Shift device and vehicle motor control device

Abstract

To provide a shift device and a motor control device for a vehicle capable of appropriately detecting abnormality of a power supply line by suppressing repetition of determination of abnormality and normality of the power supply line.SOLUTION: A shift device 100 includes a motor 11 driving a detent plate 103a (shift switching member) by power supplied from a power supply 104 mounted on a vehicle 110, a blocking unit 34 blocking conduction of a power supply line 32, and an inverter unit 35. When voltage of the power supply line 32 is smaller than a predetermined threshold value, abnormality of the power supply line 32 is determined, switching elements 35a-35f included in the inverter unit 35 are turned off, and conduction of the power supply line 32 is blocked by the blocking unit 34.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a shift device and a vehicle motor control device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, motor control devices are known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 describes a motor control device including a drive circuit. The drive circuit supplies drive power to the motor based on a power supply voltage. The drive circuit also employs a PWM inverter including a semiconductor switching element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-74915 A Summary of the Invention [Problem to be solved by the invention]

[0005] Although not described in Patent Document 1, the motor control device described in Patent Document 1 may be configured to detect an abnormality in the power line, such as a disconnection, based on a drop in the voltage of the power line. When it is determined that an abnormality in the power line has been detected, the drive switching element is turned off to prevent the charge voltage of a smoothing capacitor connected to the power line from affecting the drive of the motor, or to prevent the voltage abnormality in the power line from affecting a driver that operates a semiconductor switching element (drive switching element) of a drive circuit.

[0006] However, when the driving switching element is turned off, the voltage of the power supply line temporarily rises due to leakage current from a driver for controlling the switching operation. This may result in a false determination that the power supply line is normal (the power supply has returned). In that case, the driving switching element is turned on again as a normal operation. Then, when the driving switching element is turned on again, the rise in the voltage of the power supply line caused by the leakage current is eliminated, and the temporarily risen voltage of the power supply line falls again. In this way, the voltage of the power supply line repeatedly falls and rises, and the determination that the power supply line is abnormal and the determination that it is normal are repeated, resulting in a problem that the abnormality of the power supply line cannot be detected appropriately.

[0007] The present invention has been made to solve the problems described above, and one object of the present invention is to provide a shift device and a vehicle motor control device that are capable of properly detecting an abnormality in the power supply line by suppressing repeated determinations of an abnormality in the power supply line and a normality. [Means for solving the problem]

[0008] In order to achieve the above object, a shift device according to a first aspect of the present invention is a shift device mounted on a vehicle, the shift device including: a motor that drives a shift switching member for switching a shift position by power supplied from a power source mounted on the vehicle; a cutoff unit that cuts off continuity of a power source line for supplying power from the power source to the motor; and a drive circuit unit that includes a drive switching element that performs a switching operation and outputs power from the power source to the motor; The cutoff unit is configured to cut off conduction of a power supply line between the power supply and the drive circuit unit, and a power supply for supplying power from the power supply to the motor is provided on the power supply side of the cutoff unit. When the voltage of the power supply line is lower than a predetermined threshold value, an abnormality in the power supply line is determined, a drive switching element included in the drive circuit unit is turned off, and the interrupter unit interrupts the continuity of the power supply line.

[0009] In the shift device according to the first aspect of the present invention, as described above, when the voltage of the power supply line is smaller than a predetermined threshold, the shift device is configured to determine an abnormality in the power supply line, turn off the driving switching element included in the driving circuit unit, and cut off the continuity of the power supply line by the cutoff unit. As a result, since leakage current or the like does not flow because the continuity of the power supply line is cut off by the cutoff unit, it is possible to suppress erroneous determination of the restoration of the power supply even when the voltage of the power supply line temporarily rises. Therefore, it is possible to suppress repeated drops and rises in the voltage of the power supply line, and it is possible to suppress repeated determinations of an abnormality in the power supply line and determinations of normality. As a result, it is possible to appropriately detect an abnormality in the power supply line by suppressing repeated determinations of an abnormality in the power supply line and determinations of normality. Furthermore, since an abnormality in the power line is determined when the voltage of the power line on the power supply side of the cutoff unit is smaller than a predetermined threshold, it is possible to effectively prevent erroneous determination that the power line is normal when the voltage of the power line on the drive circuit unit side of the cutoff unit temporarily rises by cutting off the continuity of the power line with the cutoff unit. Therefore, it is possible to effectively prevent repeated determinations of an abnormality in the power line and a normality, and therefore it is possible to more appropriately detect an abnormality in the power line.

[0012] The shift device according to the first aspect preferably further includes a control unit configured to detect a voltage of the power supply line, and the control unit is configured to determine an abnormality in the power supply line when the voltage of the power supply line is lower than a predetermined threshold value, and to execute control to turn off a drive switching element included in the drive circuit unit, and to execute control to cut off continuity of the power supply line by the cut-off unit.

[0013] With this configuration, since the control unit is configured to detect the voltage of the power supply line, it is possible to easily determine an abnormality in the power supply line. Furthermore, when an abnormality in the power supply line is determined, the control unit can easily execute control to turn off the driving switching element and control to cut off the continuity of the power supply line by the cutoff unit. Therefore, the control by the control unit can easily prevent the determination of an abnormality in the power supply line and the determination of normality from being repeated, so that an abnormality in the power supply line can be easily and appropriately detected.

[0014] In the shift device according to the first aspect described above, the drive switching elements of the drive circuit unit preferably include a first drive switching element on an upper arm side and a second drive switching element on a lower arm side which are driven by a driver and connected in series to each other, and are configured to determine an abnormality in the power supply line when the voltage of the power supply line is lower than a predetermined threshold value, turn off both the first drive switching element and the second drive switching element included in the drive circuit unit, and cut off the continuity of the power supply line by a cut-off unit.

[0015] With this configuration, since both the first driving switching element on the upper arm side and the second driving switching element on the lower arm side of the driving circuit unit are turned off, it is possible to effectively suppress the supply of power to the motor from the power line in which an abnormality has occurred. Therefore, it is possible to effectively suppress the influence of the abnormality of the power line on the operation of the motor. Furthermore, since the conduction of the power line is cut off by the cutoff unit when it is determined that the abnormality of the power line has occurred, it is possible to suppress erroneous determination of the restoration of the power supply even when the voltage of the power line temporarily rises due to a leak current from the driver or the like. Therefore, when both the first driving switching element on the upper arm side and the second driving switching element on the lower arm side are turned off, it is possible to suppress repeated drops and rises in the voltage of the power line, so it is possible to effectively suppress repeated determinations of an abnormality and a normality of the power line. As a result, it is possible to more appropriately detect the abnormality of the power line.

[0016] The shift device according to the above-mentioned first aspect preferably further includes a first system group and a second system group each including a cut-off unit and a drive circuit unit, and when power is output to the motor from both the drive circuit unit of the first system group and the drive circuit unit of the second system group, if the voltage of the power supply line in the first system group is smaller than a predetermined threshold value, the shift device is configured to determine an abnormality in the power supply line in the first system group, turn off a drive switching element included in the drive circuit unit in the first system group, cut off conductivity of the power supply line by the cut-off unit in the first system group, and supply power to the motor from the drive circuit unit of the second system group.

[0017] With this configuration, the motor can be driven by power from both the first and second groups of systems, so that even if an abnormality occurs in either the first or second group of systems, the motor can be continued to be driven by the other group that is not abnormal. In addition, when it is determined that the power supply line of the first group of systems is abnormal, the operation of the drive circuit unit of the first group of systems is stopped, thereby stopping the output from the drive circuit unit of the first group of systems. In this case, a back electromotive force caused by the drive of the motor by the output from the drive circuit unit of the second group of systems is generated, and a reverse current may flow from the motor to the power supply line of the first group of systems. In contrast, in the present invention, when the voltage of the power supply line in the first group of systems is smaller than a predetermined threshold value, an abnormality in the power supply line in the first group of systems is determined, and a drive switching element included in the drive circuit unit of the first group of systems is turned off, and the conduction of the power supply line is interrupted by the interrupter in the first group of systems. Then, power is supplied to the motor from the drive circuit unit of the second group of systems. Therefore, when an abnormality occurs in the power line of the first group, the interrupter in the first group cuts off the continuity of the power line, so that even when the voltage of the power line of the first group rises due to the back electromotive force caused by the driving of the motor by the second group, it is possible to suppress erroneous determination of restoration of the power supply. As a result, even when an abnormality occurs in the power line of either the first group or the second group in a state in which power from both the first group and the second group is being output to the motor, it is possible to suppress repeated determinations of an abnormality in the power line and a normality, so that an abnormality in the power line can be detected appropriately.

[0018] A vehicle motor control device according to a second aspect of the present invention includes a motor driven by power supplied from a power supply mounted on a vehicle, a cutoff unit that cuts off conduction of a power supply line through which the power from the power supply is supplied to the motor, and a drive circuit unit that includes a drive switching element that performs a switching operation and outputs power from the power supply to the motor, The cutoff unit is configured to cut off conduction of a power supply line between the power supply and the drive circuit unit, and a power supply for supplying power from the power supply to the motor is provided on the power supply side of the cutoff unit.When the voltage of the power supply line is lower than a predetermined threshold value, an abnormality in the power supply line is determined, a drive switching element included in the drive circuit unit is turned off, and the interrupter unit interrupts the continuity of the power supply line.

[0019] In the vehicle motor control device according to the second aspect of the present invention, as described above, when the voltage of the power supply line is smaller than a predetermined threshold, the device is configured to determine an abnormality in the power supply line, turn off the driving switching element included in the driving circuit unit, and cut off the continuity of the power supply line by the cut-off unit. As a result, since leakage current or the like does not flow because the continuity of the power supply line is cut off by the cut-off unit, it is possible to suppress erroneous determination of the restoration of the power supply even when the voltage of the power supply line temporarily rises. Therefore, it is possible to suppress repeated drops and rises in the voltage of the power supply line, and it is possible to suppress repeated determinations of an abnormality in the power supply line and determinations of normality. As a result, it is possible to provide a vehicle motor control device that can appropriately detect an abnormality in the power supply line by suppressing repeated determinations of an abnormality in the power supply line and determinations of normality. Furthermore, since an abnormality in the power line is determined when the voltage of the power line on the power supply side of the cutoff unit is smaller than a predetermined threshold, it is possible to effectively prevent erroneous determination that the power line is normal when the voltage of the power line on the drive circuit unit side of the cutoff unit temporarily rises by cutting off the continuity of the power line with the cutoff unit. Therefore, it is possible to effectively prevent repeated determinations of an abnormality in the power line and a normality, and therefore it is possible to more appropriately detect an abnormality in the power line.

[0020] In the shift device according to the first aspect and the vehicle motor control device according to the second aspect, the following configurations are also possible.

[0021] (Additional note 1) That is, the cut-off unit includes two cut-off switching elements which are connected in series to have opposite polarity, and is configured to determine an abnormality in the power supply line when the voltage of the power supply line is lower than a predetermined threshold, turn off the drive switching element included in the drive circuit unit, and turn off both of the two cut-off switching elements of the cut-off unit.

[0022] With this configuration, the conduction of the power line can be interrupted by the interrupter switching element, which is a semiconductor element that does not wear out its contacts, unlike a mechanical relay. Therefore, by using an interrupter switching element with a longer life than a mechanical relay, the frequency of replacing or repairing the interrupter can be reduced. Therefore, the workload associated with replacing or repairing the interrupter can be reduced.

[0023] (Additional note 2) A method for determining a power supply abnormality for a vehicle motor according to another aspect of the present invention includes the steps of determining an abnormality in the power supply line when the voltage of the power supply line for supplying power from a power supply mounted in the vehicle to the motor is lower than a predetermined threshold value, turning off a drive switching element included in a drive circuit unit that outputs power from the power supply to the motor when an abnormality in the power supply line is determined, and cutting off continuity of the power supply line when an abnormality in the power supply line is determined.

[0024] In the method for determining a power supply abnormality of a motor for a vehicle according to another aspect of the present invention, when an abnormality in the power supply line is determined, as described above, a driving switching element included in a driving circuit unit that outputs power from a power supply to the motor is turned off. Then, the continuity of the power supply line is interrupted. As a result, since leakage current or the like does not flow by interrupting the continuity of the power supply line, it is possible to suppress erroneous determination of restoration of the power supply even when the voltage of the power supply line temporarily rises. Therefore, it is possible to suppress repeated drops and rises in the voltage of the power supply line, and it is possible to suppress repeated determinations of an abnormality and a normality of the power supply line. As a result, it is possible to provide a method for determining a power supply abnormality of a motor for a vehicle that can appropriately detect an abnormality in the power supply line by suppressing repeated determinations of an abnormality and a normality of the power supply line. [Brief description of the drawings]

[0025] [Figure 1] 1 is a block diagram showing an overall configuration of a vehicle according to an embodiment. [Diagram 2] 1 is a block diagram showing an overall configuration of a shift device according to one embodiment. FIG. [Diagram 3] 1 is a perspective view showing a schematic diagram of a shift device and a transmission mechanism according to an embodiment; [Figure 4] 1 is a circuit diagram showing a configuration of a shift device according to an embodiment; [Diagram 5] FIG. 4 is a circuit diagram illustrating a voltage rise in a power supply line according to an embodiment. [Figure 6] FIG. 4 is a flowchart illustrating an abnormality determination process for a shift device according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0027] The configuration of a shift device 100 (an example of the "shift device" and "vehicle motor control device" in the claims) of the present embodiment will be described with reference to Figs. 1 to 5.

[0028] (Shift device configuration) As shown in FIG. 1, the shift device 100 is mounted on a vehicle 110 such as an automobile. When an occupant (driver) of the vehicle 110 performs a shift switching operation via an operation unit 101 such as a shift lever (or a shift switch), an electrical shift switching control is performed on the transmission mechanism 103. That is, the position of the operation unit 101 (shift lever) is input to the shift device 100 via a shift sensor 102 connected to the operation unit 101. Then, based on a control signal transmitted from control units 31 and 41 (see FIG. 2) provided in the shift device 100 and described later, the transmission mechanism 103 is switched to any one of the shift positions P (parking), R (reverse), N (neutral), and D (drive) corresponding to the shift operation of the occupant. Such a shift switching control is called shift-by-wire (SBW).

[0029] As shown in FIG. 2, the shift device 100 includes an actuator unit 1 and a power supply device 2 for a motor.

[0030] The actuator unit 1 includes a motor 11 and a driving force transmission mechanism 12. The motor 11 is a motor for driving a detent plate 103a (an example of a "shift switching member" in the claims) described later. The motor 11 is a three-phase motor of a surface magnet type (SPM) in which a permanent magnet is incorporated on the surface of a rotor. The motor 11 is driven by three-phase (U-phase, V-phase, and W-phase) AC power supplied from a motor power supply device 2. Specifically, the motor 11 has coils U1, V1, and W1 (see FIG. 4) to which power is supplied from a first system group 30 of the motor power supply device 2 described later, and coils U2, V2, and W2 (see FIG. 4) to which power is supplied from a second system group 40 of the motor power supply device 2 described later. The motor 11 is driven by power supplied to the coils U1, V1, and W1 and the coils U2, V2, and W2. The driving force transmission mechanism 12 is configured to transmit the driving force of the motor 11 to the detent plate 103a.

[0031] 3, the transmission mechanism 103 includes a detent plate 103a and a detent spring 103b. The detent plate 103a is driven by the actuator unit 1 to switch the shift position. In other words, the shift state (P position, R position, N position, and D position) of the transmission mechanism 103 is mechanically switched by driving the detent plate 103a.

[0032] Specifically, the detent plate 103a has four valleys provided to correspond to the four shift positions (P position, R position, N position, and D position) in order to switch between the four shift positions. One end (base end) of the detent spring 103b is fixed to a casing of the transmission mechanism 103, and a roller is attached to the other end (free end) side. The detent spring 103b establishes a shift position when the roller fits into one of the four valleys of the detent plate 103a. In other words, the detent spring 103b is configured to hold the detent plate 103a at a rotation angle position corresponding to each of the P position, R position, N position, and D position.

[0033] 1, vehicle 110 is equipped with power source 104 and power source 105. Each of power source 104 and power source 105 supplies power to motor power supply device 2 for driving motor 11. Specifically, each of power source 104 and power source 105 outputs 12V DC power to motor power supply device 2. Each of power source 104 and power source 105 is, for example, a vehicle battery device, a lithium ion battery, or a capacitor.

[0034] (Configuration of motor power supply unit) As shown in FIG. 2, the motor power supply device 2 is configured to supply power to the actuator unit 1 (motor 11). The motor power supply device 2 also includes a first system group 30 and a second system group 40. The first system group 30 supplies power from a power source 104 to the motor 11. The second system group 40 supplies power from a power source 105 to the motor 11. The motor 11 is driven by power supplied from each of the first system group 30 and the second system group 40. The shift device 100 is configured to drive the motor 11 of the actuator unit 1 by simultaneously supplying power from both the first system group 30 and the second system group 40.

[0035] The first system group 30 of the motor power supply device 2 includes a control unit 31, a power supply line 32, a smoothing capacitor 33, a cutoff unit 34, an inverter unit 35 (an example of a "drive circuit unit" in the claims), and a driver 36. The second system group 40 of the motor power supply device 2 includes a control unit 41, a power supply line 42, a smoothing capacitor 43, a cutoff unit 44, an inverter unit 45 (an example of a "drive circuit unit" in the claims), and a driver 46.

[0036] <First phylogenetic group> 4, power supply line 32 electrically connects power supply 104 and motor 11 to supply power from power supply 104 to motor 11. Smoothing capacitor 33 smoothes the voltage of power supply line 32. Smoothing capacitor 33 is connected in parallel to power supply line 32 on the inverter unit 35 side (motor 11 side) of cutoff unit 34 described later.

[0037] The cutoff unit 34 cuts off the conduction of the power supply line 32. In this embodiment, the cutoff unit 34 cuts off the conduction of the power supply line 32 between the power supply 104 and the inverter unit 35 described later. The cutoff unit 34 also includes two switching elements 34a and 34b (cutoff switching elements). Specifically, the switching elements 34a and 34b perform a switching operation to switch between on and off based on a signal from the control unit 31. The two switching elements 34a and 34b are connected in series to have opposite polarities. For example, the two switching elements 34a and 34b are field effect transistors (FETs). In the cutoff unit 34, the source terminals of the field effect transistors are connected to each other. That is, the cutoff unit 34 is a non-contact relay (solid state relay) using a semiconductor. In FIG. 4, the diodes indicated by dashed lines included in the two switching elements 34a and 34b indicate parasitic diodes (body diodes) of the field effect transistors.

[0038] The inverter unit 35 outputs power from the power source 104 to the motor 11. Specifically, the inverter unit 35 converts the DC power from the power source 104 into three-phase AC power. The inverter unit 35 also includes six switching elements 35a, 35b, 35c, 35d, 35e, and 35f (one example of the "driving switching elements" in the claims) that perform switching operations. Each of the switching elements 35a to 35f is driven by a driver 36, which will be described later. The switching elements 35a to 35f are, for example, field effect transistors. In FIG. 4, the diodes indicated by dashed lines included in the switching elements 35a to 35f indicate parasitic diodes (body diodes) of the field effect transistors.

[0039] In the inverter unit 35 of this embodiment, the upper arm switching elements 35a, 35c, and 35e (an example of the "first driving switching element" in the claims) are connected in series with the lower arm switching elements 35b, 35d, and 35f (an example of the "second driving switching element" in the claims). That is, the inverter unit 35 configures a two-level three-phase inverter circuit with six switching elements 35a to 35f. The inverter unit 35 outputs the converted three-phase AC power to the U-phase, V-phase, and W-phase coils U1, V1, and W1 provided in the motor 11. For example, the output from the switching elements 35a and 35b is input to the U-phase coil U1. The output from the switching elements 35c and 35d is input to the V-phase coil V1. The output from the switching elements 35e and 35f is input to the W-phase coil W1.

[0040] The driver 36 outputs a gate signal (PWM signal: Pulse Width Modulation signal) for switching the switching operation of the switching elements 35a to 35f of the inverter unit 35. Specifically, the driver 36 outputs the gate signal to each gate terminal of the switching elements 35a to 35f based on a signal from the control unit 31, which will be described later.

[0041] The control unit 31 is a microcomputer (microcontroller) including a CPU (Central Processing Unit) and memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The control unit 31 outputs a signal for controlling the switching operation of the switching elements 35a to 35f of the inverter unit 35 to the driver .

[0042] Specifically, the control unit 31 controls the switching operations of the switching elements 35a-35f to output three-phase AC to the motor 11 in order to switch the transmission mechanism 103 to a shift position according to the shift operation by the occupant. Furthermore, when the shift operation by the occupant on the operation unit 101 is not accepted, the control unit 31 sets the inverter unit 35 to a short brake state in order to stop the driving of the motor 11. In the short brake state, the switching elements 35a, 35c, and 35e on the upper arm side are turned off, and the switching elements 35b, 35d, and 35f on the lower arm side are turned on.

[0043] Furthermore, the control unit 31 outputs a signal for controlling the operation of the cutoff unit 34 to cut off the continuity of the power supply line 32 to the switching elements 34a and 34b of the cutoff unit 34. For example, when an overcurrent, continuous current flow, or the like is detected, the control unit 31 turns off the cutoff unit 34 to cut off the continuity of the power supply line 32.

[0044] In this embodiment, the control unit 31 is configured to detect the voltage of the power supply line 32. Specifically, the control unit 31 is configured to detect the voltage at a detection point 32a of the power supply line 32 on the power supply 104 side (input side) of the cutoff unit 34.

[0045] <Second phylogenetic group> The configuration of the second system group 40 is similar to that of the first system group 30. That is, the control unit 41, the power supply line 42, the smoothing capacitor 43, the cutoff unit 44, the inverter unit 45, and the driver 46 of the second system group 40 have the same configurations as the control unit 31, the power supply line 32, the smoothing capacitor 33, the cutoff unit 34, the inverter unit 35, and the driver 36, respectively.

[0046] Specifically, in the second system group 40, power from the power source 105 is supplied to the motor 11 via a power line 42. The smoothing capacitor 43 smoothes the voltage of the power line 42. The cutoff unit 44 cuts off the continuity of the power line 42 based on a signal from the control unit 41. The cutoff unit 44 also has switching elements 44a and 44b (cutoff switching elements) connected in series to have opposite polarities to each other.

[0047] The inverter unit 45 includes six switching elements 45a, 45b, 45c, 45d, 45e, and 45f (an example of the "driving switching element" in the claims). In the inverter unit 45, like the inverter unit 35, the upper arm side switching elements 45a, 45c, and 45e (an example of the "first driving switching element" in the claims) are connected in series with the lower arm side switching elements 45b, 45d, and 45f (an example of the "second driving switching element" in the claims). That is, the inverter unit 45 configures a two-level three-phase inverter circuit by the six switching elements 45a to 45f. The U-phase, V-phase, and W-phase powers from the inverter unit 45 are output to the coils U2, V2, and W2 of the motor 11, respectively.

[0048] Then, the control unit 41 outputs a signal for controlling the switching operation of the inverter unit 45 to the driver 46. The control unit 41 also outputs a signal for controlling the operation of the cutoff unit 44 to cut off the continuity of the power supply line 42 to the switching elements 44a and 44b of the cutoff unit 44.

[0049] (Power supply abnormality judgment) The shift device 100 of this embodiment is configured to determine a power supply abnormality when the voltage of the input power is lower than a predetermined threshold due to an abnormality such as a disconnection in each of the first system group 30 and the second system group 40. In the following description, a case where a power supply abnormality is determined on the first system group 30 side will be described.

[0050] In this embodiment, the control unit 31 is configured to determine an abnormality in the power supply line 32 in the first system group 30 when the voltage of the power supply line 32 in the first system group 30 is smaller than a predetermined threshold value when power is being output to the motor 11 from both the inverter unit 35 of the first system group 30 and the inverter unit 45 of the second system group 40.

[0051] Specifically, as shown in Fig. 5, the control unit 31 determines that there is an abnormality in the power supply line 32 when the voltage at the detection point 32a of the power supply line 32 on the power supply 104 side of the interrupter unit 34 is smaller than a predetermined threshold. The predetermined threshold is stored in advance in the control unit 31. Note that Fig. 5 illustrates only the U phase (switching elements 35a and 35b) of the first system group 30. The V phase (switching elements 35c and 35d) and the W phase (switching elements 35e and 35f) are not illustrated because they operate in the same manner.

[0052] Furthermore, in this embodiment, the control unit 31 is configured to execute control (OFF command) to turn off the switching elements 35a-35f included in the inverter unit 35 when an abnormality is determined in the power supply line 32. Specifically, the control unit 31 is configured to turn off all of the switching elements 35a-35f (both the upper arm side and the lower arm side) when an abnormality is determined in the power supply line 32, thereby putting the motor 11 into a free state.

[0053] In a circuit configuration such as the shift device 100, when the switching elements 35a to 35f are turned off to put the motor 11 into a free state, a leakage current Ia from the driver 36 may flow into the power supply line 32. For example, since a parasitic diode exists in the switching element 35a on the upper arm side, the leakage current Ia flows into the input side (such as the smoothing capacitor 33) even when the switching element 35a is off. Then, the voltage of the power supply line 32 increases due to this leakage current Ia. Note that even if the switching element 35a does not have a parasitic diode, the leakage current Ia may flow into the power supply line 32 via a freewheel diode connected in parallel to the switching element 35a.

[0054] Furthermore, when a power supply abnormality is determined in the first system group 30, the shift device 100 is configured to turn off the inverter unit 35 of the first system group 30 and supply power to the motor 11 only from the inverter unit 45 of the second system group 40. Therefore, even when the output from the inverter unit 35 of the first system group 30 is stopped (when the switching elements 35a to 35f are turned off), the motor 11 continues to drive because power is supplied from the second system group 40. Therefore, a counter electromotive force is generated on the first system group 30 side due to the driving of the motor 11. Due to this counter electromotive force, a reverse current Ib flows in the power supply line 32. This reverse current Ib increases the voltage of the power supply line 32 in the same way as the leakage current Ia.

[0055] In this embodiment, the control unit 31 is configured to execute control to turn off the switching elements 35a to 35f included in the inverter unit 35 when an abnormality is determined in the power supply line 32, and to execute control to cut off the continuity of the power supply line 32 by the cutoff unit 34. Specifically, when an abnormality is determined in the power supply line 32, the control unit 31 is configured to turn off both of the two switching elements 34a and 34b of the cutoff unit 34.

[0056] That is, when an abnormality in the power supply line 32 is determined, the control unit 31 turns off the output from the inverter unit 35, and also causes the interrupter unit 34 to interrupt the continuity of the power supply line 32 in order to suppress erroneous determination of power supply restoration caused by a leak current Ia or a reverse current Ib to the power supply line 32. That is, the control unit 31 is configured to be able to determine a power supply abnormality by causing the interrupter unit 34 to interrupt the continuity of the power supply line 32, and thereby detecting only a voltage increase (power supply restoration) on the input side (power supply 104 side) of the interrupter unit 34 without detecting a voltage increase on the output side (motor 11 side) of the interrupter unit 34.

[0057] Furthermore, when an abnormality is determined in the power supply line 32, the shift device 100 outputs abnormality determination information indicating that a power supply abnormality has been determined to a vehicle-side control device (ECU: Electronic Control Unit) not shown outside the shift device 100. When the abnormality determination information is acquired, the vehicle-side control device causes a display device (not shown) to display a message indicating to an occupant that a power supply abnormality has occurred in the shift device 100, for example.

[0058] (Power supply abnormality determination method according to this embodiment) The control process of the method for determining a power supply abnormality of the motor 11 (vehicle motor) by the control unit 31 will be described below with reference to Fig. 6. In the following process, a case where a power supply abnormality is determined in the power supply line 32 of the first system group 30 will be described.

[0059] First, in step S1, it is determined whether or not the voltage of the power supply line 32 for supplying electric power from the power supply 104 mounted on the vehicle 110 to the motor 11 is lower than a predetermined threshold. If it is determined that the voltage of the power supply line 32 is lower than the predetermined threshold, the process proceeds to step S2. If it is not determined that the voltage of the power supply line 32 is lower than the predetermined threshold, the process of step S1 is repeated.

[0060] In step S2, a power abnormality in the power line 32 is determined based on the voltage of the power line 32 being lower than a predetermined threshold value. That is, it is determined that a power abnormality has occurred in the power line 32.

[0061] Next, in step S3, if it is determined that there is an abnormality in the power supply line 32, the switching elements 35a to 35f included in the inverter unit 35 that outputs the power from the power supply 104 to the motor 11 are turned off.

[0062] Next, in step S4, if it is determined that there is an abnormality in the power supply line 32, the continuity of the power supply line 32 is interrupted. Specifically, the switching elements 34a and 35b of the interrupter 34 are turned off.

[0063] Next, in step S5, abnormality determination information indicating that a power supply abnormality has been determined in the power supply line 32 of the first system group 30 is output to a vehicle-side control device (not shown) external to the shift device 100.

[0064] Either the control for turning off the switching elements 35a-35f of the inverter unit 35 in step S3 or the control for causing the cutoff unit 34 to cut off the continuity of the power supply line 32 in step S4 may be executed first. Moreover, the process in step S3 and the process in step S4 may be executed substantially simultaneously.

[0065] In the above description, a case where a power supply abnormality is detected in the power supply line 32 of the first system group 30 has been described, but when a power supply abnormality is detected in the power supply line 42 of the second system group 40, the control unit 41 executes a similar control process. That is, when the voltage of the power supply line 42 of the second system group 40 is lower than a predetermined threshold, the control unit 41 determines that a power supply abnormality has occurred in the power supply line 42 of the second system group 40. When a power supply abnormality has been determined in the power supply line 42, the control unit 41 turns off the switching elements 45a to 45f (driving switching elements) of the inverter unit 45 (driving circuit unit) and turns off the switching elements 44a and 44b (interrupting switching elements) of the interrupter 44, thereby interrupting the continuity of the power supply line 42.

[0066] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0067] In the present embodiment, as described above, when the voltage of the power supply line 32(42) is lower than a predetermined threshold, the power supply line 32(42) is determined to be abnormal, and the switching elements 35a-35f and 45a-45f (driving switching elements) included in the inverter units 35 and 45 (driving circuit units) are turned off, and the interrupter unit 34(44) interrupts the conduction of the power supply line 32(42). As a result, the interrupter unit 34(44) interrupts the conduction of the power supply line 32(42), so that the leakage current Ia and the like do not flow, and therefore, even if the voltage of the power supply line 32(42) temporarily rises, it is possible to suppress erroneous determination of the recovery of the power supply 104(105). Therefore, it is possible to suppress repeated drops and rises in the voltage of the power supply line 32(42), and therefore it is possible to suppress repeated determinations of abnormality and normality of the power supply line 32(42). As a result, by suppressing repetition of determinations of abnormality and normality of the power supply line 32 (42), it is possible to appropriately detect an abnormality in the power supply line 32 (42).

[0068] Furthermore, in this embodiment, as described above, the cut-off unit 34 (44) is configured to cut off the continuity of the power supply line 32 (42) between the power supply 104 (105) and the inverter units 35 and 45 (drive circuit units), and is configured to determine an abnormality in the power supply line 32 (42) when the voltage of the power supply line 32 (42) on the power supply 104 (105) side of the cut-off unit 34 (44) is lower than a predetermined threshold value, turn off the switching elements 35a-35f and 45a-45f (drive switching elements) included in the inverter unit 35 (45), and cut off the continuity of the power supply line 32 (42) by the cut-off unit 34 (44). Thus, when the voltage of the power line 32(42) on the power supply 104(105) side of the interrupter 34(44) is lower than a predetermined threshold, an abnormality in the power line 32(42) is determined, so that by interrupting the conduction of the power line 32(42) by the interrupter 34(44), it is possible to effectively prevent the power line 32(42) from being erroneously determined to be normal when the voltage of the power line 32(42) on the inverter unit 35(45) side of the interrupter 34(44) temporarily rises. Therefore, it is possible to effectively prevent the power line 32(42) from being repeatedly determined to be abnormal and normal, and therefore it is possible to more appropriately detect an abnormality in the power line 32(42).

[0069] In this embodiment, as described above, the control unit 31(41) is configured to detect the voltage of the power supply line 32(42), and when the voltage of the power supply line 32(42) is lower than a predetermined threshold, the control unit 31(41) is configured to determine an abnormality in the power supply line 32(42) and execute control to turn off the switching elements 35a-35f and 45a-45f (driving switching elements) included in the inverter units 35 and 45 (driving circuit units), and also execute control to cut off the continuity of the power supply line 32(42) by the cutoff unit 34(44). As a result, since the control unit 31(41) is configured to detect the voltage of the power supply line 32(42), it is possible to easily determine an abnormality in the power supply line 32(42). Furthermore, when an abnormality in the power supply line 32 (42) is determined, the control unit 31 (41) can easily execute control to turn off the switching elements 35a-35f (45a-45f) and control to cut off the continuity of the power supply line 32 (42) by the cutoff unit 34 (44). Therefore, the control by the control unit 31 (41) can easily prevent the power supply line 32 (42) from being repeatedly determined to be abnormal and normal, and therefore the abnormality in the power supply line 32 (42) can be easily and appropriately detected.

[0070] In the present embodiment, as described above, the switching elements 35a to 35f and 45a to 45f (driving switching elements) of the inverter units 35 and 45 (driving circuit units) are driven by the driver 36 (46), and the switching elements 35a, 35c, 35e and 45a, 45c, 45e (first driving switching elements) on the upper arm side and the switching elements 35b, 35d, 35f and 45b, 45d, 45f (second driving switching elements) on the lower arm side are connected in series with each other. When the voltage of the power supply line 32(42) is lower than a predetermined threshold, the inverter unit 35(45) determines that the power supply line 32(42) is abnormal, turns off both the switching elements 35a, 35c, 35e (45a, 45c, 45e) and the switching elements 35b, 35d, 35f (45b, 45d, 45f) included in the inverter unit 35(45), and interrupts the continuity of the power supply line 32(42) by the interrupter unit 34(44). As a result, the inverter unit 35(45) turns off both the switching elements 35a, 35c, 35e (45a, 45c, 45e) on the upper arm side and the switching elements 35b, 35d, 35f (45b, 45d, 45f) on the lower arm side, so that it is possible to effectively prevent power from being supplied to the motor 11 from the power supply line 32(42) in which an abnormality has occurred. Therefore, it is possible to effectively suppress the influence of the abnormality of the power supply line 32 (42) on the operation of the motor 11. Furthermore, since the interrupter 34 (44) cuts off the continuity of the power supply line 32 (42) when it is determined that the power supply line 32 (42) is abnormal, it is possible to suppress erroneous determination of the restoration of the power supply 104 (105) even when the voltage of the power supply line 32 (42) temporarily rises due to the leakage current Ia from the driver 36 (46) or the like. Therefore, when both the switching elements 35a, 35c, 35e (45a, 45c, 45e) on the upper arm side and the switching elements 35b, 35d, 35f (45b, 45d, 45f) on the lower arm side are turned off, it is possible to suppress repeated drops and rises in the voltage of the power supply line 32 (42), so it is possible to effectively suppress repeated determinations of the abnormality and normality of the power supply line 32 (42). As a result, it is possible to more appropriately detect the abnormality of the power supply line 32 (42).

[0071] In addition, in this embodiment, as described above, the first system group 30 and the second system group 40 each include a cut-off unit 34 (44) and inverter units 35 and 45 (drive circuit units), and when power is output to the motor 11 from both the inverter unit 35 of the first system group 30 and the inverter unit 45 of the second system group 40, if the voltage of the power supply line 32 in the first system group 30 is smaller than a predetermined threshold value, an abnormality in the power supply line 32 in the first system group 30 is determined, the switching elements 35a to 35f (drive switching elements) included in the inverter unit 35 in the first system group 30 are turned off, the conduction of the power supply line 32 is cut off by the cut-off unit 34 in the first system group 30, and power is supplied to the motor 11 from the inverter unit 45 of the second system group 40. As a result, the motor 11 can be driven by power from both the first system group 30 and the second system group 40, so that even if an abnormality occurs in one of the first system group 30 and the second system group 40, the motor 11 can continue to be driven by the other system that is not abnormal. Furthermore, if it is determined that the power supply line 32 of the first system group 30 is abnormal, the operation of the inverter unit 35 of the first system group 30 is stopped, thereby stopping the output from the inverter unit 35 of the first system group 30. In this case, a back electromotive force caused by the drive of the motor 11 by the output from the inverter unit 45 of the second system group 40 is generated, and a reverse current Ib may flow from the motor 11 into the power supply line 32 of the first system group 30. In contrast, in this embodiment, when the voltage of the power supply line 32 in the first system group 30 is lower than a predetermined threshold value, an abnormality in the power supply line 32 in the first system group 30 is determined, and the switching elements 35a-35f included in the inverter unit 35 in the first system group 30 are turned off, and the conduction of the power supply line 32 is interrupted by the interrupter unit 34 in the first system group 30. Then, power is supplied to the motor 11 from the inverter unit 45 of the second system group 40.Therefore, when an abnormality occurs in the power supply line 32 of the first system group 30, the interrupter 34 in the first system group 30 interrupts the conduction of the power supply line 32, so that even when the voltage of the power supply line 32 of the first system group 30 rises due to the back electromotive force caused by the driving of the motor 11 by the second system group 40, it is possible to suppress erroneous determination of the restoration of the power supply 104. As a result, even when an abnormality occurs in the power supply line 32 (42) of either the first system group 30 or the second system group 40 in a state in which power from both the first system group 30 and the second system group 40 is output to the motor 11, it is possible to suppress repeated determination of an abnormality and a normality of the power supply line 32 (42), so that an abnormality in the power supply line 32 (42) can be appropriately detected.

[0072] [Variations] The above-described embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the above-described embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0073] For example, in the above embodiment, the control unit 31 (41) that controls the switching operation of the inverter unit 35 (45) detects the voltage of the power supply line 32 (42), but the present invention is not limited to this. In the present invention, a voltage detection unit separate from the control unit 31 (41) may be provided. In that case, the control unit 31 (41) may determine a power supply abnormality by acquiring a detection value detected by the voltage detection unit. In addition, the voltage detection unit may include, for example, a comparator, and may be configured to output an abnormality detection signal indicating a power supply abnormality to the control unit 31 (41) when the voltage of the power supply line 32 (42) is lower than a predetermined threshold value.

[0074] In the above embodiment, the inverter units 35 and 45 (drive circuit units) are configured to output two levels of three-phase AC, but the present invention is not limited to this. For example, the drive circuit units may be multilevel inverters with three or more levels. The drive circuit units may be configured to output one-phase AC power instead of three-phase AC power.

[0075] In the above embodiment, an example of the dual-system drive shift device 100 having the first system group 30 and the second system group 40 has been shown, but the present invention is not limited to this. For example, the shift device 100 may be a single-system drive shift device in which the motor 11 is driven by power supplied from one system. Even in the single-system drive mode, when an abnormality in the power supply line 32 (42) is determined, the voltage of the power supply line 32 (42) increases due to the leakage current Ia from the driver 36 (46). Therefore, by interrupting the continuity of the power supply line 32 (42) by the interrupter 34 (44), it is possible to prevent the power supply line 32 (42) from being repeatedly determined to be abnormal and normal.

[0076] In the above embodiment, the first system group 30 and the second system group 40 have the control unit 31 and the control unit 41, respectively, but the present invention is not limited to this. For example, the first system group 30 and the second system group 40 may be configured to be controlled by a common control unit (microcomputer).

[0077] In the above embodiment, the first system group 30 and the second system group 40 are supplied with power from separate power sources 104 and 105, respectively, but the present invention is not limited to this. For example, the first system group 30 and the second system group 40 may be configured to receive power from a single common power source.

[0078] In the above embodiment, the interrupter 34 (44) is a solid-state relay having the switching elements 34a and 34b (44a and 44b), but the present invention is not limited to this. For example, the interrupter 34 (44) may be a mechanical relay. Furthermore, the switching elements 34a and 34b (44a and 44b) of the interrupter 34 (44) may be semiconductor switches in general, not limited to field effect transistors (FETs).

[0079] In the above embodiment, the switching elements 35a-35f (45a-45f) of the inverter units 35 and 45 (drive circuit units) are field effect transistors (FETs), but the present invention is not limited to this. For example, the switching elements (drive switching elements) included in the inverter unit 35 (45) may be semiconductor switches in general, not limited to FETs.

[0080] In addition, in the above embodiment, an example of power supply abnormality determination in the shift device 100 for an automobile is shown, but the present invention is not limited to this. For example, the shift device may be mounted on a vehicle other than an automobile, such as a train. Furthermore, the power supply abnormality determination according to the present invention may be applied to a vehicle motor control device other than a shift device, such as an electric power steering device.

[0081] In the above embodiment, for convenience of explanation, the control processing of each of the control units 31 and 41 is explained using a flow-driven flowchart in which the processing is performed in order according to the processing flow, but the present invention is not limited to this. In the present invention, the control processing of the control unit may be performed by an event-driven processing in which processing is performed on an event-by-event basis. In this case, the control processing may be performed completely event-driven, or may be performed in a combination of event-driven and flow-driven. [Explanation of symbols]

[0082] 11 Motor 30 1st phylogenetic group 31, 41 Control section 32, 42 Power lines 34, 44 Breaking section 35, 45 Inverter section (drive circuit section) 35a, 35c, 35e, 45a, 45c, 45e Switching elements (driving switching elements, first driving switching elements) 35b, 35d, 35f, 45b, 45d, 45f Switching elements (driving switching elements, second driving switching elements) 36, 46 Driver 40 2nd phylogenetic group 100 Shift device (vehicle motor control device) 103a Detent plate (shift switching member) 104, 105 Power supply 110 vehicles

Claims

1. A shift device mounted on a vehicle, a motor that drives a shift switching member for switching a shift position by electric power supplied from a power source mounted on the vehicle; a cutoff unit that cuts off conduction of a power supply line for supplying electric power from the power supply to the motor; a drive circuit unit including a drive switching element that performs a switching operation and outputs power from the power source to the motor; the interrupter is configured to interrupt conduction of the power supply line between the power supply and the drive circuit unit, a power supply line for supplying power from the power supply to the motor, the power supply line being located on the power supply side of the cut-off unit, being lower than a predetermined threshold value; a shift device configured to determine an abnormality in the power supply line, turn off the drive switching element included in the drive circuit unit, and cut off continuity of the power supply line by the cut-off unit.

2. a controller configured to detect a voltage on the power line; 2. The shift device according to claim 1, wherein the control unit is configured to determine an abnormality in the power supply line when a voltage of the power supply line is lower than the predetermined threshold value, and to execute control to turn off the drive switching element included in the drive circuit unit and to execute control to cut off continuity of the power supply line by the cutoff unit.

3. the drive switching elements of the drive circuit unit include a first drive switching element on an upper arm side and a second drive switching element on a lower arm side, the first drive switching element and the second drive switching element being driven by a driver and connected in series to each other, 3. The shift device according to claim 1, further comprising: a first driving switching element and a second driving switching element included in the drive circuit unit, the first driving switching element and the second driving switching element being turned off when the voltage of the power supply line is lower than the predetermined threshold value; and the first driving switching element and the second driving switching element being turned off when the voltage of the power supply line is lower than the predetermined threshold value.

4. a first group of systems and a second group of systems each including the interrupter and the drive circuit unit; 4. The shift device according to claim 1, wherein, when power is output to the motor from both the drive circuit unit of the first system group and the drive circuit unit of the second system group, if a voltage of the power supply line in the first system group is smaller than the predetermined threshold value, the shift device determines an abnormality in the power supply line in the first system group, turns off the drive switching element included in the drive circuit unit in the first system group, and interrupts continuity of the power supply line by the interrupter in the first system group, and supplies power to the motor from the drive circuit unit of the second system group.

5. A motor driven by power supplied from a power source mounted on the vehicle; a cutoff unit that cuts off conduction of a power supply line for supplying electric power from the power supply to the motor; a drive circuit unit including a drive switching element that performs a switching operation and outputs power from the power source to the motor; the interrupter is configured to interrupt conduction of the power supply line between the power supply and the drive circuit unit, a power supply line for supplying power from the power supply to the motor, the power supply line being connected to the power supply side of the power supply circuitry; a drive switching element included in the drive circuitry being turned off and the power supply line being cut off by the cut-off unit;

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