Vehicle control system

Abstract

This helps to prevent drivers from experiencing an unexpected sudden appearance of a vehicle. [Solution] When driving in the first mode and using motor-only driving, the engine and motor are controlled to drive with the required driving torque within the range of the first upper limit torque. When driving in the first mode and using hybrid driving, and when driving in a second mode different from the first mode, the engine and motor are controlled to drive with the required driving torque within the range of the second upper limit torque, which is larger than the first upper limit torque. When transitioning from motor-only driving to hybrid driving while driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, if the accelerator pedal opening is constant, the engine and motor are controlled to drive with the required driving torque within the range of the first upper limit torque.

Description

Technical Field

[0001] This disclosure relates to a vehicle control device.

Background Art

[0002] Conventionally, as this type of vehicle control device, there has been proposed one used in a vehicle including a motor and an engine, which controls the motor and the engine (see, for example, Patent Document 1). In this device, the engine and the motor are controlled to travel in a plurality of modes including a first mode that prioritizes motor travel without using the power of the engine compared to hybrid travel using the power of the engine. In this vehicle control device, in the first mode, the motor and the engine that travel at the travel required torque within the range of the first upper limit torque are controlled. Also, in the second mode different from the first mode, the motor and the engine that travel at the travel required torque within the range of the second upper limit torque greater than the first upper limit torque are controlled.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above vehicle control device, when the travel required torque is limited by the first upper limit torque during travel in the first mode, if switching from the first mode to the second mode, since the second upper limit torque is greater than the first upper limit torque, the actual torque for travel increases, giving the driver an unexpected sense of jerk.

[0005] The main object of the vehicle control device of this disclosure is to suppress giving the driver an unexpected sense of jerk.

Means for Solving the Problems

[0006] The vehicle control device of this disclosure employs the following means to achieve the above-mentioned main objective. The vehicle control device of this disclosure is used in a vehicle comprising an engine, a motor, an inverter for driving the motor, a battery connected to the inverter via a power line, and a charger connected to the power line for charging the battery using external power, and controls the engine and the inverter to operate in a plurality of modes, including a first mode that prioritizes motor driving without using the engine's power over hybrid driving using the engine's power, wherein when operating in the first mode and in motor driving, the engine controls the engine to operate with a driving request torque required for driving within a first upper limit torque range. The gist of this is to control the engine and the motor so that when driving in the first mode and in hybrid driving mode, and when driving in a second mode different from the first mode, the engine and the motor are controlled to drive with the requested driving torque within the range of a second upper limit torque that is larger than the first upper limit torque, and when transitioning from motor driving to hybrid driving while driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, the engine and the motor are controlled so that the vehicle drives with the requested driving torque within the range of the first upper limit torque when the opening of the accelerator pedal is constant.

[0007] In the vehicle control device of this disclosure, when the vehicle is traveling in the first mode and using motor-only driving, the engine and motor are controlled to travel with the required driving torque within the range of the first upper limit torque. When the vehicle is traveling in the first mode and using hybrid driving, and when the vehicle is traveling in a second mode different from the first mode, the engine and motor are controlled to travel with the required driving torque within the range of the second upper limit torque, which is larger than the first upper limit torque. When the vehicle transitions from motor-only driving to hybrid driving while traveling in the first mode, or when the vehicle transitions from the first mode to the second mode, the engine and motor are controlled to travel with the required driving torque within the range of the first upper limit torque, provided that the accelerator pedal opening is constant. When the accelerator pedal opening is constant, it is assumed that the driver desires to travel at a constant speed. Therefore, when the accelerator pedal opening is constant, controlling the engine and motor to travel with the required driving torque within the range of the first upper limit torque can suppress the driver from experiencing an unexpected sudden acceleration.

[0008] In the vehicle control device of this disclosure, when transitioning from motor-driven driving to hybrid driving by starting the engine during driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, the engine and the motor may be controlled so that when the accelerator pedal is pressed down from a state where the accelerator pedal opening is constant, the driving torque used for driving increases within the range of the second upper limit torque with a predetermined amount of change over time. When the accelerator pedal is pressed down, it is assumed that the driver intends to accelerate. Therefore, when transitioning from motor-driven driving to hybrid driving by starting the engine during driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, the engine and the motor may be controlled so that when the accelerator pedal is pressed down from a state where the accelerator pedal opening is constant, the driving torque used for driving increases within the range of the second upper limit torque with a predetermined amount of change over time, thereby suppressing vehicle behavior contrary to the driver's intentions.

[0009] Furthermore, in the vehicle control device of this disclosure, when transitioning from motor driving to hybrid driving by starting the engine during driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, the engine and motor may be controlled so that the driving torque used for driving within the range of the first upper limit torque decreases with a predetermined amount of change over time until the accelerator pedal is released from a constant opening and the driving request torque falls below the first upper limit torque. When the accelerator pedal is released, it is assumed that the driver intends to decelerate. Therefore, when transitioning from motor driving to hybrid driving by starting the engine during driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, the engine and motor may be controlled so that the driving torque used for driving within the range of the first upper limit torque decreases with a predetermined amount of change over time until the accelerator pedal is released from a constant opening and the driving request torque falls below the first upper limit torque, thereby suppressing the driver from feeling an unexpected sudden acceleration. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a hybrid vehicle equipped with a vehicle control device according to an embodiment of the present disclosure. [Figure 2] This flowchart shows an example of a transition control routine executed by HVECU. [Figure 3] This is an explanatory diagram illustrating an example of the time variation of accelerator opening (Acc), driving request torque (Td*), upper limit torque (Tmax), and driving mode. [Modes for carrying out the invention]

[0011] Embodiments of this disclosure will be described with reference to the drawings. Figure 1 is a schematic diagram of a hybrid vehicle 20 equipped with a vehicle control device according to an embodiment of this disclosure. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, a charger 60, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0012] Engine 22 is configured as an internal combustion engine that outputs power using gasoline, diesel fuel, or the like. Engine 22 is operated and controlled by an electronic control unit for the engine (hereinafter referred to as "engine ECU") 24.

[0013] The engine ECU 24, although not shown in the diagram, is configured as a microprocessor centered around a CPU. In addition to the CPU, it includes a ROM for storing processing programs, RAM for temporarily storing data, input / output ports, and communication ports. Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 via its input ports. Examples of signals input to the engine ECU 24 include the crank angle θcr from the crank position sensor 23, which detects the rotational position of the crankshaft 26 of the engine 22, and the throttle opening TH from the throttle valve position sensor, which detects the position of the throttle valve. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via its output ports. 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 regarding the operating status of the engine 22 to the HVECU 70 as needed. The engine ECU 24 calculates the rotational speed of the crankshaft 26, i.e., the rotational speed of the engine 22 Ne, based on the crank angle θcr from the crank position sensor 23.

[0014] The planetary gear 30 is configured as a single-pinion type planetary gear mechanism. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. The drive shaft 36, which is connected to the drive wheels 38a and 38b via a differential gear 37, is connected to the ring gear of the planetary gear 30. The crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28.

[0015] Motor MG1 is configured, for example, as a synchronous generator-motor, and as described above, its rotor is connected to the sun gear of the planetary gear 30. Motor MG2 is configured, for example, as a synchronous generator-motor, and its rotor is connected to the drive shaft 36. Inverters 41 and 42 are connected to the battery 50 via a power line 54. Motors MG1 and MG2 are driven to rotation by a motor electronic control unit (hereinafter referred to as "motor ECU") 40, which controls the switching of multiple switching elements (not shown) of inverters 41 and 42.

[0016] The motor ECU 40, although not shown in the diagram, is configured as a microprocessor centered around a CPU. In addition to the CPU, it includes a ROM for storing processing programs, a RAM for temporarily storing data, input / output ports, and communication ports. Signals from various sensors necessary for driving and controlling motors MG1 and MG2 are input to the motor ECU 40 via its input ports. Signals input to the motor ECU 40 include the rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 that detect the rotational position of the rotors of motors MG1 and MG2, and the phase currents from current sensors that detect the current flowing through each phase of motors MG1 and MG2. Switching control signals to multiple switching elements of inverters 41 and 42 (not shown) are output from the motor ECU 40 via its output ports. The motor ECU 40 is connected to the HVECU 70 via its communication port and drives and controls motors MG1 and MG2 based on control signals from the HVECU 70, and outputs data regarding the driving status of motors MG1 and MG2 to the HVECU 70 as needed. The motor ECU 40 calculates the rotational speeds Nm1 and Nm2 of motors MG1 and MG2 based on the rotational positions θm1 and θm2 of the rotors of motors MG1 and MG2, as detected by rotational position sensors 43 and 44.

[0017] The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery. As described above, this battery 50 is connected to inverters 41 and 42 via power lines 54. The battery 50 is managed by an electronic control unit for batteries (hereinafter referred to as "battery ECU") 52.

[0018] The battery ECU 52, although not shown in the diagram, is configured as a microprocessor centered around a CPU. In addition to the CPU, it includes ROM for storing processing programs, RAM for temporarily storing data, input / output ports, and communication ports. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via its input ports. Examples of signals input to the battery ECU 52 include the battery voltage Vb from the voltage sensor 51a installed between the terminals of the battery 50, the battery current Ib from the current sensor 51b attached to the output terminal of the battery 50, and the battery temperature Tb from the temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port and outputs data regarding the state of the battery 50 to the HVECU 70 as needed. The battery ECU 52 calculates the state of charge (SOC) based on the integrated value of the battery current Ib from the current sensor 51b. The state of charge (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.

[0019] The charger 60 is connected to the power line 54 and is configured to charge the battery 50 using power from an external power source 69, such as a household power outlet, when the power plug 61 is connected to an external power source 69. The charger 60 includes an AC / DC converter and a DC / DC converter. The AC / DC converter converts the AC power from the external power source 69 supplied via the power plug 61 to DC power. The DC / DC converter converts the voltage of the DC power from the AC / DC converter and supplies it to the battery 50. When the power plug 61 is connected to the external power source 69, the charger 60 supplies power from the external power source 69 to the battery 50 by controlling the AC / DC converter and the DC / DC converter via the HVECU 70.

[0020] The HVECU 70 is configured as a microprocessor centered around a CPU, which, in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, a flash memory 72, input / output ports, and communication ports. Signals from various sensors are input into the HVECU 70 via the input ports. Examples of the signals input into the HVECU 70 include an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, an accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, a brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, etc. Also, the vehicle speed V from the vehicle speed sensor 88, etc. can be included. Further, a connection signal SWC from the connection switch 62 attached to the power plug 61 for determining whether the power plug 61 is connected to the external power source 69, etc. can be included. Control signals to the charger 60, etc. are output from the HVECU 70 via the output ports. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via communication ports, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

[0021] In the hybrid vehicle 20 of the embodiment thus configured, in the EV priority mode (first mode) or the hybrid mode (second mode), hybrid driving (HV driving) that involves driving the engine 22 or motor driving (EV driving) that runs on the power from the motor MG2 without driving the engine 22 is performed.

[0022] In an embodiment, when the HVECU 70 is parked with the system off (system stopped) at a charging point such as home or a charging station, and the power plug 61 is connected to the external power source 69, the charger 60 is controlled so that the battery 50 is charged using the power from the external power source 69. When the system is turned on (system startup), the driving mode temporarily becomes the hybrid mode. However, when the state of charge SOC of the battery 50 is greater than the threshold Shv1 (e.g., 45%, 50%, 55%, etc.) when the system is turned on (system startup), until the state of charge SOC of the battery 50 reaches the threshold Shv2 (e.g., 25%, 30%, 35%, etc.) or less, the vehicle travels in the EV priority mode. After the state of charge SOC of the battery 50 reaches the threshold Shv2 or less, the vehicle travels in the hybrid mode until the system is turned off. Also, when the state of charge SOC of the battery 50 is less than the threshold Shv1 when the system is turned on, the vehicle travels in the hybrid mode until the system is turned off.

[0023] When traveling in the motor driving mode in the EV priority mode or the hybrid mode, first, the HVECU 70 sets the required driving torque Td* required for driving based on the accelerator opening Acc and the vehicle speed V. Subsequently, the smaller torque between the upper limit torque Tmax and the required driving torque Td* is set as the required torque Tr* required for the drive shaft 36. The upper limit torque Tmax is set to the first upper limit torque Tmax1 when traveling in the motor driving mode in the EV priority mode, and is set to the second upper limit torque Tmax2 greater than the first upper limit torque Tmax1 when traveling in the motor driving mode in the hybrid mode. Then, the value 0 is set for the torque command Tm1* of the motor MG1, and the torque command Tm2* of the motor MG2 is set so that the required torque Tr* is output to the drive shaft 36. Then, the torque commands Tm1*, Tm2* of the motors MG1, MG2 are transmitted to the motor ECU 40. When the motor ECU 40 receives the torque commands Tm1*, Tm2* of the motors MG1, MG2, the motor ECU 40 performs switching control of the switching elements of the inverters 41, 42 so that the motors MG1, MG2 are driven by the torque commands Tm1*, Tm2*.

[0024] In EV priority mode or hybrid mode, when driving in hybrid mode, the HVECU70 first sets the required driving torque Td* based on the accelerator opening Acc and vehicle speed V. Next, it sets the required torque Tr* for the drive shaft 36 as the smaller of the upper limit torque Tmax and the required driving torque Td*, and calculates the required driving power Pr* by multiplying the set required torque Tr* by the rotational speed Nr of the drive shaft 36. The upper limit torque Tmax is set to the second upper limit torque Tmax2 when driving in hybrid mode. Here, the rotational speed Nr of the drive shaft 36 can be the rotational speed Nm2 of the motor MG2, the rotational speed obtained by multiplying the vehicle speed V by a conversion factor, etc. Then, it calculates the required power Pe* required for the vehicle by subtracting the charge / discharge required power Pb* of the battery 50 (positive value when discharging from the battery 50) from the driving power Pr*. Here, the charge / discharge required power Pb* is set to 0 when the battery 50's state of charge (SOC) is at the target SOC* (a predetermined value or the SOC when switching from EV priority mode) in hybrid mode, to a negative value (for charging) when the SOC is less than the target SOC*, and to a positive value (for discharging) when the SOC is greater than the target SOC*. In addition, the charge / discharge required power Pb* is set to 0 regardless of the SOC when in EV priority mode. Next, the target rotational speed Ne* and target torque Te* of the engine 22 are set using the required power Pe* and the operating line for efficiently operating the engine 22. Overall, the target rotational speed Ne* and target torque Te* are greater when the required power Pe* is large than when the required power Pe* is small. Next, rotational speed feedback control is used to set the torque command Tm1* for motor MG1 so that the rotational speed Ne of engine 22 becomes the target rotational speed Ne*, and the torque command Tm2* for motor MG2 is set so that the required torque Tr* is output to the drive shaft 36. Then, the target rotational speed Ne* and target torque Te* of engine 22 are transmitted to the engine ECU 24, and the torque commands Tm1* and Tm2* of motors MG1 and MG2 are transmitted to the motor ECU 40.When the engine ECU 24 receives the target rotational speed Ne* and target torque Te* of the engine 22, it controls the intake air volume, fuel injection, ignition, etc. of the engine 22 so that the engine 22 is operated based on the received target rotational speed Ne* and target torque Te*. When the motor ECU 40 receives torque commands Tm1* and Tm2* for motors MG1 and MG2, it controls the switching of multiple switching elements of inverters 41 and 42 so that motors MG1 and MG2 are driven by the torque commands Tm1* and Tm2*.

[0025] When the vehicle is running on the motor in EV priority mode, the HVECU70 starts the engine 22 and switches to hybrid driving in EV priority mode when a request is made to operate the engine 22 to ensure the performance (heating performance) of the air conditioning system that uses the engine 22 as a heat source. When the vehicle is running in hybrid driving in EV priority mode, the HVECU70 stops the engine 22 and switches to motor driving when a request is no longer made to operate the engine 22 to ensure the performance (heating performance) of the air conditioning system that uses the engine 22 as a heat source.

[0026] Next, we will describe the operation of the hybrid vehicle 20 equipped with the vehicle control device of the embodiment configured in this way, in particular, the operation when setting the required torque Tr* when transitioning from motor driving in EV priority mode to hybrid driving. Figure 2 is a flowchart of an example of a transition control routine executed by the HVECU 70. This routine is executed by the CPU of the HVECU 70 when transitioning from motor driving in EV priority mode to hybrid driving.

[0027] When this routine is executed, the HVECU70 determines whether the accelerator opening Acc from the accelerator pedal position sensor 84 is constant (S100). If the accelerator opening Acc is constant, the HVECU70 sets the upper limit torque Tmax to the first upper limit torque Tmax1 (S110). Then, the HVECU70 sets the requested torque Tr* to the smaller of the driving request torque Td* based on the accelerator opening Acc and vehicle speed V and the upper limit torque Tmax (S120). Once the requested torque Tr* is set in this way, the HVECU70 uses the requested torque Tr* to control the engine 22 and motors MG1 and MG2 in the same manner as the hybrid driving in the EV priority mode described above (S190), and then terminates this routine. In this way, when the accelerator opening Acc is constant, the HVECU70 can control the engine 22 and motors MG1 and MG2 to drive with the driving request torque Td* within the range of the upper limit torque Tmax (=Tmax1).

[0028] If the accelerator opening Acc is not constant in S100, HVECU70 determines whether the accelerator opening Acc is increasing or not (S130). If the accelerator opening Acc is increasing, HVECU70 sets the upper limit torque Tmax to the second upper limit torque Tmax2 (S140). Then, HVECU70 sets the requested torque Tr* to the smaller of the sum of the previously set requested torque Tr* (previous Tr*) and the time change amount ΔTr, and the upper limit torque Tmax (S150). The time change amount ΔTr is a predetermined value as the amount of change required to change the requested torque Tr* quickly enough so as not to cause shock to the vehicle. Once the requested torque Tr* is set in this way, HVECU70 uses the requested torque Tr* to control the engine 22 and motors MG1 and MG2 in the same manner as the hybrid driving in the EV priority mode described above (S190), and then terminates this routine. Thus, when the accelerator pedal opening Acc is increasing, that is, when the accelerator pedal 83 is pressed down, the HVECU 70 controls the engine 22 and motors MG1 and MG2 so that the driving request torque Td* increases within the range of the upper limit torque Tmax (=Tmax2).

[0029] In S130, when the accelerator opening Acc is not increasing, that is, when the accelerator opening Acc is decreasing, the HVECU 70 determines whether the requested driving torque Td* is less than or equal to the first upper limit torque Tmax1 (S160). If the requested driving torque Td* exceeds the first upper limit torque Tmax1, the HVECU 70 sets the upper limit torque Tmax to the first upper limit torque Tmax1 (S110). Then, the HVECU 70 sets the requested torque Tr* to the smaller of the requested driving torque Td* and the upper limit torque Tmax, which are based on the accelerator opening Acc and the vehicle speed V (S120). Now, since the requested driving torque Td* exceeds the first upper limit torque Tmax1, the upper limit torque Tmax (=Tmax1) is set to the requested torque Tr*. Once the requested torque Tr* is set, the HVECU70 uses the requested torque Tr* to control the engine 22 and motors MG1 and MG2 in the same manner as the hybrid driving in the EV priority mode described above (S190), and then terminates this routine. In this way, when the accelerator opening Acc is decreasing and the requested driving torque Td* exceeds the first upper limit torque Tmax1, the HVECU70 controls the engine 22 and motors MG1 and MG2 to drive with the requested driving torque Td* within the range of the upper limit torque Tmax (=Tmax1) (in this case, to drive with the upper limit torque Tmax).

[0030] In S160, if the requested driving torque Td* is less than or equal to the first upper limit torque Tmax1, the upper limit torque Tmax is set to the second upper limit torque Tmax2 (S170). Then, the HVECU 70 sets the requested torque Tr* to the smaller of the previously set requested torque Tr* (previous Tr*) minus the time change amount ΔTr, and the upper limit torque Tmax (S180). Once the requested torque Tr* is set in this way, the HVECU 70 uses the requested torque Tr* to control the engine 22 and motors MG1 and MG2 in the same manner as the hybrid driving in the EV priority mode described above (S190), and then terminates this routine. In this way, when the accelerator opening Acc is decreasing, that is, when the accelerator pedal 83 is released, the HVECU 70 controls the engine 22 and motors MG1 and MG2 so that the requested driving torque Td* decreases within the range of the upper limit torque Tmax (=Tmax2).

[0031] Figure 3 is an explanatory diagram illustrating an example of the time variation of accelerator opening Acc, driving request torque Td*, upper limit torque Tmax, and driving mode. When the hybrid vehicle 20 is turned on (system started) at time t0, the driving mode is initially set to hybrid mode. When the battery charge ratio SOC of the battery 50 is greater than the threshold Shv1 at the time of system on (system started) (time t1), the driving mode becomes motor driving in EV priority mode. At this time, the upper limit torque Tmax is set to the first upper limit torque Tmax1. At time t2, when a request is made to operate the engine 22 to ensure the performance (heating performance) of the air conditioning system, the driving mode becomes hybrid driving in EV priority mode. At this time, when the accelerator opening Acc is constant, the upper limit torque Tmax is maintained at the first upper limit torque Tmax1 (S100, S110). When the accelerator opening Acc is constant, it is assumed that the driver desires to drive at a constant speed. Therefore, when the accelerator opening Acc is constant, the engine 22 and motors MG1 and MG2 are controlled to drive with a driving request torque Td* within the range of the upper limit torque Tmax (=Tmax1), thereby suppressing the driver from experiencing an unexpected sudden lurching sensation.

[0032] When the accelerator pedal 83 is pressed down at time t3 (when the accelerator opening Acc increases), the upper limit torque Tmax is set to the second upper limit torque Tmax2, and the smaller of the sum of the previously set required torque Tr* (previous Tr*) and the upper limit torque Tmax is set as the required torque Tr*. Using the required torque Tr*, the engine 22 and motors MG1 and MG2 are controlled in the same manner as the hybrid driving in the EV priority mode described above (S130~S150). When the accelerator pedal is pressed down, it is assumed that the driver intends to accelerate. Therefore, when transitioning from motor driving to hybrid driving by starting the engine 22 in EV priority mode, when the accelerator pedal 83 is pressed down from a state where the accelerator opening Acc is constant, the engine 22 and motors MG1 and MG2 are controlled so that the driving torque (torque output to the drive shaft 36) increases with a time variation ΔTr within the range of the upper limit torque Tmax (=Tmax2), thereby suppressing vehicle behavior contrary to the driver's intentions.

[0033] At time t4, when the accelerator opening Acc is constant and the request to operate the engine 22 to ensure the performance (heating performance) of the air conditioning system is stopped, the driving mode becomes motor driving in EV priority mode, and the upper limit torque Tmax is set to the first upper limit torque Tmax1. At time t5, when the request to operate the engine 22 to ensure the performance (heating performance) of the air conditioning system is made again, the driving mode becomes hybrid driving again in EV priority mode. At this time, when the accelerator pedal 83 is released (accelerator opening Acc decreases), the driving request torque Td* decreases, but the upper limit torque Tmax is set to the first upper limit torque Tmax1 until the driving request torque Td* falls below the first upper limit torque Tmax1 (S160, S110). When the accelerator pedal 83 is released, it is assumed that the driver intends to decelerate. Therefore, when transitioning from motor-driven driving in EV priority mode to hybrid driving by starting the engine 22, when the accelerator pedal 83 is released from a constant accelerator opening Acc, the engine 22 and motors MG1 and MG2 are controlled so that the driving torque (torque output to the drive shaft 36) decreases with a time variation amount ΔTr within the range of the upper limit torque Tmax (=Tmax1) until the driving request torque Td* becomes less than or equal to the first upper limit torque Tmax1. This suppresses the driver from experiencing an unexpected sudden lurch.

[0034] According to the hybrid vehicle 20 equipped with the vehicle control device of this embodiment described above, when transitioning from motor driving to hybrid driving while driving in EV priority mode, if the accelerator opening Acc is constant, the engine 22 and motors MG1 and MG2 are controlled to drive with a driving request torque Td* within the range of the upper limit torque Tmax (=Tmax1), thereby suppressing the driver from experiencing an unexpected sudden movement.

[0035] Furthermore, when transitioning from motor-driven driving to hybrid driving by starting the engine 22 in EV-priority mode, when the accelerator pedal 83 is pressed down from a constant accelerator opening Acc, the engine 22 and motors MG1 and MG2 are controlled so that the driving torque (torque output to the drive shaft 36) increases with a time variation ΔTr within the upper limit torque Tmax (=Tmax2), thereby suppressing vehicle behavior contrary to the driver's intentions.

[0036] Furthermore, when transitioning from motor-driven operation in EV-priority mode to hybrid driving by starting the engine 22, when the accelerator pedal 83 is released from a constant accelerator opening Acc, the engine 22 and motors MG1 and MG2 are controlled so that the driving torque (torque output to the drive shaft 36) decreases with a time variation ΔTr within the range of the upper limit torque Tmax (=Tmax1) until the driving request torque Td* becomes less than or equal to the first upper limit torque Tmax1. This suppresses the driver from experiencing an unexpected sudden lurch.

[0037] In the embodiment described above, the transition control routine shown in Figure 2 is executed when transitioning from motor-driven driving in EV-priority mode to hybrid driving. However, the transition control routine shown in Figure 2 may be executed either when transitioning from motor-driven driving in EV-priority mode to hybrid driving, or when transitioning from EV-priority mode to hybrid mode, or simultaneously when transitioning from EV-priority mode to hybrid mode.

[0038] In the above embodiment, if the accelerator opening Acc has not increased in S130 without executing the processes in S160 to S180, the upper limit torque Tmax may be set to the second upper limit torque Tmax2 and then S120 and S190 may be executed. Also, if the accelerator opening Acc is not constant in S100 without executing S130 to S150, S160 may be executed. Furthermore, if the accelerator opening Acc is not constant in S100 without executing the processes in S130 to S180, the upper limit torque Tmax may be set to the second upper limit torque Tmax2 and then S120 and S190 may be executed.

[0039] In the embodiments described above, the vehicle control device of the present disclosure is used in a hybrid vehicle 20 comprising an engine 22, motors MG1 and MG2, planetary gears 30, inverters 41 and 42, a battery 50, and a charger 60. However, the vehicle control device of the present disclosure may be used in any vehicle comprising an engine, motors, an inverter that drives the motors, a battery connected to the inverters via a power line, and a charger connected to the power line and used to charge the battery with external power.

[0040] Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem is merely an example to specifically explain the form in which the embodiment implements the invention described in the section on means for solving the problem, and does not limit the elements of the invention described in the section on means for solving the problem. In other words, the interpretation of the invention described in the section on means for solving the problem should be based on the description in that section, and the embodiment is merely one specific example of the invention described in the section on means for solving the problem.

[0041] The above describes the forms for implementing this disclosure using embodiments, but this disclosure is not limited in any way to these embodiments, and can of course be implemented in various forms without departing from the gist of this disclosure. [Industrial applicability]

[0042] This disclosure can be used in industries such as the manufacturing of vehicle control devices. [Explanation of Symbols]

[0043] 20 Hybrid vehicles, 22 Engines, 24 Engine ECUs, 40 Motor ECUs, 41, 42 Inverters, 50 Batteries, 60 Chargers, 70 HVECUs, MG1, MG2 Motors.

Claims

1. A vehicle control device used in a vehicle comprising an engine, a motor, an inverter for driving the motor, a battery connected to the inverter via a power line, and a charger connected to the power line for charging the battery using external power, which controls the engine and the inverter to operate in a plurality of modes, including a first mode that prioritizes motor-driven operation without using the engine's power over hybrid driving using the engine's power, When the vehicle is traveling in the first mode and using the motor, the engine and the motor are controlled to travel with the required driving torque within the range of the first upper limit torque, and when the vehicle is traveling in the first mode and using the hybrid driving mode, and when the vehicle is traveling in a second mode different from the first mode, the engine and the motor are controlled to travel with the required driving torque within the range of the second upper limit torque, which is larger than the first upper limit torque. When transitioning from motor-driven driving to hybrid driving during driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, if the accelerator pedal opening is constant, the engine and the motor are controlled to drive with the requested driving torque within the range of the first upper limit torque. Vehicle control device.

2. A vehicle control device according to claim 1, When transitioning from motor-driven driving to hybrid driving by starting the engine during driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, the engine and motor are controlled so that the driving torque used for driving increases within the range of the second upper limit torque with a predetermined amount of change over time when the accelerator pedal is pressed down from a state where the opening of the accelerator pedal is constant. Vehicle control device.

3. A vehicle control device according to claim 1, When transitioning from motor-driven driving to hybrid driving by starting the engine during driving in the first mode, or when transitioning from driving in the first mode to driving in the second mode, the engine and motor are controlled so that the driving torque used for driving decreases within the range of the first upper limit torque with a predetermined amount of change over time, until the accelerator pedal is released from a constant opening position and the driving request torque falls below the first upper limit torque. Vehicle control device.

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