Vehicle control device

Abstract

To provide a vehicle control device capable of preventing occurrence of burning of a cable connecting a traveling power source composed of a permanent magnet motor generator and an invertor and achieving extension of a travel distance during saving travel.SOLUTION: A motor MG is composed of a permanent magnet shaped motor generator and is driven during engine travel. An electronic control device 90 (a) includes an engine control ECU 92 and an MG control ECU 94 controlling an MG control invertor 50 driving the motor MG and different from the engine control ECU 92, (b) makes the motor MG an undriven state and also executes saving travel by an engine 12 when the engine control ECU 92 determines that the MG control ECU 94 fails, and (c) stops the saving travel when a cable temperature THcb as a temperature of an MG cable 60 connecting the motor MG and the MG control invertor 50 exceeds a determination temperature THcb_jdg.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle equipped with a first power source for running and a second power source for running configured by a permanent magnet motor generator. [Background technology]

[0002] Vehicles equipped with an engine and a motor generator as a power source for traveling are known, in which the motor generator is connected to a power transmission path between the engine and a pair of drive wheels so as to transmit power, and an automatic transmission is connected to the power transmission path. For example, a vehicle control device described in Patent Document 1 is such a vehicle. In the vehicle control device described in Patent Document 1, during evacuation traveling using the engine as a power source, if the rotational speed of the motor generator exceeds a predetermined threshold, the automatic transmission is upshifted to reduce the rotational speed of the motor generator. If the rotational speed of the motor generator remains above the predetermined threshold for a predetermined period of time even after the automatic transmission is upshifted, the evacuation traveling is stopped. This prevents the motor generator from overheating to the point where it could malfunction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-121351 Summary of the Invention [Problem to be solved by the invention]

[0004] If the ECU (Electronic Control Unit) that controls the inverter that drives the motor generator fails, it is possible to prevent the permanent magnet motor generator from overheating and failing by stopping the function of the failed ECU and putting the motor generator into a non-driving state. In this case, a short circuit in the inverter that controls the motor generator to be in a non-driving state cannot be detected. Therefore, if both an ECU failure and a short circuit in the inverter occur, there is a risk of an overcurrent flowing and burning the cable connecting the motor generator and the inverter.

[0005] The present invention has been made against the background of the above circumstances, and its purpose is to provide a vehicle control device that can prevent the cable connecting the inverter to a driving power source consisting of a permanent magnet motor generator from burning, and can also extend the driving distance during evacuation driving. [Means for solving the problem]

[0006] The gist of the present invention is a control device for a vehicle having a first power source for driving and a second power source for driving consisting of a permanent magnet motor generator and which is rotated when in a non-driven state while driving using the first power source, the control device including: (a) a first control device unit; and a second control device unit which controls an inverter that drives the second power source and is different from the first control device unit; (b) when the first control device unit determines that the second control device unit has failed, the second power source is put into a non-driven state and evacuation driving is performed using the first power source; and (c) when the temperature of the cable connecting the second power source and the inverter exceeds a predetermined judgment temperature, the control device cancels the evacuation driving. [Effects of the Invention]

[0007] The vehicle control device of the present invention includes: (a) a first control device; and a second control device that controls an inverter that drives the second power source and is different from the first control device. (b) When the first control device determines that the second control device has failed, the second power source is deactivated and evacuation travel is performed using the first power source. (c) When the temperature of a cable connecting the second power source and the inverter exceeds a predetermined threshold temperature, the evacuation travel is canceled. When a permanent magnet motor generator, which is the second power source, is rotated during evacuation travel, a back electromotive force is generated in the stator coil provided in the second power source. In this case, if a short circuit occurs in any of the inverter's switching elements, an overcurrent may flow in the cable. While the second power source and the inverter can be easily cooled using cooling oil or a cooling fan, the cable must be designed to be more difficult to cool. If the cable temperature is below a predetermined judgment temperature, the evacuation travel continues to extend the distance of the evacuation travel, and if the cable temperature exceeds the predetermined judgment temperature, the evacuation travel is stopped to prevent the cable from burning. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a vehicle equipped with an electronic control device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an MG control inverter, a battery, an electric motor, an MG cable, and an electronic control device shown in FIG. [Figure 3] 2 is an example of a flowchart illustrating a main part of the control operation of the electronic control device shown in FIG. [Figure 4] FIG. 10 is a schematic configuration diagram of a vehicle equipped with an electronic control device according to a second embodiment of the present invention. [Figure 5] 5 is an example of a flowchart illustrating a main part of the control operation of the electronic control device shown in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. Note that in each embodiment, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of each part are not necessarily drawn accurately. [Example]

[0010] FIG. 1 is a schematic configuration diagram of a vehicle 10 equipped with an electronic control device 90 according to a first embodiment of the present invention.

[0011] The vehicle 10 includes an engine 12 as a power source for traveling, and an electric motor MG as a power source for traveling. The vehicle 10 includes a power transmission device 16 on a power transmission path PT between the engine 12 and a pair of drive wheels 14. The power transmission device 16 includes, in order from the engine 12 side, a clutch K0, an electric motor MG, a clutch WSC, an automatic transmission 26, and a differential 30, all of which are well-known components. The vehicle 10 also includes a hydraulic control circuit 40, an MG control inverter 50, a battery 70, and an electronic control device 90.

[0012] The engine 12 is a well-known internal combustion engine and corresponds to the "first power source" in the present invention. The electric motor MG is configured as a permanent magnet motor generator having both an electric motor function and a generator function. For example, the electric motor MG is a three-phase synchronous motor with a surface magnet type or embedded magnet type permanent magnet provided on the rotor. The electric motor MG is rotationally driven via an MG control inverter 50 by power stored in a battery 70. An MG cable 60 electrically connects the stator coil Cs (see FIG. 2) of the electric motor MG to the MG control inverter 50, which supplies and receives power to the stator coil Cs. The electric motor MG corresponds to the "second power source" in the present invention. The MG cable 60 corresponds to the "cable" in the present invention.

[0013] The hydraulic control circuit 40 uses, for example, the hydraulic pressure of hydraulic oil discharged from an oil pump (not shown) as the source pressure, and supplies the necessary hydraulic oil to each part of the power transmission device 16 to control each part of the power transmission device 16. Control of each part of the power transmission device 16 includes, for example, control of engagement and disengagement of the clutch K0, control of engagement and disengagement of the clutch WSC, control of shifting of the automatic transmission 26, control of the amount of lubricating oil supplied, etc.

[0014] The MG control inverter 50 is a power supply circuit that is provided between the electric motor MG and the battery 70 and converts DC to AC and AC to DC under the control of the electronic control device 90. The MG control inverter 50 corresponds to the "inverter" in this invention.

[0015] The battery 70 is a rechargeable secondary battery, and is used to supply power for driving the electric motor MG and to store electric power generated by the electric motor MG through regeneration.

[0016] The electronic control device 90 includes, for example, an engine control ECU 92 that mainly controls the operating state (= operating state or stopped state) of the engine 12, an MG control ECU 94 that mainly controls the operating state (= driven state or non-driven state) of the electric motor MG via the MG control inverter 50, a hydraulic control ECU 96 that controls the hydraulic control circuit 40, and an integrated ECU 98 that coordinates and controls these. The integrated ECU 98 controls the operating states of the engine 12, the electric motor MG, and the powertrain 16 via the engine control ECU 92, the MG control ECU 94, and the hydraulic control ECU 96, respectively, so that a required driving torque Trdem [N·m] required by the driver is transmitted to the pair of driving wheels 14. For example, the required driving torque Trdem required by the driver for the pair of driving wheels 14 is calculated based on an accelerator opening θacc [%], which is the amount of accelerator operation by the driver indicating the magnitude of the driver's acceleration operation, and a vehicle speed V [km / h]. The engine control ECU 92, MG control ECU 94, hydraulic control ECU 96, and integrated ECU 98 in the electronic control device 90 are connected to a communication network using, for example, a well-known CAN (Controller Area Network) communication circuit. This allows the ECUs to input and output data to and from each other. Each ECU includes, for example, a so-called microcomputer, and performs various controls of the vehicle 10 by processing signals according to pre-stored programs. The electronic control device 90 corresponds to the "control device" in this invention.

[0017] The electronic control device 90 receives various signals (e.g., accelerator opening θacc, vehicle speed V, etc.) based on detection values ​​from various sensors (e.g., accelerator opening sensor 80, vehicle speed sensor 82, etc.). The engine control ECU 92 receives a cable temperature THcb [°C] from a temperature sensor 86 that detects the temperature of the MG cable 60, for example. The cable temperature THcb is the temperature of the MG cable 60. As will be described later, the MG cable 60 includes three cables: a U-phase cable 60u, a V-phase cable 60v, and a W-phase cable 60w. The cable temperature THcb represents the cable temperatures THcbu [°C], THcbv [°C], and THcbw [°C] of these three cables. The temperature sensor 86 corresponds to the "temperature sensor" in this invention. The engine control ECU 92 outputs an engine control signal Se for controlling the operation of the engine 12. The MG control ECU 94 receives an inverter voltage Vinv [V] (see FIG. 2) from a voltage sensor 84 that detects the voltage between the positive and negative pole lines of the MG control inverter 50. The MG control ECU 94 outputs an MG control signal Smg for controlling the rotation of the electric motor MG. The hydraulic control ECU 96 outputs a hydraulic control signal Sp for controlling the engagement and disengagement of the clutch K0, the engagement and disengagement of the clutch WSC, the shift control of the automatic transmission 26, and the amount of lubricating oil supplied.

[0018] The vehicle 10 can be selectively switched between a BEV (Battery Electric Vehicle) driving mode, which realizes BEV (Battery Electric Vehicle) driving using only the electric motor MG as a power source; an HEV (Hybrid Electric Vehicle) driving mode, which realizes HEV (Hybrid Electric Vehicle) driving using the engine 12 and the electric motor MG as power sources; and an engine driving mode, which realizes engine driving using only the engine 12 as a power source. During BEV driving, the clutch K0 is released and the clutch WSC is engaged. During HEV driving and engine driving, both the clutch WSC and the clutch WSC are engaged. During engine driving, the rotor of the electric motor MG is rotated by the power output from the engine 12. In other words, the electric motor MG is configured to rotate along with the engine while driving, even when in a non-driving state. The "non-driving state" refers to a state in which the electric motor MG is not controlled to be rotationally driven by the MG control inverter 50. Specifically, all of the switching elements 56a to 56f included in the MG control inverter 50, which will be described later, are controlled to be in the OFF state.

[0019] FIG. 2 is a diagram illustrating the MG control inverter 50, the battery 70, the electric motor MG, the MG cable 60, and the electronic control device 90 shown in FIG.

[0020] The MG control inverter 50 has a well-known configuration and includes switching elements 56a to 56f and diodes 58a to 58f. Hereinafter, when the switching elements 56a to 56f are not particularly distinguished from one another, they will be referred to as switching elements 56. The MG control inverter 50 includes a pair of switching elements 56a and 56b, a pair of switching elements 56c and 56d, and a pair of switching elements 56e and 56f, each connected in series between a positive electrode line and a negative electrode line to which power is supplied from a battery 70. The switching elements 56 are, for example, insulated gate bipolar transistors (IGBTs) or power MOSFETs, and in this embodiment, are N-channel power MOSFETs. Diodes 58a to 58f are connected in parallel to the switching elements 56a to 56f, respectively.

[0021] The upper arm 52 of the MG control inverter 50 is a circuit that supplies current from the positive pole line to the electric motor MG, which is a load, and is composed of switching elements 56a, 56c, 56e and diodes 58a, 58c, 58e. The lower arm 54 of the MG control inverter 50 is a circuit that draws current from the electric motor MG, which is a load, to the negative pole line, and is composed of switching elements 56b, 56d, 56f and diodes 58b, 58d, 58f.

[0022] The connection point between the switching element 56a and the switching element 56b, the connection point between the switching element 56c and the switching element 56d, and the connection point between the switching element 56e and the switching element 56f are electrically connected to the U-phase, V-phase, and W-phase connection terminals of the motor MG, respectively. In this embodiment, the number of phases of the motor MG is "3." For example, the MG cable 60 includes three cables corresponding to the number of phases of the motor MG: a U-phase cable 60u, a V-phase cable 60v, and a W-phase cable 60w. Hereinafter, in this embodiment, when the U-phase cable 60u, the V-phase cable 60v, and the W-phase cable 60w of the MG cable 60 are not particularly distinguished, they will be simply referred to as "three cables." The three cables electrically connect the MG control inverter 50 to the U-phase, the V-phase, and the W-phase of the motor MG, respectively. Note that "three cables" corresponds to "multiple cables" in this invention.

[0023] The temperature sensor 86 includes temperature sensors 86u, 86v, and 86w provided on three cables, respectively. The temperatures detected by the temperature sensors 86u, 86v, and 86w are referred to as cable temperatures THcbu, THcbv, and THcbw, respectively.

[0024] The electronic control unit 90 determines whether the MG control ECU 94 has failed. For example, if an ECU other than the MG control ECU 94 (in this embodiment, the engine control ECU 92) receives abnormal data from the MG control ECU 94 via the CAN communication circuit, the ECU determines that the MG control ECU 94 has failed. If it is determined that the MG control ECU 94 has failed, the electronic control unit 90 stops the function of the MG control ECU 94 to deactivate the electric motor MG and performs control to enable evacuation running in the engine running mode. The engine control ECU 92 corresponds to the "first control device unit" in this invention, and the MG control ECU 94 corresponds to the "second control device unit" in this invention.

[0025] Next, a conventional example will be described. Conventionally, when the MG control ECU 94 is functioning, the MG control ECU 94 determines whether a short-circuit fault has occurred in any of the switching elements 56 of the MG control inverter 50 while controlling the electric motor MG to be in a driving state. A "short-circuit fault" is a fault that results in a constant on-state. A "driving state" is a state in which the electric motor MG is controlled so as to be driven by the MG control inverter 50. In the driving state, three-phase AC is generated by the MG control inverter 50 while controlling the pair of switching elements 56a, 56b, the pair of switching elements 56c, 56d, and the pair of switching elements 56e, 56f so that both the upper arm 52 side and the lower arm 54 side are not simultaneously on. When a short-circuit fault occurs in any of the switching elements 56, both the upper arm 52 side and the lower arm 54 side of either the pair of switching elements 56a and 56b, the pair of switching elements 56c and 56d, or the pair of switching elements 56e and 56f are simultaneously turned on, causing the inverter voltage Vinv to drop. For example, when the electric motor MG is controlled to be in a driving state and the inverter voltage Vinv falls below a determination voltage Vinv_jdg, the MG control ECU 94 determines that a short-circuit fault has occurred. The determination voltage Vinv_jdg is a predetermined determination value determined in advance through experimentation or design in order to determine the occurrence of a short-circuit fault.

[0026] When the MG control ECU 94 is stopped, the electric motor MG is controlled to a non-driven state and all of the switching elements 56 are turned off. Therefore, the inverter voltage Vinv does not decrease, and it is not possible to determine whether a short-circuit fault has occurred. As a result, if the electronic control unit 90 executes evacuation running in the engine running mode, there is a risk that the MG cable 60 will burn out due to a short-circuit fault in the MG control inverter 50. However, the only way to prevent the MG cable 60 from burning out is for the electronic control unit 90 to not execute evacuation running.

[0027] Returning to this embodiment, during evacuation running in the engine running mode, the engine control ECU 92 determines whether the cable temperature THcb exceeds a judgment temperature THcb_jdg [°C]. The judgment temperature THcb_jdg is a predetermined temperature that is determined experimentally or by design as a temperature at which the MG cable 60 will not burn. The cable temperature THcb corresponds to the "cable temperature" in this invention, and the judgment temperature THcb_jdg corresponds to the "predetermined judgment temperature" in this invention.

[0028] During evacuation travel, the rotor of the electric motor MG is rotated, generating a back electromotive force in the stator coil Cs. For example, if a short-circuit fault occurs in the switching element 56a, this back electromotive force may cause an overcurrent to flow through the MG cable 60, which may burn out the MG cable 60, as shown by the dashed-dotted line in FIG. 2. In this case, the current flowing through the U-phase cable 60u is the sum of the current flowing through the V-phase cable 60v and the current flowing through the W-phase cable 60w. Thus, depending on which of the switching elements 56 has a short-circuit fault, the currents flowing through the three cables may be uneven.

[0029] For example, whether the cable temperature THcb exceeds the determination temperature THcb_jdg is determined for each of the cable line temperatures THcbu, THcbv, and THcbw. This is because the currents flowing through the three cables are uneven due to the occurrence of short-circuit failures in different switching elements 56. Preferably, the cable line temperatures THcbu, THcbv, and THcbw are detected at the location with the lowest heat resistance in each of the three cables. The location with the lowest heat resistance is a predetermined location determined experimentally or by design.

[0030] For example, if the temperature sensor 86u fails, the cable temperature THcbu may be calculated based on the cable temperatures THcbv and THcbw, and it may be determined whether the calculated cable temperature THcbu exceeds the determination temperature THcb_jdg. For example, assuming that the current flowing through the U-phase cable 60u is the sum of the current flowing through the V-phase cable 60v and the current flowing through the W-phase cable 60w, the cable temperature THcbu can be calculated by applying the actual cable temperatures THcbv and THcbw to a map in which the relationships between the cable temperatures THcbv and THcbw and the cable temperature THcbu are determined in advance by experiment or design and stored.

[0031] For example, if the temperature sensor 86u and the temperature sensor 86v fail, the cable temperature THcbu may be calculated based on the cable temperature THcbw, and it may be determined whether the calculated cable temperature THcbu exceeds the determination temperature THcb_jdg. For example, assuming that the current flowing through the U-phase cable 60u is twice the current flowing through the W-phase cable 60w, the cable temperature THcbu can be calculated by applying the actual cable temperature THcbw to a map in which the relationship between the cable temperature THcbw and the cable temperature THcbu is determined in advance by experiment or design and stored.

[0032] In this way, whether the cable temperature THcb exceeds the determination temperature THcb_jdg may be determined based on some of the temperatures of the three cables. When the cable temperatures THcbu, THcbv, and THcbw are detected by the temperature sensors 86u, 86v, and 86w, respectively, the cable temperature THcbu has no error relative to the actual temperature. In contrast, the cable temperature THcbu calculated based on the cable temperatures THcbv and THcbw has an error relative to the actual temperature, and the cable temperature THcbu calculated based only on the cable temperature THcbw has an even larger error relative to the actual temperature. To reliably prevent burnout of the MG cable 60, the greater the error between the cable temperature THcbu and the actual temperature, the more the determination temperature THcb_jdg needs to be lowered.

[0033] During evacuation running in the engine running mode, if the engine control ECU 92 determines that the cable temperature THcb exceeds the determination temperature THcb_jdg, the electronic control unit 90 stops the evacuation running and stops the vehicle 10.

[0034] FIG. 3 is an example of a flowchart illustrating the main control operations of the electronic control device 90 shown in FIG.

[0035] First, in step (hereinafter, step will be omitted) S10, it is determined whether or not the MG control ECU 94 has failed. If the determination in S10 is NO, the process returns. If the determination in S10 is YES, the electric motor MG is put into a non-driven state in S20, and evacuation traveling in the engine traveling mode is performed. Preferably, in this case, the driver is notified that evacuation traveling has started. After S20 is performed, it is determined in S30 whether or not the cable temperature THcb exceeds the determination temperature THcb_jdg. If the determination in S30 is NO, S20 is performed again, that is, the evacuation traveling continues. Preferably, if the cable temperature THcb approaches and is likely to exceed the determination temperature THcb_jdg, the driver is notified that the evacuation traveling may be canceled. If the determination in S30 is YES, the evacuation traveling is canceled and the vehicle 10 is stopped in S40. Preferably, in this case, the driver is notified that the evacuation traveling has been canceled. After S40 is executed, the process ends.

[0036] According to this embodiment, (a) the electronic control device 90 includes an engine control ECU 92 and an MG control ECU 94, which controls the MG control inverter 50 that drives the electric motor MG and is separate from the engine control ECU 92. (b) If the engine control ECU 92 determines that the MG control ECU 94 has failed, the electric motor MG is deactivated and evacuation travel is performed in engine running mode. (c) If the cable temperature THcb exceeds the threshold temperature THcb_jdg, the evacuation travel is stopped. When the electric motor MG, which is a permanent magnet motor generator, rotates during evacuation travel, a back electromotive force is generated in the stator coil Cs. In this case, if a short circuit occurs in any of the switching elements 56, an overcurrent may flow in the MG cable 60. While the electric motor MG and the MG control inverter 50 can be easily cooled using cooling oil or a cooling fan, the MG cable 60 must be designed to be more difficult to cool. If the cable temperature THcb is equal to or lower than the judgment temperature THcb_jdg, the evacuation driving is continued to extend the distance of the evacuation driving, and if the cable temperature THcb exceeds the judgment temperature THcb_jdg, the evacuation driving is stopped to prevent the MG cable 60 from burning out.

[0037] According to this embodiment, (a) the MG cable 60 includes three cable wires corresponding to the number of phases of the electric motor MG, and (b) whether the cable temperature THcb exceeds the judgment temperature THcb_jdg is judged for each of the three cable wires. Even if the currents flowing through the three cable wires are uneven due to the occurrence of a short-circuit fault, the judgment is made for each of the three cable wires, thereby preventing burnout in all three cable wires.

[0038] According to this embodiment, (a) the MG cable 60 includes three cable wires corresponding to the number of phases of the electric motor MG, and (b) if the temperature sensor 86u fails or if the temperature sensors 86u and 86v fail, whether the cable temperature THcb exceeds the determination temperature THcb_jdg is determined based on some of the temperatures of the three cable wires detected by the non-failed temperature sensors 86. In this way, even if some of the temperature sensors 86 that detect the temperatures of the three cable wires fail, the determination can be made based on the temperatures detected by the remaining cable wires. [Example]

[0039] 4 is a schematic configuration diagram of a vehicle 110 equipped with an electronic control device 190 according to a second embodiment of the present invention. In the second embodiment, the description will focus on parts that are different from the first embodiment described above, and parts that are substantially the same in function as the first embodiment will be assigned the same reference numerals and descriptions thereof will be omitted as appropriate.

[0040] The vehicle 110 is equipped with a front-wheel drive motor MGf and a rear-wheel drive motor MGr, which are power sources for traveling. The front-wheel drive motor MGf is connected to a pair of front wheels 14f via a front-wheel output shaft 28f and a front-wheel differential 30f, which are well-known configurations. The rear-wheel drive motor MGr is connected to a pair of rear wheels 14r via a rear-wheel output shaft 28r and a rear-wheel differential 30r, which are well-known configurations. The vehicle 110 also includes an MGf control inverter 50f, an MGr control inverter 50r, a battery 70, and an electronic control device 190.

[0041] The front-wheel drive motor MGf and the rear-wheel drive motor MGr have the same configuration as the motor MG in the first embodiment, and are each configured as a permanent magnet motor generator having both a motor function and a generator function. The front-wheel drive motor MGf and the rear-wheel drive motor MGr are rotated and driven by power stored in a battery 70 via an MGf control inverter 50f and an MGr control inverter 50r, respectively. An MGf cable 60f electrically connects a stator coil (not shown) in the front-wheel drive motor MGf to the MGf control inverter 50f that supplies and receives power to the stator coil. The front-wheel drive motor MGf corresponds to the "second power source" in this invention. The MGf cable 60f corresponds to the "cable" in this invention. The MGr cable 60r electrically connects a stator coil (not shown) in the rear-wheel drive motor MGr to the MGr control inverter 50r that supplies and receives power to the stator coil. The rear-wheel drive electric motor MGr corresponds to the "first power source" in the present invention. For example, like the MG cable 60 described above, the MGf cable 60f includes three cable wires corresponding to the number of phases of the front-wheel drive electric motor MGf. The three cable wires of the MGf cable 60f electrically connect the MGf control inverter 50f to the U phase, V phase, and W phase of the front-wheel drive electric motor MGf, respectively. Similarly, the MGr cable 60r also includes three cable wires corresponding to the number of phases of the rear-wheel drive electric motor MGr. The three cable wires of the MGf cable 60f correspond to the "plurality of cable wires" in the present invention. Hereinafter, in this embodiment, the three cable wires of the MGf cable 60f will be simply referred to as "three cable wires."

[0042] The MGf control inverter 50f is a power supply circuit provided between the front-wheel drive motor MGf and the battery 70, and is controlled by the electronic control device 190 to convert DC to AC or AC to DC. The MGr control inverter 50r is a power supply circuit provided between the rear-wheel drive motor MGr and the battery 70, and is controlled by the electronic control device 190 to convert DC to AC or AC to DC. The MGf control inverter 50f according to this embodiment corresponds to the "inverter" according to the present invention.

[0043] The hydraulic control circuit 140 is a control circuit that controls the amount of lubricating oil supplied to cool, for example, the front wheel drive motor MGf and the rear wheel drive motor MGr, using the hydraulic pressure of the hydraulic oil OIL discharged from an oil pump (not shown) as the source pressure.

[0044] The electronic control device 190 includes an MGf control ECU 94f that mainly controls the operating state of the front-wheel drive electric motor MGf via an MGf control inverter 50f, an MGr control ECU 94r that mainly controls the operating state of the rear-wheel drive electric motor MGr via an MGr control inverter 50r, a hydraulic control ECU 196 that controls the hydraulic control circuit 140, and an integrated ECU 198 that coordinates and controls these. The integrated ECU 198 controls the operating states of the front-wheel drive electric motor MGf and the rear-wheel drive electric motor MGr via the MGf control ECU 94f and the MGr control ECU 94r, respectively, so that a required drive torque Trdem requested by, for example, a driver is transmitted to the drive wheels (a pair of front wheels 14f and / or a pair of rear wheels 14r). The MGf control ECU 94f, MGr control ECU 94r, hydraulic control ECU 196, and integrated ECU 198 in the electronic control device 190 are each connected to a communication network using, for example, a CAN communication circuit. The electronic control device 190 corresponds to the "control device" of the present invention.

[0045] The electronic control unit 190 receives various signals (e.g., accelerator opening θacc, vehicle speed V, etc.) based on detection values ​​from various sensors (e.g., accelerator opening sensor 80, vehicle speed sensor 82, etc.). The MGf control ECU 94f receives a cable temperature THcbr [°C] from a temperature sensor 86r that detects the temperature of the MGr cable 60r. The MGr control ECU 94r receives a cable temperature THcbf [°C] from a temperature sensor 86f that detects the temperature of the MGf cable 60f. The temperature sensor 86f corresponds to the "temperature sensor" in this invention. The cable temperature THcbf is the temperature of the MGf cable 60f and is a temperature that represents the temperature of each of the three cable wires of the MGf cable 60f described above. The cable temperature THcbr is the temperature of the MGr cable 60r and is a temperature that represents the temperature of each of the three cable wires of the MGr cable 60r described above. The MGf control ECU 94f outputs an MGf control signal Smgf for controlling the rotation of the front-wheel drive electric motor MGf. The MGr control ECU 94r outputs an MGr control signal Smgr for controlling the rotation of the rear-wheel drive electric motor MGr. The MGf control ECU 94f receives an inverter voltage Vinvf [V] from a voltage sensor 84f that detects the voltage between the positive and negative pole lines of the MGf control inverter 50f. The MGr control ECU 94r receives an inverter voltage Vinvr [V] from a voltage sensor 84r that detects the voltage between the positive and negative pole lines of the MGr control inverter 50r. The hydraulic control ECU 196 outputs a hydraulic control signal Sp for controlling the amount of lubricating oil supplied, etc.

[0046] The vehicle 110 can be selectively switched between a front-wheel drive mode that realizes front-wheel drive running using only the front-wheel drive electric motor MGf as a power source, a rear-wheel drive mode that realizes rear-wheel drive running using only the rear-wheel drive electric motor MGr as a power source, and a four-wheel drive mode that realizes four-wheel drive running using both the front-wheel drive electric motor MGf and the rear-wheel drive electric motor MGr as power sources. The front-wheel drive mode, rear-wheel drive mode, and four-wheel drive mode are all BEV driving modes.

[0047] In the rear-wheel drive mode, the front-wheel drive motor MGf is in a non-drive state. During rear-wheel drive driving, the front-wheel drive motor MGf is in a non-drive state, but the rotor of the front-wheel drive motor MGf is in a rotating state as power output from the rear-wheel drive motor MGr is transmitted via the pair of front wheels 14f and the front-wheel differential 30f. In other words, the front-wheel drive motor MGf is configured to rotate along with the rear-wheel drive motor even when in a non-drive state. In the front-wheel drive mode, the rear-wheel drive motor MGr is in a non-drive state. The rear-wheel drive motor MGr is configured to rotate along with the front-wheel drive motor even when in a non-drive state. The "non-drive state" refers to a state in which the front-wheel drive motor MGf or the rear-wheel drive motor MGr is not controlled to rotate by the MGf control inverter 50f or the MGr control inverter 50r, respectively.

[0048] Next, the control of the electronic control unit 190 when the MGf control ECU 94f fails will be described. Note that the control of the electronic control unit 190 when the MGr control ECU 94r fails can be achieved by simply switching the control for the pair of front wheels 14f and the control for the pair of rear wheels 14r, and therefore a description thereof will be omitted.

[0049] The electronic control unit 190 determines whether the MGf control ECU 94f has failed. For example, an ECU other than the MGf control ECU 94f (the MGr control ECU 94r in this embodiment) determines that the MGf control ECU 94f has failed if data received from the MGf control ECU 94f via the CAN communication circuit is abnormal. If it is determined that the MGf control ECU 94f has failed, the electronic control unit 190 stops the function of the MGf control ECU 94f to put the front-wheel drive electric motor MGf in a non-drive state and performs control so that evacuation running in the rear-wheel drive running mode is possible. The MGr control ECU 94r corresponds to the "first control device unit" in this invention, and the MGf control ECU 94f corresponds to the "second control device unit" in this invention.

[0050] During evacuation traveling in the rear-wheel drive traveling mode, the MGr control ECU 94r determines whether the cable temperature THcbf exceeds a threshold temperature THcbf_jdg [°C]. The threshold temperature THcbf_jdg is a predetermined temperature determined experimentally or by design as a temperature at which the MGf cable 60f will not burn. The cable temperature THcbf corresponds to the "cable temperature" in this invention, and the threshold temperature THcbf_jdg corresponds to the "predetermined threshold temperature" in this invention. Although a detailed description will be omitted, as in the first embodiment described above, (a) whether the cable temperature THcbf exceeds the threshold temperature THcbf_jdg may be determined for each of the three cable lines. (b) If one of the temperature sensors 86f detecting the temperatures of the three cable lines fails, whether the cable temperature THcbf exceeds the threshold temperature THcbf_jdg may be determined based on a portion of the cable line temperatures detected by the remaining temperature sensors 86f. During evacuation running in the rear-wheel drive running mode, if it is determined that the cable temperature THcbf exceeds the determination temperature THcbf_jdg, the electronic control unit 190 stops the evacuation running and stops the vehicle 110.

[0051] FIG. 5 is an example of a flowchart illustrating the main control operations of electronic control device 190 shown in FIG.

[0052] First, in S110, it is determined whether the MGf control ECU 94f has a malfunction. If the determination in S110 is YES, in S120, the front-wheel drive electric motor MGf is put into a non-driven state, and evacuation traveling in the rear-wheel drive traveling mode is performed. Preferably, in this case, the driver is notified that evacuation traveling has started. After S120 is performed, in S130, it is determined whether the cable temperature THcbf exceeds the judgment temperature THcbf_jdg. If the determination in S130 is NO, S120 is performed again, that is, evacuation traveling in the rear-wheel drive traveling mode is continued. Preferably, if the cable temperature THcbf approaches and is likely to exceed the judgment temperature THcbf_jdg, the driver is notified that the evacuation traveling may be canceled. If the determination in S130 is YES, in S140, the evacuation traveling is canceled and the vehicle 110 is stopped. Preferably, in this case, the driver is notified that the evacuation travel has been canceled. After execution of S140, the process ends. If the determination in S110 is NO, the process returns.

[0053] According to this embodiment, (a) the electronic control device 190 includes an MGr control ECU 94r and an MGf control ECU 94f that controls the MGf control inverter 50f that drives the front-wheel drive electric motor MGf and is different from the MGr control ECU 94r, (b) when the MGr control ECU 94r determines that the MGf control ECU 94f has failed, the front-wheel drive electric motor MGf is put into a non-driven state and evacuation traveling is performed in the rear-wheel drive traveling mode, and (c) when the cable temperature THcbf exceeds a threshold temperature THcbf_jdg, the evacuation traveling is stopped. As a result, when the cable temperature THcbf is equal to or lower than the threshold temperature THcbf_jdg, the evacuation traveling continues to extend the traveling distance of the evacuation traveling, and when the cable temperature THcbf exceeds the threshold temperature THcbf_jdg, the evacuation traveling is stopped to prevent the MGf cable 60f from burning.

[0054] According to this embodiment, the MGf cable 60f includes three cable wires corresponding to the number of phases of the front-wheel drive electric motor MGf, and similarly to the above-described first embodiment, (a) whether the cable temperature THcbf exceeds the threshold temperature THcbf_jdg may be determined for each of the three cable wires, or (b) if one of the temperature sensors 86f detecting the temperatures of the three cable wires fails, whether the cable temperature THcbf exceeds the threshold temperature THcbf_jdg may be determined based on some of the temperatures of the cable wires detected by the temperature sensors 86f that are not failed. This provides the same effects as the first embodiment.

[0055] The above-described embodiments of the present invention are merely illustrative, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[0056] In the first embodiment, it is the engine control ECU 92 that determines whether the MG control ECU 94 has failed, and in the second embodiment, it is the MGr control ECU 94r that determines whether the MGf control ECU 94f has failed, but this is not limiting. Any ECU other than the ECU whose failure is determined may be, for example, the hydraulic control ECU 96, the integrated ECU 98, the hydraulic control ECU 196, the integrated ECU 198, or the like.

[0057] In the second embodiment described above, the control of the electronic control unit 190 when the MGf control ECU 94f fails has been described, but the present invention is also applicable to the case when the MGr control ECU 94r fails.

[0058] In the first embodiment described above, the temperatures of all three cables are detected by the temperature sensor 86, and whether the cable temperature THcb exceeds the judgment temperature THcb_jdg is determined for each of the three cables. In the second embodiment described above, the temperatures of all three cables are detected by the temperature sensor 86f, and whether the cable temperature THcbf exceeds the judgment temperature THcbf_jdg is determined for each of the three cables. However, the present invention is not limited to these embodiments. For example, only some of the temperatures of the three cables may be detected by the temperature sensors 86 and 86f, and whether the cable temperature THcb exceeds the judgment temperature THcb_jdg or whether the cable temperature THcbf exceeds the judgment temperature THcbf_jdg may be determined based on some of the detected temperatures of the three cables. In this case, the determination is made in the same manner as when some of the temperature sensors 86 and 86f fail, as described in the first and second embodiments. This reduces the number of temperature sensors and therefore the cost compared to when temperature sensors are provided on all three cable lines.

[0059] In the first and second embodiments described above, the electric motor MG, the front wheel drive electric motor MGf, and the rear wheel drive electric motor MGr each have three phases, but the present invention is not limited to this and may have other numbers of phases.

[0060] In the above-described first and second embodiments, each ECU is connected to a network that communicates using a CAN communication circuit, but the ECUs may be connected in any manner as long as the necessary data can be input and output between them.

[0061] In the first embodiment described above, the vehicle 10 is provided with the clutch WSC, but the present invention is also applicable to a vehicle provided with a torque converter instead of the clutch WSC. [Explanation of symbols]

[0062] 10, 110: vehicle, 12: engine (first power source), 50: MG control inverter (inverter), 50f: MGf control inverter (inverter), 60: MG cable (cable), 60f: MGf cable (cable), 60u: U-phase cable wire (cable wire), 60v: V-phase cable wire (cable wire), 60w: W-phase cable wire (cable wire), 86: temperature sensor (temperature sensor), 86f: temperature sensor (temperature sensor), 90, 190: electronic control unit (control unit), 92: engine control E CU (first control device unit), 94: MG control ECU (second control device unit), 94f: MGf control ECU (second control device unit), 94r: MGr control ECU (first control device unit), MG: electric motor (second power source), MGf: front wheel drive electric motor (second power source), MGr: rear wheel drive electric motor (first power source), THcb: cable temperature (temperature of cable), THcb_jdg: judgment temperature (predetermined judgment temperature), THcbf: cable temperature (temperature of cable), THcbf_jdg: judgment temperature (predetermined judgment temperature)

Claims

1. A control device for a vehicle including a first power source for running, and a second power source for running which is formed by a permanent magnet motor generator and which is rotated in a non-driving state while running using the first power source, a first control device unit and a second control device unit that controls an inverter that drives the second power source and is different from the first control device unit; When the first control device determines that the second control device has failed, the second power source is put into a non-driving state and evacuation travel is performed using the first power source; When the temperature of the cable connecting the second power source and the inverter exceeds a predetermined judgment temperature, the evacuation traveling is stopped. A vehicle control device characterized by:

2. the cable includes a plurality of cable wires corresponding to the number of phases of the second power source, Whether the temperature of the cable exceeds the determination temperature is determined for each of the plurality of cable lines.

2. The vehicle control device according to claim 1.

3. the cable includes a plurality of cable wires corresponding to the number of phases of the second power source, Whether the temperature of the cable exceeds the determination temperature is determined based on a portion of the temperatures of the plurality of cable wires.

2. The vehicle control device according to claim 1.

4. When some of the temperature sensors that detect the temperatures of the plurality of cable wires fail, it is determined whether the temperature of the cable exceeds the determination temperature based on the part of the temperature of the cable wires detected by the temperature sensors that are not faulty.

4. The vehicle control device according to claim 3.

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