Motor power supply unit

Abstract

To provide a motor power supply device capable of suppressing erroneous determination on a failure diagnosis of a power supply side semiconductor switch even when a ground fault occurs between the power supply of a power supply line and the power supply side semiconductor switch.SOLUTION: A motor power supply device 3 is arranged to be closer to a first power supply 31a than a first power supply side semiconductor switch 31c on a first power supply line 31b, and includes a first power supply side voltage detector 31e for detecting the voltage of the first power supply line 31b, and a controller 31i for controlling determination on a state of power supply from the first power supply 31a to the first power supply side semiconductor switch 31c based on a measured value of the first power supply side voltage detector 31e.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a power supply device for a motor, and more particularly to a power supply device for a motor that supplies power to drive a motor. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a power supply device for a motor that supplies power to drive a motor is known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a power supply unit (power supply device for a motor) that supplies power to drive a motor. The power supply unit includes a main power supply, a sub-power supply, a sub-power supply supply line, a first MOSFET, a second MOSFET, and a microcomputer. The sub-power supply is provided separately from the main power supply. The sub-power supply supply line is connected to the sub-power supply and supplies power from the sub-power supply to the motor. The first MOSFET is disposed closer to the sub-power supply side than the second MOSFET on the sub-power supply supply line. The second MOSFET is connected in series with the first MOSFET on the sub-power supply supply line. The microcomputer is configured to control the on / off of each of the first MOSFET and the second MOSFET.

[0004] The microcomputer in the above-mentioned Patent Document 1 is configured to determine the presence or absence of short-circuit / open circuit failures in each of the first MOSFET and the second MOSFET while the first MOSFET and the second MOSFET are turned on and off. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-102478 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the power supply unit of Patent Document 1, if a ground fault occurs between the sub-power supply and the first MOSFET on the sub-power supply line, there is a risk of erroneous fault diagnosis in the on-fault diagnosis of the first MOSFET and in the off-fault diagnosis of the first MOSFET. Specifically, when a fault diagnosis of the first MOSFET is performed with the first MOSFET on and the second MOSFET off, if a ground fault occurs between the sub-power supply and the first MOSFET on the sub-power supply line, the voltage of the first MOSFET becomes 0V. In this case, even if the on-operation of the first MOSFET is normal, the microcomputer erroneously determines that an open fault has occurred, in which the off-state of the first MOSFET cannot be released. Also, when a fault diagnosis of the first MOSFET is performed with the first MOSFET off and the second MOSFET off, if a ground fault occurs between the sub-power supply and the first MOSFET on the sub-power supply line, the voltage of the first MOSFET becomes 0V. In this case, even if the first MOSFET has a short-circuit fault (short-circuit fault), the microcomputer erroneously determines that the off-operation of the first MOSFET is normal. As described above, the power supply unit of Patent Document 1 has a problem in that when a ground fault occurs between the sub-power supply (power supply) of the sub-power supply supply line (power supply line) and the first MOSFET (power supply side semiconductor switch), a fault diagnosis of the first MOSFET (power supply side semiconductor switch) may result in an erroneous fault diagnosis.

[0007] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power supply device for a motor that is capable of suppressing erroneous determinations in the fault diagnosis of a power supply-side semiconductor switch even when a ground fault occurs between the power supply of the power supply line and the power supply-side semiconductor switch. [Means for solving the problem]

[0008] In order to achieve the above object, a power supply device for a motor in one aspect of the present invention includes a first power source and a motor driven by power supplied from the first power source, a first power supply line electrically connecting the first power source and the motor, a first power source side semiconductor switch arranged on the first power supply line on the first power supply side, a first output side semiconductor switch connected in series to the first power source side semiconductor switch on the first power supply line and arranged on the output side, and a first power source side voltage detection unit arranged on the first power supply line on the first power supply side of the first power source side semiconductor switch and detecting a voltage of the first power supply line, two power supply units each including an output side voltage detection unit that is disposed on the first power supply line closer to the motor than the first output side semiconductor switch and detects a voltage of the first power supply line; and a control unit that performs control to determine a state of power supply from the first power source to the first power source side semiconductor switch based on a measurement value of the first power source side voltage detection unit. One of the two power supply units includes, in addition to the first power supply side voltage detection unit and the output side voltage detection unit, an intermediate voltage detection unit that is disposed between the first power supply side semiconductor switch and the first output side semiconductor switch and detects the voltage of the first power supply line, and the other of the two power supply units does not include an intermediate voltage detection unit and includes the first power supply side voltage detection unit and the output side voltage detection unit. .

[0009] As described above, a motor power supply device according to one aspect of the present invention includes a control unit that performs control to determine the state of power supply from the first power source to the first power source side semiconductor switch based on a measurement value of the first power source side voltage detection unit. As a result, even if a ground fault occurs between the first power source and the first power source side semiconductor switch on the first power supply line, the control unit can accurately determine the ground fault based on the measurement value of the first power source side voltage detection unit, so that erroneous determinations in the fault diagnosis can be suppressed in the fault diagnosis of the ON operation of the first power source side semiconductor switch and the fault diagnosis of the OFF operation of the first power source side semiconductor switch.

[0010] In the motor power supply device according to the above aspect, it is preferable to is controlled The control unit is configured to diagnose failures in the first power supply side semiconductor switch and the first output side semiconductor switch based on voltage values ​​detected by the first power supply side voltage detection unit and the output side voltage detection unit, respectively, in a first state in which the first power supply side semiconductor switch and the first output side semiconductor switch are turned on.

[0011] With this configuration, it is possible to diagnose faults in the first power supply side semiconductor switch and the first output side semiconductor switch without placing a voltage detection unit between the first power supply side semiconductor switch and the first output side semiconductor switch, thereby suppressing an increase in the number of components in the motor power supply device (circuit).

[0012] In this case, the control unit is preferably configured to diagnose a failure of the first output-side semiconductor switch based on the voltage values ​​detected by each of the first power supply side voltage detection unit and the output side voltage detection unit in a second state in which all of the first power supply side semiconductor switches and the first output side semiconductor switches are turned off.

[0013] With this configuration, in the case of an on-failure (short-circuit failure) in which the first power supply semiconductor switch cannot be released from its on state, a voltage is detected by the output-side voltage detection unit if the first output-side semiconductor switch has an on-failure, and a voltage is not detected by the output-side voltage detection unit if the first output-side semiconductor switch is normal, so that the result of the diagnosis of an on-failure of the first output-side semiconductor switch can be used as the result of the diagnosis of an on-failure of the first power supply semiconductor switch. As a result, by diagnosing only the failure of the first output-side semiconductor switch without diagnosing the failure of the first power supply semiconductor switch, it is possible to diagnose the on-failure of each of the first power supply voltage detection unit and the output-side voltage detection unit, thereby reducing the processing load of the failure diagnosis on the control unit.

[0014] In the motor power supply device having the output side voltage detection unit, preferably , regulation The control unit is configured to diagnose, in a first state, failures in the first power supply side semiconductor switch and the first output side semiconductor switch based on voltage values ​​detected by each of the first power supply side voltage detection unit, the output side voltage detection unit, and the intermediate section voltage detection unit.

[0015] With this configuration, by providing an intermediate section voltage detection unit, it is possible to directly diagnose a failure in the first power supply side semiconductor switch, thereby improving the accuracy of the diagnosis results for the first power supply side semiconductor switch.

[0016] The motor power supply device including the intermediate section voltage detection unit preferably further includes a second power supply provided separately from the first power supply, a second power supply line electrically connecting the second power supply and the motor, a second power supply side semiconductor switch arranged on the second power supply side of the second power supply line, a second output side semiconductor switch connected in series to the second power supply side semiconductor switch on the second power supply line and arranged on the output side, and a second power supply side voltage detection unit arranged on the second power supply line closer to the second power supply side than the second power supply side semiconductor switch and detecting a voltage of the second power supply line, and the control unit is configured to diagnose failures in the first power supply side semiconductor switch and the second output side semiconductor switch based on voltage values ​​detected by each of the first power supply side voltage detection unit, the output side voltage detection unit, and the intermediate section voltage detection unit in a third state in which the first power supply side semiconductor switch, the second power supply side semiconductor switch, the first output side semiconductor switch, and the second output side semiconductor switch are all turned off.

[0017] With this configuration, the second power source side voltage detection unit can accurately determine when a ground fault has occurred between the second power source on the second power supply line and the second power source side semiconductor switch, thereby suppressing erroneous determination in fault diagnosis. Also, by diagnosing a fault in the first power source side semiconductor switch using the intermediate section voltage detection unit, the first power source side semiconductor switch can be directly diagnosed, thereby accurately detecting an on fault in the first power source side semiconductor switch.

[0018] In the motor power supply device including the second power supply side detection unit, preferably, in the first state, the control unit: Moreover, in a state in which the second power supply side semiconductor switch and the second output side semiconductor switch are turned on, The second output-side semiconductor switch is diagnosed for a fault based on the voltage values ​​detected by the output-side voltage detector, the intermediate section voltage detector, and the second power supply-side voltage detector.

[0019] With this configuration, it is possible to diagnose an off failure (open failure) in which the second output side semiconductor switch cannot be released from the off state without using the first power supply side voltage detection unit, thereby reducing the processing load on the control unit when diagnosing an off failure of the second output side semiconductor switch.

[0020] In the motor power supply device including the above-mentioned second power supply side detection unit, the control unit is preferably configured to diagnose a failure of the first output side semiconductor switch based on the voltage values ​​detected by each of the first power supply side voltage detection unit, the output side voltage detection unit, and the intermediate section voltage detection unit, or to diagnose a failure of the second output side semiconductor switch based on the voltage values ​​detected by each of the output side voltage detection unit, the intermediate section voltage detection unit, and the second power supply side voltage detection unit, in a fourth state in which the second power supply side semiconductor switch and the second output side semiconductor switch are turned on.

[0021] With this configuration, it is possible to diagnose an ON failure of the first output-side semiconductor switch without using the second power supply voltage detection unit, thereby reducing the processing load on the control unit when diagnosing an OFF failure of the first output-side semiconductor switch. Also, it is possible to diagnose an OFF failure of the second output-side semiconductor switch without using the first power supply voltage detection unit, thereby reducing the processing load on the control unit when diagnosing an OFF failure of the second output-side semiconductor switch.

[0022] In the motor power supply device that performs fault diagnosis in the above-mentioned fourth state, preferably, the device further includes a pre-charge capacitor that is arranged on the first power supply line on the first power supply side of the output side voltage detection unit and is pre-charged by an external power supply, and the control unit is configured to control discharging the pre-charge capacitor before the second state, the third state, and the fourth state in which the first power supply side semiconductor switch and the first output side semiconductor switch are all turned off.

[0023] With this configuration, the pre-charge capacitor can prevent an inrush current from flowing toward the output side detection unit. Also, by discharging the pre-charge capacitor before the motor power supply device is put into the second, third or fourth state, the output side voltage detection unit can detect the voltage that has passed through the semiconductor switch, so that fault diagnosis of the semiconductor switch can be performed accurately in the motor power supply device.

[0024] In the motor power supply device according to the above aspect, the following configuration is also possible.

[0025] (Additional note 1) That is, in the motor power supply device equipped with the above-mentioned pre-charge capacitor, the control unit is configured to perform control not to diagnose a fault in the first state, the second state, the third state, and the fourth state based on the occurrence of a charging abnormality in the pre-charge capacitor.

[0026] With this configuration, it is possible to reliably prevent inrush current from flowing toward the output side detection unit when diagnosing a fault in the first, second, third, and fourth states, thereby preventing erroneous detection in the fault diagnosis of the semiconductor switch caused by inrush current.

[0027] (Additional note 2) In the motor power supply device equipped with the above-mentioned output side voltage detection unit, the control unit is preferably configured to perform control to terminate the failure diagnosis based on detection of a failure in at least one of the first power supply side semiconductor switch and the first output side semiconductor switch in the first state.

[0028] With this configuration, it is possible to suppress erroneous detection of a semiconductor switch failure caused by a malfunction of at least one of the failed first power supply side semiconductor switch and the first output side semiconductor switch, and therefore it is possible to accurately perform failure diagnosis of the semiconductor switches in the motor power supply device. Also, since the failure diagnosis is terminated based on detection of a failure of at least one of the first power supply side semiconductor switch and the first output side semiconductor switch in the first state, it is possible to reduce the processing load of the control unit compared to the case where the failure diagnosis is continued.

[0029] (Additional note 3) In the motor power supply device that diagnoses a fault in the first output side semiconductor switch in the above-mentioned second state, the control unit is configured to perform control to terminate the fault diagnosis based on detection of a fault in the first output side semiconductor switch in the second state.

[0030] With this configuration, it is possible to suppress erroneous detection of a semiconductor switch failure due to a malfunction of the failed first output semiconductor switch, and therefore it is possible to accurately perform failure diagnosis of the semiconductor switch in the motor power supply device. Also, in the second state, since the failure diagnosis is terminated based on the detection of a failure of the first output semiconductor switch, it is possible to reduce the processing load on the control unit compared to the case where the failure diagnosis is continued.

[0031] (Additional note 4) In the motor power supply device that diagnoses a fault in the first power supply side semiconductor switch in the above-mentioned third state, the control unit is configured to perform control to terminate the fault diagnosis based on detection of a fault in the first power supply side semiconductor switch in the third state.

[0032] With this configuration, it is possible to suppress erroneous detection of a semiconductor switch failure due to a malfunction of the failed first power supply side semiconductor switch, and therefore it is possible to accurately perform failure diagnosis of the semiconductor switch in the motor power supply device. Also, in the third state, since the failure diagnosis is terminated based on the detection of a failure of the first power supply side semiconductor switch, it is possible to reduce the processing load on the control unit compared to the case where the failure diagnosis is continued.

[0033] (Claim 5) In the motor power supply device that diagnoses a fault in the first output side semiconductor switch or the second output side semiconductor switch in the above-mentioned fourth state, the control unit is configured to perform control to determine whether or not to diagnose a fault in the first output side semiconductor switch and whether or not to diagnose a fault in the second output side semiconductor switch in the fourth state based on the type of the second power supply.

[0034] With this configuration, the processing load on the control unit can be reduced compared to when a fault diagnosis of the semiconductor switch is performed in the fourth state regardless of the type of the second power supply. [Brief description of the drawings]

[0035] [Figure 1] 1 is a perspective view showing a schematic overall configuration of a shift device according to a first embodiment. [Diagram 2] 3A and 3B are diagrams illustrating a structure of a detent plate that constitutes the shift device according to the first embodiment. [Diagram 3] 1 is a diagram showing a schematic configuration of a motor power supply device according to a first embodiment; [Figure 4] 4 is a timing chart for fault diagnosis in the motor power supply device according to the first embodiment. [Diagram 5] 4 is a table showing diagnostic results of a first diagnostic state of a first main semiconductor switch in the motor power supply device according to the first embodiment. [Figure 6] 4 is a table showing diagnostic results of a first diagnostic state of a second main semiconductor switch in the motor power supply device according to the first embodiment. [Figure 7] 4 is a table showing diagnostic results of a first diagnostic state of a first sub semiconductor switch in the motor power supply device according to the first embodiment. [Figure 8] 4 is a table showing diagnostic results of a first diagnostic state of a second sub semiconductor switch in the motor power supply device according to the first embodiment. [Figure 9] 5 is a table showing diagnostic results of a second diagnostic state of a second main semiconductor switch in the motor power supply device according to the first embodiment. [Figure 10] 5 is a table showing diagnostic results of a second diagnostic state of a first sub semiconductor switch in the motor power supply device according to the first embodiment. [Figure 11] 13 is a table showing diagnostic results of a second diagnostic state of a fourth sub semiconductor switch in the motor power supply device according to the first embodiment. [Figure 12] 10 is a table showing diagnostic results of a third diagnostic state of a second sub semiconductor switch in the motor power supply device according to the first embodiment. [Figure 13] 13 is a table showing diagnostic results of a fourth sub semiconductor switch in a third diagnostic state in the motor power supply device according to the first embodiment. [Figure 14] 4 is a flowchart showing a main side fault diagnosis process of the motor power supply device according to the first embodiment. [Figure 15] 5 is a flowchart showing a part of a sub-side fault diagnosis process of the motor power supply device according to the first embodiment. [Figure 16] 13 is a flowchart showing the remainder of the sub-side fault diagnosis processing of the motor power supply device according to the first embodiment. [Figure 17] FIG. 11 is a diagram showing a schematic configuration of a motor power supply device according to a second embodiment. [Figure 18] 10 is a timing chart for fault diagnosis in the motor power supply device according to the second embodiment. [Figure 19] 13 is a table showing diagnostic results of a second diagnostic state of a fourth sub semiconductor switch in the motor power supply device according to the second embodiment. [Figure 20] FIG. 13 is a diagram showing a schematic configuration of a motor power supply device according to a third embodiment. [Figure 21] 13 is a timing chart for fault diagnosis in the motor power supply device according to the third embodiment. [Figure 22] 13 is a table showing diagnostic results of a first diagnostic state of a first semiconductor switch in the motor power supply device according to the third embodiment. [Figure 23] 13 is a table showing diagnostic results of a first diagnostic state of a second semiconductor switch in the motor power supply device according to the third embodiment. [Figure 24] 13 is a table showing diagnostic results of a second diagnostic state of the first sub semiconductor switch in the motor power supply device according to the third embodiment. [Diagram 25] 13 is a table showing diagnostic results of a second diagnostic state of a fourth semiconductor switch in the motor power supply device according to the third embodiment. [Figure 26] 13 is a table showing diagnostic results of a third diagnostic state of a second semiconductor switch in the motor power supply device according to the third embodiment. [Figure 27] 13 is a table showing diagnostic results of a fourth semiconductor switch in a third diagnostic state in the motor power supply device according to the third embodiment. [Figure 28] 13 is a flowchart showing a part of a fault diagnosis process of a power supply device for a motor according to a third embodiment. [Figure 29] 13 is a flowchart showing the remaining part of the fault diagnosis process of the motor power supply device according to the third embodiment. [Diagram 30] FIG. 13 is a diagram showing a schematic configuration of a motor power supply device according to a fourth embodiment. [Diagram 31] 13 is a timing chart for fault diagnosis in the motor power supply device according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0037] [First embodiment] The configuration of a motor power supply device 3 of the first embodiment will be described with reference to Figures 1 to 13. The motor power supply device 3 is a device for driving the motor 11 of the shift device 100.

[0038] The shift device 100 is mounted on a vehicle such as an automobile. As shown in FIG. 1, when an occupant (driver) of the vehicle performs a shift switching operation via an operation unit such as a shift lever (or a shift switch), an electrical shift switching control is performed on the transmission mechanism. That is, the position of the shift lever is input to the shift device 100 via a shift sensor provided in the operation unit. Then, based on a control signal transmitted from a dedicated main-side microcomputer 31i and a sub-side microcomputer 32o (described later) provided in the shift device 100, the transmission mechanism is switched to 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).

[0039] The shift device 100 includes an actuator unit 1, a shift switching mechanism 2, and a motor power supply device 3 (see FIG. 3). The shift switching mechanism 2 is mechanically connected to a manual spool valve (not shown) of a hydraulic valve body in a hydraulic control circuit (not shown) in the transmission mechanism, and to a parking mechanism. The shift switching mechanism 2 is configured to mechanically switch the shift state (P position, R position, N position, and D position) of the transmission by driving the shift switching mechanism 2.

[0040] 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 21, which will be described later. The motor 11 is a three-phase motor of a surface permanent magnet type (SPM) in which permanent magnets are incorporated into the surface of the rotor. The driving force transmission mechanism 12 is configured to transmit the driving force of the motor 11 to the detent plate 21. The driving force transmission mechanism 12 includes a reduction mechanism (not shown) and an output shaft 12a.

[0041] 1, the shift switching mechanism 2 is driven by an actuator unit 1. The shift switching mechanism 2 includes a detent plate 21 and a detent spring 22. The detent spring 22 is configured to hold the detent plate 21 at rotation angle positions corresponding to the P position, the R position, the N position, and the D position, respectively.

[0042] 2, the detent plate 21 has a plurality (four) of valleys 21a, 21b, 21c and 21d (plurality of valleys) provided to correspond to the shift positions (P position, R position, N position and D position). The valleys 21a, 21b, 21c and 21d form a cam surface Ca having a continuous undulating shape on the detent plate 21. Adjacent valleys (for example, valleys 21a and 21b, valleys 21b and 21c, etc.) are separated by a peak M having one apex T. The detent spring 22 has a base end fixed to a casing of the speed change mechanism, and a roller portion 22a attached to the free end side. The roller portion 22a of the detent spring 22 constantly presses against the cam surface Ca (any position of the valley portion 21a, the valley portion 21b, the valley portion 21c, the valley portion 21d, or the peak portion M). The detent spring 22 establishes a shift position in a state where it is fitted into any of the plurality of valley portions 21a, the valley portion 21b, the valley portion 21c, and the valley portion 21d.

[0043] 3, the motor power supply device 3 is configured to supply power to the actuator unit 1. The motor power supply device 3 includes a main power supply unit 31 and a sub-side power supply unit 32. The motor 11 is driven by power supplied from each of the main power supply unit 31 and the sub-side power supply unit 32.

[0044] The main side power supply unit 31 has a main side power supply 31a (an example of a "first power supply" in the claims), a main power supply line 31b (an example of a "first power supply line" in the claims), a first main semiconductor switch 31c (an example of a "first power supply side semiconductor switch" in the claims), and a second main semiconductor switch 31d (an example of a "first output side semiconductor switch" in the claims).

[0045] The main power supply 31a is a lithium battery or a capacitor. The main power supply line 31b electrically connects the main power supply 31a and the motor 11. Each of the first main semiconductor switch 31c and the second main semiconductor switch 31d is a field effect transistor (FET). The first main semiconductor switch 31c is disposed on the main power supply line 31b on the main power supply 31a side. The second main semiconductor switch 31d is connected in series to the first main semiconductor switch 31c on the main power supply line 31b and is disposed on the output side.

[0046] The main power supply unit 31 includes a first main voltage detector 31e (an example of a "first power supply voltage detector" in the claims) and a second main voltage detector 31f (an example of an "output voltage detector" in the claims). The first main voltage detector 31e detects the voltage between the main power supply 31a and the first main semiconductor switch 31c on the main power supply line 31b. The first main voltage detector 31e is disposed on the main power supply line 31b closer to the main power supply 31a than the first main semiconductor switch 31c. The second main voltage detector 31f detects the voltage on the main power supply line 31b closer to the motor 11 than the second main semiconductor switch 31d. The second main voltage detector 31f is disposed on the main power supply line 31b closer to the motor 11 than the second main voltage detector 31f.

[0047] The main power supply unit 31 includes a main capacitor 31g (an example of a "pre-charge capacitor" in the claims) and a first motor circuit 31h. The main capacitor 31g is pre-charged by a system power supply 102 (an example of an "external power supply" in the claims) electrically connected via a pre-charge circuit 101. The main capacitor 31g is disposed on the main power supply line 31b on the main power supply 31a side of the second main voltage detection unit 31f. The first motor circuit 31h transmits a control signal for controlling the motor 11 to the motor 11.

[0048] The main power supply unit 31 includes a main microcomputer 31i (one example of a "control unit" in the claims). The main microcomputer 31i is configured to control the on / off of each of the first main semiconductor switch 31c and the second main semiconductor switch 31d. The main microcomputer 31i is electrically connected to each of the first main voltage detection unit 31e, the second main voltage detection unit 31f, the first main semiconductor switch 31c, and the second main semiconductor switch 31d. The main microcomputer 31i has a CPU (Central Processing Unit) and a storage unit having memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory).

[0049] The sub-side power supply unit 32 has a first sub-side power supply 32a (an example of a "first power supply" in the claims), a first sub power supply line 32b (an example of a "first power supply line" in the claims), a first sub semiconductor switch 32c (an example of a "first power supply side semiconductor switch" in the claims), and a second sub semiconductor switch 32d (an example of a "first output side semiconductor switch" in the claims).

[0050] The first sub power supply line 32b electrically connects the first sub side power supply 32a and the motor 11. Each of the first sub semiconductor switch 32c and the second sub semiconductor switch 32d is a FET. The first sub semiconductor switch 32c is arranged on the first sub side power supply 32a side on the first sub power supply line 32b. The second sub semiconductor switch 32d is connected in series to the first sub semiconductor switch 32c on the first sub power supply line 32b and is arranged on the output side.

[0051] The sub-side power supply unit 32 has a first sub-voltage detection unit 32e (an example of a ``first power supply side voltage detection unit'' as claimed in the claims), a second sub-voltage detection unit 32f (an example of an ``intermediate section voltage detection unit'' as claimed in the claims), and a third sub-voltage detection unit 32g (an example of an ``output side voltage detection unit'' as claimed in the claims).

[0052] The first sub voltage detector 32e detects the voltage between the first sub side power supply 32a and the first sub semiconductor switch 32c on the first sub power supply line 32b. The first sub voltage detector 32e is disposed on the first sub power supply line 32b closer to the first sub side power supply 32a than the first sub semiconductor switch 32c. The second sub voltage detector 32f detects the voltage between the first sub semiconductor switch 32c and the second sub semiconductor switch 32d on the first sub power supply line 32b. The second sub voltage detector 32f is disposed on the first sub power supply line 32b between the first sub semiconductor switch 32c and the second sub semiconductor switch 32d. The third sub voltage detector 32g detects the voltage on the first sub power supply line 32b closer to the motor 11 than the second sub semiconductor switch 32d. The third sub-voltage detection unit 32g is disposed on the first sub-power supply line 32b closer to the motor 11 than the second sub-voltage detection unit 32f.

[0053] The sub-side power supply unit 32 has a sub capacitor 32h (referred to as a "pre-charge capacitor" in the claims) and a second motor circuit 32i. The sub capacitor 32h is pre-charged by a system power supply 102 electrically connected via a pre-charge circuit 101. The sub capacitor 32h is disposed on the first sub-side power supply 32a side of the second sub voltage detection unit 32f on the first sub power supply line 32b. The second motor circuit 32i transmits a control signal for controlling the motor 11 to the motor 11.

[0054] The sub-side power supply unit 32 has a second sub-side power supply 32j (an example of a "second power supply" in the claims), a second sub power supply line 32k (an example of a "second power supply line" in the claims), a third sub semiconductor switch 32l (an example of a "second power supply side semiconductor switch" in the claims), and a fourth sub semiconductor switch 32m (an example of a "second output side semiconductor switch" in the claims).

[0055] The second sub-side power supply 32j is provided separately from the first sub-side power supply 32a. The second sub-side power supply 32j is a lithium battery. The second sub-side power supply line 32k electrically connects the second sub-side power supply 32j and the motor 11. The third sub-side semiconductor switch 32l and the fourth sub-side semiconductor switch 32m are each a FET. The third sub-side semiconductor switch 32l is disposed on the second sub-side power supply 32j side on the second sub-side power supply line 32k. The fourth sub-side semiconductor switch 32m is connected in series to the third sub-side semiconductor switch 32l on the second sub-side power supply line 32k and is disposed on the output side.

[0056] The sub-side power supply unit 32 includes a fourth sub-voltage detection unit 32n (an example of a "second power source side voltage detection unit" in the claims).

[0057] The fourth sub voltage detection unit 32n detects the voltage between the second sub-side power supply 32j and the third sub semiconductor switch 32l on the second sub power supply line 32k. The fourth sub voltage detection unit 32n is disposed on the second sub power supply line 32k closer to the second sub-side power supply 32j than the third sub semiconductor switch 32l.

[0058] The sub-side power supply unit 32 includes a sub-side microcomputer 32o (one example of a "control unit" in the claims). The sub-side microcomputer 32o is configured to control the on / off of each of the third sub semiconductor switch 32l and the fourth sub semiconductor switch 32m. The sub-side microcomputer 32o is electrically connected to each of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, the third sub voltage detection unit 32g, the fourth sub voltage detection unit 32n, the first sub semiconductor switch 32c, the second sub semiconductor switch 32d, the third sub semiconductor switch 32l, and the fourth sub semiconductor switch 32m. The sub-side microcomputer 32o has a CPU and a storage unit having memories such as ROM and RAM.

[0059] (Fault diagnosis) As shown in FIG. 3, in the motor power supply device 3 of the first embodiment, a first main voltage detection unit 31e, a first sub voltage detection unit 32e and a fourth sub voltage detection unit 32n are provided to suppress erroneous diagnosis of failures in each of the first main semiconductor switch 31c, the first sub semiconductor switch 32c and the third sub semiconductor switch 32l.

[0060] Specifically, the main-side microcontroller 31i is configured to perform control to determine the state of power supply from the main-side power supply 31a to the first main semiconductor switch 31c based on the measurement value of the first main voltage detection unit 31e, in order to confirm whether power is being supplied normally from the main-side power supply 31a.

[0061] In addition, the sub-side microcontroller 32o is configured to perform control to determine the state of power supply from the first sub-side power supply 32a to the first sub semiconductor switch 32c based on the measurement value of the first sub voltage detection unit 32e, in order to confirm whether power is being supplied normally from the first sub-side power supply 32a.

[0062] In addition, the sub-side microcontroller 32o is configured to perform control to determine the state of power supply from the second sub-side power supply 32j to the third sub-side semiconductor switch 32l based on the measurement value of the fourth sub-side voltage detection unit 32n, in order to confirm whether power is being supplied normally from the second sub-side power supply 32j.

[0063] In the motor power supply device 3, three types of fault diagnosis are performed, namely, a first diagnostic state D1 (an example of the "first state" in the claims), a second diagnostic state D2 (an example of the "second state" and "third state" in the claims), and a third diagnostic state D3 (an example of the "fourth state" in the claims), as shown in Fig. 4. The first diagnostic state D1 is a fault diagnosis of the FET performed when the ignition is turned on (at start-up).

[0064] In the first diagnostic state D1, a fault diagnosis is performed with the first main semiconductor switch 31c and the second main semiconductor switch 31d turned on, or with the first sub semiconductor switch 32c and the second sub semiconductor switch 32d turned on. The second diagnostic state D2 and the third diagnostic state D3 are fault diagnosis of FETs performed when the ignition is off (in sleep mode). In the second diagnostic state D2, a fault diagnosis is performed with the first main semiconductor switch 31c and the second main semiconductor switch 31d turned off, or with the first sub semiconductor switch 32c, the second sub semiconductor switch 32d, the third sub semiconductor switch 32l, and the fourth sub semiconductor switch 32m turned off. In the third diagnostic state D3, a fault diagnosis is performed with the third sub semiconductor switch 32l and the fourth sub semiconductor switch 32m turned on.

[0065] The first diagnostic state D1, the second diagnostic state D2 and the third diagnostic state D3 will be described below in that order.

[0066] First, before the first diagnostic state D1, the main-side microcomputer 31i is configured to perform control to charge (precharge) the main capacitor 31g by supplying power from the system power supply 102. At this time, the main-side microcomputer 31i is configured not to perform the first diagnostic state D1 based on the detection of a charging abnormality in the main capacitor 31g.

[0067] Similarly, before the first diagnostic state D1, the sub-side microcomputer 32o is configured to perform control to charge (precharge) the sub capacitor 32h by supplying power from the system power supply 102. At this time, the sub-side microcomputer 32o is configured not to perform the first diagnostic state D1 based on the detection of a charging abnormality in the sub capacitor 32h.

[0068] As shown in Figures 4 and 5, the main side microcontroller 31i is configured to diagnose a fault in the first main semiconductor switch 31c (shown as "MA1 reverse connection" in Figure 4) in a first diagnostic state D1 in which the first main semiconductor switch 31c and the second main semiconductor switch 31d are turned on.

[0069] When the first main semiconductor switch 31c is normal, the first main voltage detection unit 31e detects a voltage above a threshold value (indicated as "H" in Figure 5), and the second main voltage detection unit 31f detects a voltage above a threshold value (indicated as "H" in Figure 5).

[0070] Furthermore, when the first main semiconductor switch 31c is broken, the first main voltage detection unit 31e detects a voltage equal to or higher than the threshold value (shown as "H" in FIG. 5), and the second main voltage detection unit 31f detects a voltage lower than the threshold value (shown as "L" in FIG. 5). This makes it possible to detect an OFF failure of the first main semiconductor switch 31c.

[0071] As shown in Figures 4 and 6, the main side microcontroller 31i is configured to diagnose a fault in the second main semiconductor switch 31d (referred to as "upstream of MA1" in Figure 4) in a first diagnostic state D1 in which the first main semiconductor switch 31c and the second main semiconductor switch 31d are turned on.

[0072] When the second main semiconductor switch 31d is normal, the first main voltage detection unit 31e detects a voltage above a threshold value (indicated as "H" in Figure 6), and the second main voltage detection unit 31f detects a voltage above a threshold value (indicated as "H" in Figure 6).

[0073] Furthermore, when the second main semiconductor switch 31d is faulty, the first main voltage detection unit 31e detects a voltage equal to or higher than the threshold value (shown as "H" in FIG. 6), and the second main voltage detection unit 31f detects a voltage lower than the threshold value (shown as "L" in FIG. 6). This makes it possible to detect an OFF fault in the second main semiconductor switch 31d.

[0074] Here, the main side microcontroller 31i is configured to perform control to terminate the first diagnostic state D1 based on detecting a failure in at least one of the first main semiconductor switch 31c and the second main semiconductor switch 31d in the first diagnostic state D1.

[0075] As shown in Figures 4 and 7, the sub-side microcontroller 32o is configured to diagnose a failure of the first sub semiconductor switch 32c (referred to as "MAB upstream" in Figure 4) based on the voltage values ​​detected by each of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, and the third sub voltage detection unit 32g in a first diagnostic state D1 in which the first sub semiconductor switch 32c and the second sub semiconductor switch 32d are turned on.

[0076] When the first sub semiconductor switch 32c is normal, the first sub voltage detection unit 32e detects a voltage above the threshold value (indicated as "H" in Figure 7), the second sub voltage detection unit 32f detects a voltage above the threshold value (indicated as "H" in Figure 7), and the third sub voltage detection unit 32g detects a voltage above the threshold value (indicated as "H" in Figure 7).

[0077] Furthermore, when the first sub semiconductor switch 32c has failed, the first sub voltage detection unit 32e detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 7), the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in FIG. 7), and the third sub voltage detection unit 32g detects a voltage below the threshold value (indicated as "L" in FIG. 7). This makes it possible to detect an OFF failure of the first sub semiconductor switch 32c.

[0078] As shown in Figures 4 and 8, the sub-side microcontroller 32o is configured to diagnose a failure of the second sub semiconductor switch 32d (shown as "MAB reverse connection" in Figure 4) based on the voltage values ​​detected by each of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, and the third sub voltage detection unit 32g in a first diagnostic state D1 in which the first sub semiconductor switch 32c and the second sub semiconductor switch 32d are turned on.

[0079] When the second sub semiconductor switch 32d is normal, the first sub voltage detection unit 32e detects a voltage above the threshold value (indicated as "H" in Figure 8), the second sub voltage detection unit 32f detects a voltage above the threshold value (indicated as "H" in Figure 8), and the third sub voltage detection unit 32g detects a voltage above the threshold value (indicated as "H" in Figure 8).

[0080] Furthermore, when the second sub semiconductor switch 32d has failed, the first sub voltage detection unit 32e detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 8), the second sub voltage detection unit 32f detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 8), and the third sub voltage detection unit 32g detects a voltage lower than the threshold value (indicated as "L" in FIG. 8). This makes it possible to detect an OFF failure of the second sub semiconductor switch 32d.

[0081] Here, the sub-side microcontroller 32o is configured to perform control to terminate the first diagnostic state D1 based on detecting a failure in at least one of the first sub semiconductor switch 32c and the second sub semiconductor switch 32d in the first diagnostic state D1.

[0082] 4, the main-side microcomputer 31i is configured to perform control to discharge the main capacitor 31g before the second diagnostic state D2 so that power is supplied to the second main-side voltage detection unit 31f. Also, the sub-side microcomputer 32o is configured to perform control to discharge the sub-side capacitor 32h before the second diagnostic state D2 so that power is supplied to the second sub-side voltage detection unit 32f.

[0083] As shown in Figures 4 and 9, in a second diagnostic state D2 in which the first main semiconductor switch 31c and the second main semiconductor switch 31d are all turned off, the main side microcontroller 31i is configured to diagnose a failure of the second main semiconductor switch 31d (referred to as "upstream of MA1" in Figure 4) based on the voltage values ​​detected by each of the first main voltage detection unit 31e and the second main voltage detection unit 31f.

[0084] When the second main semiconductor switch 31d is normal, the first main voltage detection unit 31e detects a voltage above the threshold value (indicated as "H" in Figure 9), and the second main voltage detection unit 31f detects a voltage below the threshold value (indicated as "L" in Figure 9).

[0085] Furthermore, when the second main semiconductor switch 31d is broken, the first main voltage detection unit 31e detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 9), and the second main voltage detection unit 31f detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 9). This makes it possible to detect an ON failure of the second main semiconductor switch 31d.

[0086] Here, the main microcomputer 31i is configured to perform control to end the failure diagnosis based on the detection of a failure in the second main semiconductor switch 31d in the second diagnosis state D2.

[0087] As shown in Figures 4 and 10, the sub-side microcontroller 32o is configured to diagnose a failure of the first sub semiconductor switch 32c (referred to as "MAB upstream" in Figure 4) based on the voltage values ​​detected by each of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, and the third sub voltage detection unit 32g in a second diagnostic state D2 in which the first sub semiconductor switch 32c, the second sub semiconductor switch 32d, the third sub semiconductor switch 32l, and the fourth sub semiconductor switch 32m are turned off.

[0088] When the first sub semiconductor switch 32c is normal, the first sub voltage detection unit 32e detects a voltage above the threshold value (indicated as "H" in Figure 10), the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in Figure 10), and the third sub voltage detection unit 32g detects a voltage below the threshold value (indicated as "L" in Figure 10).

[0089] Furthermore, when the first sub semiconductor switch 32c has failed, the first sub voltage detection unit 32e detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 10), the second sub voltage detection unit 32f detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 10), and the third sub voltage detection unit 32g detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 10). This makes it possible to detect an ON failure of the first sub semiconductor switch 32c.

[0090] Here, the sub-microcomputer 32o is configured to perform control to end the failure diagnosis based on the detection of a failure in the first sub semiconductor switch 32c in the second diagnostic state D2.

[0091] As shown in Figures 4 and 11, the sub-side microcontroller 32o is configured to diagnose a failure of the fourth sub semiconductor switch 32m (referred to as "upstream of MA2" in Figure 4) based on the voltage values ​​detected by each of the second sub voltage detection unit 32f, the third sub voltage detection unit 32g, and the fourth sub voltage detection unit 32n in a second diagnostic state D2 in which the first sub semiconductor switch 32c, the second sub semiconductor switch 32d, the third sub semiconductor switch 32l, and the fourth sub semiconductor switch 32m are turned off.

[0092] When the fourth sub semiconductor switch 32m is normal, the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in Figure 11), the third sub voltage detection unit 32g detects a voltage below the threshold value (indicated as "L" in Figure 11), and the fourth sub voltage detection unit 32n detects a voltage above the threshold value (indicated as "H" in Figure 11).

[0093] Furthermore, when the fourth sub semiconductor switch 32m has failed, the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in FIG. 11), the third sub voltage detection unit 32g detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 11), and the fourth sub voltage detection unit 32n detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 11). This makes it possible to detect an ON failure of the fourth sub semiconductor switch 32m.

[0094] Here, the sub-microcomputer 32o is configured to perform control to end the failure diagnosis based on the detection of a failure in the fourth sub semiconductor switch 32m in the second diagnosis state D2.

[0095] 4, after the second diagnostic state D2, the main-side microcomputer 31i is configured to perform control to charge (precharge) the main capacitor 31g by supplying power from the system power supply 102. At this time, the main-side microcomputer 31i is configured not to perform the third diagnostic state D3 based on the detection of a charging abnormality in the main capacitor 31g.

[0096] Similarly, after the second diagnostic state D2, the sub-side microcomputer 32o is configured to perform control to charge (precharge) the sub-use capacitor 32h by supplying power from the system power supply 102. At this time, the sub-side microcomputer 32o is configured not to perform the third diagnostic state D3 based on the detection of a charging abnormality in the sub-use capacitor 32h.

[0097] 4, the main-side microcomputer 31i is configured to perform control to discharge the main capacitor 31g before the third diagnosis state D3, and the sub-side microcomputer 32o is configured to perform control to discharge the sub capacitor 32h before the third diagnosis state D3.

[0098] After discharging, the sub-side microcomputer 32o is configured to perform control to determine whether or not to diagnose a fault in the second sub semiconductor switch 32d and whether or not to diagnose a fault in the fourth sub semiconductor switch 32m in the third diagnostic state D3 based on the type of the second sub-side power supply 32j. Here, the sub-side microcomputer 32o is configured to perform a diagnosis for both a fault in the second sub semiconductor switch 32d and a fault in the fourth sub semiconductor switch 32m in the third diagnostic state D3 based on the fact that the second sub-side power supply 32j is a lithium battery.

[0099] As shown in Figures 4 and 12, in the third diagnostic state D3 in which the third sub semiconductor switch 32l and the fourth sub semiconductor switch 32m are turned on, the sub-side microcontroller 32o is configured to perform control to diagnose a fault in the second sub semiconductor switch 32d (denoted as "MAB reverse connection" in Figure 4) based on the voltage values ​​detected by each of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f and the third sub voltage detection unit 32g.

[0100] When the second sub semiconductor switch 32d is normal, the first sub voltage detection unit 32e detects a voltage above the threshold value (indicated as "H" in Figure 12), the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in Figure 12), and the third sub voltage detection unit 32g detects a voltage above the threshold value (indicated as "H" in Figure 12).

[0101] Furthermore, when the second sub semiconductor switch 32d has failed, the first sub voltage detection unit 32e detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 12), the second sub voltage detection unit 32f detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 12), and the third sub voltage detection unit 32g detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 12). This makes it possible to detect an ON failure of the second sub semiconductor switch 32d.

[0102] As shown in Figures 4 and 13, in a third diagnostic state D3 in which the third sub semiconductor switch 32l and the fourth sub semiconductor switch 32m are turned on, the sub-side microcontroller 32o is configured to diagnose a failure of the fourth sub semiconductor switch 32m (referred to as "upstream of MA2" in Figure 4) based on the voltage values ​​detected by each of the second sub voltage detection unit 32f, the third sub voltage detection unit 32g, and the fourth sub voltage detection unit 32n.

[0103] When the fourth sub semiconductor switch 32m is normal, the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in Figure 13), the third sub voltage detection unit 32g detects a voltage above the threshold value (indicated as "H" in Figure 13), and the fourth sub voltage detection unit 32n detects a voltage above the threshold value (indicated as "H" in Figure 13).

[0104] Furthermore, when the fourth sub semiconductor switch 32m has failed, the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in FIG. 13), the third sub voltage detection unit 32g detects a voltage below the threshold value (indicated as "L" in FIG. 13), and the fourth sub voltage detection unit 32n detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 13). This makes it possible to detect an OFF failure of the fourth sub semiconductor switch 32m.

[0105] Here, since the diagnosis result for a failure of the third sub semiconductor switch 32l will be the same as the diagnosis result for a failure of the fourth sub semiconductor switch 32m, the diagnosis result for a failure of the fourth sub semiconductor switch 32m is used as the diagnosis result for a failure of the third sub semiconductor switch 32l.

[0106] (Main side fault diagnosis processing) Hereinafter, the main-side fault diagnosis process for first main semiconductor switch 31c and second main semiconductor switch 31d in main-side power supply unit 31 will be described with reference to FIG.

[0107] In step S1, the main-side microcomputer 31i performs a first failure diagnosis. That is, in the main-side microcomputer 31i, in the first diagnostic state D1, an OFF failure diagnosis is performed on the first main semiconductor switch 31c based on the voltage values ​​of the first main voltage detector 31e and the second main voltage detector 31f. In the main-side microcomputer 31i, in the first diagnostic state D1, an OFF failure diagnosis is performed on the second main semiconductor switch 31d based on the voltage values ​​of the first main voltage detector 31e and the second main voltage detector 31f.

[0108] In step S2, the main-side microcomputer 31i judges whether or not a failure has been detected in at least one of the first main semiconductor switch 31c and the second main semiconductor switch 31d. If a failure has been detected, the main-side failure diagnosis process is terminated, and if no failure has been detected, the process proceeds to step S3. In step S3, the main-side microcomputer 31i judges whether or not a first condition is satisfied. The first condition is that the ignition switch is off, the failure diagnosis has been changed from a prohibited state to an permitted state, the main capacitor 31g is normally charged, and the drive of the motor 11 has stopped. If the first condition is satisfied, the process proceeds to step S4, and if the first condition is not satisfied, step S3 is repeated.

[0109] In step S4, the main-side microcomputer 31i waits until the main capacitor 31g is discharged. In step S5, the main-side microcomputer 31i determines whether or not a second condition is satisfied. The second condition is that a predetermined time has elapsed and both the first main semiconductor switch 31c and the second main semiconductor switch 31d are turned off. If the second condition is satisfied, the process proceeds to step S6, and if the second condition is not satisfied, the process returns to step S4.

[0110] In step S6, the main-side microcomputer 31i performs a second fault diagnosis. That is, in the second diagnostic state D2, the main-side microcomputer 31i performs an ON fault diagnosis of the second main semiconductor switch 31d based on the voltage values ​​of the first main voltage detector 31e and the second main voltage detector 31f. In step S7, the main-side microcomputer 31i determines whether a predetermined time has elapsed. If the predetermined time has elapsed, the main-side fault diagnosis ends, and if the predetermined time has not elapsed, the process returns to step S6.

[0111] (Sub-side fault diagnosis processing) Below, the sub-side fault diagnosis processing for the first sub-semiconductor switch 32c, the second sub-semiconductor switch 32d, the third sub-semiconductor switch 32l and the fourth sub-semiconductor switch 32m in the sub-side power supply unit 32 will be described with reference to Figures 15 and 16.

[0112] In step S101, the sub-side microcomputer 32o performs a first failure diagnosis. That is, in the first diagnostic state D1, the sub-side microcomputer 32o performs an OFF failure diagnosis of the first sub semiconductor switch 32c based on the voltage values ​​of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, and the third sub voltage detection unit 32g. In the first diagnostic state D1, the sub-side microcomputer 32o performs an OFF failure diagnosis of the second sub semiconductor switch 32d based on the voltage values ​​of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, and the third sub voltage detection unit 32g. In the first diagnostic state D1, the sub-side microcomputer 32o performs an OFF failure diagnosis of the fourth sub semiconductor switch 32m based on the voltage values ​​of the second sub voltage detection unit 32f, the third sub voltage detection unit 32g, and the fourth sub voltage detection unit 32n.

[0113] In step S102, the sub-side microcomputer 32o judges whether or not a fault has been detected in at least one of the first sub-use semiconductor switch 32c, the second sub-use semiconductor switch 32d, and the fourth sub-use semiconductor switch 32m. If a fault has been detected, the sub-side fault diagnosis process is terminated, and if no fault has been detected, the process proceeds to step S103. In step S103, the sub-side microcomputer 32o judges whether or not a first condition is satisfied. The first condition is that the ignition switch is off, the fault diagnosis has been changed from a prohibited state to an permitted state, the sub-use capacitor 32h is normally charged, and the drive of the motor 11 has stopped. If the first condition is satisfied, the process proceeds to step S104, and if the first condition is not satisfied, step S103 is repeated.

[0114] In step S104, the sub-side microcomputer 32o waits until the sub-use capacitor 32h is discharged. In step S105, the sub-side microcomputer 32o determines whether or not a second condition is satisfied. The second condition is that a predetermined time has elapsed and the first sub-use semiconductor switch 32c, the second sub-use semiconductor switch 32d, the third sub-use semiconductor switch 32l, and the fourth sub-use semiconductor switch 32m are all turned off. If the second condition is satisfied, the process proceeds to step S6, and if the second condition is not satisfied, the process returns to step S104.

[0115] In step S106, the sub-side microcomputer 32o performs a second fault diagnosis. That is, in the second diagnostic state D2, the sub-side microcomputer 32o performs an ON fault diagnosis of the first sub semiconductor switch 32c based on the voltage values ​​of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, and the third sub voltage detection unit 32g. In the second diagnostic state D2, the sub-side microcomputer 32o performs an ON fault diagnosis of the fourth sub semiconductor switch 32m based on the voltage values ​​of the second sub voltage detection unit 32f, the third sub voltage detection unit 32g, and the fourth sub voltage detection unit 32n.

[0116] In step S107, the sub-side microcomputer 32o determines whether a predetermined time has elapsed. If the predetermined time has elapsed, the process proceeds to step S108, and if the predetermined time has not elapsed, the process returns to step S106. In step S108, the sub-side microcomputer 32o determines whether a third condition is satisfied. The third condition is that the power supply type of the second power supply 32j is not set, that the power supply type of the second power supply 32j is a capacitor, or that a fault is detected in the second fault diagnosis. If the second condition is satisfied, the sub-side fault diagnosis process is terminated, and if the second condition is not satisfied, the process proceeds to step S109.

[0117] In step S109, the sub-microcomputer 32o waits until the sub-use capacitor 32h is charged. By proceeding from A in Fig. 15 to A in Fig. 16, the process proceeds from step S109 to step S110.

[0118] As shown in Fig. 16, in step S110, the sub-side microcomputer 32o determines whether or not a fourth condition is satisfied. The fourth condition is that charging of the sub-use capacitor 32h is completed, the first sub-use semiconductor switch 32c is off, the second sub-use semiconductor switch 32d is off, the third sub-use semiconductor switch 32l is on, and the fourth sub-use semiconductor switch 32m is on. If the fourth condition is satisfied, the process proceeds to step S111, and if the fourth condition is not satisfied, step S110 is repeated. In step S111, the sub-side microcomputer 32o waits until the sub-use capacitor 32h is discharged.

[0119] In step S112, the sub-side microcomputer 32o determines whether a fifth condition is satisfied. The fifth condition is that a predetermined time has elapsed, the first sub semiconductor switch 32c is off, the second sub semiconductor switch 32d is off, the third sub semiconductor switch 32l is on, and the fourth sub semiconductor switch 32m is on. If the fifth condition is satisfied, the process proceeds to step S113, and if the fifth condition is not satisfied, the process returns to step S111.

[0120] In step S113, the sub-side microcomputer 32o performs a third fault diagnosis. That is, in the third diagnostic state D3, the sub-side microcomputer 32o performs an ON fault diagnosis of the second sub semiconductor switch 32d based on the voltage values ​​of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, and the third sub voltage detection unit 32g. In the third diagnostic state D3, the sub-side microcomputer 32o performs an OFF fault diagnosis of the fourth sub semiconductor switch 32m based on the voltage values ​​of the second sub voltage detection unit 32f, the third sub voltage detection unit 32g, and the fourth sub voltage detection unit 32n.

[0121] In step S114, the sub-microcomputer 32o determines whether a predetermined time has elapsed. If the predetermined time has elapsed, the main-side fault diagnosis process is terminated, and if the predetermined time has not elapsed, the process returns to step S113.

[0122] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0123] In the first embodiment, as described above, the motor power supply device 3 includes a main side microcontroller 31i (sub side microcontroller 32o) that performs control to determine the state of power supply from the main side power supply 31a (first sub side power supply 32a) to the first main semiconductor switch 31c (first sub semiconductor switch 32c) based on the measurement value of the first main voltage detection unit 31e (first sub voltage detection unit 32e). As a result, even if a ground fault occurs between the main side power supply 31a (first sub side power supply 32a) on the main power supply line 31b (first sub power supply line 32b) and the first main semiconductor switch 31c (first sub semiconductor switch 32c), the main side microcontroller 31i (sub side microcontroller 32o) can accurately determine the ground fault based on the measurement value of the first main voltage detection unit 31e (first sub voltage detection unit 32e), so that erroneous determination of the fault diagnosis can be suppressed in the fault diagnosis of the on operation of the first main semiconductor switch 31c (first sub semiconductor switch 32c).

[0124] In the first embodiment, as described above, the motor power supply device 3 is disposed on the main power supply line 31b closer to the motor 11 than the second main semiconductor switch 31d, and includes the second main voltage detector 31f that detects the voltage of the main power supply line 31b. The main-side microcomputer 31i is configured to diagnose failures of the first main semiconductor switch 31c and the second main semiconductor switch 31d based on the voltage values ​​detected by the first main voltage detector 31e and the second main voltage detector 31f in the first diagnostic state D1 in which the first main semiconductor switch 31c and the second main semiconductor switch 31d are turned on. This allows the first main semiconductor switch 31c and the second main semiconductor switch 31d to be diagnosed for failures without disposing a voltage detector between the first main semiconductor switch 31c and the second main semiconductor switch 31d, thereby suppressing an increase in the number of components of the motor power supply device 3 (circuit).

[0125] In the first embodiment, as described above, the main-side microcomputer 31i is configured to diagnose a failure of the second main semiconductor switch 31d based on the voltage values ​​detected by the first main voltage detection unit 31e and the second main voltage detection unit 31f in the second diagnostic state D2 in which the first main semiconductor switch 31c and the second main semiconductor switch 31d are all turned off. As a result, when the first main semiconductor switch 31c has an on failure in which the on state cannot be released, if the second main semiconductor switch 31d has an on failure, a voltage is detected by the second main voltage detection unit 31f, and if the second main semiconductor switch 31d is normal, a voltage is not detected by the second main voltage detection unit 31f. Therefore, the diagnosis result of the on failure of the second main semiconductor switch 31d can be used as the diagnosis result of the on failure of the first main semiconductor switch 31c. As a result, by diagnosing only the failure of the second main semiconductor switch 31d without diagnosing the failure of the first main semiconductor switch 31c, it is possible to diagnose on failures of the first main voltage detection unit 31e and the second main voltage detection unit 31f, thereby reducing the processing load of failure diagnosis on the main-side microcontroller 31i.

[0126] In the first embodiment, as described above, the motor power supply device 3 includes a second sub-voltage detector 32f that is disposed between the first sub-semiconductor switch 32c and the second sub-semiconductor switch 32d and detects the voltage of the first sub-power supply line 32b. The sub-side microcomputer 32o is configured to diagnose failures of the first sub-semiconductor switch 32c and the second sub-semiconductor switch 32d in the first diagnostic state D1 based on the voltage values ​​detected by the first sub-semiconductor switch 32e, the third sub-semiconductor switch 32g, and the second sub-semiconductor switch 32f. Thus, by providing the second sub-semiconductor voltage detector 32f, it is possible to directly diagnose failures of the first sub-semiconductor switch 32c, thereby improving the accuracy of the diagnosis result of the first sub-semiconductor switch 32c.

[0127] In the first embodiment, as described above, the motor power supply device 3 includes the second sub-side power supply 32j provided separately from the first sub-side power supply 32a, and the second sub-side power supply line 32k that electrically connects the second sub-side power supply 32j and the motor 11. The motor power supply device 3 includes a third sub semiconductor switch 32l arranged on the second sub-side power supply 32j side on the second sub power supply line 32k, and a fourth sub semiconductor switch 32m connected in series to the third sub semiconductor switch 32l on the second sub power supply line 32k and arranged on the output side. The motor power supply device 3 includes a fourth sub voltage detection unit 32n that is arranged on the second sub-side power supply 32j side of the third sub semiconductor switch 32l on the second sub power supply line 32k and detects the voltage of the second sub power supply line 32k. The sub-side microcomputer 32o is configured to diagnose failures of the first sub semiconductor switch 32c and the fourth sub semiconductor switch 32m based on the voltage values ​​detected by the first sub voltage detection unit 32e, the third sub voltage detection unit 32g, and the second sub voltage detection unit 32f in a second diagnostic state D2 in which the first sub semiconductor switch 32c, the third sub semiconductor switch 32l, the second sub semiconductor switch 32d, and the fourth sub semiconductor switch 32m are all turned off. This allows the fourth sub voltage detection unit 32n to accurately determine that a ground fault has occurred between the second sub-side power supply 32j on the second sub power supply line 32k and the third sub semiconductor switch 32l, thereby suppressing erroneous determinations in the failure diagnosis. Furthermore, by diagnosing a failure of the first sub semiconductor switch 32c using the second sub voltage detection unit 32f, the first sub semiconductor switch 32c can be directly diagnosed, so that an on failure of the first sub semiconductor switch 32c can be accurately detected.

[0128] In the first embodiment, as described above, the sub-side microcomputer 32o is configured to diagnose a failure of the second sub semiconductor switch 32d based on the voltage values ​​detected by each of the first sub voltage detection unit 32e, the third sub voltage detection unit 32g, and the second sub voltage detection unit 32f in the third diagnostic state D3 in which the third sub semiconductor switch 32l and the fourth sub semiconductor switch 32m are turned on, or to diagnose a failure of the fourth sub semiconductor switch 32m based on the voltage values ​​detected by each of the third sub voltage detection unit 32g, the second sub voltage detection unit 32f, and the fourth sub voltage detection unit 32n. This allows the second sub semiconductor switch 32d to be diagnosed as having an ON failure without using the fourth sub voltage detection unit 32n, thereby reducing the processing load of the sub-side microcomputer 32o when diagnosing an ON failure of the second sub semiconductor switch 32d. In addition, since it is possible to diagnose that the fourth sub semiconductor switch 32m has an OFF fault without using the first sub voltage detection unit 32e, it is possible to reduce the processing load on the sub-side microcontroller 32o when diagnosing an OFF fault of the fourth sub semiconductor switch 32m.

[0129] In the first embodiment, as described above, the motor power supply device 3 includes a main capacitor 31g (sub capacitor 32h) disposed on the main power supply line 31b (first sub power supply line 32b) on the main power supply 31a (first sub power supply 32a) side of the second main voltage detection unit 31f (third sub voltage detection unit 32g) and precharged by the system power supply 102. The main microcomputer 31i is configured to control the main capacitor 31g to be discharged before the second diagnostic state D2. The sub microcomputer 32o is configured to control the sub capacitor 32h to be discharged before the second diagnostic state D2 and the third diagnostic state D3. This allows the main capacitor 31g (sub capacitor 32h) to suppress an inrush current from flowing toward the second main voltage detection unit 31f (third sub voltage detection unit 32g). Furthermore, by discharging the main capacitor 31g (sub capacitor 32h) before placing the motor power supply 3 in the second diagnostic state D2 or the third diagnostic state D3, the voltage that has passed through the semiconductor switch can be detected in the second main voltage detection unit 31f (third sub voltage detection unit 32g), thereby making it possible to accurately diagnose a fault in the semiconductor switch in the motor power supply 3.

[0130] [Second embodiment] Next, a motor power supply device 203 of a second embodiment will be described with reference to Figures 17 to 19. In particular, unlike the motor power supply device 3 of the first embodiment in which the second sub-side power supply 32j is a lithium battery, in the motor power supply device 203 of the second embodiment, the second sub-side power supply 232j is a capacitor. Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0131] 17, the motor power supply device 203 is configured to supply power to the motor 11. The motor power supply device 203 of the second embodiment includes a main-side power supply unit 31 and a sub-side power supply unit 232. The motor 11 is driven by power supplied from each of the main-side power supply unit 31 and the sub-side power supply unit 232.

[0132] The sub-side power supply unit 232 includes a second sub-side power supply 232j (an example of a "second power supply" in the claims), a second sub power supply line 32k (an example of a "second power supply line" in the claims), a third sub semiconductor switch 32l (an example of a "second power supply side semiconductor switch" in the claims), and a fourth sub semiconductor switch 32m (an example of a "second output side semiconductor switch" in the claims).

[0133] The second sub-side power supply 232j is provided separately from the first sub-side power supply 32a. The second sub-side power supply 232j is a capacitor. When a capacitor is used as the second sub-side power supply 232j in the motor power supply device 3, power is not supplied from the first sub-side power supply 32a to the motor 11.

[0134] (Fault diagnosis) In the motor power supply device 3, three types of fault diagnosis are performed, namely, a first diagnostic state D1 (an example of the "first state" in the claims), a second diagnostic state D2 (an example of the "second state" and "third state" in the claims), and a third diagnostic state D3 (an example of the "fourth state" in the claims), as shown in Fig. 18. The first diagnostic state D1, the second diagnostic state D2, and the third diagnostic state D3 will be described below in that order.

[0135] Note that descriptions of the same configurations as the first diagnostic state D1, the second diagnostic state D2, and the third diagnostic state D3 of the first embodiment will be omitted. Also, when a capacitor is used for the second sub-side power supply 232j in the motor power supply device 3, the third diagnostic state D3 is not performed (skipped).

[0136] As in the first embodiment, the main side microcontroller 31i is configured to diagnose faults in the first main semiconductor switch 31c (referred to as "MA1 reverse connection" in FIG. 18) and the second main semiconductor switch 31d (referred to as "MA1 upstream" in FIG. 18) in a first diagnostic state D1 in which the first main semiconductor switch 31c and the second main semiconductor switch 31d are turned on, as shown in FIG. 18.

[0137] As shown in Figures 18 and 19, the sub-side microcontroller 32o is configured to diagnose a fault in the fourth sub semiconductor switch 32m (referred to as "upstream of MA2" in Figure 18) based on the voltage values ​​detected by each of the second sub voltage detection unit 32f, the third sub voltage detection unit 32g, and the fourth sub voltage detection unit 32n in a first diagnostic state D1 in which the first sub semiconductor switch 32c and the second sub semiconductor switch 32d are turned on.

[0138] When the fourth sub semiconductor switch 32m is normal, the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in Figure 19), the third sub voltage detection unit 32g detects a voltage above the threshold value (indicated as "H" in Figure 19), and the fourth sub voltage detection unit 32n detects a voltage above the threshold value (indicated as "H" in Figure 19).

[0139] Furthermore, when the fourth sub semiconductor switch 32m has failed, the second sub voltage detection unit 32f detects a voltage below the threshold value (indicated as "L" in FIG. 19), the third sub voltage detection unit 32g detects a voltage equal to or higher than the threshold value (indicated as "L" in FIG. 19), and the fourth sub voltage detection unit 32n detects a voltage equal to or higher than the threshold value (indicated as "H" in FIG. 19). This makes it possible to detect an OFF failure of the fourth sub semiconductor switch 32m.

[0140] Furthermore, similarly to the first embodiment, the main-side microcomputer 31i is configured to diagnose failures in the second main semiconductor switch 31d and the fourth sub semiconductor switch 32m in the second diagnostic state D2 as shown in Fig. 18. The other configurations of the second embodiment are similar to those of the first embodiment.

[0141] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0142] In the second embodiment, as described above, the motor power supply device 203 includes a main-side microcomputer 31i (sub-side microcomputer 32o) that performs control to determine the state of power supply from the main-side power supply 31a (first sub-side power supply 32a) to the first main semiconductor switch 31c (first sub semiconductor switch 32c) based on a measurement value of the first main voltage detection unit 31e (first sub voltage detection unit 32e). This makes it possible to suppress erroneous determinations in the failure diagnosis of the first main semiconductor switch 31c (first sub semiconductor switch 32c).

[0143] In the second embodiment, as described above, the sub-side microcomputer 32o is configured to diagnose a failure of the fourth sub semiconductor switch 32m in the first diagnostic state D1 based on the voltage values ​​detected by each of the third sub voltage detection unit 32g, the second sub voltage detection unit 32f, and the fourth sub voltage detection unit 32n. This makes it possible to diagnose an OFF failure in which the fourth sub semiconductor switch 32m cannot be released from the OFF state without using the first sub voltage detection unit 32e, thereby reducing the processing load of the sub-side microcomputer 32o when diagnosing an OFF failure of the fourth sub semiconductor switch 32m. Other effects of the second embodiment are similar to those of the first embodiment.

[0144] [Third embodiment] Next, a motor power supply device 303 of a third embodiment will be described with reference to Fig. 20. In particular, unlike the motor power supply device 3 of the first embodiment that includes a main microcomputer 31i and a sub microcomputer 32o, the motor power supply device 303 of the third embodiment is provided with one microcomputer 332o. Note that in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0145] In the shift device 100 of the third embodiment, the detent spring 22 is configured to hold the detent plate (not shown) at rotational angle positions corresponding to the P position and the non-P position, respectively.

[0146] 20, the motor power supply device 303 is configured to supply power to the actuator unit 1. The motor power supply device 303 includes a first power source 32a, a first power supply line 32b, a first semiconductor switch 32c (an example of a "first power supply side semiconductor switch" in the claims), and a second semiconductor switch 32d (an example of a "first output side semiconductor switch" in the claims).

[0147] The motor power supply device 303 includes a first voltage detection unit 32e (an example of a "first power supply side voltage detection unit" in the claims), a second voltage detection unit 32f (an example of an "intermediate part voltage detection unit" in the claims), and a third voltage detection unit 32g (an example of an "output side voltage detection unit" in the claims). The motor power supply device 303 includes a pre-charge capacitor 32h and a motor circuit 32i.

[0148] The motor power supply device 303 includes a second power supply 32j, a second power supply line 32k, a third semiconductor switch 32l (an example of a "second power supply side semiconductor switch" in the claims), and a fourth semiconductor switch 32m (an example of a "second output side semiconductor switch" in the claims). The second power supply 32j is provided separately from the first power supply 32a. The second power supply 32j is a capacitor or a lithium battery.

[0149] The motor power supply device 303 includes a fourth voltage detection section 32n (an example of a "second power supply side voltage detection section" in the claims) and a microcomputer 332o (an example of a "control section" in the claims).

[0150] (Fault diagnosis) As shown in FIG. 21, the motor power supply device 303 performs three types of fault diagnosis: a first diagnostic state D1 (an example of the "first state" in the claims), a second diagnostic state D2 (an example of the "third state" in the claims), and a third diagnostic state D3 (an example of the "fourth state" in the claims).

[0151] Similarly, before the first diagnostic state D1, the microcomputer 332o is configured to perform control to charge (precharge) the precharge capacitor 32h by supplying power from the system power supply 102. At this time, the microcomputer 332o is configured not to perform the first diagnostic state D1 based on the detection of a charging abnormality in the precharge capacitor 32h.

[0152] 21 and 22, the microcomputer 332o is configured to diagnose a failure of the first semiconductor switch 32c (denoted as "MA1 upstream" in FIG. 21) based on the voltage values ​​detected by the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g in a first diagnostic state D1 in which the first semiconductor switch 32c and the second semiconductor switch 32d are turned on. Note that the diagnosis result of the failure of the first semiconductor switch 32c is the same as the diagnosis result of the first sub semiconductor switch 32c in the first embodiment in the first diagnostic state D1, and therefore a description thereof will be omitted.

[0153] 21 and 23, the microcomputer 332o is configured to diagnose a failure of the second semiconductor switch 32d (denoted as "MA1 reverse connection" in FIG. 21) based on the voltage values ​​detected by the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g in a first diagnostic state D1 in which the first semiconductor switch 32c and the second semiconductor switch 32d are turned on. Note that the diagnosis result of the failure of the second semiconductor switch 32d is the same as the diagnosis result of the second sub semiconductor switch 32d in the first embodiment in the first diagnostic state D1, and therefore a description thereof will be omitted.

[0154] As shown in FIG. 21, the microcomputer 332o is configured to perform control to discharge the pre-charge capacitor 32h before the second diagnostic state D2 so that power is supplied to the second voltage detection unit 32f.

[0155] 21 and 24, the microcomputer 332o is configured to diagnose a failure of the first semiconductor switch 32c (denoted as "MA1 upstream" in FIG. 4) based on the voltage values ​​detected by the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g in the second diagnostic state D2 in which the first semiconductor switch 32c, the second semiconductor switch 32d, the third semiconductor switch 32l, and the fourth semiconductor switch 32m are turned off. Note that the diagnosis result of the failure of the first semiconductor switch 32c is the same as the diagnosis result of the first sub semiconductor switch 32c in the second diagnostic state D2 in the first embodiment, and therefore a description thereof will be omitted.

[0156] Here, the microcomputer 332o is configured to perform control to end the failure diagnosis based on the detection of a failure in the first semiconductor switch 32c in the second diagnostic state D2.

[0157] 21 and 25, the microcomputer 332o is configured to diagnose a failure of the fourth semiconductor switch 32m (described as "MA2 upstream" in FIG. 21) based on the voltage values ​​detected by the second voltage detection unit 32f, the third voltage detection unit 32g, and the fourth voltage detection unit 32n in the second diagnostic state D2 in which the first semiconductor switch 32c, the second semiconductor switch 32d, the third semiconductor switch 32l, and the fourth semiconductor switch 32m are turned off. Note that the diagnosis result of the failure of the fourth semiconductor switch 32m is the same as the diagnosis result of the fourth sub semiconductor switch 32m in the second diagnostic state D2 in the first embodiment, and therefore a description thereof will be omitted.

[0158] Here, the microcomputer 332o is configured to perform control to end the failure diagnosis based on the detection of a failure in the fourth sub semiconductor switch 32m in the second diagnosis state D2.

[0159] As shown in Fig. 21, the microcomputer 332o is configured to perform control to discharge the precharge capacitor 32h before the third diagnostic state D3. After the discharge, the microcomputer 332o is configured to perform control to determine whether or not to diagnose a fault in the second semiconductor switch 32d and whether or not to diagnose a fault in the fourth semiconductor switch 32m in the third diagnostic state D3, based on whether or not the second power source 32j is not set. Here, the microcomputer 332o is configured to perform a diagnosis of both a fault in the second semiconductor switch 32d and a fault in the fourth semiconductor switch 32m in the third diagnostic state D3, based on the second power source 32j being a capacitor or a lithium battery.

[0160] 21 and 26, the microcomputer 332o is configured to perform control for diagnosing a failure of the second semiconductor switch 32d (denoted as "MA1 reverse connection" in FIG. 21) based on the voltage values ​​detected by the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g in the third diagnostic state D3 in which the third semiconductor switch 32l and the fourth semiconductor switch 32m are turned on. Note that the diagnosis result of the failure of the second semiconductor switch 32d is the same as the diagnosis result of the second sub semiconductor switch 32d in the third diagnostic state D3 in the first embodiment, and therefore a description thereof will be omitted.

[0161] 21 and 27, the microcomputer 332o is configured to diagnose a failure of the fourth semiconductor switch 32m (denoted as "MA2 upstream" in FIG. 21) based on the voltage values ​​detected by the second voltage detection unit 32f, the third voltage detection unit 32g, and the fourth voltage detection unit 32n in the third diagnostic state D3 in which the third semiconductor switch 32l and the fourth semiconductor switch 32m are turned on. Note that the diagnosis result of the failure of the fourth semiconductor switch 32m is the same as the diagnosis result of the fourth sub semiconductor switch 32m in the third diagnostic state D3 in the first embodiment, and therefore a description thereof will be omitted.

[0162] Here, the diagnosis result for a failure of the third semiconductor switch 32l will be the same as the diagnosis result for a failure of the fourth semiconductor switch 32m, and therefore the diagnosis result for a failure of the fourth semiconductor switch 32m is used as the diagnosis result for a failure of the third semiconductor switch 32l.

[0163] After the fault diagnosis is completed, the motor power supply device 303 stops operating the device based on a stop signal sent from an external system (vehicle control system). The other configurations of the third embodiment are the same as those of the first embodiment.

[0164] (Fault diagnosis processing) Hereinafter, the fault diagnosis process for the first semiconductor switch 32c, the second semiconductor switch 32d and the fourth semiconductor switch 32m will be described with reference to FIGS.

[0165] In step S301, the microcomputer 332o performs a first fault diagnosis. That is, in the first diagnostic state D1, the microcomputer 332o performs an OFF fault diagnosis of the first semiconductor switch 32c and the second semiconductor switch 32d based on the voltage values ​​of the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g.

[0166] In step S302, the microcomputer 332o judges whether or not a failure has been detected in at least one of the first semiconductor switch 32c and the second semiconductor switch 32d. If a failure has been detected, the failure diagnosis process is terminated, and if no failure has been detected, the process proceeds to step S303. In step S303, the microcomputer 332o judges whether or not a first condition is satisfied. The first condition is that the ignition switch is off, the failure diagnosis has been changed from a prohibited state to an permitted state, the precharge capacitor 32h is normally charged, and the drive of the motor 11 has stopped. If the first condition is satisfied, the process proceeds to step S304, and if the first condition is not satisfied, step S303 is repeated.

[0167] In step S304, the microcomputer 332o waits until the precharge capacitor 32h is discharged. In step S305, the microcomputer 332o determines whether or not a second condition is satisfied. The second condition is that a predetermined time has elapsed and the first semiconductor switch 32c, the second semiconductor switch 32d, the third semiconductor switch 32l, and the fourth semiconductor switch 32m are all turned off. If the second condition is satisfied, the process proceeds to step S306, and if the second condition is not satisfied, the process returns to step S304.

[0168] In step S306, the microcomputer 332o performs a second fault diagnosis. That is, in the second diagnostic state D2, the microcomputer 332o performs an on-fault diagnosis of the first semiconductor switch 32c based on the voltage values ​​of the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g. In the second diagnostic state D2, the microcomputer 332o performs an on-fault diagnosis of the fourth semiconductor switch 32m based on the voltage values ​​of the second voltage detection unit 32f, the third voltage detection unit 32g, and the fourth voltage detection unit 32n.

[0169] In step S307, the microcomputer 332o determines whether a predetermined time has elapsed. If the predetermined time has elapsed, the process proceeds to step S308, and if the predetermined time has not elapsed, the process returns to step S306. In step S308, the microcomputer 332o determines whether a third condition is satisfied. The third condition is whether the power supply type of the second power supply 32j is not set, or whether the second fault diagnosis detects the presence of a fault. If the second condition is satisfied, the sub-side fault diagnosis process is terminated, and if the second condition is not satisfied, the process proceeds to step S309.

[0170] In step S309, the microcomputer 332o waits until the precharge capacitor 32h is charged. By proceeding from A in Fig. 28 to A in Fig. 29, the process proceeds from step S309 to step S310.

[0171] As shown in Fig. 29, in step S310, the microcomputer 332o judges whether or not a fourth condition is satisfied. The fourth condition is that the charging of the precharge capacitor 32h is completed, the first semiconductor switch 32c is off, the second semiconductor switch 32d is off, the third semiconductor switch 32l is on, and the fourth semiconductor switch 32m is on. If the fourth condition is satisfied, the process proceeds to step S311, and if the fourth condition is not satisfied, step S310 is repeated. In step S311, the microcomputer 332o waits until the precharge capacitor 32h is discharged.

[0172] In step S312, the microcomputer 332o determines whether a fifth condition is satisfied. The fifth condition is that a predetermined time has elapsed, the first sub semiconductor switch 32c is off, the second sub semiconductor switch 32d is off, the third sub semiconductor switch 32l is on, and the fourth sub semiconductor switch 32m is on. If the fifth condition is satisfied, the process proceeds to step S313, and if the fifth condition is not satisfied, the process returns to step S311.

[0173] In step S313, the microcomputer 332o performs a third fault diagnosis. That is, in the third diagnostic state D3, the microcomputer 332o performs an ON fault diagnosis of the second semiconductor switch 32d based on the voltage values ​​of the first sub voltage detection unit 32e, the second sub voltage detection unit 32f, and the third sub voltage detection unit 32g. In the third diagnostic state D3, the microcomputer 332o performs an OFF fault diagnosis of the fourth semiconductor switch 32m based on the voltage values ​​of the second sub voltage detection unit 32f, the third sub voltage detection unit 32g, and the fourth sub voltage detection unit 32n.

[0174] In step S314, the microcomputer 332o determines whether or not a predetermined time has elapsed. If the predetermined time has elapsed, the failure diagnosis process ends, and if the predetermined time has not elapsed, the process returns to step S313.

[0175] (Effects of the third embodiment) In the third embodiment, the following effects can be obtained.

[0176] In the third embodiment, as described above, the motor power supply device 303 includes a microcomputer 332o that performs control to determine the state of power supply from the first power source 32a to the first semiconductor switch 32c based on the measurement value of the first voltage detection unit 32e. This makes it possible to suppress erroneous determinations in the fault diagnosis of the first semiconductor switch 32c. Other effects of the third embodiment are similar to those of the first embodiment.

[0177] [Fourth embodiment] Next, a motor power supply device 403 of a fourth embodiment will be described with reference to Figures 30 and 31. In particular, unlike the motor power supply device 303 of the third embodiment that includes a first power supply 32a and a second power supply 32j, the motor power supply device 403 of the fourth embodiment is provided with a power supply 432a. Note that in the fourth embodiment, the same reference numerals are used for configurations similar to those of the third embodiment, and descriptions thereof will be omitted.

[0178] In the shift device 100 of the fourth embodiment, the detent spring 22 is configured to hold the detent plate (not shown) at rotational angle positions corresponding to the P position and the non-P position, respectively.

[0179] 30, the motor power supply device 403 is configured to supply power to the actuator unit 1. The motor power supply device 403 includes a power supply 432a, a first power supply line 32b, a first semiconductor switch 32c (an example of a "first power supply side semiconductor switch" in the claims), and a second semiconductor switch 32d (an example of a "first output side semiconductor switch" in the claims).

[0180] The motor power supply device 403 includes a first voltage detection unit 32e (an example of a "first power supply side voltage detection unit" in the claims), a second voltage detection unit 32f (an example of an "intermediate voltage detection unit" in the claims), and a third voltage detection unit 32g (an example of an "output side voltage detection unit" in the claims). The motor power supply device 403 includes a precharge capacitor 32h, a motor circuit 32i, and a microcomputer 432o (an example of a "control unit" in the claims).

[0181] (Fault diagnosis) As shown in FIG. 31, the motor power supply device 403 performs three types of fault diagnosis: a first diagnostic state D1 (an example of the "first state" in the claims), a second diagnostic state D2 (an example of the "third state" in the claims), and a third diagnostic state D3 (an example of the "fourth state" in the claims).

[0182] Similarly, before the first diagnostic state D1, the microcomputer 432o is configured to perform control to charge (precharge) the precharge capacitor 32h by supplying power from the system power supply 102. At this time, the microcomputer 432o is configured not to perform the first diagnostic state D1 based on the detection of a charging abnormality in the precharge capacitor 32h.

[0183] 31, the microcomputer 432o is configured to diagnose a failure of the first semiconductor switch 32c (denoted as "MA1 upstream" in FIG. 31) based on the voltage values ​​detected by the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g in a first diagnostic state D1 in which the first semiconductor switch 32c and the second semiconductor switch 32d are turned on. Note that the diagnosis result of the failure of the first semiconductor switch 32c is the same as the diagnosis result of the first semiconductor switch 32c in the first diagnostic state D1 in the third embodiment, and therefore a description thereof will be omitted.

[0184] 31, the microcomputer 432o is configured to diagnose a failure of the second semiconductor switch 32d (indicated as "MA1 reverse connection" in FIG. 31) based on the voltage values ​​detected by the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g in a first diagnostic state D1 in which the first semiconductor switch 32c and the second semiconductor switch 32d are turned on. Note that the diagnosis result of the failure of the second semiconductor switch 32d is the same as the diagnosis result of the second semiconductor switch 32d in the first diagnostic state D1 in the third embodiment, and therefore a description thereof will be omitted.

[0185] As shown in FIG. 31, the microcomputer 432o is configured to perform control to discharge the pre-charge capacitor 32h before the second diagnostic state D2 so that power is supplied to the second voltage detection unit 32f.

[0186] 31, the microcomputer 432o is configured to diagnose a failure of the first semiconductor switch 32c (denoted as "MA1 upstream" in FIG. 31) based on the voltage values ​​detected by the first voltage detection unit 32e, the second voltage detection unit 32f, and the third voltage detection unit 32g in the second diagnostic state D2 in which the first semiconductor switch 32c, the second semiconductor switch 32d, the third semiconductor switch 32l, and the fourth semiconductor switch 32m are turned off. Note that the diagnosis result of the failure of the first semiconductor switch 32c is the same as the diagnosis result of the first semiconductor switch 32c in the second diagnostic state D2 in the third embodiment, and therefore a description thereof will be omitted.

[0187] In addition, in the motor power supply device 403, since the power supply on the second power supply 32j side (backup side) of the third embodiment is not set, the third diagnostic state D3 is not performed (skipped). The other configurations of the fourth embodiment are similar to those of the third embodiment.

[0188] (Effects of the fourth embodiment) In the fourth embodiment, the following effects can be obtained.

[0189] In the fourth embodiment, as described above, the motor power supply device 403 includes a microcomputer 432o that performs control to determine the state of power supply from the power supply 432a to the first semiconductor switch 32c based on the measurement value of the first voltage detection unit 32e. This makes it possible to suppress erroneous determinations in the failure diagnosis of the first semiconductor switch 32c. Note that other effects of the fourth embodiment are similar to those of the third embodiment.

[0190] [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.

[0191] For example, in the above embodiment, an example has been shown in which the motor power supply device 3 (203, 303, 403) of the present invention is applied to the shift device 100 for an automobile, but the present invention is not limited to this. In the present invention, the motor power supply device may be applied to a shift device other than that for an automobile, such as a train, or may be applied to a device other than a shift device.

[0192] In the above embodiment, for convenience of explanation, the control processing of each of the main microcomputer 31i (control unit), the sub microcomputer 32o (control unit), the microcomputer 332o (control unit), and the microcomputer 432o (control unit) 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]

[0193] 3, 203, 303, 403 Motor power supply 11 Motor 31a Main power supply (first power supply) 31b Main power supply line (first power supply line) 31c 1st main semiconductor switch (1st power supply side semiconductor switch) 31d Second main semiconductor switch (first output side semiconductor switch) 31e First main voltage detection unit (first power supply side voltage detection unit) 31f Second main voltage detector (output voltage detector) 31g Main capacitor (precharge capacitor) 31i Main microcomputer (control unit) 32a 1st sub-side power supply, 1st power supply (1st power supply) 32b First sub power supply line, first power supply line (first power supply line) 32c First sub-semiconductor switch, first semiconductor switch (first power supply side semiconductor switch) 32d Second sub-semiconductor switch, second semiconductor switch (first output side semiconductor switch) 32e First sub-voltage detection unit, first voltage detection unit (first power supply side voltage detection unit) 32f Second sub voltage detector, second voltage detector (intermediate voltage detector) 32g Third sub voltage detector, third voltage detector (output voltage detector) 32h Sub capacitor, precharge capacitor (precharge capacitor) 32j, 232j Second sub-side power supply (second power supply), second power supply 32k Second sub power supply line (second power supply line), second power supply line 32l Third sub-semiconductor switch (second power supply side semiconductor switch), third semiconductor switch 32m 4th sub-semiconductor switch (2nd output side semiconductor switch), 4th semiconductor switch 32n 4th sub-voltage detection unit, 4th voltage detection unit (2nd power supply side voltage detection unit) 32o Sub-microcomputer (control unit) 332o, 432o Microcomputer (control unit)

Claims

1. A first power source; a motor driven by power supplied from the first power source; a first power supply line electrically connecting the first power source and the motor; a first power supply side semiconductor switch disposed on the first power supply line on the first power supply side; a first output-side semiconductor switch connected in series to the first power supply-side semiconductor switch on the first power supply line and disposed on an output side; a first power supply side voltage detection unit that is disposed on the first power supply line closer to the first power supply side than the first power supply side semiconductor switch and detects a voltage of the first power supply line; two power supply units each including an output side voltage detection unit disposed on the first power supply line closer to the motor than the first output side semiconductor switch and configured to detect a voltage of the first power supply line; a control unit that performs control to determine a state of power supply from the first power source to the first power source side semiconductor switch based on a measurement value of the first power source side voltage detection unit, one of the two power supply units further includes, in addition to the first power supply side voltage detection unit and the output side voltage detection unit, an intermediate voltage detection unit that is disposed between the first power supply side semiconductor switch and the first output side semiconductor switch and detects a voltage of the first power supply line; the other of the two power supply units does not include the intermediate section voltage detection unit, and includes the first power supply side voltage detection unit and the output side voltage detection unit.

2. A power supply device for a motor as described in claim 1, wherein the control unit is configured to diagnose failures in the first power supply side semiconductor switch and the first output side semiconductor switch based on the voltage values ​​detected by the first power supply side voltage detection unit and the output side voltage detection unit in a first state in which the first power supply side semiconductor switch and the first output side semiconductor switch are turned on.

3. 3. The motor power supply device according to claim 2, wherein the control unit is configured to diagnose a failure of the first output-side semiconductor switch based on voltage values ​​detected by the first power supply side voltage detection unit and the output-side voltage detection unit in a second state in which the first power supply side semiconductor switch and the first output-side semiconductor switch are all turned off.

4. A power supply device for a motor as described in claim 2 or 3, wherein the control unit is configured to diagnose failures in the first power supply side semiconductor switch and the first output side semiconductor switch based on the voltage values ​​detected by each of the first power supply side voltage detection unit, the output side voltage detection unit, and the intermediate voltage detection unit in the first state.

5. a second power source provided separately from the first power source; a second power supply line electrically connecting the second power source and the motor; a second power supply side semiconductor switch disposed on the second power supply line on the second power supply side; a second output-side semiconductor switch connected in series to the second power supply-side semiconductor switch on the second power supply line and disposed on an output side; a second power supply side voltage detection unit that is disposed on the second power supply line closer to the second power supply side than the second power supply side semiconductor switch and detects a voltage of the second power supply line, 5. The motor power supply device according to claim 4, wherein the control unit is configured to diagnose failures in the first power supply side semiconductor switch and the second output side semiconductor switch based on voltage values ​​detected by each of the first power supply side voltage detection unit, the output side voltage detection unit, and the intermediate section voltage detection unit in a third state in which the first power supply side semiconductor switch, the second power supply side semiconductor switch, the first output side semiconductor switch, and the second output side semiconductor switch are all turned off.

6. 6. The motor power supply device according to claim 5, wherein the control unit is configured to diagnose a failure of the second output-side semiconductor switch based on voltage values ​​detected by the output-side voltage detection unit, the intermediate section voltage detection unit, and the second power supply-side voltage detection unit, in the first state and with the second power supply-side semiconductor switch and the second output-side semiconductor switch turned on.

7. 7. The motor power supply device according to claim 5, wherein, in a fourth state in which the second power supply side semiconductor switch and the second output side semiconductor switch are turned on, the control unit is configured to diagnose a failure of the first output side semiconductor switch based on voltage values ​​detected by each of the first power supply side voltage detection unit, the output side voltage detection unit, and the intermediate section voltage detection unit, or to diagnose a failure of the second output side semiconductor switch based on voltage values ​​detected by each of the output side voltage detection unit, the intermediate section voltage detection unit, and the second power supply side voltage detection unit.

8. a pre-charge capacitor disposed on the first power supply line on the first power supply side of the output voltage detection unit and pre-charged by an external power supply; 8. The motor power supply device according to claim 7, wherein the control unit is configured to perform control to discharge the pre-charge capacitor before a second state, a third state, and a fourth state in which all of the first power supply side semiconductor switches and the first output side semiconductor switches are turned off.

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