JP2020091027A - Shift-by-wire system - Google Patents

Abstract

To provide a shift-by-wire system capable of specifying a drive circuit in which abnormality has occurred, among a plurality of drive circuits for driving a motor.SOLUTION: A shift-by-wire system 1 comprising two control systems 100 each having a drive circuit 102 of a motor 31 has an abnormality detection unit 131, a fluctuation unit 132, and an abnormality specification unit 133. The abnormality detection unit 131 detects an abnormality in the energization pattern fixation based on decrease in a rotation speed. The fluctuating unit 132 fluctuates an energization amount by a fluctuating system while maintaining the energization amount by a maintenance system. The abnormality specification unit 133 specifies the maintenance system as an abnormal system when the fluctuation of the rotation speed follows the fluctuation of the energization amount.SELECTED DRAWING: Figure 1

Description

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

Patent Literature 1 discloses a shift-by-wire system in which a motor driven based on a signal indicating a shift range selected by a driver operates a shift range switching mechanism in a transmission. 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 and the current value of the detected rotation angle. The control unit sequentially outputs a 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 in accordance with 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.

JP, 2018-112238, A

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

However, the abnormality pattern that occurs in the control system includes an abnormality that does not follow the switching of the drive signal and that fixes the energization pattern to the motor as an abnormality in the drive circuit. When such an abnormality occurs in either control system, the drive of the motor by the other system is suppressed. 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 using the rotation angle sensor. Therefore, with the monitoring by the rotation angle sensor, it may be difficult to identify the control system having the drive circuit in which the drive circuit has an abnormality.

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

The above objective is achieved by a combination of the features recited in independent claims, and the subclaims define further advantageous embodiments of the present disclosure. The reference numerals in parentheses in the claims indicate the correspondence with the specific means described in the embodiments described below as one aspect, 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 a shift range of a transmission (20) by a motor (31) driven based on a range signal indicating a shift range selected by a vehicle driver. A shift-by-wire system, in which a drive circuit (102) that drives a motor by switching an 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 detect the rotation angle. Two control systems (100) each having a drive control unit (122) that controls switching of the energization pattern by the drive circuit based on the rotation angle, and both of the drive control units in each control system are based on the range signal. When the motor is being driven, an abnormality detection unit (131) that detects an abnormality in switching the energization pattern of the drive circuit in any one of the control systems based on the decrease in the rotation speed of the motor, and One is the maintenance system and the other is the variation system, and the variation unit (132) that maintains the amount of electricity supplied by the drive circuit in the maintenance system and varies the amount of electricity supplied by the drive circuit in the variation system, and the variation in the rotation speed of the motor. An abnormality identifying unit (133) that identifies the maintenance system as an abnormal system in which an abnormality has occurred in the drive circuit when following a change in the energization amount by the unit.

According to the above configuration, when an abnormality in the energization pattern is fixed in one of the drive circuits due to the abnormality detection unit, the drive circuit in which the abnormality has occurred suppresses the rotation of the motor with a force according to the energization amount. To do. Further, the drive circuit in which no abnormality has occurred accelerates the rotation of the motor with a force having a magnitude according to the amount of electricity supplied. Therefore, when there is an abnormality in the maintenance system side when the energization amount of the fluctuating system is changed by the fluctuating part, the rotation speed of the motor follows the fluctuation of the energization amount and fluctuates. If it is, it fluctuates contrary to the fluctuation of the energization amount. As a result, the abnormality specifying unit can determine which control system is the abnormal system based on whether the rotation speed calculated using the rotation angle detecting unit follows the fluctuation of the energization amount by the fluctuation unit. Becomes Therefore, the shift-by-wire system can specify the control circuit having the drive circuit in which the abnormality has occurred.

Another shift-by-wire system of the present disclosure is a shift-by-wire system that switches a shift range of a transmission (20) by a motor (31) driven based on a range signal indicating a shift range selected by a vehicle driver. 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. In the case where two control systems (100) each having a drive control unit (122) for controlling switching of the energization pattern by the drive circuit, and each control system suspends energization to the motor based on the range signal. One of the control systems is the maintenance system and the other is the variation system, and the stop of the energization by the drive circuit of the maintenance system is maintained, and the energization and energization pattern switching by the drive circuit of the variation system is performed in the shift range of the transmission. An abnormality that identifies the variation system as an abnormality system in which an abnormality has occurred in the drive circuit when the motor is stopped against switching between the energization and energization pattern switching by the variation unit (132) that is executed within the range to be maintained. And a specifying unit (133).

According to the above configuration, when an abnormality in the energization pattern is fixed in one of the drive circuits due to the abnormality detection unit, the drive circuit in which the abnormality has occurred suppresses the rotation of the motor with a force according to the energization amount. To do. Further, the drive circuit in which no abnormality has occurred accelerates the rotation of the motor with a force having a magnitude according to the amount of electricity supplied. Therefore, the rotation speed of the motor is stopped against energization when an abnormality occurs on the fluctuation system side when the fluctuation system is energized by the fluctuation unit. As a result, the abnormality identifying unit can determine whether the variable system is an abnormal system based on whether or not the rotation speed calculated using the rotation angle detection unit increases by following the energization by the changing unit. .. Therefore, the shift-by-wire system can specify the control circuit having the drive circuit in which the abnormality has occurred.

It is a figure which shows the structure of a shift-by-wire system. It is a figure which shows the structure of a range switching mechanism. 6 is a flowchart showing an example of processing in one control device 110. 7 is a flowchart showing an example of processing in the other control device 110. It is a flow chart which shows an example of processing in one control device 110 in a second embodiment. It is a flow chart which shows an example of processing in other control device 110 in a second embodiment. It is a flow chart which shows an example of processing in control device 110 in a third embodiment.

Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. In the description of each embodiment, corresponding components may be denoted by the same reference numerals and redundant description may be omitted. When only a part of the configuration is described, the above-described embodiments can be applied to other parts of the configuration. Further, not only the combination of the configurations explicitly described in the description of each embodiment, but also the configuration may be partially combined even if it is not explicitly described unless there is a 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 a shift range of a transmission 20 in a vehicle according to a shift range selected by an operation of a driver on a selector device 10. It is a system to let. 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 receives 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 the 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 using, for example, a magnetic sensor, and outputs a range signal indicating the shift range corresponding to the current position.

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

The range switching mechanism 21 is a mechanism for switching the hydraulic fluid flow path in the transmission 20 to a 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 about the central axis.

The detent plate 23 is a flat plate-shaped member that is connected to the shaft 22 and rotates together with the shaft 22. The detent plate 23 is arranged such that both surfaces thereof face the direction along the central axis of the shaft 22 so as to spread from the shaft 22 in the outer peripheral direction. The detent plate 23 linearly moves the range switching valve 25 and the parking lock mechanism 2 to the arrangement corresponding to the shift range according to the change in the posture due to the rotation. A plurality of notches that are recessed toward the central axis of the shaft 22 are formed on the outer peripheral edge of the detent plate 23. The detent plate 23 is formed with four notches corresponding to 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 that 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 the urging force toward the central axis of the shaft 22. The detent spring 24 holds the attitude of the detent plate 23 by engaging with the notch when the attitude 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 held by maintaining the posture, that is, by restricting the rotation. When the attitude of the detent spring 24 is changed by the operation of the actuator 30, the detent spring 24 temporarily releases the engagement with the notch, and allows the detent plate 23 to rotate. Specifically, when the detent plate 23 is rotated to a position outside the engagement angle range, the detent plate 23 is pushed by the detent plate 23 in a direction away from the shaft 22 and elastically deformed. The pushed detent spring 24 temporarily disengages the detent plate 23 from the notch until the detent plate 23 reaches a posture in the engagement angle range of any of the notches.

The range switching valve 25 is a so-called spool valve which is formed in a columnar shape and is movable along the extending direction. The range switching valve 25 moves to an arrangement corresponding to each shift range with a change in the attitude of the detent plate 23. The range switching valve 25 switches the shift range of the transmission 20 by switching the flow path of hydraulic oil according to the position.

The actuator 30 is a device that rotates 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, for example, 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 in which an electric current is applied and an attraction force with respect to the rotor generated according to the switching. The attractive force is generated in a direction according to the relationship between the current position of each salient pole of the rotor, which is 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 directions of the suction force are the same. The motor 31 rotates at a speed according to the switching of the energization pattern in a range that can be followed by acceleration/deceleration by the generated suction force.

The motor 31 is provided with two sets of three-phase coils in an arrangement in which the electrical angles of the respective phases are substantially the same. The motor 31 energizes both of the two sets in synchronization with the energization pattern and its switching, thereby rotating the rotor with the attraction force that is the sum of the attraction forces of both. 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 31 is energized, the torque and the maximum speed are limited as the suction force is reduced, as compared to when both are energized.

When the energization pattern of one of the two sets of coils is fixed, the coil on the fixed side generates a suction force in a direction opposite to the rotation direction and in a direction according to the amount of energization at some rotation angles. .. As a result, when the energization pattern of one coil is fixed, even if the energization pattern is switched by the other coil to generate the suction force for rotating the rotor, the rotation is stopped or stalls.

The reduction gear 32 is configured to include 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. The speed reducer 32 decelerates a rotation angle of, for example, several rotations of the motor 31 so that the attitude of the detent plate 23 changes once.

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

The rotation angle sensor 101 is a sensor for detecting the rotation angle of the rotor of the motor 31. The rotation angle sensor 101 is provided by, for example, a magnetic sensor such as a Hall element, and detects a periodic fluctuation of a magnetic field generated by a magnetic member that rotates together with the rotor. Specifically, the rotation angle sensor 101 is arranged so as to face the irregularities or magnetic poles formed at a predetermined angular interval on the outer circumference of the disk-shaped magnetic member. The rotation angle sensor 101 detects unevenness or passage of a magnetic pole due to the 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.

A plurality of rotation angle sensors 101 are arranged as a set around the magnetic member so that the rotation angle sensor 101 has a predetermined angular interval smaller than the interval between the irregularities or the magnetic poles. The control device 110 can specify the rotation direction of the rotor based on the order of detection of fluctuations in the set.

The drive circuit 102 is a circuit that drives the motor 31 by supplying electric power supplied from the power supply 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 in charge of energization of 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 is a circuit that includes, for example, a relay, and that changes the amount of energization to the motor 31, that is, the amount of current passed through the motor 31. The energization changing 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 the electric power from the power source 3 is supplied to the drive circuit 102 and a state in which the electric power is supplied to the drive circuit 102 by opening/closing in accordance with an opening/closing signal from the control device 110. The energization changing unit 103 changes the amount of current passed through the motor 31 between a magnitude according to the voltage applied from the power source 3 and zero by switching between supply and interruption 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 substantial storage medium in which software is recorded non-temporarily, and a processor core 112 that executes software. The control device 110 performs the functions of the rotation angle detection unit 121 and the drive control unit 122 by executing the software in the processor core 112.

The rotation angle detection unit 121 detects the rotation angle of the rotor of 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 number of rotations 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 variation of the detected rotation angle. The rotation angle detection unit 121 mutually communicates with the rotation angle detection unit 121 in the control device 110 of the other control system 100 to mutually check 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 sequentially outputting drive signals to the drive circuits 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. To do.

The drive control unit 122 calculates the rotation direction of the motor 31 for changing from the current posture of the detent plate 23 to the target posture, and the necessary rotation speed. The drive control unit 122 sets the transition of the rotation speed until the motor 31 starts to rotate, completes the rotation of the required rotation speed, and stops the rotation as the target rotation speed. The target rotation speed is set so as to make a transition within the range of acceleration/deceleration and maximum speed that are possible with the suction force generated by the motor 31. Therefore, for example, when the driving by the other control system 100 is stopped, the target rotation speed is set or updated within the range of the acceleration/deceleration and the maximum speed that can be controlled only by the control system 100 including itself. The drive control unit 122 sequentially generates and outputs drive signals 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 variation unit 132, and an abnormality identification unit 133 for detecting the fixation of the energization pattern from each control system 100 to the motor 31 and for identifying the fixed control system 100. It is configured to function. In each control device 110, these functions in the present embodiment are exhibited by the processor core 112 that executes the software recorded in the memory 111, in addition to the functions as the rotation angle detection unit 121 and the drive control unit 122. There is. Note that some or all of the functions of the control device 110, including these functions, may be realized by hardware using a processor having a logic circuit array such as an ASIC.

The abnormality detection unit 131 detects, as an abnormality in any one of the control systems 100, a fixed energization pattern which is an abnormality in switching the energization pattern in the drive circuit 102. The energization pattern fixation is an abnormality in which the energization pattern from the drive circuit 102 to the motor 31 is fixed against 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 units 122 of both control systems 100 drive the drive circuit 102 to drive the motor 31, the abnormality detection unit 131 detects the energization pattern fixation 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 between the rotation speed and the target rotation speed is equal to or greater than a predetermined speed difference threshold, the abnormality detection unit 131 regards the rotation speed as being in a lowered state and determines that the energization pattern has been fixed. That is, when the drive control unit 122 accelerates or maintains the speed of the motor 31, if the stopped state continues or stalls, it is considered that the reduced rotation speed occurs.

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

The fluctuation unit 132 of the present embodiment temporarily reduces the amount of electricity supplied from the fluctuation system to zero. The changing 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 variation unit 132 causes the drive control unit 122 to continue to generate the drive signal even during the period in which the energization amount is changed to zero.

The abnormality identifying 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 variation of the rotation speed when the variation of the energization amount is performed by the variation unit 132. The abnormality identifying unit 133 determines which of the maintenance system and the variation system corresponds to the abnormal 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 reducing the energization amount, the abnormality identifying unit 133 of the present embodiment considers that the fluctuation of the rotation speed follows the variation of the energization amount, and determines the maintenance system. Identify as abnormal system. When the rotation speed recovers after reducing the energization amount, the abnormality identifying unit 133 considers that the variation of the rotation speed does not follow the variation of the energization amount, and identifies the variation system as the abnormal system.

However, the state where the rotation speed continues to decrease in the present embodiment indicates a state in which the rotation speed at the time when a predetermined recovery time has elapsed from the start of the decrease in the amount of energization is equal to or lower than the rotation speed at the time when the decrease starts. The state in which the rotation speed has been recovered indicates 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 the decrease, the rotation speed calculated at the time when the recovery time has elapsed is larger than the rotation speed calculated at the time when the decrease starts. .. For example, when the rotation angle detection unit 121 calculates the rotation speed based on the variation 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 identifying unit 133 stops energization of the motor 31 by the control system 100 identified as the abnormal system. For example, the abnormality identifying unit 133 stops the control device 110 of the abnormal system and opens the relay of the energization changing unit 103 to stop the power supply from the abnormal system. That is, when the maintenance system is identified as an abnormal system, the abnormality identifying unit 133 stops energization by the maintenance system and resumes energization by the variable system and switching of energization patterns. Further, when the variation system is identified as the abnormal system, the abnormality identifying unit 133 causes the maintenance system to continue energization and switching of the energization pattern, and stops the control device 110 of the variation 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 receiving a request for shift range switching, each control device 110 periodically executes one of the processes shown in FIG. 3 and FIG. 4 until completion of driving according to the set target rotation speed. That is, one control device 110 cyclically executes the process shown in FIG. 3 from S101, and the other control device 110 cyclically executes the process shown in FIG. 4 from S201.

First, the processing of FIG. 3 will be described. In S101, it is determined whether or not the rotation speed is reduced. If the rotation speed is not reduced, 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 ends.

In S103, the relay of the energization changing unit 103 is opened to temporarily stop the energization of the motor 31 from the control system 100 including itself. That is, the control system 100 including itself is set as the fluctuating system, and the other control system 100 is set as the maintaining system, and the amount of electricity supplied from the fluctuating system is changed.

In S104, the control device 110 of the other control system 100 is notified that the power supply 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 power supply was stopped. If the rotation speed is recovered, the process proceeds to S106, and if not, the process proceeds to S108.

In S106, the control system 100 including itself is considered to be an abnormal system, and the energization from the control system 100 including itself is terminated. In step 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 illustrated in FIG. 3 ends.

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 power supply from the control system 100 including itself is restarted.

Next, the processing of FIG. 4 will be described. In S201, it is determined whether or not the rotation speed is reduced. If the rotation speed has not decreased, 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 ends.

In S203, it is determined whether or not the situation is such that it is determined whether or not the rotation speed has been recovered, based on the reception of the notification that the power supply has been stopped from the other control device 110. That is, it is determined whether the recovery time has elapsed from the reception of the notification. If it has not been received, or if the recovery time has not elapsed from the reception, it is judged that it is not in the situation to judge whether or not it has been recovered, and the process proceeds to S202 to continue the normal energization control. When the recovery time has elapsed from the reception of the notification, it is determined that the recovery is performed, and the process proceeds to S204.

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

In S205, it is determined that the control system 100 including itself is an abnormal system, and the power supply 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 ends.

[Summary of First Embodiment]
As described above, according to the first embodiment described above, when one of the drive circuits 102 has an abnormality in fixing the energization pattern by the abnormality detection unit 131, the size of the drive circuit 102 in which the abnormality has occurred depends on the energization amount. Suppresses the rotation of the motor 31. Further, the drive circuit 102 in which no abnormality has occurred accelerates the rotation of the motor 31 with a force having a magnitude according to the fluctuation of the energization amount. Therefore, the rotation speed of the motor 31 changes following the fluctuation of the energization amount when the fluctuation of the energization amount of the fluctuation system by the fluctuation unit 132 causes an abnormality on the side of the maintenance system, and causes an abnormality on the fluctuation system side. When it occurs, it fluctuates against the fluctuation of the energization amount.

As a result, the abnormality identifying unit 133 determines which control system 100 is the abnormal system based on whether the rotation speed calculated using the rotation angle detecting unit 121 follows the fluctuation of the energization amount by the changing unit 132. It becomes possible to judge whether there is any. Therefore, the shift-by-wire system 1 can specify the control system 100 having the drive circuit 102 in which an abnormality has occurred.

Further, the changing unit 132 of the present embodiment stops the energization of the motor 31 from the drive circuit 102 of the changing system. Therefore, when the variable system side is the abnormal system, the suppression of the rotation by the abnormal system can be stopped before the abnormal system is specified by the abnormality specifying unit 133. Therefore, when the variable system side is the abnormal system, the time from the detection of the energization pattern fixation by the abnormality detection 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 accordingly, the functions of the changing unit 132 and the abnormality specifying unit 133 are also changed. It is partially different from the first embodiment.

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

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

The abnormality identifying 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 when the amount of decrease in the energization amount has increased, and that the amount of decrease has not followed when the amount of decrease has decreased. In other words, the abnormality identifying unit 133 identifies the abnormal system by determining whether 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 fluctuation system is specified as an abnormal system because the decrease amount is a negative or zero value, that is, it does not follow. The abnormality specifying unit 133 mutually checks the specified results, and when the results match each other, determines the determination result.

[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 instead 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 from S301, and the other periodically executes the process shown in FIG. 6 from S401. To execute.

First, the processing 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, and reduces 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 energization amount from the control system 100 including itself is reduced.

S305 is a process corresponding to S105, and is a process for determining which control system 100 corresponds to the abnormal system based on the amount of decrease in the rotation speed. If the amount of decrease has decreased, that is, if the deceleration pace has been eased or the vehicle has started to accelerate, the control system 100 including itself is determined to be an abnormal system, and the process proceeds to S307. When the amount of decrease increases, the other control system is determined to be an abnormal system and the process proceeds to S306.

In S306, the result of the determination in S305, that is, the determination that the other control system is the 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 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 the abnormal system determined by the coincidence of the determination results is the control system 100 including itself. If it is the 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 processing 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 for determining an abnormal system based on the amount of decrease in the rotation speed. If the amount of decrease has decreased, that is, if the deceleration pace has been eased or the vehicle has started to accelerate, the other control system is determined to be an abnormal system and the process proceeds to S405. When the amount of decrease increases, the control system 100 including itself is determined to be an abnormal system and the process proceeds to S406.

In S405, the result of the determination in S404, that is, the determination that the other control system is the abnormal system is transmitted to the other control device 110. In S406, the result of the determination in S404, that is, 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 the abnormal system determined by the agreement of the determination results is the control system 100 including itself. If it is the 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 the normal energization control. S409 and S410 are the same processes as S205 and S206.

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

Further, in the present embodiment, the varying unit 132 reduces the amount of electricity supplied from the varying 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 rotation direction zero. Therefore, in identifying the abnormal system, the shift-by-wire system 1 can suppress the decrease in the rotation speed regardless of the abnormal system side.

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

The fluctuating unit 132 of the third embodiment temporarily fluctuates the energization amount of the fluctuating system even when the detection of the energization pattern fixation by the abnormality detecting unit 131 has not occurred. Specifically, the fluctuating unit 132 sets one of them to the fluctuating system in a state where the shift range is not requested to be switched by the range signal, that is, a state where rotation is not required, and the fluctuating system temporarily To switch between energization and energization pattern.

The fluctuation unit 132 causes the fluctuation system to switch between energization and energization patterns so as to drive the motor 31. The fluctuating unit 132 causes the energization and the energization pattern to be switched within the range where the shift range is maintained, that is, within the range where the shift range is not switched. The fluctuating unit 132 switches between energization and energization patterns so as to rotate the motor 31 within a range that does not deviate from the engagement angle range corresponding to the shift range at that time. The changing 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 fluctuating unit 132 alternately switches the control system 100 set as the fluctuating system, and causes energization at predetermined time intervals. The fluctuating unit 132 may perform energization a plurality of times regardless of the rotation direction as long as the shift range is maintained. Alternatively, the motor 31 may be driven so as to reciprocate within the engagement angle range by changing the rotation direction each time power is supplied.

The abnormality identifying unit 133 according to the third embodiment determines whether the variation system is based on whether the motor 31 is rotating when the variation unit 132 temporarily energizes the variation system and switches the energization pattern. Determine whether it is an abnormal system. Specifically, when the motor 31 is stopped despite the temporary energization and the switching of the energization pattern being performed, it is determined that the variable system is an abnormal system. Note that the motor 31 is stopped means that the motor 31 is stopped at a rotation angle such that the rotation of the motor 31 is less than a predetermined rotation angle and that rotates in one cycle of energization pattern switching.

[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. 7. The two control devices 110 cyclically execute the processing shown in FIG. 7 in order from S501 in a state where the ignition switch is turned on.

In S501, it is determined whether a shift range switching request is received. If not received, the process proceeds to S502, and if received, the process proceeds to S510.

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

In S503, it is determined whether 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 is ended.

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

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

In step S507, a flag indicating that the diagnosis has been performed and that the control system 100 including itself is not an abnormal system but normal as a result of the diagnosis is set. In S508, a flag indicating that the diagnosis has been performed and the control system 100 including itself is an abnormal system is set as a result of the diagnosis. In S509, the other control device 110 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 the system is diagnosed as an abnormal system, only the other control system 100 is energized, and the process shown in FIG. 7 ends without energizing itself.

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

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

Further, in the present embodiment, the abnormality identifying unit 133 determines whether the motor 31 rotates according to the temporary change in the energization amount performed by the changing unit 132 in a state where the shift range switching is not requested. The abnormal strain can be identified. Therefore, the shift-by-wire system 1 can drive the motor 31 without using the abnormal system specified in advance when requested to switch the shift range. Therefore, in the shift-by-wire system 1, when the shift range is requested to be switched, it is difficult to suppress the driving by fixing the energization pattern.

<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 modifications can be made without departing from the scope. In the following description, elements having the same reference numerals as those used up to now are the same as the elements having the same reference numerals in the previous embodiments, unless otherwise specified. Further, when only a part of the configuration is described, the above-described embodiments can be applied to other parts of the configuration.

In the above-described embodiment, the functions of the abnormality detecting unit 131, the changing unit 132, and the abnormality identifying unit 133 are exhibited in each of the two control devices 110, and cooperate to identify the abnormal system. However, each function described above may be exerted only by one control device 110 and may be controlled by the other control device 110 as well. Further, each function described above may be configured to be exhibited in an electronic control device that is separate from each control device 110. Even in such a case, each function may be realized by executing software in the processor core 112 such as a CPU, or may be realized by hardware such as an ASIC. Moreover, you may be implement|achieved by those combinations.

In the above-described first embodiment and second embodiment, the changing unit 132 performs a change in the energization amount from the fluctuation system side that reduces the energization amount, including reducing the energization amount to zero. . However, it is also possible to temporarily increase the voltage applied to the motor 31 from the drive circuit 102 on the variable system side so as to perform the variation for increasing the energization amount. In this case, the abnormality identifying unit 133 may identify the maintenance system as the abnormal system by following the fluctuation when the rotation speed increases with the increase in the energization amount. Further, the method of changing the energization amount can be appropriately changed, such as changing the effective energization amount by changing the on-duty of the switch in the drive circuit 102.

In the above-described embodiment, the abnormality detection unit 131 detects the energization pattern fixation 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 part, 122 drive control part, 131 abnormality detection part, 132 variation part, 133 abnormality identification part

Claims (4)

A shift-by-wire system for switching a shift range of a transmission (20) by a motor (31) driven based on a range signal indicating a shift range selected by a vehicle driver,
A drive circuit (102) for driving the motor by switching the energization pattern for the motor, a rotation angle detection unit (121) for sequentially detecting the rotation angle of the motor, and a rotation angle detected by the rotation angle detection unit. Two control systems (100) each having a drive control unit (122) that controls switching of energization patterns by the drive circuit based on the above;
When both of the drive control units in each of the control systems drive the motor based on the range signal, the drive circuit in any one of the control systems based on a decrease in the rotation speed of the motor. An abnormality detection unit (131) for detecting an abnormality in switching the energization pattern of
One of the control systems is a maintenance system and the other is a variation system, and a variation unit (132) that maintains the amount of electricity supplied by the drive circuit in the maintenance system and varies the amount of electricity supplied by the drive circuit in the variation system. ,
A shift-by-wire including an abnormality specifying unit (133) that specifies 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 by the fluctuation unit. system. The fluctuation unit stops energization of the motor by the drive circuit of the fluctuation system when the malfunction detection unit detects a malfunction,
The shift-by-wire system according to claim 1, wherein the abnormality identifying unit identifies the maintenance system as the abnormal system when the decrease in the rotation speed continues after stopping the energization by the variable system. When the abnormality detection unit detects an abnormality, the variation unit reduces the amount of electricity supplied to the motor by the drive circuit of the variation system,
The shift-by-wire system according to claim 1, wherein the abnormality identifying unit identifies the maintenance system as the abnormal system when the decrease in the rotation speed increases after reducing the energization amount by the variable system. A shift-by-wire system for switching a shift range of a transmission (20) by a motor (31) driven based on a range signal indicating a shift range selected by a vehicle driver,
A drive circuit (102) for driving the motor by switching the energization pattern for the motor, a rotation angle detection unit (121) for sequentially detecting the rotation angle of the motor, and a rotation angle detected by the rotation angle detection unit. Two control systems (100) each having a drive control unit (122) that controls switching of energization patterns by the drive circuit based on the above;
When each of the control systems has stopped energizing the motor based on the range signal, one of the control systems is a maintenance system and the other is a variation system, and the energization by the drive circuit of the maintenance system is performed. A variation unit (132) that maintains the stop and performs energization and energization pattern switching by the drive circuit of the variation system within a range that maintains the shift range of the transmission,
An abnormality identifying 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 against switching between energization and energization pattern switching by the varying unit. Shift-by-wire system.

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