JP6749194B2 - In-vehicle motor failure diagnosis device - Google Patents

Description

The present invention relates to an on-vehicle motor failure diagnosis device.

BACKGROUND ART Conventionally, there is known a vehicle (hereinafter, also referred to as “idle stop vehicle”) capable of executing an idle stop control in which an engine is automatically stopped when a vehicle stops traveling and the engine is restarted when the vehicle starts traveling. .. As an idle stop vehicle, power is usually supplied to the motor generator from a power source different from the starter power source (power source for auxiliary machinery) to crank the engine and restart the engine. There is a vehicle configured to supply power to a starter from an auxiliary power source to crank the engine and restart the engine in an impossible situation.

Further, there is a hybrid vehicle having an engine and a drive motor as a drive source of the vehicle. The hybrid vehicle is provided with a high-voltage battery as a power source for a drive motor and the like, in addition to a low-voltage battery as a power source for auxiliary devices and a starter in the vehicle. In a hybrid vehicle as well, power is normally supplied from the high-voltage battery to the motor generator to crank the engine and restart the engine.If the engine cannot be restarted by the motor generator, the low-voltage battery is used as the starter. There are vehicles configured to supply power to crank the engine and restart the engine.

In these idle stop vehicles and hybrid vehicles, if the starter is out of order, the engine cannot be started by the starter even when the engine cannot be restarted by the motor generator. However, when the starter is used only in a situation where the engine cannot be restarted by the motor generator, there is no opportunity to perform failure diagnosis of the starter system.

On the other hand, in Patent Document 1, when the key switch is turned on at the beginning of vehicle operation, the starter is driven by a manual operation circuit that supplies electric power from the battery to the starter via the key switch, and the manual operation is performed after a predetermined time has elapsed. An engine starting device for an idle stop vehicle is disclosed, which includes a control circuit that drives a starter by an automatic driving circuit that supplies electric power from a battery to the starter via an idle stop relay instead of the circuit. Such an engine starter diagnoses whether or not there is an abnormality in the starter based on the switching of the idle stop relay on or off and the battery voltage when the engine is first started when the vehicle starts operating.

JP, 2003-322961, A

However, the engine starter disclosed in Patent Document 1 diagnoses the starter failure only when the engine is first started. Therefore, if the starter fails during operation of the vehicle, the engine is no longer restarted. May not be possible, and limp home (emergency avoidance) driving may not be possible. Further, the engine starter described in Patent Document 1 makes a diagnosis based on the amount of decrease in the battery voltage when the starter is driven by a manual operation circuit or an automatic operation circuit, or the current value flowing in the battery. Although it is possible to diagnose whether or not the electric circuit system is short-circuited or disconnected, it does not diagnose the characteristics of the starter body. Therefore, even if there is no abnormality in the diagnosis result, the engine may not be restarted.

The present invention has been made in view of the above problems, and an object of the present invention is to improve the reliability of a diagnosis result of a starter, which makes it impossible to restart the engine and to perform a limp home operation. It is an object of the present invention to provide a new and improved in-vehicle motor failure diagnosis device capable of avoiding an impossible situation.

In order to solve the above problems, according to an aspect of the present invention, it is driven by power supply from a first power source, has at least one function of a drive source of a vehicle and a generator, and starts an engine. And a second motor that is mechanically coupled to the first motor and that is driven by a power supply from a second power source different from the first power source and that is used to start the engine. A motor and a second motor that performs a failure diagnosis of the second motor based on the power supplied to the second motor when power is supplied from the second power supply to the second motor to drive the second motor. A first diagnostic unit and a second diagnostic unit that diagnoses a failure of the second motor based on the power generated by the second motor when the second motor is rotated by driving the first motor. An on-vehicle motor failure diagnosis device is provided.

It further comprises a first switching unit that switches on or off the supply of electric power from the second power source to the second motor, and the first diagnosis unit causes the first switching unit to switch from the second power source to the second power source. The failure diagnosis of the second motor may be performed based on the change in the power supplied to the second motor when the power supply to the motor is switched on or off.

The first diagnosis unit may determine that the second motor is abnormal when the amount of change in the output power of the second power supply is not within the predetermined range.

A second switching unit that switches connection or disconnection between the output shaft of the second motor and the crankshaft of the engine is further included, and the first diagnosis unit uses the second switching unit to connect the output shaft of the second motor to the output shaft of the second motor. The failure diagnosis of the second motor may be performed by opening the connection with the crankshaft of the engine.

The second diagnosis unit rotates the crankshaft of the engine by the first motor, and the second switching unit controls the crankshaft of the second motor by connecting the output shaft of the second motor and the crankshaft of the engine. The failure diagnosis of the second motor may be performed based on the change in the generated power.

The second diagnosis unit may determine that the second motor is abnormal when the amount of change in the power generated by the second motor is not within the predetermined range.

The engine may be cranked using the first motor before at least the failure diagnosis by the second diagnosis unit is started.

When the engine is started during the control of the vehicle, after the cranking of the engine is started by the first motor, the failure diagnosis of the second motor by the first diagnostic unit and the second diagnostic unit is performed. Good.

The failure diagnosis may be performed by the second diagnosis unit when the result of the diagnosis by the first diagnosis unit is normal.

The vehicle is travel-controlled at least in the first traveling mode by the driving force of the first motor or in the second traveling mode by the driving force of the first motor and the engine, and the first diagnostic unit or the first diagnostic unit is used. At least one of the second diagnostic units may prohibit the first traveling mode and continue driving the engine when the second motor is abnormal.

The vehicle is subjected to idle stop control in which the engine is automatically stopped when the vehicle is stopped and the engine is restarted when the vehicle starts, and at least one of the first diagnostic unit and the second diagnostic unit is a second motor. When an abnormality occurs, the idle stop control may be prohibited and the engine drive may be continued.

As described above, according to the present invention, it is possible to improve the reliability of the diagnosis result of the starter and avoid the situation where the engine cannot be restarted and the limp home operation cannot be performed.

It is a schematic diagram which shows the system structural example of the vehicle which concerns on embodiment of this invention. It is explanatory drawing which shows the example of a circuit structure of a starter system. It is explanatory drawing which shows the example of a circuit structure of a motor generator system. It is a block diagram which shows the structural example of a control apparatus. It is explanatory drawing which shows the relationship between the rotation speed of a starter, and a generated electric current. It is a flow chart which shows the main routine of failure diagnosis control of a starter. It is a flowchart which shows the subroutine of the failure diagnosis control of a starter. It is explanatory drawing which shows the battery input/output electric power by the failure diagnosis control of a starter. It is explanatory drawing which shows the battery input/output electric power by another failure diagnosis control of a starter.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, and duplicate description will be omitted.

<1. Vehicle system configuration>
First, with reference to FIG. 1, an example of a vehicle system configuration to which a vehicle-mounted motor failure diagnosis apparatus according to an embodiment of the present invention can be applied will be described. FIG. 1 is a schematic diagram showing a system configuration example of a hybrid vehicle.

The vehicle includes an engine 10, a starter 20, a motor generator 30, an automatic transmission 40, a drive motor 45, and drive wheels 61. Such a vehicle is an example of a hybrid vehicle in which the engine 10 and the drive motor 45 can be used together as a drive source. In the vehicle according to the present embodiment, the starter 20 corresponds to the second motor and the motor generator 30 corresponds to the first motor.

In such a hybrid vehicle, the driving force of the vehicle is controlled while the traveling mode is switched between the engine traveling mode, the EV traveling mode, and the hybrid traveling mode. The engine running mode is a mode in which the vehicle is driven by the torque output from the engine 10, and is mainly a running mode during limp home operation. The EV traveling mode corresponds to the first traveling mode and is a mode in which the vehicle is driven by the torque output from the drive motor 45. The hybrid travel mode corresponds to the second travel mode and is a mode in which the vehicle is driven by the torque output from the drive motor 45 and the torque output from the engine 10.

The engine 10 is an internal combustion engine that produces torque using gasoline, diesel, or the like as fuel, and has a crankshaft 11 as an output shaft. The crankshaft 11 is connected to the automatic transmission 40 via a torque converter, a clutch or the like (not shown).

The drive motor 45 is, for example, a three-phase AC motor, and is connected to a high-voltage battery (for example, 200V) 160 via an inverter 49. In the present embodiment, the high voltage battery 160 corresponds to the first power source. The drive motor 45 has a function as a drive motor that receives power from the high-voltage battery 160 and is driven (power running) to generate a driving force of the vehicle, and is regeneratively driven when the vehicle is decelerated to move the drive wheels 61. It has a function as a generator that generates electric power by using energy. Further, the drive motor 45 may have a function as a generator that generates electric power using the output of the engine 10.

When the drive motor 45 functions as a drive motor of the vehicle, the inverter 49 converts the DC power supplied from the high-voltage battery 160 into AC power and drives the drive motor 45. When the drive motor 45 functions as a generator, the inverter 49 converts the AC power generated by the drive motor 45 into DC power and charges the high voltage battery 160.

The automatic transmission 40 includes, for example, a continuously variable transmission such as a CVT (Continuously Variable Transmission). The automatic transmission 40 converts the rotational torque transmitted from the engine 10 via the crankshaft 11 into a gear ratio according to the running state of the vehicle and transmits the rotational torque to the output shaft 41. For example, a clutch mechanism may be provided in the automatic transmission 40 to switch connection/disconnection between the engine 10 and the output shaft 41 or between the drive motor 45 and the output shaft 41.

The starter 20 as the second motor is driven by being supplied with electric power from the low voltage battery 130, and cranks the engine 10 to start the engine 10. In the present embodiment, the low voltage battery 130 corresponds to the second power source. The output shaft 25 of the starter 20 is connected to the crankshaft 11 of the engine 10 via a gear or the like, and the crankshaft 11 of the engine 10 also rotates as the output shaft 25 of the starter 20 rotates. The starter 20 has a starter motor, a starter pinion and a starter pinion gear, which are not shown. The starter motor is, for example, a DC motor, and energization is switched on or off by the starter drive relay 128.

The starter pinion is fixed to the motor shaft of the starter motor and can mesh with the starter pinion gear fixed to the output shaft 25 of the starter 20. The starter pinion and the starter pinion gear are engaged or disengaged by a pinion drive relay 129, and whether the motor shaft of the starter motor and the output shaft 25 are connected or not is switched. The starter drive relay 128 and the pinion drive relay 129 are drive-controlled by a control device (ECU: Electronic Control Unit) 100. In this embodiment, the starter drive relay 128 corresponds to the first switching unit, and the pinion drive relay 129 corresponds to the second switching unit.

FIG. 2 shows a circuit configuration of a power supply system of a low voltage battery 130 as a second power supply for supplying electric power to the starter 20. Electric power output from the low-voltage battery 130 is converted into a desired voltage by the DCDC converter 120 and supplied to the starter 20 and various electric loads 150. Examples of the electric load 150 include, but are not limited to, auxiliary equipment such as vehicle-mounted air conditioners and audio equipment. A starter drive relay 128 and a pinion drive relay 129 are provided in parallel between the low voltage battery 130 and the starter 20. The starter drive relay 128 is a switch that switches on or off the drive current of the starter motor. The pinion drive relay 129 is a switch that switches ON or OFF engagement of the starter pinion and the starter pinion gear.

The starter drive relay 128 and the pinion drive relay 129 are provided in the starter 20, for example. The starter drive relay 128 and the pinion drive relay 129 are switched on or off based on a drive instruction from the control device 100. The low-voltage battery 130 is provided with an IBS (Intelligent Battery Sensor) 135. The IBS 135 detects the input/output current and the input/output voltage of the low voltage battery 130. Information on the detected input/output current and input/output voltage is transmitted to the control device 100.

Returning to FIG. 1, the motor generator 30 is driven by being supplied with power from the high-voltage battery 160 as the first power source, and cranks the engine 10 to start the engine 10. The output shaft 35 of the motor generator 30 is connected to the crankshaft 11 of the engine 10 by a gear or the like, and the crankshaft 11 of the engine 10 also rotates as the output shaft 35 of the motor generator 30 rotates. The motor generator 30 also has a function as a generator. For example, when the crankshaft 11 of the engine 10 is rotated from the automatic transmission 40 side, the motor generator 30 is also rotated to generate electric power. .. The high-voltage battery 160 is charged with the generated power.

FIG. 3 shows the circuit configuration of the power supply system of the high-voltage battery 160 that supplies power to the motor generator 30. The electric power output from the high voltage battery 160 is supplied to the motor generator 30. That is, the motor generator 30 is supplied with electric power by using the high voltage battery 160, which is different from the low voltage battery 130 that is the power source of the starter 20, as the power source. Motor generator 30 is driven based on a drive instruction from control device 100.

In the vehicle according to the present embodiment, when the engine 10 is started, the engine 10 is normally cranked using the motor generator 30. When the motor generator 30 cannot start the engine 10, the starter 20 is used to crank the engine 10. That is, the starter 20 is used in an emergency. For example, when the abnormality of the hybrid system is detected while the vehicle is traveling in the EV traveling mode and the motor generator 30 cannot be driven, the starter 20 is driven to start the engine 10. In this case, the engine 10 is driven at a low output and the vehicle runs in the limp home operation mode.

At this time, if the starter 20 is out of order, the engine 10 can no longer be started, and the limp home operation cannot be performed together with the abnormality of the hybrid system. Therefore, even if the starter 20 is not used, it is necessary to diagnose whether the starter 20 has a failure. If a failure of the starter 20 is found, the engine 10 should not be stopped, that is, the EV drive mode should not be entered or the engine 10 should be automatically stopped by idle stop control. The vehicle is controlled.

<2. Controller>
Next, a configuration example of the control device 100 that executes the failure diagnosis control of the starter 20 will be described. FIG. 4 is a block diagram showing an example of the configuration of the control device 100. The control device 100 mainly includes a microcomputer such as a CPU. FIG. 4 shows functional blocks of the configuration of the control device 100, which are related to the failure diagnosis control of the starter 20. Although the illustrated control device 100 is configured as a single control device, the control device 100 may be configured such that a plurality of control devices can communicate with each other.

The control device 100 includes an HV control unit (hybrid control unit) 101, an engine control unit 102, a motor control unit 103, a starter drive circuit 104, a motor generator (ISG/MG) drive circuit 105, and a display control unit 106. And a starter diagnosis control unit 111. The starter diagnosis control unit 111 has a first diagnosis unit 112 and a second diagnosis unit 113. The HV control unit 101, the engine control unit 102, the motor control unit 103, the display control unit 106, and the starter diagnosis control unit 111 may be functions realized by executing a software program by the CPU, for example.

The control device 100 also includes a storage element (not shown) such as a RAM (Random Access Memory) or a ROM (Read Only Memory). For example, the ROM stores software programs executed by the CPU and various parameters used for arithmetic processing. Further, the RAM stores sensor information acquired by the control device 100, a calculation processing result, and the like. The control device 100 includes a sensor signal of the ISG 135 provided in the low-voltage battery 130, a sensor signal of a current sensor that detects a control current of the DCDC converter 120, a sensor signal of an accelerator sensor that detects a depression amount of an accelerator pedal, A sensor signal of a rotation sensor that detects an engine speed, a sensor signal of a vehicle speed sensor that detects a vehicle speed, and the like are input.

The HV control unit 101 calculates the required torque for the vehicle based on the accelerator pedal depression amount, the engine speed, the vehicle speed, etc., and determines the vehicle traveling mode (engine traveling mode, EV traveling mode, hybrid traveling mode). The HV control unit 101 distributes the calculated required torque to the engine 10 and the drive motor 45, and sends a drive instruction to the engine control unit 102 and the motor control unit 103.

The motor control unit 103 controls the electric power supplied to the drive motor 45 based on the drive instruction from the HV control unit 101 to drive the drive motor 45. Specifically, the motor control unit 103 controls the power supplied to the drive motor 45 by controlling the inverter 49.

The engine control unit 102 controls the engine 10 based on the drive instruction from the HV control unit 101. Specifically, the engine control unit 102 controls the engine 10 by controlling the drive of fuel injection valves and spark plugs provided in the engine 10. Further, when starting the engine 10, the engine control unit 102 transmits a drive instruction to the motor generator drive circuit 105 and causes the motor generator 30 to crank the engine 10 to start the engine 10. When starting the engine 10, the engine control unit 102 sends a signal to the starter diagnosis control unit 111 to notify the start of the engine 10.

However, in a situation where the engine 10 cannot be started by the motor generator 30, such as when the hybrid system is abnormal or the charge amount of the high-voltage battery 160 is low, the engine control unit 102 drives the starter drive circuit 104. The instruction is transmitted, and the starter 20 cranks the engine 10 to start the engine 10.

The display control unit 106 controls the display device 125 in the vehicle interior such as the display surface of the instrument panel. In the present embodiment, the display control unit 106 controls the display device 125 to display the result of the failure diagnosis of the starter 20.

The first diagnosis unit 112 of the starter diagnosis control unit 111 supplies electric power from the low-voltage battery 130 to the starter 20 to drive the starter 20 based on the electric power supplied to the starter 20. Fault diagnosis (hereinafter, also referred to as “first diagnosis”). In the present embodiment, the first diagnosis unit 112 diagnoses a failure of the starter 20 based on a change in the power supplied to the starter 20 when the power supply from the low-voltage battery 130 to the starter 20 is switched on or off. I do. The diagnosis by the first diagnosis unit 112 is performed mainly for diagnosing whether or not there is a failure on an electric circuit that supplies power to the starter 20. For example, if the pinion drive relay 129 is turned off, the first diagnosis can be executed at any time.

Specifically, in the first diagnosis unit 112, the amount of change in the supply current to the starter 20 when the pinion drive relay 129 is turned off and the starter drive relay 128 is switched from off to on is within a predetermined range. Or not. The supply current Ist_A to the starter 20 is obtained by subtracting the control current Idc of the DCDC converter 120 from the output current Ibat_out of the low voltage battery 130.

For example, when a disconnection occurs on the electric circuit, even if the starter drive relay 128 is switched from OFF to ON, the supply current Ist_A to the starter 20 does not increase, so the amount of change is significantly reduced. Further, when a short circuit occurs in the electric circuit, when the starter drive relay 128 is switched from OFF to ON, the supply current Ist to the starter 20 is suddenly increased, and the amount of change is significantly increased. Therefore, by setting the upper limit value Ist_A_hi and the lower limit value Ist_A_lo of the change amount of the supply current Ist to the starter 20 to appropriate values, the failure of the starter 20 can be detected by the first diagnosis.

In addition, the second diagnostic unit 113 of the starter diagnostic control unit 111 diagnoses a failure of the starter 20 based on the generated power of the starter 20 when the starter 20 is rotated by driving the motor generator 30 (hereinafter, referred to as “ Also referred to as "second diagnosis". In the present embodiment, the second diagnostic unit 113 determines the amount of change in the electric power generated by the starter 20 when the motor generator 30 is driven and the output shaft 25 of the starter 20 is rotated via the crankshaft 11 of the engine 10. Based on this, failure diagnosis of the starter 20 is performed. The diagnosis by the second diagnosis unit 113 is mainly performed to diagnose the characteristics of the starter motor main body.

FIG. 5 is an explanatory diagram showing the relationship between the rotation speed of the starter 20 and the generated current Ist_B. When the starter 20 is normal, the generated current Ist_B to the starter 20 increases as the rotation speed of the starter 20 increases. Therefore, the second diagnosis unit 113 can diagnose the characteristics of the starter motor main body by determining whether the generated current of the starter 20 has an appropriate value according to the rotation speed of the starter 20.

For example, the second diagnosis unit 113 calculates the rotation speed of the starter 20 from the rotation speed Ne of the engine 10 based on the gear ratio between the crankshaft 11 of the engine 10 and the output shaft 25 of the starter 20, and the generated current of the starter 20. It is possible to diagnose whether or not there is a large deviation from the value according to the rotation speed of the output shaft 25 of the starter 20. The generated current Ist_B of the starter 20 is obtained by subtracting the control current Idc of the DCDC converter 120 from the input current Ibat_in of the low voltage battery 130. The rotation speed of the output shaft 25 of the starter 20 may be detected using a rotation sensor.

Alternatively, the second diagnosis unit 113 drives the motor generator 30, and then turns on the pinion drive relay 129 after a preset time elapses and further starts the starter when the starter drive relay 128 is switched from off to on. It is determined whether or not the amount of change in the generated current of 20 is within a predetermined range. In this case, the change in the generated current Ist_B of the starter 20 can be grasped in advance according to the time during which the starter drive relay 128 is turned on. Therefore, by setting the upper limit value Ist_B_hi and the lower limit value Ist_B_lo of the change amount of the generated current Ist_B of the starter 20 to appropriate values, the failure of the starter 20 can be detected by the second diagnosis.

The failure diagnosis by the starter diagnosis control unit 111 may be executed, for example, when the vehicle travel control is performed and the EV travel mode is switched to the hybrid travel mode. At the time of shifting to the traveling mode, the motor generator 30 is driven to start the engine 10, so that the operation sound of the starter 20 is less likely to be heard by the driver or the like. Further, particularly in the second diagnosis, the crankshaft 11 of the engine 10 is rotated by the motor generator 30 to rotate the starter 20, so that the second diagnosis is executed in synchronization with the start of the engine 10 during normal traveling control. Can be made.

Further, by performing the failure diagnosis of the starter 20 when the travel mode shifts from the EV travel mode to the hybrid travel mode, even if a failure of the starter 20 is detected, the engine 10 is still operating at that time. Therefore, the engine 10 can be maintained in the operating state. Therefore, in a situation where the engine 10 cannot be started by the motor generator 30, it is possible to avoid a situation in which the engine 10 cannot be started by the starter 20 and even limp home operation is impossible.

Further, when the failure diagnosis of the starter 20 is performed when the travel mode is changed from the EV travel mode to the hybrid travel mode, the starter diagnosis control unit 111 has no abnormality in the result of the first diagnosis by the first diagnosis unit 112. At times, the second diagnosis unit 113 may perform the second diagnosis. That is, when it is estimated that a short circuit or a disconnection has occurred on the electric circuit that supplies power to the starter 20, the second diagnosis is omitted without connecting the starter 20 and the engine 10 at that time. Therefore, it may be determined that the starter 20 has a failure.

The starter diagnosis control unit 111 notifies the HV control unit 101 of an abnormality of the starter 20 when a failure of the starter 20 is detected by either the first diagnosis unit 112 or the second diagnosis unit 113. To prohibit the EV traveling mode and continue driving the engine 10. As a result, in a situation where the engine 10 cannot be started by the motor generator 30 and the starter 20, it is possible to avoid the situation in which the engine 10 does not stop and even the limp home operation is impossible.

<3. Starter diagnostic control method>
Next, an example of a diagnostic control method of the starter 20 by the control device 100 according to the present embodiment will be described based on FIGS. 6 to 8. FIG. 6 is a flowchart showing a main routine of the diagnostic control method of the starter 20, and FIG. 7 is a flowchart showing a subroutine of a failure diagnostic process of the starter 20. Further, FIG. 8 shows the states of the starter drive relay 128 and the pinion drive relay 129 during the diagnostic control of the starter 20, the engine speed and the starter speed, the current supplied or generated to the starter 20, and the voltage of the low-voltage battery 130. It shows the transition.

In the following example of the starter diagnosis control method, the first diagnosis and the second diagnosis are executed according to the same flowchart. Therefore, in FIG. 7 and the following description, the current value of the low-voltage system when the starter drive relay 128 is on is represented as Ist_on without distinguishing the supply current to the starter 20 and the generated current of the starter 20. The current value of the low-voltage system when the starter drive relay 128 is off is represented by Ist_off.

In FIG. 6, for example, the HV control unit 101 switches the traveling mode from the EV traveling mode (first traveling mode) to the hybrid (second traveling mode), and instructs the engine control unit 103 to drive the engine 10. Then, the engine control unit 103 outputs a drive instruction to the motor generator drive circuit 105 and sends a signal to the starter diagnosis control unit 111 to inform the drive of the motor generator 30 (step S12). When receiving the signal, the first diagnosis unit 112 of the starter diagnosis control unit 111 executes the first diagnosis (step S14).

The first diagnosis process is executed as follows, for example. As shown in FIG. 7, first, the first diagnostic unit 112 keeps both the starter drive relay 128 and the pinion drive relay 129 off for a period until time t1 and outputs the output current value Ist_off( of the low voltage battery 130). =Ibat-Idc) is held at a constant value (step S32). Next, the first diagnosis unit 112 turns on the starter drive relay 128 at time t1 (step S34). Next, the first diagnosis unit 112 calculates the supply current Ist_on (=Ibat-Idc) from the low voltage battery 130 to the starter 20 with the starter drive relay 128 turned on (step S36).

Next, the first diagnosis unit 112 obtains a change amount (|Ist_off−Ist_on|) of the supply current from the low-voltage battery 130 to the starter 20, and determines whether this change amount is within a predetermined range set in advance. The determination is made (step S38). The upper limit value Ist_on and the lower limit value Ist_off of the predetermined range in the first diagnosis are set to appropriate values as threshold values capable of detecting the presence or absence of disconnection or short circuit on the electric circuit that supplies power to the starter 20.

When the amount of change in the current supplied to the starter 20 is within the predetermined range (S38: Yes), the first diagnosis unit 112 determines that the diagnosis result of the first diagnosis is normal (step S40). On the other hand, when the amount of change in the supply current to the starter 20 is not within the predetermined range (S38: No), the first diagnosis unit 112 determines that the diagnosis result of the first diagnosis is abnormal (step S42). .. After determining the diagnosis result of the first diagnosis, at time t2, the first diagnosis unit 112 turns off the starter drive relay 128 (step S44), and ends the subroutine of the failure diagnosis process of the starter 20.

Returning to the flowchart of FIG. 6, the first diagnosis unit 112 determines whether or not there is an abnormality in the starter 20 due to the first diagnosis after the completion of the first diagnosis in step S14 (step S16). When it is determined that the starter 20 is abnormal by the first diagnosis (S16: No), the first diagnosis unit 112 prohibits the HV control unit 101 or the engine control unit 103 from stopping the engine 10. That is, the first diagnosis unit 112 causes the HV control unit 101 to prohibit switching to the EV traveling mode (step S26). When the vehicle is an idle stop vehicle, the first diagnosis unit 112 causes the engine control unit 103 to prohibit the idle stop control.

Next, the first diagnosis unit 112 notifies the driver of the failure of the starter 20 by sending a control instruction to the display control unit 106 and displaying an abnormality of the starter 20 on a display device such as an instrument panel (step). S28). When the abnormality of the starter 20 is detected by the first diagnosis, the first diagnosis unit 112 ends the diagnosis control of the starter 20 without executing the second diagnosis.

On the other hand, when the starter 20 is determined to be normal by the first diagnosis (S16: Yes), this time, at time t3, the second diagnosis unit 113 of the starter diagnosis control unit 111 turns on the pinion drive relay 129. Switch (step S18). Next, the second diagnosis section 113 executes the second diagnosis (step S20).

The second diagnostic processing is executed as follows, for example. As shown in FIG. 7, first, the second diagnosis unit 113 operates the low-voltage battery 130 while the pinion drive relay 129 is turned on and the starter drive relay 128 is turned off until the time t4. The output current value Ist_off (=Ibat-Idc) is held at a constant value (step S32). Next, the second diagnostic unit 113 turns on the starter drive relay 128 at time t4 (step S34). Next, the second diagnosis unit 113 calculates the generated current Ist_on (=Ibat-Idc) of the starter 20 while the starter drive relay 128 and the pinion drive relay 129 are turned on (step S36).

Next, the second diagnosis unit 113 obtains a variation amount (|Ist_off-Ist_on|) of the generated current of the starter 20 and determines whether or not the variation amount is within a predetermined range set in advance (step S38). .. The upper limit value Ist_on and the lower limit value Ist_off of the predetermined range in the second diagnosis are the engine speed (starter speed) with the lapse of time from the start of driving the motor generator 30 in step S12 to step S38. It is set to an appropriate value as an assumed threshold value according to the amount of increase and the characteristics of the starter rotation speed and the generated current as shown in FIG.

When the amount of change in the generated current of the starter 20 is within the predetermined range (S38: Yes), the second diagnosis unit 113 determines that the diagnosis result of the second diagnosis is normal (step S40). On the other hand, when the amount of change in the generated current of the starter 20 is not within the predetermined range (S38: No), the second diagnosis unit 113 determines that the diagnosis result of the second diagnosis is abnormal (step S42). After determining the diagnosis result of the second diagnosis, the second diagnosis unit 113 turns off the starter drive relay 128 at time t5 (step S44) and ends the subroutine of the failure diagnosis process of the starter 20.

Returning to the flowchart of FIG. 6, the second diagnosis unit 113 turns off the pinion drive relay 129 after the second diagnosis in step S20 ends (step S22). In FIG. 8, the pinion drive relay 129 is turned off at the same time as the time t5 when the starter drive relay 128 is turned off, but the time may be shifted.

Next, the second diagnosis unit 113 determines whether or not there is an abnormality in the starter 20 due to the second diagnosis (step S24). When it is determined that the starter 20 is abnormal by the second diagnosis (S24: No), the second diagnosis unit 113 prohibits the HV control unit 101 or the engine control unit 103 from stopping the engine 10. That is, the second diagnosis unit 113 causes the HV control unit 101 to prohibit switching to the EV traveling mode (step S26). When the vehicle is an idle stop vehicle, the second diagnosis unit 113 causes the engine control unit 103 to prohibit the idle stop control.

Next, the second diagnosis unit 113 sends a control instruction to the display control unit 106 to display an abnormality of the starter 20 on a display device such as an instrument panel to notify the driver of the failure of the starter 20 ( (Step S28), the failure diagnosis control of the starter 20 is completed.

On the other hand, when the starter 20 is determined to be normal by the second diagnosis (S24: Yes), the second diagnosis unit 113 ends the failure diagnosis control of the starter 20 as it is. In this case, even if the engine 10 cannot be started by the motor generator 30, the engine 10 can be started by the starter 20. Therefore, there is no particular instruction to prohibit the engine 10 from being stopped. Not issued.

The timing for executing the starter diagnostic control shown in the flowcharts of FIGS. 6 and 7 is not particularly limited. The diagnostic control may be executed all the time while the vehicle system is powered on, or may be executed at regular time intervals, or the engine 10 is started a predetermined number of times. It may be executed each time it arrives.

As described above, the starter failure diagnosis apparatus (in-vehicle motor failure diagnosis apparatus) according to the present embodiment starts the starter 20 by supplying power from the low-voltage battery 130 to the starter 20. A first diagnosis unit 112 is provided for performing a failure diagnosis of the starter 20 based on the current supplied to the starter 20. With the first diagnosis unit 112, it is possible to mainly diagnose whether or not there is an abnormality in the electric circuit that supplies power to the starter 20. Further, the starter failure diagnosis device performs the failure diagnosis of the starter 20 based on the generated current of the starter 20 when the starter 20 is rotated via the crankshaft 11 that is rotated by the drive of the motor generator 30. The diagnostic unit 113 is provided. The second diagnosis unit 113 can mainly diagnose whether or not there is an abnormality in the characteristics of the starter motor body. Therefore, the reliability of the failure diagnosis result of the starter 20 is improved, and it is possible to avoid a situation in which the engine 10 cannot be restarted and even the limp home operation cannot be performed.

Further, in the starter failure diagnosis apparatus according to the present embodiment, the failure diagnosis of the starter 20 is executed at the timing when the engine 10 is started during the traveling control of the vehicle. Therefore, when the abnormality of the starter 20 is detected, the engine 10 is in the operating state, and hence it is possible to prohibit the stop of the engine 10 and continue the operation of the engine 10 thereafter. Therefore, it is possible to secure a situation in which at least the limp home operation can be reliably executed.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to these examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

For example, in the above-described embodiment, after the driving of the motor generator 30 to start the engine 10 is started, the first diagnosis by the first diagnosis unit 112 and the second diagnosis by the second diagnosis unit 113. Were performed, the invention is not limited to such an example. For example, as shown in FIG. 9, the first diagnosis unit 112 may execute the first diagnosis at time t1 to t2 even before the drive of the motor generator 30 is started. After that, the second diagnosis unit 113 may execute the second diagnosis at time t14 to t15 after the time t13 when the driving of the motor generator 30 is started. Even when the first diagnosis and the second diagnosis are executed in this manner, it is determined whether or not there is an abnormality in the electric circuit system for supplying electric power to the starter 20 and an abnormality in the characteristics of the starter motor itself. can do.

Further, although an example in which the vehicle is a hybrid vehicle has been described in the above embodiment, the present invention is not limited to such an example. For example, the present invention may be applied to an idle stop vehicle that is equipped with only an engine as a drive source that generates a driving force of the vehicle and is capable of executing idle stop control. In this case, if the engine cannot be restarted by either the motor generator or the starter after the engine is stopped by the idle stop control, even the limp home operation is impossible. Even in an idle stop vehicle, according to the starter failure diagnosis device of the present invention, the starter failure diagnosis is performed, and when the starter failure is detected, the idle stop control is prohibited and the engine continues to be driven. By doing so, it is possible to avoid a situation where even limp home driving is impossible.

Further, in the above embodiment, the failure diagnosis is performed using the current value as the power supplied to the starter 20 and the power generated by the starter 20, but the present invention is not limited to this example. The failure diagnosis may be executed by using the voltage value as the power supplied to the starter 20 and the power generated by the starter 20. Also in this case, as shown in FIGS. 8 and 9, it is possible to diagnose the presence or absence of a failure of the starter 20 based on the amount of change in the voltage during the first diagnosis or the second diagnosis.

Further, in the above-described embodiment, the motor generator 30 as the first motor has the functions of the starter and the generator, but the present invention is not limited to this example. For example, the first motor may be a motor that is provided on the output side of the engine 10 and that has a function as a starter and a function of generating a driving torque of the vehicle. In this case, the first motor may have a regenerative power generation function.

Further, in the above-described embodiment, the motor generator 30 is a motor that rotates the starter 20 via the crankshaft 11 of the engine 10, but the present invention is not limited to this example. For example, a first motor connected to the starter 20 via a gear or the like may be provided, and the first motor may be driven to rotate the starter 20 when executing the second diagnosis.

10 engine 11 crankshaft 20 starter (second motor)
25 output shaft 30 motor generator (first motor)
35 Output Shaft 100 Control Device 111 Starter Diagnosis Control Unit 112 First Diagnosis Unit 113 Second Diagnosis Unit 128 Starter Drive Relay (First Switching Unit)
129 Pinion drive relay (second switching unit)
130 Low voltage battery (second power supply)
160 high voltage battery (first power source)

Claims (11)

A first motor driven by power supply from a first power source, having a function of at least one of a vehicle drive source and a generator, and used for starting the engine;
A second motor mechanically coupled to the first motor, driven by a power supply from a second power source different from the first power source, and used for starting the engine;
A failure diagnosis of the second motor is performed based on the power supplied to the second motor when the second motor is driven by supplying power to the second motor. A first diagnostic unit to perform,
A second diagnostic unit that performs a failure diagnosis of the second motor based on the electric power generated by the second motor when the second motor is rotated by driving the first motor;
In-vehicle motor failure diagnosis device equipped with. Further comprising a first switching unit that switches ON or OFF of power supply from the second power source to the second motor,
The first diagnosis unit supplies power to the second motor when the first switching unit switches on or off the supply of power from the second power source to the second motor. The failure diagnosis apparatus for a vehicle-mounted motor according to claim 1, wherein the failure diagnosis of the second motor is performed based on the change of the above. The failure diagnosis of the vehicle-mounted motor according to claim 2, wherein the first diagnosis unit determines that the second motor is abnormal when the amount of change in the power supplied to the second motor is not within a predetermined range. apparatus. A second switching unit that switches connection or disconnection between the output shaft of the second motor and the crankshaft of the engine,
The first diagnosis unit opens the connection between the output shaft of the second motor and the crankshaft of the engine by the second switching unit to perform a failure diagnosis of the second motor. Item 5. A vehicle-mounted motor failure diagnosis device according to any one of items 1 to 3. The second diagnosis unit rotates the crankshaft of the engine by the first motor, and connects the output shaft of the second motor and the crankshaft of the engine by the second switching unit. 5. The in-vehicle motor failure diagnosis device according to claim 4, wherein the failure diagnosis of the second motor is performed based on the change in the electric power generated by the second motor. The in-vehicle motor failure diagnosis device according to claim 5, wherein the second diagnosis unit determines that the second motor is abnormal when the amount of change in generated power of the second motor is not within a predetermined range. .. The on-vehicle motor failure diagnosis device according to claim 1, wherein the engine is cranked using the first motor before at least the failure diagnosis by the second diagnosis unit is started. .. When starting the engine during control of the vehicle, after starting cranking of the engine by the first motor, the second motor by the first diagnostic unit and the second diagnostic unit 8. The on-vehicle motor failure diagnosis device according to claim 7, which performs the failure diagnosis. The in-vehicle motor failure diagnosis device according to claim 8, wherein the failure diagnosis is performed by the second diagnosis section when there is no abnormality in the diagnosis result by the first diagnosis section. The vehicle is travel-controlled at least in a first traveling mode by the driving force of the first motor or in a second traveling mode by the driving force of the first motor and the engine,
At least one of said 1st diagnostic part or said 2nd diagnostic part prohibits said 1st driving mode at the time of abnormality of said 2nd motor, and continues driving of said engine. 9. A failure diagnostic device for a vehicle-mounted motor according to any one of 9 above. The vehicle is automatically stopped when the vehicle is stopped, idle stop control is performed to restart the engine when the vehicle starts,
10. The at least one of the first diagnostic unit and the second diagnostic unit prohibits the idle stop control and continues driving of the engine when the second motor is abnormal. The failure diagnosis device for a vehicle-mounted motor according to any one of claims 1.

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