JP7035990B2 - Shift-by-wire system - Google Patents

Description

The present disclosure relates to a shift-by-wire system that controls shift range switching of a vehicle.

Patent Document 1 discloses a shift-by-wire system that operates a shift range switching mechanism in a transmission by a motor driven based on a signal indicating a shift range selected by a driver. The shift-by-wire system of Patent Document 1 includes a rotation angle sensor, a control unit, and a drive circuit. The rotation angle sensor sequentially detects the rotation angle of the motor that operates the switching mechanism. The control unit sequentially determines the energization pattern of the motor based on the selected shift range, the current value of the detected rotation angle, and the like. The control unit sequentially outputs the drive signal corresponding to the determined energization pattern to the drive circuit. The drive circuit drives the motor by sequentially switching the energization pattern of the motor according to the switching of the drive signal from the shift control device. The control unit performs feedback control by monitoring the motor driven by the drive circuit and the switching mechanism with a rotation angle sensor or the like.

Japanese Unexamined Patent Publication No. 2018-11238

In a shift-by-wire system, a configuration in which a series of control systems including a rotation angle sensor, a control unit, and a drive circuit are provided for a motor is being studied. With such a configuration, even when the drive of the motor is interrupted due to an abnormality of the rotation angle sensor in one control system, the operation of the motor can be continued by the drive by the other control system.

However, the pattern of abnormality occurring in the control system includes an abnormality in the drive circuit that does not follow the switching of the drive signal and fixes the energization pattern to the motor. When such an abnormality occurs in any of the control systems, it suppresses the driving of the motor by the other system. As a result, when an abnormality occurs in which the energization pattern is fixed in one control system, the other control system is also fed back to the control unit as an abnormality in the rotation speed calculated by using the rotation angle sensor. Therefore, it may be difficult to identify the control system having the drive circuit in which the drive circuit has an abnormality in the monitoring by the rotation angle sensor.

An object of the present disclosure is to provide a shift-by-wire system capable of identifying a control system having a drive circuit in which an abnormality has occurred among a plurality of drive circuits for driving a motor.

The above object is achieved by a combination of the features described in the independent claims, and the sub-claims provide for further advantageous embodiments of the present disclosure. The reference numerals in parentheses described in the claims indicate, as one embodiment, the correspondence with the specific means described in the embodiments described later, and do not limit the technical scope of the present disclosure. ..

One shift-by-wire system of the present disclosure for achieving the above object switches the shift range of the transmission (20) by a motor (31) driven based on a range signal indicating a shift range selected by the driver of the vehicle. It is a shift-by-wire system, and is detected by a drive circuit (102) that drives the motor by switching the energization pattern for the motor, a rotation angle detection unit (121) that sequentially detects the rotation angle of the motor, and a rotation angle detection unit. Two control systems (100) each having a drive control unit (122) that controls switching of an energization pattern by a drive circuit based on a rotation angle, and both a drive control unit in each control system are based on a range signal. An abnormality detection unit (131) that detects an abnormality in switching of the energization pattern of the drive circuit in any of the control systems based on the decrease in the rotation speed of the motor when the motor is being driven, and an abnormality detection unit (131) of each control system. One is a maintenance system and the other is a variable system, and the fluctuation part (132) that changes the amount of electricity supplied by the drive circuit in the maintenance system while maintaining the amount of electricity supplied by the drive circuit in the maintenance system and the fluctuation of the rotation speed of the motor fluctuate. When the fluctuation of the energization amount by the unit is followed, the maintenance system is provided with an abnormality specifying unit (133) that identifies the maintenance system as an abnormal system in which an abnormality has occurred in the drive circuit.

According to the above configuration, when an abnormality in fixing the energization pattern occurs in any of the drive circuits by the abnormality detection unit, the drive circuit in which the abnormality occurs suppresses the rotation of the motor with a force of a magnitude corresponding to the amount of energization. do. Further, the drive circuit in which no abnormality has occurred promotes the rotation of the motor with a force having a magnitude corresponding to the amount of energization. Therefore, when the rotation speed of the motor fluctuates due to the fluctuation of the energization amount of the fluctuating part, if an abnormality occurs on the maintenance system side, the rotation speed fluctuates following the fluctuation of the energization amount, causing an abnormality on the fluctuation system side. If so, it fluctuates against the fluctuation of the amount of energization. As a result, the abnormality specifying unit can determine which control system is the abnormal system based on whether or not the rotation speed calculated by using the rotation angle detection unit follows the fluctuation of the energization amount due to the fluctuation unit. Will be. Therefore, the shift-by-wire system can identify a control circuit having a drive circuit in which an abnormality has occurred.

Another shift-by-wire system of the present disclosure is a shift-by-wire system that switches the shift range of the transmission (20) by a motor (31) driven based on a range signal indicating a shift range selected by the driver of the vehicle. Based on the drive circuit (102) that drives the motor by switching the energization pattern for the motor, the rotation angle detection unit (121) that sequentially detects the rotation angle of the motor, and the rotation angle detected by the rotation angle detection unit. Two control systems (100) each having a drive control unit (122) that controls switching of the energization pattern by the drive circuit, and when each control system stops energization to the motor based on the range signal. , One of the control systems is the maintenance system and the other is the variable system, and the stop of energization by the drive circuit of the maintenance system is maintained, and the energization and energization pattern switching by the drive circuit of the variable system is changed to the shift range of the transmission. Abnormality that identifies the variable system as an abnormal system in which an abnormality has occurred in the drive circuit when the motor is stopped contrary to the energization and switching of the energization pattern by the variable part (132) to be carried out within the range to be maintained. A specific unit (133) is provided.

According to the above configuration, when an abnormality in fixing the energization pattern occurs in any of the drive circuits by the abnormality detection unit, the drive circuit in which the abnormality occurs suppresses the rotation of the motor with a force of a magnitude corresponding to the amount of energization. do. Further, the drive circuit in which no abnormality has occurred promotes the rotation of the motor with a force having a magnitude corresponding to the amount of energization. Therefore, the rotation speed of the motor stops the rotation against the energization if an abnormality occurs on the fluctuating system side when the fluctuating system is energized by the fluctuating part. As a result, the abnormality specifying unit can determine whether the fluctuation system is an abnormality system based on whether or not the rotation speed calculated by using the rotation angle detection unit increases following the energization by the fluctuation unit. .. Therefore, the shift-by-wire system can identify a control circuit having a drive circuit in which an abnormality has occurred.

It is a figure which shows the structure of the shift-by-wire system. It is a figure which shows the structure of the range switching mechanism. It is a flowchart which shows the example of the process in one of the control devices 110. It is a flowchart which shows the example of the process in the other control device 110. It is a flowchart which shows the example of the process in one control device 110 in 2nd Embodiment. It is a flowchart which shows the example of the process in the other control device 110 in 2nd Embodiment. It is a flowchart which shows the example of the process in the control apparatus 110 in 3rd Embodiment.

Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. In the description of each embodiment, the corresponding components may be designated by the same reference numerals and duplicate description may be omitted. When only a part of the configuration is described, the embodiment described above can be applied to the other parts of the configuration. Further, it is possible not only to combine the configurations specified in the description of each embodiment but also to partially combine the configurations even if the combinations are not specified if there is no particular problem in the combination.

<First Embodiment>
As shown in FIG. 1, the shift-by-wire system 1 according to the first embodiment of the present disclosure changes the shift range of the transmission 20 according to the shift range selected by the operation of the driver for the selector device 10 in the vehicle. It is a system to let you. The shift-by-wire system 1 includes an actuator 30 and two control systems 100 in addition to the selector device 10 and the transmission 20.

The selector device 10 is a device that accepts a shift range selection operation by a driver and outputs a range signal indicating the selected shift range. For example, in the present embodiment, the range signal from the selector device 10 indicates which of the four shift ranges of parking range, reverse range, neutral range, and drive range is selected by the driver. The selector device 10 includes a selector lever 11 and a detection unit 12. The selector lever 11 moves to a position corresponding to each shift range according to the selection operation. The detection unit 12 detects the current position of the selector lever 11 by, for example, a magnetic sensor, and outputs a range signal indicating a shift range corresponding to the current position.

The transmission 20 is an automatic transmission that automatically changes the gear ratio and the like with respect to the rotational driving force transmitted from the traveling drive source to the axle. The transmission 20 automatically drives a clutch or the like to change the gear ratio or the like by controlling the flow path of the hydraulic oil and the hydraulic pressure by various valves provided inside. The transmission 20 has a range switching mechanism 21.

The range switching mechanism 21 is a mechanism for switching the flow path of the hydraulic oil in the transmission 20 to the flow path corresponding to the selected shift range. As shown in FIG. 2, the range switching mechanism 21 includes a shaft 22, a detent plate 23, a detent spring 24, and a range switching valve 25.

The shaft 22 is a columnar member connected to the output shaft of the actuator 30. The shaft 22 is driven by the actuator 30 and rotates around the central axis.

The detent plate 23 is a flat plate-shaped member connected to the shaft 22 and rotated together with the shaft 22. The detent plate 23 is arranged so as to extend in the outer peripheral direction from the shaft 22 in a posture in which both sides are oriented in a direction along the central axis of the shaft 22. The detent plate 23 linearly moves the range switching valve 25 and the parking lock mechanism 2 to an arrangement corresponding to the shift range according to the change in posture due to rotation. A plurality of notches recessed toward the central axis of the shaft 22 are formed on the outer peripheral edge portion of the detent plate 23. The detent plate 23 is formed with four notches corresponding to the four shift ranges. The detent plate 23 engages the notch corresponding to the shift range with the detent spring 24 in the engagement angle range which is the range of the posture corresponding to each shift range.

The detent spring 24 is a member that engages with the notch of the detent plate 23 by an urging force toward the central axis of the shaft 22. The detent spring 24 holds the posture of the detent plate 23 by engaging with the notch when the posture of the detent plate 23 is not changed by the operation of the actuator 30. The position of the range switching valve 25 and the like is maintained by maintaining the posture, that is, by restricting the rotation. When the posture of the detent spring 24 is changed by the operation of the actuator 30, the detent spring 24 temporarily disengages the engagement with the notch and enables the detent plate 23 to rotate. Specifically, when the detent plate 23 is rotated to a posture outside the engagement angle range, it is pushed out by the detent plate 23 in a direction away from the shaft 22 and elastically deformed. The extruded detent spring 24 temporarily disengages the notch until the detent plate 23 is in a position within the engagement angle range of either notch.

The range switching valve 25 is a so-called spool valve that is formed in a columnar shape and can move along the extending direction. The range switching valve 25 moves to an arrangement corresponding to each shift range as the posture of the detent plate 23 changes. The range switching valve 25 switches the shift range of the transmission 20 by switching the flow path of the hydraulic oil according to the position.

The actuator 30 is a device that rotationally drives the shaft 22 to move the range switching valve 25 and the like to an arrangement corresponding to the shift range indicated by the range signal. The actuator 30 has a motor 31 and a speed reducer 32.

As the motor 31, a synchronous motor such as a three-phase switched reluctance motor is used. The motor 31 is rotated by an energization pattern, that is, a phase through which a current is passed and an attractive force for a rotor generated according to the switching thereof. The suction force is generated in the direction according to the relationship between the current position of each salient pole of the rotor indicated by the rotation angle of the rotor and the energization pattern. The motor 31 continues to rotate by switching the energization pattern according to the fluctuation of the rotation angle so that the direction of the suction force is the same rotation direction. The motor 31 rotates at a speed according to the change of the energization pattern within a range that can be followed by acceleration / deceleration due to the generated suction force.

The motor 31 is provided with two sets of three-phase coils in such an arrangement that the electric angles of the respective phases are substantially matched with each other. The motor 31 is energized for both of the two sets in synchronization with the energization pattern and its switching, so that the rotor is rotated by the total suction force of both suction forces. The motor 31 can be driven even when only one of the two sets is energized to switch the energization pattern. When only one of the motors is energized, the torque and the maximum speed are limited as the suction force decreases, as compared with the case where both are energized.

When the energization pattern of one of the two sets of coils is fixed, the coil on the fixed side generates suction force in the direction opposite to the rotation direction in a magnitude corresponding to the amount of energization at some rotation angles. .. As a result, when the energization pattern of one coil is fixed, rotation stops or stalls even if the other coil switches the energization pattern to generate an attractive force for rotating the rotor.

The speed reducer 32 includes a plurality of gears and the like, and reduces the rotation of the motor 31 at a predetermined reduction ratio and transmits the rotation to the shaft 22 and the detent plate 23. For example, the speed reducer 32 decelerates and transmits a rotation angle of about several rotations in the motor 31 so as to change the posture about once in the detent plate 23.

The control system 100 is a set of a series of parts for controlling the drive of the motor 31 based on the range signal. Each of the two control systems 100 corresponds individually to one of the two sets of coils provided in the motor 31, respectively. The control system 100 energizes and switches the energization pattern for the corresponding set of coils. As shown in FIG. 1, each control system 100 includes a rotation angle sensor 101, a drive circuit 102, an energization change unit 103, and a control device 110, respectively.

The rotation angle sensor 101 is a sensor for detecting the rotation angle of the rotor in the motor 31. The rotation angle sensor 101 is provided by a magnetic sensor such as a Hall element, and detects periodic fluctuations in the magnetic field due to the magnetic member rotating with the rotor. Specifically, the rotation angle sensor 101 is arranged so as to face unevenness or magnetic poles formed on the outer periphery of a disk-shaped magnetic member at predetermined angular intervals. The rotation angle sensor 101 detects unevenness or passage of magnetic poles due to rotation of the rotor and the magnetic member based on the fluctuation of the magnetic field. The fluctuation of the magnetic field detected by the rotation angle sensor 101 enables the control device 110 to detect the rotation angle of the rotor and the like.

Further, a plurality of rotation angle sensors 101 are arranged around the magnetic member as a set so as to have a predetermined angle interval smaller than the unevenness or the interval between the magnetic poles. The control device 110 can specify the rotation direction of the rotor by the order of detecting the fluctuation in the set.

The drive circuit 102 is a circuit for driving the motor 31 by providing the electric power supplied from the power source 3 of the vehicle to the coil of the motor 31. The drive circuit 102 includes a plurality of semiconductor switches and the like. The drive circuit 102 is responsible for energizing a set of coils corresponding to the control system 100 including itself among the coils of the motor 31. The drive circuit 102 switches the energization pattern for the coil by switching the semiconductor switch according to the drive signal from the control device 110.

The energization changing unit 103 includes, for example, a relay, and is a circuit for changing the amount of energization to the motor 31, that is, the amount of current flowing through the motor 31. The energization change unit 103 of the present embodiment is a relay provided between the drive circuit 102 in the same control system 100 and the power supply 3 of the vehicle. The energization changing unit 103 switches between a state in which power is cut off from the power supply 3 and a state in which power is supplied to the drive circuit 102 by opening and closing according to an open / close signal from the control device 110. The energization change unit 103 changes the amount of current flowing through the motor 31 between the magnitude according to the applied voltage from the power supply 3 and zero by switching between supply and cutoff of electric power to the drive circuit 102.

The control device 110 is an electronic control device including, for example, a memory 111 as a non-transitional and substantive storage medium for recording software non-temporarily, and a processor core 112 for executing the software. The control device 110 exerts functions as a rotation angle detection unit 121 and a drive control unit 122 by executing software on the processor core 112.

The rotation angle detection unit 121 detects the rotation angle of the rotor in the motor 31 and the like. The rotation angle detection unit 121 sequentially detects the rotation angle based on the fluctuation of the magnetic field detected by the rotation angle sensor 101 in the same control system 100. Further, the rotation angle detection unit 121 counts the rotation speed of the motor 31 and calculates the amount of change in the rotation angle per unit time, that is, the rotation speed, based on the temporal fluctuation of the detected rotation angle. The rotation angle detection unit 121 communicates with the rotation angle detection unit 121 in the control device 110 of the other control system 100, and mutually checks each specified rotation angle and the like.

The drive control unit 122 controls the energization pattern from the drive circuit 102 to the motor 31 by outputting a sequential drive signal to the drive circuit 102 in the same control system 100. The drive control unit 122 controls switching of the energization pattern based on the range signal from the selector device 10 and the rotation angle detected by the rotation angle detection unit 121. More specifically, when the change of the shift range selected by the driver is transmitted from the selector device 10 by the range signal, the drive control unit 122 sets the posture of the detent plate 23 corresponding to the new shift range as the target posture. do.

The drive control unit 122 calculates the rotation direction of the motor 31 and the required rotation speed for changing from the current posture of the detent plate 23 to the target posture. The drive control unit 122 causes the motor 31 to start rotation, and sets the transition of the rotation speed until the rotation of the required rotation speed is completed and stopped as the target rotation speed. The target rotation speed is set so as to make a transition within a range of acceleration / deceleration and maximum speed possible by the suction force generated by the motor 31. Therefore, for example, when the drive by the other control system 100 is stopped, the target rotation speed is set or updated within the range of acceleration / deceleration and maximum speed possible only by the control system 100 including itself. The drive control unit 122 generates and outputs a sequential drive signal while receiving feedback such as the rotation angle from the rotation angle detection unit 121 so as to drive the motor 31 along the target rotation speed.

The shift-by-wire system 1 serves as an abnormality detection unit 131, a fluctuation unit 132, and an abnormality identification unit 133 for detecting the sticking of the energization pattern from each control system 100 to the motor 31 and identifying the stuck control system 100. It is configured to perform its function. These functions in the present embodiment are exhibited in each control device 110 in addition to the functions as the rotation angle detection unit 121 and the drive control unit 122 by the processor core 112 that executes the software recorded in the memory 111. There is. It should be noted that some or all of the functions exhibited by the control device 110 including these functions may be realized in terms of hardware by using a processor using a logic circuit array such as an ASIC.

The abnormality detection unit 131 detects the energization pattern fixing, which is an abnormality of the energization pattern switching in the drive circuit 102, as an abnormality in any one of the control systems 100. The energization pattern fixing is an abnormality in which the energization pattern is fixed to the motor 31 from the drive circuit 102, contrary to the switching of the drive signal output from the control device 110 by the function of the drive control unit 122. The abnormality detection unit 131 detects the energization pattern fixation based on the current rotation speed calculated by the rotation angle detection unit 121. When the drive control unit 122 of both control systems 100 drives the motor 31 to the drive circuit 102, the abnormality detection unit 131 detects that the energization pattern is fixed based on the decrease in the rotation speed.

The abnormality detection unit 131 determines that the energization pattern has been fixed when the rotation speed is lower than the speed at each time set as the target rotation speed. When the difference in rotation speed with respect to the target rotation speed is equal to or greater than a predetermined speed difference threshold value, the abnormality detection unit 131 considers that the rotation speed has decreased and determines that the energization pattern is fixed. That is, when the drive control unit 122 accelerates or maintains the speed of the motor 31, but the stopped state continues or stalls, it is considered that the state in which the rotation speed has decreased has occurred.

The fluctuation unit 132 changes the amount of electricity supplied from one of the control systems 100 to the motor 31 when the abnormality detection unit 131 detects an abnormality in fixing the energization pattern. Specifically, the variable unit 132 sets one of the two control systems 100 as a maintenance system and the other as a variable system. The fluctuation unit 132 maintains the amount of electricity supplied to the motor 31 from the drive circuit 102 of the maintenance system. That is, the fluctuation unit 132 keeps switching the energization pattern while maintaining the amount of current flowing through the coils of each phase. The fluctuation unit 132 temporarily changes the amount of electricity supplied to the motor 31 from the drive circuit 102 of the fluctuation system.

The variable unit 132 of the present embodiment temporarily reduces the amount of electricity supplied from the variable system to zero. The fluctuating unit 132 temporarily opens the relay of the energization changing unit 103 to cut off the power supply to the drive circuit 102, thereby reducing the energization amount to zero. The fluctuation unit 132 continues the generation of the drive signal by the drive control unit 122 even during the period when the energization amount is changed to zero.

The abnormality specifying unit 133 identifies an abnormal system, which is a control system in which an abnormality has occurred in the drive circuit 102, based on the fluctuation of the rotation speed when the fluctuation of the energization amount is carried out by the fluctuation unit 132. The abnormality specifying unit 133 determines which of the maintenance system and the fluctuation system corresponds to the abnormality system based on whether or not the fluctuation of the rotation speed follows the fluctuation of the energization amount. If the rotation speed continues to decrease even after the energization amount is reduced, the abnormality identification unit 133 of the present embodiment considers that the fluctuation of the rotation speed follows the fluctuation of the energization amount, and sets the maintenance system. Identify as an abnormal strain. When the rotation speed recovers after the energization amount is reduced, the abnormality specifying unit 133 considers that the fluctuation of the rotation speed does not follow the fluctuation of the energization amount, and identifies the fluctuation system as an abnormal system.

However, the state in which the rotation speed continues to decrease in the present embodiment means a state in which the rotation speed at the time when a predetermined recovery time elapses from the start of the decrease in the energization amount is equal to or less than the rotation speed at the time when the decrease starts. Further, the state in which the rotation speed is recovered means a state in which the rotation speed at the time when the recovery time has elapsed is higher than the rotation speed at the time when the decrease starts. The recovery time is set so that when the actual rotation speed increases after the start of decrease, the rotation speed calculated when the recovery time elapses is larger than the rotation speed calculated when the decrease starts. .. For example, when the rotation speed is calculated by the rotation angle detection unit 121 based on the fluctuation amount of the rotation angle within the latest predetermined time, the recovery time is set to a length equal to or longer than the predetermined time.

The abnormality specifying unit 133 stops the energization of the motor 31 by the control system 100 specified as the abnormal system. For example, the abnormality specifying unit 133 stops the energization from the abnormal system by stopping the control device 110 of the abnormal system and opening the relay of the energization changing unit 103. That is, when the maintenance system is identified as an abnormal system, the abnormality specifying unit 133 stops the energization by the maintenance system and restarts the energization by the variable system and the switching of the energization pattern. Further, when the variable system is identified as an abnormal system, the abnormality specifying unit 133 causes the maintenance system to continuously perform energization and switching of the energization pattern, and stops the control device 110 of the variable system.

[Operation of control device 110]
The operation of the control device 110 will be described with reference to the flowcharts of FIGS. 3 and 4. When the request for switching the shift range is received, each control device 110 periodically executes one of the processes shown in FIGS. 3 and 4 until the drive along the set target rotation speed is completed. That is, one control device 110 periodically executes the process shown in FIG. 3 in order from S101, and the other control device 110 periodically executes the process shown in FIG. 4 in order from S201.

First, the process of FIG. 3 will be described. In S101, it is determined whether or not the rotation speed has decreased. If the rotation speed does not decrease, the process proceeds to S102. If the rotation speed has decreased, the process proceeds to S103. In S102, drive control is performed by normal energization and energization pattern switching, and the process of FIG. 3 is completed.

In S103, by opening the relay of the energization changing unit 103, the energization of the motor 31 from the control system 100 including itself is temporarily stopped. That is, the control system 100 including itself is set as a variable system, and the other control system 100 is set as a maintenance system, and the amount of electricity supplied from the variable system is changed.

In S104, the control device 110 of the other control system 100 is notified that the energization from the control system 100 including itself has been stopped.

In S105, it is determined whether or not the rotation speed is recovered based on the rotation speed at the time when the recovery time has elapsed from the time when the energization is stopped. If the rotation speed is recovered, the process proceeds to S106, and if the rotation speed is not recovered, the process proceeds to S108.

In S106, the control system 100 including itself is regarded as an abnormal system, and the energization from the control system 100 including itself is terminated. In S107, the other control device 110, the display device provided in the vehicle, and the like are notified that an abnormality has occurred in the control system 100 including itself, and the process shown in FIG. 3 is terminated.

In S108, the control system 100 including itself is not an abnormal system, and the other control system 100 is regarded as an abnormal system, and the energization from the control system 100 including itself is restarted.

Next, the process of FIG. 4 will be described. In S201, it is determined whether or not the rotation speed has decreased. If the rotation speed does not decrease, the process proceeds to S202. If the rotation speed has decreased, the process proceeds to S203. In S202, drive control is performed by normal energization and energization pattern switching, and the process of FIG. 3 is completed.

In S203, it is determined whether or not the situation is such that the determination as to whether or not the rotation speed has been restored is performed based on the notification that the energization has been stopped from the other control device 110. That is, it is determined whether or not the recovery time has elapsed since the notification was received. If it has not been received yet, or if the recovery time has not elapsed since the reception, the process proceeds to S202 as it is not the situation to determine whether or not the recovery has occurred, and the normal energization control is continued. If the recovery time has elapsed since the notification was received, the process proceeds to S204, assuming that the situation is such that it is determined whether or not the recovery has occurred.

In S204, it is determined whether or not the rotation speed is recovered. If it is recovered, the control system 100 including itself proceeds to S202 as not being an abnormal system, and normal energization control is continued. If it has not recovered, the process proceeds to S205.

In S205, the control system 100 including itself is regarded as an abnormal system, and the energization from the control system 100 including itself is terminated. In S206, the other control device 110, the display device, and the like are notified that an abnormality has occurred in the control system 100 including itself, and the process shown in FIG. 4 is terminated.

[Summary of the first embodiment]
According to the first embodiment described above, when an abnormality in fixing the energization pattern occurs in any of the drive circuits 102 by the abnormality detection unit 131, the drive circuit 102 in which the abnormality occurs has a size according to the amount of energization. The rotation of the motor 31 is suppressed by the force of. Further, the drive circuit 102 in which no abnormality has occurred promotes the rotation of the motor 31 with a force having a magnitude corresponding to the fluctuation of the energization amount. Therefore, when the rotation speed of the motor 31 fluctuates according to the fluctuation of the energization amount when the fluctuation unit 132 changes the energization amount of the fluctuation system, if an abnormality occurs on the maintenance system side, the rotation speed fluctuates according to the fluctuation of the energization amount, and the abnormality occurs on the fluctuation system side. If it occurs, it fluctuates against the fluctuation of the amount of energization.

As a result, in the abnormality identification unit 133, which control system 100 is the abnormality system based on whether or not the rotation speed calculated by the rotation angle detection unit 121 follows the fluctuation of the energization amount by the fluctuation unit 132. It becomes possible to judge whether or not there is. Therefore, the shift-by-wire system 1 can identify the control system 100 having the drive circuit 102 in which the abnormality has occurred.

Further, the variable unit 132 of the present embodiment stops the energization of the motor 31 from the drive circuit 102 of the variable system. Therefore, when the variable system side is an abnormal system, the suppression of rotation by the abnormal system can be stopped before the abnormal system is specified by the abnormal identification unit 133. Therefore, when the variable system side is an abnormal system, the time from the detection of the energization pattern fixation by the abnormality detecting unit 131 to the recovery of the rotation speed of the motor 31 can be shortened.

<Second embodiment>
The second embodiment is a modification of the first embodiment. In the shift-by-wire system 1 in the second embodiment, the configuration of the energization changing unit 103 (see FIG. 1) is changed as compared with the first embodiment, and the functions of the variable unit 132 and the abnormality specifying unit 133 are also changed accordingly. It is partially different from the first embodiment.

The energization change unit 103 in the second embodiment is configured to be able to switch a plurality of current levels in which the energization amount from the drive circuit 102 to the motor 31 is set to other than zero. For example, the energization change unit 103 has a bypass circuit that connects to the power supply 3 via a resistor or the like and a direct circuit that directly connects to the power supply 3 as a power supply path to the drive circuit 102. The energization change unit 103 is configured to be able to switch between a state in which power is not supplied to the drive circuit 102, a state in which power is supplied through a direct circuit, and a state in which power is supplied through a bypass circuit, using a relay or the like. .. The energization change unit 103 normally supplies electric power to the drive circuit 102 through a direct circuit.

The fluctuation unit 132 in the second embodiment temporarily reduces the amount of electricity supplied to the motor 31 by the drive circuit 102 of the fluctuation system when the abnormality detection unit 131 detects that the energization pattern is fixed. The fluctuating unit 132 temporarily reduces the amount of energization by requesting the energization changing unit 103 included in the fluctuating system side to temporarily supply power to the drive circuit 102 through the bypass circuit.

The abnormality specifying unit 133 in the second embodiment determines whether or not the rotation speed follows the fluctuation of the energization amount based on the time change amount of the rotation speed. Specifically, it is determined that the amount of decrease in the rotation speed per unit time has followed the case where the amount of decrease has been increased with respect to immediately before the decrease in the amount of energization, and it is determined that the amount has not been followed when the amount has decreased. In other words, the abnormality specifying unit 133 identifies the abnormal system by determining whether or not the deceleration rate of the rotation speed follows the decrease rate of the energization amount. However, when the rotation speed increases or does not fluctuate, the fluctuating system is specified as an abnormal system assuming that the amount of decrease is a negative or zero value, that is, it does not follow. The abnormality specifying unit 133 mutually checks the specified results, and if the results are in agreement, the determination result is determined.

[Operation of control device 110]
The operation of each control device 110 in the second embodiment will be described with reference to the flowcharts of FIGS. 5 and 6. The process shown in FIGS. 5 and 6 is a process executed in place of the process of FIGS. 3 and 4 in the first embodiment. That is, of the two control devices 110 that have received the shift range switching request, one control device 110 periodically executes the process shown in FIG. 5 in order from S301, and the other periodically executes the process shown in FIG. 6 in order from S401. To execute.

First, the process of FIG. 5 will be described. S301 and S302 are the same processes as S101 and S102 (see FIG. 3). S303 is a process corresponding to S103, and temporarily changes the power supply path of the energization changing unit 103 to a bypass circuit to reduce the amount of energization to the motor 31.

S304 is a process corresponding to S104, and notifies the control device 110 of the other control system 100 that the amount of electricity supplied from the control system 100 including itself has been reduced.

S305 is a process corresponding to S105, and is a process of determining which control system 100 corresponds to the abnormal system based on the amount of decrease in the rotation speed. When the amount of decrease is reduced, that is, the deceleration pace is relaxed, or the acceleration is started, the control system 100 including itself is regarded as an abnormal system and proceeds to S307. When the amount of decrease increases, the other control system is regarded as an abnormal system and the process proceeds to S306.

In S306, the result of the determination in S305, that is, the fact that the other control system is determined to be an abnormal system is transmitted to the other control device 110. In S307, the result of the determination in S305, that is, the fact that the control system 100 including itself is determined to be an abnormal system is transmitted to the other control device 110.

In S308, it is determined whether or not the result of the determination in S305 and the result of the determination transmitted from the other control device 110 match. If they match, the process proceeds to S309, and if they do not match, the process returns to S305 to determine the abnormal system again.

In S309, it is determined whether or not the abnormal system confirmed by the agreement of the determination results is the control system 100 including itself. If it is a control system 100 including itself, the process proceeds to S310, and if it is the other control system, the process proceeds to S312.

S310 and S311 are the same processes as S106 and S107. Further, S312 is the same process as S108.

Next, the process of FIG. 6 will be described. S401, S402, and S403 are the same processes as S201, S202, and S203. S404 is a process corresponding to S204, and is a process of determining an abnormal system based on the amount of decrease in the rotation speed. When the amount of decrease is reduced, that is, the deceleration pace is relaxed or the acceleration is started, the other control system is regarded as an abnormal system and the process proceeds to S405. When the amount of decrease increases, the control system 100 including itself is regarded as an abnormal system and proceeds to S406.

In S405, the result of the determination in S404, that is, the fact that the other control system is determined to be an abnormal system is transmitted to the other control device 110. In S406, the result of the determination in S404, that is, the fact that the control system 100 including itself is determined to be an abnormal system is transmitted to the other control device 110.

In S407, it is determined whether or not the result of the determination in S404 and the result of the determination transmitted from the other control device 110 match. If they match, the process proceeds to S408, and if they do not match, the process returns to S404 to determine the abnormal system again.

In S408, it is determined whether or not the abnormal system confirmed by the agreement of the determination results is the control system 100 including itself. If it is a control system 100 including itself, the process proceeds to S409, and if it is the other control system, the process proceeds to S402 to continue normal energization control. S409 and S410 are the same processes as S205 and S206.

[Summary of the second embodiment]
According to the second embodiment described above, it is possible to identify the abnormal system which is the control system 100 in which the energization pattern is fixed, as in the first embodiment.

Further, in the present embodiment, the variable unit 132 reduces the amount of electricity supplied from the variable system to a non-zero value. Therefore, even if any of the control systems 100 is an abnormal system, the abnormal system can be specified without making the suction force in the rotational direction zero. Therefore, the shift-by-wire system 1 can suppress a decrease in the rotation speed in identifying the abnormal system regardless of the side of the abnormal system.

<Third embodiment>
The third embodiment is another modification of the first embodiment. In the shift-by-wire system 1 in the third embodiment, some of the functions exhibited by the control device 110 are different from the functions in the first embodiment. Specifically, the functions of the variable unit 132 and the abnormality specifying unit 133 are different from those of the first embodiment.

The variable unit 132 of the third embodiment temporarily changes the energized amount of the variable system even when the abnormality detection unit 131 does not detect the fixation of the energization pattern. Specifically, the variable unit 132 sets one of them as the variable system in a state where the shift range switching is not requested by the range signal, that is, in a state where rotation is not required, and the variable unit 132 is temporarily set with respect to the variable system. Is energized and the energization pattern is switched.

The fluctuating unit 132 causes the fluctuating system to energize and switch the energization pattern so as to drive the motor 31. The fluctuating unit 132 causes energization and switching of the energization pattern within a range in which the shift range is maintained, that is, within a range in which the shift range is not switched. The fluctuating unit 132 causes the motor 31 to rotate and switch the energization pattern and the energization pattern within a range that does not deviate from the engagement angle range corresponding to the shift range at that time. The fluctuating unit 132 sets the target posture within the engagement angle range corresponding to the shift range at that time, and drives the motor 31.

In a situation where it is difficult to receive a request for shift range switching, for example, when the drive range is set, the variable unit 132 alternately switches the control system 100 set as the variable system and energizes at predetermined time intervals. The variable portion 132 may be energized a plurality of times regardless of the rotation direction as long as the shift range is maintained. Further, the motor 31 may be driven so as to reciprocate within the engagement angle range by changing the rotation direction each time energization is performed.

In the abnormality specifying unit 133 of the third embodiment, when the variable unit 132 temporarily energizes the variable system and switches the energization pattern, the variable system is based on whether or not the motor 31 is rotating. Determine if it is an abnormal system. Specifically, when the motor 31 is stopped despite the temporary energization and switching of the energization pattern, it is determined that the variable system is an abnormal system. The term "motor 31 is stopped" means that the motor 31 is stopped at a rotation angle of about one cycle of energization pattern switching, such as rotation of the motor 31 being less than a predetermined rotation angle.

[Operation of control device 110]
The operation of each control device 110 in the third embodiment will be described with reference to the flowchart of FIG. The two control devices 110 periodically execute the processes shown in FIG. 7 in order from S501 in a state where the ignition switch is turned on.

In S501, it is determined whether or not the shift range switching request has been received. If not received, proceed to S502, and if received, proceed to S510.

In S502, it is determined whether or not the diagnosis has been performed based on the flag indicating the result of performing the diagnosis of the control system 100 including itself. When the flag is set and it is determined that the diagnosis has been performed, the process of FIG. 7 is terminated. If it is determined that the flag has been cleared and the diagnosis has not been performed, the process proceeds to S503.

In S503, it is determined whether or not the current shift range is the drive range. If it is in the drive range, the process proceeds to S504, and if it is not in the drive range, the process of FIG. 7 ends.

In S504, since the control system 100 including itself is set to the variable system, it is determined whether or not it is in the order of performing the diagnosis. If it is the turn to carry out the diagnosis, the process proceeds to S505, and if it is not the turn, the process of FIG. 7 is terminated.

In S505, energization and switching of the energization pattern are performed. In S506, it is determined whether or not the motor 31 has rotated due to the energization and the switching of the energization pattern carried out in S505. If the motor 31 is rotated, the process proceeds to S507, and if the motor 31 is not rotated, the process proceeds to S508.

In S507, a flag is set indicating that the diagnosis has been performed and that the control system 100 including itself is normal as a result of the diagnosis, not an abnormal system. In S508, a flag indicating that the diagnosis has been performed and that the control system 100 including itself is an abnormal system as a result of the diagnosis is set. In S509, the other control device 110 or the like is notified that the control system 100 including itself is an abnormal system.

In S510, it is determined whether or not the control system 100 including itself is diagnosed as an abnormal system. If it is diagnosed as an abnormal system, only the other control system 100 is energized, and the process shown in FIG. 7 is terminated without energizing itself.

In S511, normal energization control is performed. In S512, the flag indicating that it was normal is cleared, and the diagnosis is set to be executed again when the drive range is reached next time.

[Summary of Third Embodiment]
According to the third embodiment described above, it is possible to identify the abnormal system which is the control system 100 in which the energization pattern is fixed, as in the first embodiment.

Further, in the present embodiment, the abnormality specifying unit 133 determines whether or not the motor 31 rotates according to the temporary fluctuation of the energization amount carried out by the fluctuation unit 132 in a state where the shift range switching is not requested. Anomalous lines can be identified. Therefore, the shift-by-wire system 1 can drive the motor 31 without using a pre-specified abnormal system when the shift range is requested to be switched. Therefore, the shift-by-wire system 1 is less likely to suppress driving by fixing the energization pattern when the shift range is requested to be switched.

<Other embodiments>
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and the following modifications are also included in the technical scope of the present disclosure. Various changes can be made within the range that does not deviate. In the following description, the element having the same number as the code used so far is the same as the element having the same code in the previous embodiments, unless otherwise specified. Further, when only a part of the configuration is described, the embodiment described above can be applied to the other parts of the configuration.

In the above-described embodiment, the functions as the abnormality detection unit 131, the fluctuation unit 132, and the abnormality identification unit 133 are exhibited in each of the two control devices 110, and the abnormality system is specified in cooperation with each other. However, each of the above-mentioned functions may be exhibited only by one control device 110, and may be controlled by including the other control device 110. Further, each of the above-mentioned functions may be configured to be exhibited in an electronic control device separate from each control device 110. Even in such a case, each function may be realized by executing software in a processor core 112 such as a CPU, or may be realized in terms of hardware by an ASIC or the like. Further, it may be realized by a combination thereof.

In the first embodiment and the second embodiment described above, the variable unit 132 carries out a variation of reducing the energization amount, including reducing the energization amount to zero, as a variation of the energization amount from the variable system side. .. However, the fluctuation may be performed to increase the energization amount by temporarily boosting the voltage applied to the motor 31 from the drive circuit 102 on the variable system side. In this case, the abnormality specifying unit 133 may specify the maintenance system as an abnormal system by assuming that the fluctuation is followed when the rotation speed increases with the increase in the amount of energization. Further, the method of varying the energization amount can be appropriately changed, for example, the effective energization amount is changed by varying the on-duty of the switch in the drive circuit 102.

In the above-described embodiment, the abnormality detection unit 131 detects the fixation of the energization pattern based on the difference between the rotation speed and the target rotation speed. However, the detection conditions can be changed as appropriate, such as detection based on the deceleration rate of the rotation speed.

1 shift-by-wire system, 20 transmission, 31 motor, 100 control system, 102 drive circuit, 121 rotation angle detection unit, 122 drive control unit, 131 abnormality detection unit, 132 fluctuation unit, 133 abnormality identification unit

Claims (4)

A shift-by-wire system that switches the shift range of the transmission (20) by a motor (31) driven based on a range signal indicating the shift range selected by the vehicle driver.
The drive circuit (102) that drives the motor by switching the energization pattern for the motor, the rotation angle detection unit (121) that sequentially detects the rotation angle of the motor, and the rotation angle detected by the rotation angle detection unit. Based on this, two control systems (100) each having a drive control unit (122) that controls switching of an energization pattern by the drive circuit, and
When both of the drive control units in the control system drive the motor based on the range signal, the drive circuit in any of the control systems is based on the decrease in the rotational speed of the motor. Anomaly detection unit (131) that detects anomalies in switching the energization pattern of
With a variable unit (132) in which one of the control systems is a maintenance system and the other is a variable system, the amount of electricity supplied by the drive circuit in the maintenance system is maintained, and the amount of electricity supplied by the drive circuit in the variable system is changed. ,
Shift-by-wire including an abnormality specifying unit (133) that identifies the maintenance system as an abnormal system in which an abnormality has occurred in the drive circuit when the fluctuation of the rotation speed of the motor follows the fluctuation of the energization amount due to the fluctuation unit. system. When the abnormality detection unit detects an abnormality, the fluctuation unit stops energization of the motor by the drive circuit of the fluctuation system.
The shift-by-wire system according to claim 1, wherein the abnormality specifying unit identifies the maintenance system as the abnormal system when the rotation speed continues to decrease after the energization by the variable system is stopped. When the abnormality detection unit detects an abnormality, the fluctuation unit reduces the amount of electricity supplied to the motor by the drive circuit of the fluctuation system.
The shift-by-wire system according to claim 1, wherein the abnormality specifying unit identifies the maintenance system as the abnormal system when the decrease in the rotation speed increases after the energization amount by the variable system is reduced. A shift-by-wire system that switches the shift range of the transmission (20) by a motor (31) driven based on a range signal indicating the shift range selected by the vehicle driver.
The drive circuit (102) that drives the motor by switching the energization pattern for the motor, the rotation angle detection unit (121) that sequentially detects the rotation angle of the motor, and the rotation angle detected by the rotation angle detection unit. Based on this, two control systems (100) each having a drive control unit (122) that controls switching of an energization pattern by the drive circuit, and
When each control system stops energization of the motor based on the range signal, one of the control systems is a maintenance system and the other is a variable system, and energization by the drive circuit of the maintenance system is performed. A variable unit (132) that maintains the stoppage and performs energization and switching of the energization pattern by the drive circuit of the variable system within a range that maintains the shift range of the transmission.
It is provided with an abnormality specifying unit (133) that identifies the variable system as an abnormal system in which an abnormality has occurred in the drive circuit when the motor is stopped contrary to the energization and switching of the energization pattern by the variable unit. Shift-by-wire system.

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