is detected by the first to third inspections by “0”, and abnormality is detected by the first to third inspections by “1”. The initial state is set to “0”. Accordingly, in this case, the inspection end flag CEall representing “1” and the first to third abnormality detection flags FL1 to FL3 representing “0” are output to the steering reaction force ECU 47 and the steering ECU 48, respectively. .

  After the processes in steps S29 and S30, the inspection ECU 46 ends the execution of the fail inspection program in step S31. When the fail inspection program is executed again, the inspection ECU 46 determines “Yes” in step S11, and ends the execution of the fail inspection program in step S31. Therefore, thereafter, the fail inspection program is substantially not executed.

  Next, in the first inspection process, a case will be described in which the side surfaces of the left and right front wheels FW1 and FW2 are in contact with a road shoulder and the like and the steering in one direction is impossible. In this case, the left and right front wheels FW1 can be controlled by driving the steering electric motor 22 in order to steer the left and right front wheels FW1 and FW2 in one direction (right direction) by the processing in steps S47 and S49 in FIG. , FW2 is maintained at the initial position and is not steered in one direction. Therefore, the state where the absolute value | δ−δo | of the difference δ−δo between the actual turning angle δ and the initial turning angle δo is less than the predetermined angle δ1 continues for a predetermined time or longer. In step S41, it determines with "Yes" and progresses to step S42. In step S42, it is determined whether the turning inversion flag CF11 is “1”. The turning reversal flag CF11 is set to “1” when the left and right front wheels FW1, FW2 are steered in one direction by “1”, but are not steered in the same direction. 0 ”is set. Accordingly, in this case, the inspection ECU 46 determines “No” in step S42, and sets the steering reversal flag CF11 to “1” in step S43.

  After the process of step S43, the inspection ECU 46 executes the determination processes of steps S44 and S45. In this case, since the left and right front wheels FW1, FW2 are not steered, the steering wheel steering angle θ and the actual steered angle δ do not change. Therefore, in step S44, it is determined that “No”, that is, the absolute value | θ−θo | of the difference between the steering wheel steering angle θ and the initial steering wheel steering angle θo is less than the predetermined angle θ1. Also in step S45, it is determined that “No”, that is, the absolute value | δ−δo | of the difference between the actual turning angle δ and the initial turning angle δo is less than the predetermined angle δ2. That is, the inspection ECU 46 determines “No” in steps S44 and S45, and proceeds to step S46. In step S46, since the turning reversal flag CF11 is set to “1” by the process of step S43, it is determined “No” and the processes of steps S48 and S49 are executed.

  In step S48, the target turning angle δ * is calculated by subtracting the minute turning angle Δδ from the actual turning angle δ. In step S49, the steering electric motor 22 is controlled via the drive circuit 53, and the left and right front wheels FW1, FW2 are steered so as to reach the target turning angle δ *. However, the steering direction of the left and right front wheels FW1 and FW2 in this case is the opposite direction (that is, the left direction) to the case where the inability to steer the left and right front wheels FW1 and FW2 is detected. Therefore, if the left and right front wheels FW1 and FW2 cannot be steered only because of road shoulders, the left and right front wheels FW1 and FW2 should be steered in the opposite direction. As a result, the left and right front wheels FW1 and FW2 are gradually steered in opposite directions by repeating the execution of steps S48 and S49, and eventually the absolute value | δ−δo | becomes a predetermined angle δ2 or more. It is determined as “Yes” in step S45, and after the processing in steps S53 and S54 described above, the execution of the first inspection routine is ended in step S55.

  In this case, since the left and right front wheels FW1 and FW2 are steered in the opposite direction by driving the steered electric motor 22, it is determined that the steered electric motor 22 is normal. Then, after the execution of the first inspection routine is completed, the inspection ECU 46 executes the second inspection routine of FIG. 4 and the third inspection routine of FIG. 5 in the same manner as described above. However, in this case, since the turning reversal flag CF11 is set to “1”, the inspection ECU 46 determines “No” in step S63 of FIG. A small turning angle Δδ is added to the turning force δ, and the turning electric motor 22 is driven in step S66 to turn the left and right front wheels FW1, FW2. Accordingly, also in this case, the left and right front wheels FW1 and FW2 are steered in the opposite direction (that is, rightward) from the first inspection process, and at the end of execution of the second inspection routine, the left and right front wheels FW1 and FW2 are moved to their original positions. Returned to

  Next, a case where an abnormality has occurred in the steering electric motor 22 will be described. In this case, first, even if the steering electric motor 22 is driven and controlled so that the left and right front wheels FW1 and FW2 are steered in one direction (right direction) by the processing of steps S47 and S49 in FIG. The left and right front wheels FW1, FW2 are not steered. Accordingly, during the repeated execution of the first inspection routine, “Yes”, that is, the absolute value | δ−δo | It is determined that the state of being less than the predetermined angle δ1 has continued for a predetermined time or more, and the turning reversal flag CF11 is set to “1” in step S42.

  Then, the inspection ECU 46 steers the left and right front wheels FW1, FW2 in the other direction (left direction) by the processing of steps S48, S49 based on the turning inversion flag CF11 set to "1". The steering electric motor 22 is driven and controlled. However, in this case, since the steering electric motor 22 is abnormal, the left and right front wheels FW1, FW2 are not steered in the other direction. Therefore, during the repeated execution of the first inspection routine, “Yes” is again determined in step S41, and the process proceeds to step S42. In this case, since the turning inversion flag CF11 is set to “1”, “Yes” is determined in Step S42, and the process proceeds to Step S50.

  In step S50, the third inspection flag CF3 and the third inspection end flag CE3 are set to “1”. Next, in step S51, the inspection ECU 46 operates the alarm device 54 to notify the driver that an abnormality has occurred in the steering electric motor 22. In this case, the alarm device 54 generates an alarm sound or displays an abnormality of the electric motor 22 for steering by lamp display or text display. As described above, even if the left and right front wheels FW1 and FW2 are in contact with the road shoulder and the left and right front wheels FW1 and FW2 cannot be steered by the processing of steps S41 to S43 and S46 to S49, the left and right front wheels FW1 and FW2 are By turning left and right, the abnormality of the steering electric motor 22 is accurately determined.

  Next, in step S52, the first abnormality detection flag FL1 is set to “1”, and after the processing in steps S53 and S54 described above, the execution of the first inspection routine is ended in step S55. In this case, since both the third inspection flag CF3 and the third inspection end flag CE3 are set to “1”, when the fail inspection program in FIG. As long as 11 non-steering conditions are satisfied, “No”, “Yes”, “Yes”, and “Yes” are determined in Steps S11, S12, S14, and S27, and after the processing of Steps S29 and S30 described above Since the execution ends in step S31, the second and third inspection routines are not executed thereafter. This is because the second and third inspection processes cannot be performed when the steering electric motor 22 is abnormal.

  Next, a case where a disconnection abnormality (abnormality that is not disconnected) occurs in the second electromagnetic clutch 33 will be described. The steering electric motor 22 is steered so that the left and right front wheels FW1, FW2 are steered in one direction (right direction) or the other direction (left direction) by the processing in step S47 (or S48) and step S49 in FIG. Is controlled to drive the left and right front wheels FW1, FW2 in one direction or the other direction. In this case, a disconnection abnormality has occurred in the second electromagnetic clutch 33, the second electromagnetic clutch 33 is in the connected state, and the first electromagnetic clutch 32 is controlled in the connected state, so that the steering output shaft 24 is A power transmission is connected to the steering input shaft 12 via the cable 31. Therefore, when the left and right front wheels FW1 and FW2 are steered, the steering input shaft 12 also rotates about the axis, and the steering wheel steering angle θ also changes from the initial steering wheel steering angle θo, and the steering wheel steering angle θ and the initial steering wheel steering angle θo. The absolute value of the difference | θ−θo | gradually increases to a predetermined angle θ1 or more.

  As a result, during the repeated execution of the first inspection routine, the inspection ECU 46 determines “Yes” in step S44 and proceeds to step S51 and subsequent steps. In this case, the inspection ECU 46 activates the alarm device 54 in step S51 to notify the driver that a disconnection abnormality has occurred in the second electromagnetic clutch 33 by an alarm sound, a lamp display or a character display. .

  Next, after the processing of steps S52 to S54 described above, the execution of the first inspection routine is ended in step S55. In this case, since the first inspection end CE1 is set to “1”, when the fail inspection program of FIG. 2 is newly executed, “Yes” is determined in step S19. The processes after step S21 are executed, and then the second and third inspection routines are executed.

  Next, a case where a disconnection abnormality (abnormality that is not disconnected) occurs in the first electromagnetic clutch 32 will be described. The steering electric motor 22 is steered so that the left and right front wheels FW1 and FW2 are steered in the other direction (left direction) or one direction (right direction) by the processing in step S64 (or S65) and step S66 in FIG. When the drive control is performed, the left and right front wheels FW1, FW2 are steered in the other direction or in one direction. In this case, a disconnection abnormality has occurred in the first electromagnetic clutch 32, the first electromagnetic clutch 33 is in the connected state, and the second electromagnetic clutch 33 is controlled in the connected state. As in the case of the above, the steering output shaft 24 is connected to the steering input shaft 12 via the cable 31 so that power can be transmitted. Accordingly, in conjunction with the turning of the left and right front wheels FW1 and FW2, the steering wheel steering angle θ also changes from the initial steering wheel steering angle θo, and the absolute value of the difference between the steering wheel steering angle θ and the initial steering wheel steering angle θo | θ−θo | Gradually increases to a predetermined angle θ1 or more.

  As a result, during repeated execution of the second inspection routine, the inspection ECU 46 determines “Yes” in step S61 and proceeds to step S67 and subsequent steps. In this case, the inspection ECU 46 activates the alarm device 54 in step S67 to notify the driver that a disconnection abnormality has occurred in the first electromagnetic clutch 32 by means of an alarm sound, a lamp display or a character display. .

  In the detection of the disconnection abnormality of the first and second electromagnetic clutches 32 and 33, the rotation angle of the steering electric motor 22 and the actuality of the left and right front wheels FW1 and FW2 are determined by the processes of steps S47 to S49 and S64 to S66. Since the turning angle δ is changed gradually with time, that is, in a ramp shape, the rotation angle of the electric motor 22 for turning and the actual turning angle δ of the left and right front wheels FW1, FW2 are not increased so much. However, it may be possible to detect a disconnection abnormality of the first and second electromagnetic clutches 32 and 33. As a result, changes in the actual turning angle δ of the left and right front wheels FW1 and FW2 and the steering angle θ of the steering wheel 11 can be reduced as much as possible in order to detect disconnection abnormality of the first and second electromagnetic clutches 32 and 33. It is possible to minimize the change in the state of the vehicle accompanying the abnormality detection.

  Further, in detecting the disconnection abnormality of the first and second electromagnetic clutches 32 and 33, the steering reaction force electric motor 13 is controlled to be stopped by the processing of steps S17 and S21 of FIG. As described above, the driving torque for rotationally driving the steering input shaft 12 by the steering reaction force electric motor 13 is smaller than the driving torque for rotationally driving the steering input shaft 12 by the steering electric motor 22. Therefore, if the driving torque by the steering electric motor 22 is applied to the steering input shaft 12 via the cable 31 due to the abnormality of the first or second electromagnetic clutch 32, 33, the steering input shaft 12 is Rotation is detected and abnormality of the first or second electromagnetic clutch 32, 33 is detected. As a result, in order to detect the disconnection abnormality of the first and second electromagnetic clutches 32 and 33, even if the change in the actual turning angle δ of the left and right front wheels FW1 and FW2 and the steering angle θ of the steering handle 11 is suppressed to a small level, The abnormality can be detected with high accuracy.

  After the processing in step S67, the second abnormality detection flag FL2 is set to “1” in step S68, and the second inspection end flag CE2 is set to “1” in step S69. In step S70, the energization of the steering reaction force electric motor 13 and the steering electric motor 22 is released, and in step S71, the execution of the second inspection routine is ended. In this case, since the second inspection end flag CE2 is set to “1”, when the fail inspection program in FIG. 2 is newly executed, “Yes” is determined in step S23. Thus, the processing after step S25 is executed, and then the third inspection routine is executed.

  Next, a case where a connection abnormality (abnormality not connected) occurs in the first or second electromagnetic clutch 32, 33 will be described. When the steering reaction force electric motor 13 is driven and controlled by the processing in steps S83 and S84 of FIG. 5, if the first or second electromagnetic clutch 32, 33 is in the disconnected state, the steering electric motor 22 Since the rotation prevention of the steering input shaft 12 by the stop control does not function, the steering input shaft 12 and the steering handle 11 are rotated. Therefore, the steering wheel steering angle θ also changes from the initial steering wheel steering angle θo, and the absolute value | θ−θo | of the difference between the steering wheel steering angle θ and the initial steering wheel steering angle θo gradually increases to a predetermined angle θ2 or more.

  As a result, during the repeated execution of the third inspection routine, the inspection ECU 46 determines “Yes” in step S81 and proceeds to step S85 and subsequent steps. In this case, the inspection ECU 46 activates the alarm device 54 in step S85, and an abnormal connection occurs in the first or second electromagnetic clutch 32, 33 to the driver by an alarm sound, lamp display, or character display. Let them know.

  In the detection of the abnormal connection of the first and second electromagnetic clutches 32 and 33, the steering reaction force electric motor 13 gradually changes in time, that is, in a ramp shape, by the processing in steps S83 and S84. Since the drive control is performed by the voltage, the connection abnormality of the first or second electromagnetic clutch 32, 33 may be detected even if the change of the steering wheel angle θ is not so large. As a result, the change in the steering angle θ of the steering wheel 11 can be reduced as much as possible in order to detect the connection abnormality of the first and second electromagnetic clutches 32 and 33, and the change in the vehicle state caused by the abnormality detection can be minimized. It becomes possible to limit to the limit.

  After the process in step S85, the inspection ECU 46 sets the third abnormality detection flag FL3 to “1” in step S86, and after the processes in steps S87 to S89 described above, the third inspection routine is executed in step S71. Exit. In this case, since the third inspection end flag CE3 is set to “1”, when the fail inspection program of FIG. 2 is newly executed, the processing of steps S29 and S30 described above is performed. In step S31, the execution of the fail inspection program is terminated.

  On the other hand, the steering reaction force ECU 47 repeatedly executes the steering reaction force control program of FIG. 6 every predetermined short time after the ignition switch is turned on. The execution of the steering reaction force control program is started in step S100, and the steering reaction force ECU 47 determines in step S101 whether the inspection end flag CEall is “1”. That is, it is determined whether the inspection end flag CEall set to “1” indicating the end of the inspection is input from the inspection ECU 46. If the inspection end flag CEall set to “1” has not been input, “No” is determined in step S101, and the execution of the steering reaction force control program is ended in step S106.

  If the inspection end flag CEall set to “1” has been input, the steering reaction force ECU 47 determines “Yes” in step S101, and the first to the first to the first input from the inspection ECU 46 in step S102. It is determined whether all of the third abnormality detection flags FL1 to FL3 are set to “0” that does not indicate abnormality detection. If any of the first to third abnormality detection flags FL1 to FL3 is “1”, “No” is determined in step S102, and the steering reaction force control program is executed in step S106. Exit. Therefore, the substantial process of the steering reaction force control program is not executed before the above-described abnormality inspection is completed and when abnormality is detected by the abnormality inspection. Accordingly, in this case, the operation of the steering reaction force electric motor 13 is not controlled.

  When the abnormality inspection is completed without detecting an abnormality, the steering reaction force ECU 47 determines “Yes” in steps S101 and S102, and executes the processes in and after step S103. In step S 103, the steering reaction force ECU 47 inputs the steering wheel steering angle θ from the steering angle sensor 41 and the vehicle speed V from the vehicle speed sensor 44. Next, in step S104, the steering reaction force ECU 47 refers to the steering reaction force table provided in the ROM, and calculates the target steering reaction force Th * that changes according to the steering angle θ and the vehicle speed V. calculate. As shown in FIG. 9, the steering reaction force table stores a plurality of target steering reaction forces Th * that increase nonlinearly as the steering wheel steering angle θh increases for each of a plurality of representative vehicle speed values. Instead of using this steering reaction force table, the target steering reaction force Th * that changes according to the steering angle θh and the vehicle speed V is defined in advance by a function, and the target steering is performed by using the function. The reaction force Th * may be calculated.

  Next, in step S105, the steering reaction force ECU 47 causes the steering reaction force electric motor 13 to flow a drive current corresponding to the calculated target steering reaction force Th * in cooperation with the drive circuit 52, thereby causing the step. In S106, the execution of the steering reaction force control program is temporarily terminated. The steering reaction force electric motor 13 drives the steering input shaft 12 with a rotational torque corresponding to the target steering reaction force Th *. As a result, the target steering reaction force Th * by the steering reaction force electric motor 13 is given to the turning operation of the steering handle 11, and the driver rotates the steering handle 11 while feeling an appropriate steering reaction force. Can be operated.

  Further, after turning on the ignition switch, the steering ECU 48 repeatedly executes the steering control program of FIG. 7 every predetermined short time. Execution of this steering control program is started in step S200, and the steering ECU 48, in the same manner as in the steering reaction force control program, in step S201, S202, the inspection end flag CEall and the first to third Anomaly detection flags FL1 to FL3 are input and checked. Also in this case, if the inspection end flag CEall set to “1” is not input, “No” is determined in step S201, and the execution of the steering control program is ended in step S208. Further, if any of the first to third abnormality detection flags FL1 to FL3 is “1”, it is determined as “No” in Step S202, and the steering control program is executed in Step S208. Exit. Therefore, when an abnormality is detected before the above-described abnormality inspection and is detected by the abnormality inspection, the substantial processing of the steering control program is not executed, and the steering electric motor 22 is not controlled.

  When the abnormality inspection is completed without detecting an abnormality, the steering ECU 48 determines “Yes” in steps S201 and S202, and executes the processes in and after step S203. In step S203, the steering ECU 48 inputs the steering wheel steering angle θ from the steering angle sensor 41, the actual steering angle δ from the steering angle sensor 43, and the vehicle speed V from the vehicle speed sensor 44, respectively. Next, in step S204, the steering ECU 48 refers to the steering angle table stored in the ROM, and calculates the target steering angle δ * that changes according to the steering angle θ. As shown in FIG. 10, the steered angle table stores a steered wire target steered angle δ * that increases nonlinearly as the steering wheel steering angle θ increases. The rate of change of the target turning angle δ * with respect to the steering angle θ of the steering wheel is small within a small range of the absolute value | θ | of the steering wheel steering angle θ, and increases as the absolute value | θ | of the steering angle of the steering wheel θ increases. Is set to Instead of using this turning angle table, a function indicating the relationship between the steering wheel steering angle θ and the target turning angle δ * is prepared in advance, and the target for the standby wire is used by using the same function. The turning angle δ * may be calculated.

  Next, in step S205, the steering ECU 48 refers to a vehicle speed coefficient table stored in the ROM, and calculates a vehicle speed coefficient K that changes according to the vehicle speed V. As shown in FIG. 11, the vehicle speed coefficient table is larger than “1” within a small range of the vehicle speed V, smaller than “1” within a large range of the vehicle speed V, and sandwiches “1” as the vehicle speed V increases. The vehicle speed coefficient Ka that decreases nonlinearly is stored. Instead of using the vehicle speed coefficient table, a function indicating the relationship between the vehicle speed V and the vehicle speed coefficient Ka is prepared in advance, and the vehicle speed coefficient K for the standby wire is calculated using the function. It may be.

  After determining the target turning angle δ * and the vehicle speed coefficient K, the steering ECU 48 finally multiplies the calculated target turning angle δ * by the calculated vehicle speed coefficient K in step S206. A target turning angle δ * is calculated. In step S207, the difference δ * −δ between the turning angles δ * and δ is used via the drive circuit 53 so that the actual turning angle δ becomes equal to the final target turning angle δ *. The rotation of the electric motor 22 for turning is controlled. Thereafter, the execution of the steering control program is terminated in step S208. As a result, the steering electric motor 22 is rotationally driven, drives the rack bar 21 in the axial direction via the screw feed mechanism 23, and steers the left and right front wheels FW1, FW2 to the target turning angle δ *.

  By such steering control, as shown in FIG. 10, the left and right front wheels FW1 and FW2 are steered small with respect to the change in the steering angle θ within a small range of the steering angle θ, and the steering angle θ is large. The vehicle is steered greatly with respect to the change in the steering angle θ within the range. As a result, the left and right front wheels FW1, FW2 are steered to a large steered angle without changing the steering handle 11. 11, the left and right front wheels FW1 and FW2 are steered greatly with respect to the steering wheel steering angle θ when the vehicle speed V is low, and are steered small with respect to the steering wheel steering angle θ when the vehicle speed V increases. .

  Furthermore, the present invention is not limited to the above-described embodiment, and various modifications can be employed within the scope of the present invention.

  For example, in the above embodiment, the steering electric motor 22 is driven and controlled so that the left and right front wheels FW1, FW2 are initially steered rightward by the processing of the first inspection routine, and then the first inspection routine or the second By the processing of the inspection routine, the steering electric motor 22 is drive-controlled so that the left and right front wheels FW1, FW2 are steered leftward. However, instead of this, the steering electric motor 22 is driven and controlled so that the left and right front wheels FW1, FW2 are initially steered leftward by the processing of the first inspection routine, and then the first inspection routine or the second The steering electric motor 22 may be driven and controlled so that the left and right front wheels FW1, FW2 are steered to the right by the processing of the inspection routine.

  In the above embodiment, the disconnection abnormality of the second electromagnetic clutch 33 is detected by executing the first inspection routine, and the disconnection abnormality of the first electromagnetic clutch 32 is detected by executing the second inspection routine. . However, instead of this, the disconnection abnormality of the first electromagnetic clutch 32 is detected by executing the first inspection routine, and the disconnection abnormality of the second electromagnetic clutch 33 is detected by executing the second inspection routine. Good. In this case, when the first inspection routine is executed, the first electromagnetic clutch 32 is controlled to be disconnected and the second electromagnetic clutch 33 is controlled to be connected. Further, during the execution of the second inspection routine, the first electromagnetic clutch 32 is controlled to be connected and the second electromagnetic clutch 33 is controlled to be disconnected.

  Moreover, in the said embodiment, the case where this invention was applied to the steering device of the steer-by-wire system vehicle provided with the intermittent device containing the two electromagnetic clutches 32 and 33 was demonstrated. However, the present invention can also be applied to a steer-by-wire vehicle steering apparatus including an interrupting device including one electromagnetic clutch between the input steering shaft 12 and the output steering shaft 24. In this case, both in the first inspection routine and in the second inspection routine of the above embodiment, the one electromagnetic clutch may be controlled to be disconnected to detect a disconnection abnormality of the electromagnetic clutch.

  In the above embodiment, the steering of the steering wheel 11 and the rotation of the steering reaction force electric motor 13 are detected using the steering angle θ detected by the steering angle sensor 41, and the left and right front wheels FW1, FW2 are rotated. The rotation of the rudder and the turning electric motor 22 is detected using the actual turning angle δ detected by the turning angle sensor 43. However, the rotation angles of the steering reaction force electric motor 13 and the steering electric motor 22 may be used instead of or in combination with the outputs of the sensors 41 and 43. In this case, a motor rotation angle sensor for detecting the rotation angles of the motors 13 and 22 is assembled to the steering reaction force electric motor 13 and the steering electric motor 22, respectively, and the output of these motor rotation angle sensors is used. That's fine.

  In the embodiment, the steering handle 11 that is rotated is adopted. However, the present invention is also applied to a vehicle steering apparatus that uses a steering handle that steers the left and right front wheels FW1 and FW2 by a linear operation such as a joystick instead of the steering handle 11.

1 is an overall schematic diagram of a vehicle steering apparatus according to an embodiment of the present invention. 2 is a flowchart of a fail inspection program executed by the inspection ECU in FIG. 1. It is a flowchart which shows the detail of the 1st test | inspection routine of FIG. It is a flowchart which shows the detail of the 2nd test | inspection routine of FIG. It is a flowchart which shows the detail of the 3rd test | inspection routine of FIG. It is a flowchart of the steering reaction force control program executed by the steering reaction force ECU of FIG. It is a flowchart of the steering control program performed by ECU for steering of FIG. It is a figure which shows the time change of the actual turning angle and drive voltage value which show the control aspect of the electric motor for steering and the electric motor for steering reaction force for abnormality detection. It is a graph which shows the relationship between a steering wheel steering angle and a target steering reaction force. It is a graph which shows the relationship between a steering wheel steering angle and a target turning angle. It is a graph which shows the relationship between a vehicle speed and a vehicle speed coefficient.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Steering handle, 12 ... Steering input shaft, 13 ... Electric motor for steering reaction force, 21 ... Rack bar, 22 ... Electric motor for turning, 24 ... Steering output shaft, 31 ... Cable, 32, 33 ... Electromagnetic clutch, DESCRIPTION OF SYMBOLS 41 ... Steering angle sensor 42 ... Steering torque sensor 43 ... Steering angle sensor 44 ... Vehicle speed sensor 46 ... Inspection ECU 47 ... Steering reaction force ECU 48 ... Steering ECU 55 ... Transmission

Claims (7)

An input member connected to the steering handle and displaced in conjunction with the steering handle;
An output member connected to the steered wheel and displaced in conjunction with the steered wheel;
It is interposed between the input member and the output member and selectively switched to a disconnected state and a connected state, and in the disconnected state, the input member and the output member are disconnected so as not to be able to transmit power, and are connected. An intermittent device for connecting the input member and the output member so as to be capable of transmitting power;
A steering reaction force electric motor connected to the input member for applying a reaction force to the steering operation of the steering wheel;
In a steer-by-wire vehicle steering apparatus, comprising: an electric motor for steering that is connected to the output member and displaces the output member in accordance with a steering operation of the steering handle to steer the steered wheels;
A steering angle sensor for detecting the steering angle of the steering wheel;
Steering detected by the steering angle sensor when the electric motor for turning is rotated by rotating the electric motor for turning by a predetermined amount in directions opposite to each other with the intermittent device set to a disconnected state. An abnormality detection device for a vehicle steering system, comprising: an abnormality detection means for detecting a disconnection abnormality of the intermittent device when the angle changes. In the abnormality detection apparatus for the vehicle steering apparatus according to claim 1,
The abnormality detecting means;
First driving means for rotating the steering electric motor by a predetermined amount in one direction;
Second driving means for rotating the electric motor for steering by a predetermined amount in a direction opposite to the one direction after rotating the electric motor for steering by a predetermined amount in the one direction by the first driving means; ,
A vehicle steering apparatus comprising: a first abnormality detection unit configured to detect a disconnection abnormality of the intermittent device on the condition that the steering angle detected by the steering angle sensor has changed when the electric motor for turning is rotated. For detecting abnormalities. In the abnormality detection apparatus for the vehicle steering apparatus according to claim 2,
The first driving means;
First direction drive control means for driving and controlling the steered electric motor to rotate the steered electric motor by a predetermined amount in the first direction;
Non-rotation detecting means for detecting non-rotation of the electric motor for turning;
When the non-rotation of the steered electric motor is detected by the non-rotation detecting means during the drive control of the steered electric motor by the first direction drive control means, the steered electric motor is moved in the first direction. An abnormality detection device for a steering device for a vehicle, comprising: a second direction drive control means for driving and controlling the steering electric motor to rotate in a second direction opposite to the first direction. In the abnormality detection apparatus for the vehicle steering apparatus according to claim 3,
In addition to the abnormality detection means,
When the non-rotation of the turning electric motor is detected by the non-rotation detecting means during the drive control of the turning electric motor by the second direction drive control means, an abnormality of the turning electric motor is detected. An abnormality detection device for a vehicle steering system, characterized in that a second abnormality detection means is provided. An abnormality detection device for a vehicle steering device according to any one of claims 2 to 4,
The abnormality detection device for a vehicle steering device, wherein the first and second drive means gradually change the rotation angle of the electric motor for turning as time elapses. In the abnormality detection device for a vehicle steering device according to any one of claims 1 to 5,
The output torque of the steering electric motor is set to be larger than the output torque of the steering reaction force electric motor, and
Static control means for controlling the steering reaction force electric motor so that the steering reaction force electric motor does not rotate when the turning electric motor is rotated to detect disconnection abnormality of the interrupting device. An abnormality detection device for a vehicle steering apparatus provided. In the abnormality detection device for a vehicle steering device according to any one of claims 1 to 6,
The interrupting device is composed of first and second interrupters that are connected in series via a cable and selectively switched to a connected state and a disconnected state, respectively.
The abnormality detection device sets one of the first and second interrupters to a disconnected state, and sets the other interrupter of the first and second interrupters to a connected state. An abnormality detection device for a vehicle steering device, characterized in that a disconnection abnormality of the intermittent device is detected by setting.

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