Vehicle control device

Abstract

To suppress overspeed of a first motor and overcharging of a battery.SOLUTION: A vehicle control device is used for a hybrid vehicle and controls an engine, first and second motors, and a brake device so that required braking torque is applied to a vehicle when braking is required. When an abnormality occurs in brake control using the brake device during deceleration, the vehicle control device reduces an absolute value of the required braking torque compared to when the brake control is normal or limits the absolute value of the required braking torque to a predetermined upper limit. Thus, the vehicle control device can suppress overspeed of the first motor and overcharging of a battery.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle control device. [Background technology]

[0002] A conventional vehicle control device of this type has been proposed for use in a vehicle equipped with a motor and a brake device that has a master cylinder that generates brake oil pressure according to the amount of depression of the brake pedal and applies braking torque to each wheel (see, for example, Patent Document 1). In this device, when an abnormality occurs in the master cylinder, the vehicle is stopped by braking torque generated by regenerative braking of the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-1775 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a hybrid vehicle equipped with an engine, a first motor, a planetary gear with a sun gear, a ring gear, and a carrier connected in that order to three shafts (the rotor of the first motor, a drive shaft connected to the axle, and the engine output shaft), a second motor connected to the drive shaft, a battery that exchanges power with the first and second motors, and a brake device that applies braking torque to wheels connected to the axle, when braking is required, the engine, the first and second motors, and the brake device are controlled by cutting fuel to the engine so that the required braking torque acts on the vehicle. In this case, because the inertia of the first motor is smaller than that of the engine, the rotational speed of the first motor increases, which can lead to over-rotation. If torque is output in a direction that reduces the rotational speed of the first motor to prevent such over-rotation, the first motor enters a power generating state, which inputs excessive power to the battery, potentially overcharging it. In particular, it is recognized as a major issue that if any abnormality occurs in the brake control using the brake device, the brake control cannot be executed properly, which makes it more likely that the first motor will over-rotate or the battery will overcharge.

[0005] The vehicle control device of the present disclosure has a primary object to suppress over-rotation of the first motor and over-charging of the battery. [Means for solving the problem]

[0006] The vehicle control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The vehicle control device of the present disclosure is used in a hybrid vehicle including an engine, a first motor, a planetary gear in which a sun gear, a ring gear, and a carrier are connected in this order to three shafts: a rotor of the first motor, a drive shaft connected to an axle, and an output shaft of the engine, a second motor connected to the drive shaft, a battery that exchanges power with the first and second motors, and a brake device that applies braking torque to wheels connected to the axle, and when braking is required, the vehicle control device controls the engine, the first and second motors, and the brake device so that a required braking torque acts on the vehicle, The gist of the invention is that when an abnormality occurs in the brake control using the brake device, the absolute value of the required braking torque is reduced compared to when the brake control is normal, or the absolute value of the required braking torque is set to a predetermined upper limit value or less.

[0008] In the vehicle control device disclosed herein, when an abnormality occurs in brake control using the brake device, the absolute value of the required braking torque is reduced or the upper limit of the absolute value of the required braking torque is lowered compared to when brake control is normal. This reduces the charging power generated by braking to charge the battery and increases the torque output from the first motor in a direction that reduces the rotational speed. As a result, over-rotation of the first motor and over-charging of the battery can be suppressed.

[0009] In the vehicle control device of the present disclosure, if an abnormality related to the brake control occurs during deceleration and if locking of the second motor is not detected, the required braking torque may be set to an unlocked braking torque, and if locking of the second motor is detected, the absolute value of the required braking torque may be set to be smaller than the unlocked braking torque or may be set to be equal to or less than the predetermined upper limit. In this way, when locking of the second motor is detected, over-rotation of the first motor and over-charging of the battery can be more appropriately suppressed.

[0010] In the vehicle control device of the present disclosure, the abnormality related to brake control may be at least one of an abnormality related to an antilock brake system function that controls the brake device so as to unlock the wheel when the wheel is locked, and an abnormality in which information on the brake operation amount cannot be acquired. In this way, when at least one of an abnormality related to the antilock brake system function and an abnormality in which information on the brake operation amount cannot be acquired occurs, over-rotation of the first motor and over-charging of the battery can be suppressed.

[0011] In this case, if an abnormality related to the brake control occurs during deceleration and locking of the second motor is detected, and the abnormality related to the brake control is an abnormality in which information on the brake operation amount cannot be obtained, the absolute value of the required braking torque may be set to be smaller than when the abnormality related to the brake control is an abnormality in which the anti-lock brake system function cannot be executed. When the abnormality related to the brake control is an abnormality in which information on the brake operation amount cannot be obtained, detection of locking of the second motor may be delayed compared to when the abnormality related to the brake control is an abnormality in which the anti-lock brake system function cannot be executed. Therefore, by setting the absolute value of the required braking torque to be smaller when the abnormality related to the brake control is an abnormality in which information on the brake operation amount cannot be obtained compared to when the abnormality related to the brake control is an abnormality in which the anti-lock brake system function cannot be executed, overspeeding of the first motor and overcharging of the battery can be more appropriately suppressed.

[0012] Furthermore, in the vehicle control device of the present disclosure, when an abnormality related to the brake control occurs during deceleration, the absolute value of the required braking torque may be set smaller when the absolute value of the input limit, which is the maximum allowable power that may be charged from the battery, is small compared to when it is large. In this way, overcharging of the battery can be more appropriately suppressed. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing the outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention; [Figure 2] FIG. 4 is an explanatory diagram showing an example of a required braking torque setting map; [Figure 3] 4 is a flowchart showing an example of a deceleration control routine. [Figure 4] FIG. 4 is an explanatory diagram showing an example of a basic braking torque setting map. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 of this embodiment. As shown in the figure, the hybrid vehicle 20 of this embodiment includes an engine 22, a planetary gear 30, a motor MG1 (first motor), a motor MG2 (second motor), inverters 41 and 42, a battery 50, a hybrid electronic control unit (hereinafter referred to as "HVECU") 70, and a brake device 90.

[0015] The engine 22 is configured as an internal combustion engine that outputs power using gasoline, diesel, etc. as fuel. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 24.

[0016] Although not shown, the engine ECU 24 is configured as a microprocessor centered around a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, input / output ports, and communication ports. Signals from various sensors required for controlling the operation of the engine 22 are input to the engine ECU 24 via an input port. Examples of signals input to the engine ECU 24 include a crank angle θcr from a crank position sensor 23 that detects the rotational position of a crankshaft (output shaft) 26 of the engine 22, and a throttle opening TH from a throttle valve position sensor that detects the position of a throttle valve. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via an output port. Examples of signals output from the engine ECU 24 include a drive control signal to a throttle motor that adjusts the position of the throttle valve, a drive control signal to a fuel injection valve, and a drive control signal to an ignition coil integrated with an igniter. The engine ECU 24 is connected to the HVECU 70 via a communication port, and controls the operation of the engine 22 based on control signals from the HVECU 70, and outputs data relating to the operating state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 calculates the rotation speed of the crankshaft 26, i.e., the rotation speed Ne of the engine 22, based on the crank angle θcr from the crank position sensor 23.

[0017] The planetary gear 30 is configured as a single-pinion planetary gear mechanism. A rotor of a motor MG1 is connected to a sun gear of the planetary gear 30. A drive shaft 36 is connected to an axle 37 connected to drive wheels 39a, 39b via a differential gear 38, and a carrier of the planetary gear 30 is connected to the crankshaft 26 of the engine 22 via a damper 28.

[0018] The motor MG1 is configured as, for example, a synchronous generator motor, and as described above, its rotor is connected to the sun gear of the planetary gear 30. The motor MG2 is configured as, for example, a synchronous generator motor, and its rotor is connected to the drive shaft 36 via a reduction gear (not shown). The inverters 41, 42 are connected to a battery 50 via a power line 54. The motors MG1, MG2 are rotationally driven by a motor electronic control unit (hereinafter referred to as "motor ECU") 40 that controls the switching of multiple switching elements (not shown) of the inverters 41, 42.

[0019] The motor ECU 40 is configured as a microprocessor centered around a CPU (not shown). In addition to the CPU, the motor ECU 40 includes a ROM for storing processing programs, a RAM for temporarily storing data, input / output ports, and a communication port. Signals from various sensors required for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input port. Examples of signals input to the motor ECU 40 include rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and phase currents from current sensors that detect the currents flowing through each phase of the motors MG1 and MG2. The motor ECU 40 outputs switching control signals to switching elements (not shown) of the inverters 41 and 42 via the output port. The motor ECU 40 is connected to the HVECU 70 via the communication port. The motor ECU 40 controls the driving of the motors MG1 and MG2 based on control signals from the HVECU 70 and outputs data related to the driving status of the motors MG1 and MG2 to the HVECU 70 as needed. The motor ECU 40 calculates the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotation positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotation position detection sensors 43 and 44.

[0020] Battery 50 is configured as, for example, a lithium ion secondary battery or a nickel-metal hydride secondary battery, and is connected to inverters 41 and 42 via power line 54. Battery 50 is managed by a battery electronic control unit (hereinafter referred to as "battery ECU") 52.

[0021] Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU. In addition to the CPU, the battery ECU 52 includes a ROM for storing processing programs, a RAM for temporarily storing data, input / output ports, and a communication port. Signals from various sensors required for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include a battery voltage VB from a voltage sensor 51a installed between the terminals of the battery 50, a battery current IB from a current sensor 51b attached to the output terminal of the battery 50, and a battery temperature TB from a temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via the communication port and outputs data related to the status of the battery 50 to the HVECU 70 as needed. The battery ECU 52 calculates a power storage percentage SOC based on an integrated value of the battery current IB from the current sensor 51b. The power storage percentage SOC is the ratio of the amount of power that can be discharged from the battery 50 to the total capacity of the battery 50. The battery ECU 52 also calculates input / output limits Win and Wout, which are the maximum allowable power that can be charged and discharged from the battery 50, based on the power storage rate SOC and the battery temperature TB.

[0022] The braking device 90 includes brake pads 96a, 96b, 96c, and 96d attached to the driving wheels 39a and 39b and the driven wheels 39c and 39d, and a brake actuator 94. The brake actuator 94 is configured as an actuator for applying braking torque to the driving wheels 39a and 39b and the driven wheels 39c and 39d by adjusting the hydraulic pressure of brake wheel cylinders (not shown) that drive the brake pads 96a, 96b, 96c, and 96d. The brake actuator 94 is driven and controlled by a brake electronic control unit (hereinafter referred to as a "brake ECU") 92.

[0023] Although not shown, the brake ECU 92 is configured as a microprocessor centered around a CPU, and in addition to the CPU, is equipped with a ROM for storing processing programs, a RAM for temporarily storing data, an input / output port, and a communication port. Signals from various sensors required for driving and controlling the brake actuator 94 are input to the brake ECU 92 via the input port. Drive control signals and other signals to the brake actuator 94 are output from the brake ECU 92 via the output port. The brake ECU 92 is connected to the HVECU 70 via the communication port.

[0024] The brake ECU 92 also performs functions such as an anti-lock braking system (ABS) that prevents either the drive wheels 39a, 39b or the driven wheels 39c, 39d from locking and slipping when the driver depresses the brake pedal 85, a traction control (TRC) that prevents either the drive wheels 39a, 39b from slipping due to spinning when the driver depresses the accelerator pedal 83, and a vehicle stance control (VSC) that maintains the vehicle's stance when turning.

[0025] Although not shown, the HVECU 70 is configured as a microprocessor centered around a CPU. In addition to the CPU, the HVECU 70 includes a ROM for storing processing programs, a RAM for temporarily storing data, input / output ports, and communication ports. Signals from various sensors are input to the HVECU 70 via the input ports. Examples of signals input to the HVECU 70 include an ignition signal from an ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81. Other signals include an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the depression amount of an accelerator pedal 83, a brake pedal position (brake operation amount) BP from a brake pedal position sensor 86 that detects the depression amount of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 88. As described above, the HVECU 70 is connected to the engine ECU 24, motor ECU 40, and battery ECU 52 via the communication ports, and exchanges various control signals and data with the engine ECU 24, motor ECU 40, battery ECU 52, and brake ECU 92.

[0026] The hybrid vehicle 20 of this embodiment configured as described above runs in one of a plurality of running modes, including a hybrid running (HV running) mode and an electric running (EV running) mode. Here, the HV running mode is a mode in which the vehicle runs using power from the engine 22 and power from the motors MG1 and MG2 while the engine 22 is running. The EV running mode is a mode in which the vehicle runs using power from the motor MG2 without running the engine 22.

[0027] In the HV driving mode, the HVECU 70 sets a required torque Td* required for driving based on the accelerator pedal position Acc and the vehicle speed V, and calculates a required driving power Pd* required for driving by multiplying the set required torque Td* by the rotation speed Nd of the drive shaft 36 (the rotation speed Nm2 of the motor MG2). Next, the required driving power Pe* is set by subtracting a required charging / discharging power Pb* (a positive value when discharging from the battery 50) based on the state of charge of the battery 50 from the required driving power Pd*. Next, a target rotation speed Ne* and a target torque Te* for the engine 22 are set so that the required power Pe* is output from the engine 22. The target rotation speed Ne* and the target torque Te* are set by determining in advance an optimal operating line for the driving points (rotation speed, torque) of the engine 22 that optimize fuel economy while taking noise, vibration, etc. into account. Next, the torque command Tm1* for motor MG1 and the torque command Tm2* for motor MG2 are set so that the engine 22 rotates at the target rotation speed Ne* and a required torque Td* is output to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. The target rotation speed Ne* and target torque Te* for the engine 22 are then sent to the engine ECU 24, and the torque commands Tm1* and Tm2* for the motors MG1 and MG2 are sent to the motor ECU 40. The engine ECU 24 controls the intake air amount, fuel injection, ignition, and the like for the engine 22 so that the engine 22 operates based on the target rotation speed Ne* and the target torque Te*. The motor ECU 40 controls the switching of the transistors of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1* and Tm2*.

[0028] In the EV driving mode, the HVECU 70 sets the required torque Td* based on the accelerator opening Acc and the vehicle speed V, sets the torque command Tm1* for the motor MG1 to 0, and sets the torque command Tm2* for the motor MG2 so that the required torque Td* is output to the drive shaft 36 within the range of the input / output limits Win and Wout. The HVECU 70 then transmits the torque commands Tm1* and Tm2* for the motors MG1 and MG2 to the motor ECU 40. The control of the inverters 41 and 42 by the motor ECU 40 has been described above.

[0029] Furthermore, in the hybrid vehicle 20 of this embodiment, when no abnormality occurs in the brake control using the brake device 90, the following braking control is executed when the driver depresses the brake pedal 85, i.e., when a braking request is made. In the braking control, when the driver depresses the brake pedal 85, a required braking torque Tb* is applied to the vehicle according to the depression amount of the brake pedal 85 and the vehicle speed V. That is, first, the required braking torque Tb* to be applied to the vehicle is set according to the brake pedal position BP from the brake pedal position sensor 86. The required braking torque Tb* is set using a required braking torque setting map. An example of the required braking torque setting map is shown in FIG. 2. As shown in the figure, the absolute value of the required braking torque Tb* is set to be larger when the brake pedal position BP is large compared to when it is small, and to be larger when the vehicle speed V is large compared to when it is small. Next, a fuel cut command for the engine 22 is transmitted to the engine ECU 24. Upon receiving the fuel cut command, the engine ECU 24 executes a fuel cut to stop the supply of fuel to the engine 22. Then, the rotation speed Ne of the engine 22 is reduced in accordance with the vehicle speed V, and torque commands Tm1* and Tm2* of the motors MG1 and MG2 are set so that a required braking torque Tb* is output to the drive shaft 36 within the range of the input limit Win of the battery 50. Next, the braking torque deficiency obtained by subtracting the torque command Tm2* from the required braking torque Tb* is set as a target brake command Br* to be applied by the brake device 90. Then, the motor MG2 is drive-controlled by the motor ECU 40 using the torque command Tm2*, and the brake actuator 94 is drive-controlled by the brake ECU 92 using the target brake command Br*.

[0030] The brake ECU 92 also performs functions such as an antilock brake system (ABS) that prevents any of the drive wheels 39a, 39b or the driven wheels 39c, 39d from locking and slipping when the driver depresses the brake pedal 85, a traction control (TRC) that prevents any of the drive wheels 39a, 39b from slipping due to spinning when the driver depresses the accelerator pedal 83, and a vehicle stability control (VSC) that maintains the vehicle's position when the vehicle is turning. Therefore, the brake device 90 and the brake ECU 92 function not only as a normal brake device that applies braking torque when the driver depresses the brake pedal 85, but also as a slip suppression device that suppresses slip when the drive wheels 39a, 39b lock or spin. The ABS is initiated when any one of the driving wheel speeds Vdr, Vdl and driven wheel speeds Vnr, Vnl from the wheel speed sensors 98a-98d becomes smaller than the estimated vehicle speed Vb by more than a predetermined amount, and is terminated when the difference between this wheel speed and the estimated vehicle speed Vb remains stable within a predetermined range for a predetermined time period. The estimated vehicle speed Vb can be estimated based on signals from the wheel speed sensors 98a-98d and a signal from an acceleration sensor (not shown) that detects the acceleration of the vehicle.

[0031] Next, a description will be given of the operation of the hybrid vehicle 20 configured as above, particularly the operation when an abnormality occurs in the brake control using the brake device 90. Fig. 3 is a flowchart showing an example of a deceleration control routine executed by the HVECU 70. This routine is repeatedly executed at predetermined time intervals (for example, every few msec) during deceleration.

[0032] When this routine is executed, the CPU of the HVECU 70 executes a process of inputting the vehicle speed V, the rotation speed Nm2, and the input limit Win (S100). The vehicle speed V is input as a value detected by the vehicle speed sensor 88. The rotation speed Nm2 is calculated by the motor ECU 40 and input via communication. The input limit Win is calculated by the battery ECU 52 and input via communication.

[0033] Next, the CPU of the HVECU 70 determines whether or not an abnormality has occurred in the brake control using the brake device 90 (S110). Abnormalities in the brake control using the brake device 90 include a first abnormality in which the brake pedal position BP cannot be acquired because a signal is not input from the brake pedal position sensor 86, and a second abnormality in which the ABS cannot be executed because a signal is not input from the wheel speed sensors 98a to 98d. If no abnormality has occurred in the brake control using the brake device 90 in S110, the CPU of the HVECU 70 ends this routine.

[0034] If an abnormality in brake control using the brake device 90 occurs in S110, the routine then determines whether the motor MG2 is locked (S120) and whether the absolute value of the input limit Win is equal to or greater than a positive threshold value Wref (S130). S120 determines that the motor MG2 is locked if the rotation speed Nm2 of the motor MG2 has decreased significantly compared to the previous time this routine was executed. The threshold value Wref in S130 is a threshold value for determining whether the absolute value of the input limit Win of the battery 50 is small.

[0035] If the motor MG2 is not locked in S120 or if the absolute value of the input limit Win is equal to or greater than the threshold value Wref in S130, this routine ends. In this case, the braking control described above is executed.

[0036] If the motor MG2 is locked in S120 and the absolute value of the input limit Win is less than the threshold value Wref, the routine then determines whether a first abnormality has occurred as an abnormality related to brake control (S140) and whether a second abnormality has occurred as an abnormality related to brake control (S150). If neither the first nor second abnormality has occurred in S140 or S150, the routine ends. In this case, the above-described braking control is executed.

[0037] When a first abnormality occurs in S140 or a second abnormality occurs in S150, a required braking torque Tb* to be applied to the vehicle is set in accordance with the vehicle speed V and the input limit Win (S160). The required braking torque Tb* is set by multiplying the basic braking torque Tbb corresponding to the vehicle speed V by a coefficient K corresponding to the input limit Win.

[0038] The basic braking torque Tbb is set using a braking torque setting map. An example of the basic braking torque setting map is shown in FIG. 4. In the figure, the dashed line represents the relationship between the vehicle speed V and the required braking torque Tb* when the brake pedal position BP is 0% in the required braking torque setting map shown in FIG. 2. As shown in the figure, the absolute value of the basic braking torque Tbb is set to tend to be larger when the vehicle speed V is high than when the vehicle speed V is low. Furthermore, in the first and second abnormalities, the absolute value of the basic braking torque Tbb is set to be smaller at the same vehicle speed V compared to the relationship between the vehicle speed V and the required braking torque Tb* when the brake pedal position BP is 0% in the required braking torque setting map. This is to reduce the charging power generated by braking to charge the battery 50 and increase the torque in a direction that suppresses an increase in the rotational speed output from the motor MG1, thereby suppressing over-rotation of the motor MG1 and over-charging of the battery 50. Furthermore, the absolute value of basic braking torque Tbb is set smaller during the first abnormality than during the second abnormality at the same vehicle speed V. This is because, during the first abnormality, the brake pedal position BP cannot be received from the brake pedal position sensor 86, so the absolute value of basic braking torque Tbb is set smaller, i.e., the absolute value of required braking torque Tb* is set smaller, thereby more reliably suppressing overspeed of motor MG1 and overcharge of battery 50. Coefficient K is a positive value that is set smaller when the absolute value of input limit Win is small than when it is large. This is because the absolute value of required braking torque Tb* is set smaller when the absolute value of input limit Win is small than when it is large, thereby suppressing overcharge of battery 50. Therefore, required braking torque Tb* is set to suppress overspeed of motor MG1 and overcharge of battery 50.

[0039] Once the required braking torque Tb* has been set in this manner, the control braking torque Tbc* is set to the larger of the value obtained by varying the previous Tbc*, which is the control braking torque Tbc* set the previous time this routine was executed, by an amount ΔTb toward the required braking torque Tb*, and the required braking torque Tb* using the following equation (1) (S170). In equation (1), "n" is set to the value -1 when the required braking torque Tb* is equal to or greater than the previous Tbc*, and is set to the value 1 when the required braking torque Tb* is less than the previous Tbc*. The amount ΔTb* is a value determined in advance through experiments, analysis, machine learning, etc. as a jerk that does not give the occupant a feeling of excessive deceleration or acceleration. By varying the control braking torque Tbc* by the amount ΔTb in this way, it is possible to prevent the occupant from feeling uncomfortable due to a sudden change in vehicle acceleration.

[0040] Tbc*=max(previous Tbc*-n ΔTb,Tb*) (1)

[0041] Once the control braking torque Tbc* is set in this manner, the motors MG1 and MG2 are controlled so that the control braking torque Tbc* acts on the vehicle (S180), and this routine ends. In this case, in the braking control described above, the required braking torque Tb* is used as the control braking torque Tbc* to control the engine 22 and the motors MG1 and MG2. Through this control, over-rotation of the motor MG1 can be suppressed, and over-charging of the battery 50 can also be suppressed.

[0042] Note that while steps S100 to S180 are being repeatedly executed, if the brake control returns to normal in step S100, if the lock of motor MG2 is released in step S120, if the absolute value of input limit Win becomes equal to or greater than threshold value Wref in step S130, or if the vehicle temporarily stops, the required braking torque Tb* is set using the same method as in the braking control described above, and the control braking torque Tbc* is set using equation (1) described above, and motors MG1 and MG2 are controlled so that the control braking torque Tbc* acts on the vehicle. This makes it possible to prevent occupants from feeling uncomfortable due to a sudden change in vehicle acceleration.

[0043] According to the hybrid vehicle 20 equipped with the vehicle control device of this embodiment described above, when an abnormality occurs in the brake control using the brake device 90 during deceleration, the absolute value of the required braking torque Tbf* is made smaller than when the brake control is normal, thereby suppressing over-rotation of the motor MG1 and suppressing overcharging of the battery 50.

[0044] Furthermore, in the vehicle control device of the present disclosure, the abnormality related to brake control is at least one of a first abnormality in which the brake pedal position BP cannot be acquired because a signal is not input from the brake pedal position sensor 86, and a second abnormality in which the ABS cannot be executed because a signal is not input from the wheel speed sensors 98a to 98d, thereby making it possible to suppress over-rotation of the motor MG1 and over-charging of the battery 50 when at least one of the first and second abnormalities occurs.

[0045] Furthermore, if an abnormality in brake control occurs during deceleration and a lock of motor MG2 is detected, when the abnormality in brake control is a first abnormality, the absolute value of the required braking torque Tbf can be set smaller than when the abnormality in brake control is a second abnormality, thereby more appropriately suppressing over-rotation of motor MG1 and over-charging of battery 50.

[0046] Furthermore, when an abnormality occurs in the brake control during deceleration, the absolute value of the required braking torque Tbf is set to be smaller when the absolute value of the input limit Win of the battery 50 is small than when it is large, thereby more appropriately suppressing overcharging of the battery 50.

[0047] Furthermore, if an abnormality related to the brake control occurs during deceleration and no locking of the motor MG2 is detected, the required braking torque Tb* may be set to the same torque as that for braking control, and if a locking of the motor MG2 is detected, the absolute value of the required braking torque Tb* may be set to be smaller than the unlocked braking torque (required braking torque in braking control) when no locking of the motor MG2 is detected. In this way, when a locking of the motor MG2 is detected, over-rotation of the motor MG1 and over-charging of the battery 50 can be more appropriately suppressed.

[0048] In the above-described embodiment, the determination processes of S120 to S150 are executed when an abnormality occurs in S110 related to brake control using the brake device 90. However, at least one of the determination processes of S120 to S150 may be executed, or S120 to S150 may not be executed.

[0049] In the above-described embodiment, the required braking torque Tb* to be applied to the vehicle is set in S160 in accordance with the vehicle speed V and the input limit Win. However, the required braking torque Tb* may be set using only one of the vehicle speed V and the input limit Win. Furthermore, the required braking torque Tb* may be set to be larger (smaller in absolute value) than the required braking torque Tb* in the required braking torque setting map shown in FIG. 2, regardless of the vehicle speed V or the input limit Win. Furthermore, the absolute value of the required braking torque Tb* may be set to be equal to or smaller than a predetermined upper limit value. In this case, the predetermined upper limit value may be set to be larger (smaller in absolute value) than the required braking torque Tb* when the brake pedal position BP is 0% in the required braking torque setting map shown in FIG. 2.

[0050] The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0051] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments and can, of course, be implemented in various forms within the scope of the gist of the present disclosure. [Industrial Applicability]

[0052] The present disclosure is applicable to a vehicle control device. [Explanation of symbols]

[0053] 70 Hybrid Electronic Control Unit (HVECU), 90 Brake system.

Claims

1. A vehicle control device used in a hybrid vehicle including an engine, a first motor, a planetary gear having a sun gear, a ring gear, and a carrier connected in this order to three shafts: a rotor of the first motor, a drive shaft connected to an axle, and an output shaft of the engine, a second motor connected to the drive shaft, a battery that exchanges electric power with the first and second motors, and a brake device that applies braking torque to wheels connected to the axle, the vehicle control device controlling the engine, the first and second motors, and the brake device so that a required braking torque acts on the vehicle when braking is required, When an abnormality occurs in the brake control using the brake device during the deceleration, the absolute value of the required braking torque is reduced compared to when the brake control is normal, or the absolute value of the required braking torque is set to a predetermined upper limit value or less. Vehicle control device.

2. 2. The vehicle control device according to claim 1, When an abnormality related to the brake control occurs during the deceleration, if locking of the second motor is not detected, the required braking torque is set to a non-locked braking torque, and if locking of the second motor is detected, the absolute value of the required braking torque is set to be smaller than the non-locked braking torque, or the absolute value of the required braking torque is set to be equal to or less than the predetermined upper limit value. Vehicle control device.

3. 2. The vehicle control device according to claim 1, The abnormality related to the brake control is at least one of an abnormality in which information on the amount of brake operation cannot be acquired and an abnormality in which an antilock brake system function that controls the brake device so as to release the lock of the wheel when the lock of the wheel is detected cannot be executed. Vehicle control device.

4. 4. The vehicle control device according to claim 3, When an abnormality related to the brake control occurs during the deceleration and locking of the second motor is detected, if the abnormality related to the brake control is an abnormality that makes it impossible to acquire information on the brake operation amount, the absolute value of the required braking torque is set to be smaller than when the abnormality related to the brake control is an abnormality that makes it impossible to execute the antilock brake system function. Vehicle control device.

5. 2. The vehicle control device according to claim 1, When an abnormality related to the brake control occurs during the deceleration, the absolute value of the required braking torque is set to be smaller when the absolute value of the input limit, which is the maximum allowable power that may be charged to the battery, is small compared to when the absolute value is large. Vehicle control device.

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