Control device

Abstract

To provide a technology that can suppress a deterioration of acceleration performance during engine start-up in a hybrid vehicle while the vehicle is in motion.SOLUTION: A hybrid ECU 80 in one embodiment obtains: a drive torque of a motor 20 necessary for a vehicle 1 to perform a predetermined acceleration powered only by the motor 20 based on a state of the vehicle 1; a total necessary output of the motor 20 when the vehicle 1 is accelerated for a given period of time and an engine 10 is started at a same time based on the obtained drive torque of the motor 20 and starting torque of the motor 20; and a maximum output that a battery 30 can provide to the motor 20 based on a condition of the battery 30. If the necessary output of the motor 20 is greater than the maximum output of the battery 30, the engine 10 in a stopped state is started or the engine 10 is kept running. If the necessary output of the motor 20 is less than the maximum output of the battery 30, the engine 10 in operating state is stopped or the engine 10 is kept stopped.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] For example, there is disclosed a technique for stopping an engine when the energy or wheel driving force acting on an axle of a hybrid vehicle that transmits the power of only a driving electric motor or both a driving electric motor and an engine to drive wheels is equal to or less than a predetermined value (see Patent Document 1).

[0003] Patent Document 1 discloses that the above-described predetermined value for determination is set as a value with a margin so that no delay occurs at the time of restarting the engine assuming re-acceleration.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, for example, depending on the state of the remaining amount or temperature of a battery that supplies power to a driving electric motor, the maximum output (maximum power) that the battery can supply to the driving electric motor or the like may decrease. Further, for example, at the time of starting the engine, the battery needs to output not only the power (electric power) required for the driving electric motor to drive the vehicle but also the power (electric power) required for the starting electric motor to start the engine.

[0006] However, in Patent Document 1, the decrease in the maximum output of the battery and the output from the battery for starting the engine are not considered. Therefore, for example, when starting the engine, the power available for the electric motor for driving the vehicle is limited by the decrease in the maximum output of the battery and the power used for starting the engine, and as a result, it may not be possible to obtain the desired acceleration performance when starting the engine.

[0007] Therefore, in view of the above problems, an object of the present disclosure is to provide a technology capable of suppressing deterioration of acceleration performance when starting the engine during traveling in a hybrid vehicle.

Means for Solving the Problems

[0008] To achieve the above object, in one embodiment of the present disclosure, a vehicle control device having an engine, a first electric motor, a second electric motor capable of starting the engine, and a battery capable of supplying power to the first electric motor and the second electric motor, and rotating drive wheels with the power of the first electric motor alone or the power transmitted from the engine and the first electric motor to travel, a torque acquisition unit that acquires the torque of the first electric motor necessary for the vehicle to perform a predetermined acceleration with the power of only the first electric motor among the engine and the first electric motor based on the state of the vehicle; a necessary output acquisition unit that acquires the total necessary output of the first electric motor and the second electric motor when the predetermined acceleration of the vehicle and the start of the engine are performed simultaneously based on the torque of the first electric motor acquired by the torque acquisition unit and the torque of the second electric motor necessary for starting the engine; a maximum output acquisition unit that acquires the maximum output that the battery can supply to the first electric motor and the second electric motor based on the state of the battery; When the required output is greater than the maximum output, start the engine in the stopped state or maintain the operation of the engine. When the required output is less than the maximum output, stop the engine in the operating state or maintain the stopped state of the engine, and a control unit for doing so. 、 The predetermined acceleration is either one of the first acceleration state of the vehicle requested by the driver of the vehicle and the second acceleration state with the minimum acceleration required at the start of the acceleration of the vehicle, in which the acceleration is the same as or greater than the other, The torque acquisition unit acquires the torque of the first electric motor required for either one of the acceleration states, and varies the acceleration of the second acceleration state according to the speed of the vehicle is provided. A control device is provided. Also, in other embodiments of the present disclosure, A control device for a vehicle having an engine, a first electric motor, a second electric motor capable of starting the engine, and a battery capable of supplying power to the first electric motor and the second electric motor, and rotating drive wheels with the power transmitted from the first electric motor or the engine and the first electric motor to travel, A torque acquisition unit that acquires the torque of the first electric motor required for the vehicle to perform a predetermined acceleration with only the power of the first electric motor among the engine and the first electric motor based on the state of the vehicle, Based on the torque of the first electric motor acquired by the torque acquisition unit and the torque of the second electric motor required for starting the engine, a required output acquisition unit that acquires the total required output of the first electric motor and the second electric motor when the predetermined acceleration of the vehicle and the start of the engine are performed simultaneously, A maximum output acquisition unit that acquires the maximum output that the battery can supply to the first electric motor and the second electric motor based on the state of the battery, A control unit that starts the engine in a stopped state or maintains the operation of the engine when the required output is greater than the maximum output, and stops the engine in an operating state or maintains the stopped state of the engine when the required output is less than the maximum output, The predetermined acceleration is either one of the first acceleration state of the vehicle requested by the driver of the vehicle and the second acceleration state with the minimum acceleration required at the start of the acceleration of the vehicle, in which the acceleration is the same as or greater than the other, The torque acquisition unit acquires the torque of the first electric motor required for either one of the acceleration states, and increases the acceleration of the second acceleration state when it is determined that the degree of importance of the acceleration performance of the vehicle by the driver of the vehicle is relatively high based on the state of the vehicle, compared to when it is determined to be relatively low, A control device is provided.

[0009] According to the present embodiment, when the required output considering the output of the second electric motor at the time of engine start is greater than the maximum output according to the state of the battery, the engine can be put into an operating state. Therefore, for example, when the available power of the first electric motor is limited due to a decrease in the maximum output of the battery or the power used for starting the engine, stopping the engine or maintaining the stopped state of the engine is prohibited. Thus, the control device can suppress deterioration of acceleration performance at the time of engine start during traveling in a hybrid vehicle.

Advantages of the Invention

[0010] According to the above-described embodiment, in a hybrid vehicle, it is possible to suppress deterioration of acceleration performance at the time of engine start during traveling.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described with reference to the drawings.

[0013] [First Example of Vehicle Configuration] With reference to FIGS. 1 to 3, a first example of the configuration of the vehicle 1 according to the present embodiment will be described.

[0014] FIG. 1 is a diagram showing a first example of the configuration of the vehicle 1. FIG. 2 is a functional block diagram showing a first example of the functional configuration of the hybrid ECU 80. FIG. 3 is a diagram showing the relationship between the torque of the motor 20 required for the vehicle 1 to obtain a predetermined acceleration and the accelerator opening.

[0015] As shown in FIG. 1, the vehicle 1 includes an engine 10, an engine ECU (Electronic Control Unit) 15, a motor 20, a motor ECU 25, a battery 30, a battery ECU 35, a power conversion device 40, a clutch 45, a power transmission mechanism 50, drive wheels 60, a vehicle state data output device 70, and a hybrid ECU 80.

[0016] The vehicle 1 is a hybrid vehicle capable of transmitting the power of only the motor 20 or the power of the engine 10 and the motor 20 to the drive wheels 60 through the power transmission mechanism 50 for running.

[0017] The engine 10 is one of the power sources (prime movers) of the vehicle 1. The crankshaft of the engine 10 is connected to the rotating shaft of the motor 20 via the clutch 45. The engine 10 is, for example, a gasoline engine or a diesel engine.

[0018] The engine ECU 15 performs drive control of the engine 10 under the control of the hybrid ECU 80. Specifically, the engine ECU 15 may take in the outputs of various sensors related to the state of the engine 10, grasp the state of the engine 10, and output commands to various actuators related to the engine 10 to perform drive control of the engine 10. The various sensors include sensors built into the engine 10 (such as a crank angle sensor or a cam angle sensor, etc.) and sensors provided around the engine 10 (such as a throttle sensor, etc.). The various actuators include actuators built into the engine 10 (such as an injector, etc.) and actuators provided around the engine 10 (such as a throttle valve, etc.).

[0019] The motor 20 (an example of the first electric motor and the second electric motor) is one of the power sources (prime movers) of the vehicle 1. One end of the output shaft of the motor 20 is connected to the power transmission mechanism 50, and power is transmitted to the drive wheels 60 through the power transmission mechanism 50. Further, when the vehicle 1 decelerates, the motor 20 is driven by the power (braking energy) from the drive wheels 60 through the power transmission mechanism 50 to perform regenerative power generation. Also, the other end of the output shaft of the motor 20 is connected to the rotating shaft of the engine 10 via the clutch 45 and is also used for starting the engine 10. The motor 20 is, for example, a motor generator driven by three-phase alternating current and is driven by the power supplied from the battery 30 via the power conversion device 40.

[0020] The motor ECU 25 controls the driving of the motor 20 under the control of the hybrid ECU 80. Specifically, the motor ECU 25 may control the operation of the motor 20 by controlling the power conversion device 40 while grasping the states of the motor 20 and the power conversion device 40 based on the outputs of various sensors built in the motor 20 and the power conversion device 40. The various sensors include, for example, a current sensor and a voltage sensor for measuring the current and voltage of the motor 20, a rotation speed sensor for measuring the rotation speed of the motor 20, and the like. Also, the motor ECU 25 transmits (feeds back) data on the states of the motor 20 and the power conversion device 40 to the hybrid ECU 80.

[0021] The battery 30 is a power storage device as a power supply for the motor 20. The battery 30 outputs, for example, direct current power at a very high voltage of several hundred volts. The battery 30 is, for example, a lithium-ion battery.

[0022] The battery ECU 35 monitors various states of the battery 30 based on data captured from various sensors built into the battery 30 under the control of the hybrid ECU 80. The various sensors include, for example, a current sensor, a voltage sensor, a temperature sensor, etc. that measure the current, voltage, and temperature for each battery cell. Specifically, the battery ECU 35 monitors the remaining capacity (SOC: State Of Charge), degradation state, temperature state, voltage balance for each battery cell, etc. of the battery 30. Further, the battery ECU 35 transmits (feeds back) data regarding various states of the battery 30 to the hybrid ECU 80.

[0023] The power conversion device 40 outputs drive power (e.g., three-phase AC power) to the motor 20 or charges the battery 30 with the regenerative power of the motor 20 using the DC power supplied from the battery 30 under the control of the motor ECU 25. The power conversion device 40 includes, for example, an inverter circuit capable of converting DC power into three-phase AC power for driving the motor 20 or converting the regenerative power (three-phase AC power) of the motor 20 into DC power. Further, the power conversion device 40 may include a boost-buck circuit that boosts the output voltage of the battery 30 or steps down the regenerative power and outputs it to the battery 30.

[0024] The clutch 45 is provided on the power transmission shaft between the engine 10 and the motor 20, and switches between a connected state in which the power transmission shaft on the engine 10 side and the power transmission shaft on the motor 20 side are completely connected and a disconnected state in which they are blocked. Further, the clutch 45 has a slipping state in which power is transmitted while slipping between the power transmission shaft on the engine 10 side and the power transmission shaft on the motor 20 side. Thereby, when the clutch 45 is switched to the disconnected state, only the power of the motor 20 is transmitted to the drive wheels 60 via the power transmission mechanism 50, and the engine 10 can be stopped. Specifically, one end of the clutch 45 may be connected to the output shaft of the engine 10, and the other end may be connected to the other end of the output shaft of the motor 20. The clutch 45 is, for example, an electromagnetic clutch that operates under the control of the engine ECU 15 or the hybrid ECU 80.

[0025] The power transmission mechanism 50 transmits the power of the motor 20 or the engine 10 and the motor 20 to the drive wheels 60. The power transmission mechanism 50 includes a transmission 51, a differential 52, and a drive shaft 53.

[0026] The transmission 51 is connected to one end of the output shaft of the motor 20 and outputs the power of the output shaft of the motor 20 after decelerating or accelerating it according to the gear ratio of the selected gear stage.

[0027] The differential 52 transmits the output of the transmission 51 to the left and right drive wheels 60 through the left and right drive shafts 53 and absorbs the speed difference during the turning of the left and right drive wheels 60.

[0028] The drive shaft 53 connects between the differential 52 and each of the left and right drive wheels 60 and transmits the power output from the differential 52 to the left and right drive wheels 60.

[0029] The drive wheels 60 are driven by the power of only the motor 20 or the power of both the engine 10 and the motor 20 transmitted through the power transmission mechanism 50 to drive the vehicle 1. The drive wheels 60 may be front wheels or rear wheels.

[0030] The vehicle state data output device 70 outputs data related to the state of the vehicle 1. The output of the vehicle state data output device 70 is taken into the hybrid ECU 80 through a one-to-one communication line or an in-vehicle network. The vehicle state data output device 70 includes, for example, an accelerator sensor 71, a wheel speed sensor 72, an acceleration sensor 73, and a mode selector 74.

[0031] The accelerator sensor 71 measures the operation amount (accelerator opening) of the accelerator pedal of the vehicle 1 and outputs measurement data related to the accelerator opening.

[0032] The wheel speed sensor 72 measures the rotational speed (wheel speed) of the drive wheels 60 or the driven wheels of the vehicle 1 and outputs measurement data related to the wheel speed of the vehicle 1.

[0033] The acceleration sensor 73 measures the acceleration of the vehicle 1 in the longitudinal and lateral directions, and outputs measurement data regarding the acceleration of the vehicle 1 in the longitudinal and lateral directions.

[0034] The mode selector 74 is an input device used for the driver of the vehicle 1 to select one driving mode from a plurality of driving modes. The plurality of driving modes may be realized, for example, by changing the control specifications of the engine 10 and the motor 20. The plurality of driving modes include, for example, a "sports mode" that emphasizes the motion performance such as the acceleration performance of the vehicle 1, an "eco mode" that emphasizes the energy-saving performance such as the fuel consumption performance and the power consumption performance of the vehicle 1, and a "normal mode" that balances the motion performance and the energy-saving performance of the vehicle 1, etc.

[0035] The hybrid ECU 80 (an example of a control device) performs integrated control of the engine 10 and the motor 20 through the engine ECU 15 and the motor ECU 25. For example, the hybrid ECU 80 switches whether to drive the drive wheels 60 with only the power of the motor 20 or to drive the drive wheels 60 with the power of both the engine 10 and the motor 20 according to the state of the vehicle 1.

[0036] The function of the hybrid ECU 80 is realized by any hardware, or any combination of hardware and software, etc. The hybrid ECU 80 is mainly configured by a computer including, for example, an auxiliary storage device 81, a memory device 82, a CPU (Central Processing Unit) 83, and an interface 84. The same may apply to the above-mentioned engine ECU 15, motor ECU 25, and battery ECU 35.

[0037] The auxiliary storage device 81 is a non-volatile storage means, stores the program installed in the hybrid ECU 80, and stores the files and data necessary for processing. The auxiliary storage device 81 is, for example, a ROM (Read Only Memory).

[0038] When there is an instruction to start a program, for example, the memory device 82 loads the program in the auxiliary storage device 81 so that the CPU 83 can read it. The memory device 82 is, for example, a RAM (Random Access Memory).

[0039] The CPU 83 executes the program loaded in the memory device 82 and realizes various functions of the hybrid ECU 80 according to the instructions of the program.

[0040] The interface 84 is used, for example, to connect to an in-vehicle network or to connect one-to-one with various sensors, actuators, etc. The interface 84 may include a plurality of different types of interfaces according to the type of the connection target.

[0041] The program that realizes various functions of the hybrid ECU 80 is provided, for example, by a dedicated tool connected by a detachable cable to a connector for a predetermined external connection. The connector for the external connection is, for example, a DLC (Data Link Coupler) and is connected to the in-vehicle network to which the hybrid ECU 80 is connected. The program is installed in the auxiliary storage device 81 of the hybrid ECU 80 via the cable, the connector, and the in-vehicle network from the dedicated tool as a recording medium in response to a predetermined operation in the dedicated tool. Also, the program may be downloaded from another computer outside the vehicle 1 through a predetermined communication line and installed in the auxiliary storage device 81. The same may apply to the programs that realize various functions of the above-described engine ECU 15, motor ECU 25, and battery ECU 35.

[0042] As shown in FIG. 2, the hybrid ECU 80 includes, as functional units, a driving torque acquisition unit 801, a required torque acquisition unit 802, a required output acquisition unit 803, a maximum output acquisition unit 804, and a hybrid control unit 805. The functions of the driving torque acquisition unit 801, the required torque acquisition unit 802, the required output acquisition unit 803, the maximum output acquisition unit 804, and the hybrid control unit 805 are realized, for example, by a program installed in the auxiliary storage device 81 being loaded into the memory device 82 and executed by the CPU 83.

[0043] The driving torque acquisition unit 801 (an example of a torque acquisition unit) acquires the torque of the motor 20 (hereinafter, "driving torque") required for the vehicle 1 to obtain a predetermined acceleration when it is assumed that the driving wheels 60 are driven only by the power of the motor 20. The predetermined acceleration means, when there is an acceleration request from the driver of the vehicle 1, the acceleration state (an example of a first acceleration state) requested by the driver of the vehicle 1. The acceleration state requested by the driver of the vehicle 1 specifically means an acceleration state corresponding to the operation amount (throttle opening) of the accelerator pedal of the vehicle 1, and the case where there is an acceleration request from the driver of the vehicle 1 means the case where the throttle opening of the vehicle 1 exceeds a predetermined standard. Further, the predetermined acceleration means, when there is no acceleration request from the driver of the vehicle 1, the acceleration state (an example of a second acceleration state) that is minimally required at the start of acceleration (re-acceleration) of the vehicle 1. The acceleration state at the minimally required acceleration at the start of acceleration of the vehicle 1 represents the acceleration state at the minimally required acceleration at which the driver of the vehicle 1 does not feel discomfort or dissatisfaction when changing the throttle opening of the vehicle 1 from a state below a predetermined standard to a state above the predetermined standard. For example, the minimally required acceleration at the start of acceleration of the vehicle 1 is predetermined based on a sensory evaluation in a test using a real vehicle or a driving simulator with a plurality of subjects.

[0044] For example, the drive torque acquisition unit 801 acquires the drive torque using the map 300 in FIG. 3 based on the output of the accelerator sensor 71. The data of the map 300 is stored, for example, in a predetermined recording area of the auxiliary storage device 81 of the hybrid ECU 80. The data of the map 300 may be pre-registered at the time of the factory shipment of the vehicle 1, or may be registered afterwards from the above dedicated tool after the factory shipment of the vehicle 1, or may be registered by being downloaded from another external computer. The same may apply to various data used in the processing of the hybrid ECU 80 hereinafter.

[0045] The map 300 is configured in such a manner that the drive torque map 310 of the motor 20 corresponding to the accelerator opening is corrected by the line 320 with the drive torque (predetermined value DTlim) of the motor 20 corresponding to the acceleration state at the minimum required acceleration during the acceleration of the vehicle 1 as the lower limit.

[0046] In this example, the state where the accelerator opening is equal to or greater than the threshold value APth or exceeds the threshold value APth corresponds to the case where there is a request for acceleration from the driver of the vehicle 1, and the state where the accelerator opening is less than the threshold value APth or less than or equal to the threshold value APth corresponds to the case where there is no request for acceleration from the driver of the vehicle 1. Specifically, when the accelerator opening is in the range from 0 (zero) to the threshold value APth, the drive torque acquisition unit 801 acquires the predetermined value DTlim corresponding to the minimum required acceleration state at the start of the acceleration of the vehicle 1 as the drive torque of the motor 20. On the other hand, when the accelerator opening exceeds the threshold value APth, the drive torque acquisition unit 801 acquires a value corresponding to the accelerator opening as the drive torque of the motor 20.

[0047] Also, for example, the minimum required acceleration at the start of the acceleration of the vehicle 1 may be varied based on the speed of the vehicle 1. In this case, the predetermined value DTlim is varied by varying the minimum required acceleration at the start of the acceleration of the vehicle 1. This is because the minimum acceleration at which the driver does not feel discomfort or dissatisfaction may change depending on the speed of the vehicle 1. The drive torque acquisition unit 801 can acquire the current speed of the vehicle 1 based on the output of the wheel speed sensor 72, for example.

[0048] The driving torque acquisition unit 801 may acquire, for example, the minimum required acceleration at the start of acceleration of the vehicle 1 from the current speed of the vehicle 1 by using a relational expression, a map, or the like that represents the relationship between the speed of the vehicle 1 and the minimum required acceleration at the start of acceleration of the vehicle 1. Then, the driving torque acquisition unit 801 may acquire a predetermined value DTlim from the minimum required acceleration at the time of acceleration of the vehicle 1 by using, for example, a relational expression, a map, or the like based on the basic physical law of the following formula (1).

[0049] (Driving torque) = (vehicle weight) · (acceleration) · (tire radius) / (total gear ratio) ··· (1)

[0050] Alternatively, the driving torque acquisition unit 801 may directly acquire the predetermined value DTlim from the speed of the vehicle 1 by using, for example, a relational expression or a map that combines these relational expressions or maps into one.

[0051] Alternatively, for example, the predetermined value DTlim may be variable in consideration of the influence of various resistances acting on the vehicle 1. Specifically, the predetermined value DTlim may be variable in consideration of the running resistance (air resistance and rolling resistance) of the vehicle 1, the gradient resistance, and the like. The driving torque acquisition unit 801 can acquire, for example, the gradient in the traveling direction of the place where the vehicle 1 is traveling based on the output of the acceleration sensor 73.

[0052] The driving torque acquisition unit 801 may approximately acquire the running resistance of the vehicle 1 from the speed V (measured value) of the vehicle 1 by using, for example, the following formula (2) or a map based on the formula (2).

[0053] (Running resistance) = aV 2 + bV + c ··· (2) Note that the coefficients a, b, and c are defined in advance through experiments, computer simulations, or the like.

[0054] Alternatively, the driving torque acquisition unit 801 may acquire the gradient resistance of the vehicle 1 from the gradient θ in the traveling direction of the place where the vehicle 1 is traveling by using, for example, the following formula (3) or a map based on the formula (3).

[0055] (Gradient resistance) = (vehicle weight) · (acceleration due to gravity) · sinθ ···(3)

[0056] Then, the drive torque acquisition unit 801 may acquire the drive torque (predetermined value DTlim) of the motor 20, for example, by considering various resistances including the above-described running resistance and gradient resistance, and using a map based on the following formula (4) or formula (4). Thereby, the drive torque acquisition unit 801 can more appropriately derive the drive torque (predetermined value DTlim) of the motor 20 for realizing the minimum necessary acceleration at the start of acceleration of the vehicle 1 according to the state of the vehicle 1.

[0057] (Drive torque) = {(vehicle weight) · (acceleration) + (various resistances)} · (tire radius) / (overall gear ratio) ···(4)

[0058] Data such as these relational expressions and maps are stored, for example, in a predetermined storage area of the auxiliary storage device 81. Thereby, the drive torque acquisition unit 801 can read the data of the auxiliary storage device 81 and acquire the predetermined value DTlim.

[0059] Also, for example, the minimum necessary acceleration at the start of acceleration of the vehicle 1 may be variable based on the degree of importance the driver of the vehicle 1 places on the acceleration performance of the vehicle 1. In this case, when the minimum necessary acceleration at the start of acceleration of the vehicle 1 is variable, the predetermined value DTlim is variable. For example, the minimum acceleration that causes no discomfort or dissatisfaction may be different between a driver who values acceleration performance more than energy-saving performance of the vehicle 1 and a driver who values energy-saving performance more than acceleration performance of the vehicle 1.

[0060] The driving torque acquisition unit 801 may variably control the minimum required acceleration at the start of acceleration of the vehicle 1 in three steps so that the minimum required acceleration at the start of acceleration of the vehicle 1 decreases in the order of a driver who relatively values the acceleration performance of the vehicle 1, a driver who values the balance between the acceleration performance and the energy-saving performance of the vehicle 1, and a driver who relatively values the energy-saving performance of the vehicle 1. Further, the driving torque acquisition unit 801 may variably control the minimum required acceleration at the start of acceleration of the vehicle 1 in two steps, four steps or more, or continuously vary it so that the minimum required acceleration at the start of acceleration of the vehicle 1 increases as the degree of importance placed by the driver of the vehicle 1 on the acceleration performance of the vehicle 1 increases.

[0061] For example, the driving torque acquisition unit 801 may determine (predict) the degree of importance between the acceleration performance and the energy-saving performance of the vehicle 1 by the driver of the vehicle 1 based on the selected driving mode of the vehicle 1. The driving torque acquisition unit 801 can acquire the selected driving mode of the vehicle 1 based on the output of the mode selector 74. Specifically, when the selected driving mode of the vehicle 1 is the "sports mode", the driving torque acquisition unit 801 may determine that the driver of the vehicle 1 values the acceleration performance. Also, when the selected driving mode of the vehicle 1 is the "normal mode", the driving torque acquisition unit 801 may determine that the driver of the vehicle 1 values the balance between the acceleration performance and the energy-saving performance. Further, when the selected driving mode of the vehicle 1 is the "eco mode", the driving torque acquisition unit 801 may determine that the driver of the vehicle 1 relatively values the energy-saving performance.

[0062] Also, for example, the driving torque acquisition unit 801 may determine (predict) the degree of importance between the acceleration performance and the energy-saving performance of the vehicle 1 by the driver of the vehicle 1 based on the time-series history of the acceleration in the longitudinal and lateral directions of the vehicle 1. Specifically, the degree of importance placed by the driver of the vehicle 1 on the acceleration performance may be determined such that the greater the variation range of the acceleration in the longitudinal and lateral directions of the vehicle 1, the higher the degree of importance placed by the driver of the vehicle 1 on the acceleration performance.

[0063] The required torque acquisition unit 802 acquires the torque of the motor 20 (hereinafter, "required torque") necessary when the above-described predetermined acceleration of the vehicle 1 and the start of the engine 10 are simultaneously performed by the motor 20. Specifically, the required torque acquisition unit 802 may acquire the sum of the drive torque of the motor 20 acquired by the drive torque acquisition unit 801 and the torque of the motor 20 (hereinafter, "starting torque") necessary to start the engine 10 as the required torque of the motor 20. The starting torque is, for example, defined in advance through experiments or computer simulations related to the vehicle 1, and data related to the starting torque is stored in advance in a predetermined storage area of the auxiliary storage device 81, for example.

[0064] The required output acquisition unit 803 acquires the output (power) of the motor 20 (hereinafter, "required output") Preq necessary when the above-described predetermined acceleration of the vehicle 1 and the start of the engine 10 are simultaneously performed by the motor 20. Specifically, the required output acquisition unit 803 may acquire (calculate) the required output Preq of the motor 20 based on the required torque acquired by the required torque acquisition unit 802 and the rotational speed (rotational velocity) of the motor 20 at the start of the engine 10. The rotational speed of the motor 20 at the start of the engine 10 is, for example, the current rotational speed of the motor 20. The required output acquisition unit 803 can acquire the current rotational speed of the motor 20 based on the data taken in from the motor ECU 25.

[0065] Still, the required output acquisition unit 803 may acquire the output of the motor 20 required for the above-described predetermined acceleration of the vehicle 1 (hereinafter, "driving output") and the output of the motor 20 required for starting the engine 10 (hereinafter, "starting output"), and acquire the sum of the driving output and the starting output as the required output Preq. Specifically, the required output acquisition unit 803 may acquire (calculate) the driving output based on the driving torque of the motor 20 acquired by the driving torque acquisition unit 801 and the rotational speed of the motor 20 at the time of starting the engine 10 (for example, the current rotational speed of the motor 20). Further, the required output acquisition unit 803 may acquire (calculate) the starting torque based on the starting torque of the motor 20 defined in advance and the rotational speed of the motor 20 at the time of starting the engine 10. In this case, the required torque acquisition unit 802 may be omitted.

[0066] The maximum output acquisition unit 804 acquires the maximum output (maximum power) Pmax that the battery 30 can output based on the state of the battery 30. For example, the maximum output Pmax of the battery 30 changes depending on the state of the battery 30 such as the remaining capacity (SOC) and the temperature state of the battery 30. The maximum output acquisition unit 804 can acquire various states such as the SOC and the temperature state of the battery 30 based on the data related to the battery 30 taken in from the battery ECU 35. The maximum output acquisition unit 804 may acquire the maximum output Pmax of the battery 30 from the current state of the battery 30 using a relational expression, a map, or the like showing the relationship between various states of the battery 30 and the maximum output Pmax of the battery 30. This relational expression, map, or the like is stored in advance in the auxiliary storage device 81.

[0067] The hybrid control unit 805 (an example of a control unit) controls the lower-level engine ECU 15 and motor ECU 25 according to various states of the vehicle 1, and performs integrated control regarding the engine 10 and the motor 20 through these. For example, the hybrid control unit 805 determines whether to operate or stop the engine 10. Details will be described later (see FIGS. 4 and 5).

[0068] [Control Processing of Hybrid ECU] Next, with reference to FIGS. 4 and 5, the control process of the hybrid ECU 80 will be described.

[0069] <First Example of Control Process> FIG. 4 is a flowchart schematically showing a first example of the control process of the hybrid ECU 80. This flowchart is repeatedly executed, for example, from after the completion of the initial process at the start of the vehicle 1 until before the start of the end process at the stop of the vehicle 1. The start of the vehicle 1 represents, for example, the ON of the ignition switch, and the stop of the vehicle 1 represents, for example, the OFF of the ignition switch. The same applies to the case of the second example (FIG. 5) described later.

[0070] As shown in FIG. 4, in step S102, the drive torque acquisition unit 801 acquires the torque (drive torque) of the motor 20 required for the vehicle 1 to obtain the above-mentioned predetermined acceleration assuming that the drive wheels 60 are driven only by the power of the motor 20.

[0071] When the process of step S102 is completed, the hybrid ECU 80 proceeds to step S104.

[0072] In step S104, the required torque acquisition unit 802 acquires the torque (required torque) of the motor 20 when the above-mentioned predetermined acceleration of the vehicle 1 by the power of the motor 20 alone and the start of the engine 10 are performed simultaneously.

[0073] When the process of step S104 is completed, the hybrid ECU 80 proceeds to step S106.

[0074] In step S106, the required output acquisition unit 803 acquires the required output Preq of the motor 20 when the above-mentioned predetermined acceleration of the vehicle 1 by the power of the motor 20 alone and the start of the engine 10 are performed simultaneously, based on the required torque of the motor 20 acquired in step S104.

[0075] As described above, when the required output acquisition unit 803 acquires and sums up each of the drive output and the start output to obtain the required output Preq, the process of step S104 is omitted.

[0076] When the process of step S106 is completed, the hybrid ECU 80 proceeds to step S108.

[0077] In step S108, the maximum output acquisition unit 804 acquires the maximum output of the battery 30 that can be supplied to the motor 20 based on the current state of the battery 30.

[0078] When the process of step S108 is completed, the hybrid ECU 80 proceeds to step S110.

[0079] In step S110, the hybrid control unit 805 determines whether the required output Preq is greater than the maximum output Pmax. If the required output Preq is greater than the maximum output Pmax, the hybrid control unit 805 proceeds to step S112; if the required output Preq is less than or equal to the maximum output, the hybrid control unit 805 proceeds to step S114.

[0080] Note that in this step, the hybrid control unit 805 may also determine whether the required output Preq is greater than or equal to the maximum output Pmax. In this case, if the required output Preq is greater than or equal to the maximum output Pmax, the hybrid control unit 805 proceeds to step S112; if the required output Preq is less than the maximum output Pmax, the hybrid control unit 805 proceeds to step S114. The same applies to step S210 in FIG. 5 described later.

[0081] In step S112, the hybrid control unit 805 determines to put the engine 10 in an operating state.

[0082] Specifically, when the engine 10 is in an operating state, the hybrid control unit 805 maintains that state. For example, when the accelerator opening is relatively large, if the engine 10 were to be stopped, then later when starting the engine 10, the output of the motor 20 alone would not be sufficient to achieve the acceleration of the vehicle 1 required by the driver while starting the engine 10. Also, for example, when the accelerator opening is relatively small, if the engine 10 were to be stopped, then later when the accelerator opening becomes large, the output of the motor 20 alone would not be sufficient to achieve the minimum required acceleration at the start of acceleration of the vehicle 1 while starting the engine 10. More specifically, when the engine 10 is in an operating state, the hybrid control unit 805 outputs a command to the engine ECU 15 to achieve the normal output state and torque state according to the state of the vehicle 1 in order to maintain the operating state of the engine 10.

[0083] Further, when the engine 10 is in a stopped state, the hybrid control unit 805 starts the engine 10. For example, when the accelerator opening is relatively small, if the accelerator opening later becomes large, the output of the motor 20 alone would not be sufficient to achieve the minimum required acceleration at the start of acceleration of the vehicle 1 while starting the engine 10. More specifically, when the engine 10 is in a stopped state, the hybrid control unit 805 outputs a start command for the engine 10 to the engine ECU 15 and the motor ECU 25. In this case, the hybrid ECU 80, the engine ECU 15, or the motor ECU 25 outputs a command (control current) to the clutch 45 to switch the clutch 45 from the disengaged state to the engaged state. Also, the motor ECU 25 controls the power conversion device 40 so as to output not only the torque for the motor 20 to drive the drive wheels 60 but also the torque for starting the engine 10. Then, the engine ECU 15 appropriately controls various actuators such as the injector (fuel injection device) and the fuel pump in accordance with the rotation of the motor 20 to start the engine 10. Thereby, the engine 10 starts.

[0084] According to the processing of steps S110 and S112 in this example, as described above, even when the accelerator opening is relatively small (i.e., when there is no acceleration request from the driver of vehicle 1), if the required output Preq is greater than the maximum output Pmax, the engine 10 is started. Therefore, in a state where the accelerator opening is relatively large (i.e., when there is an acceleration request from the driver of vehicle 1), the engine 10 will not stop.

[0085] When the processing of step S112 is completed, the hybrid ECU 80 ends the processing of this flowchart.

[0086] On the other hand, in step S114, the hybrid control unit 805 determines to stop the engine 10.

[0087] Specifically, when the engine 10 is in a stopped state, the hybrid control unit 805 maintains that state. For example, when the accelerator opening is relatively small, in the stopped state of the engine 10, even if the accelerator opening increases, only the output of the motor 20 can be used to realize the minimum required acceleration at the start of acceleration of vehicle 1 without starting the engine 10.

[0088] Also, when the engine 10 is in an operating state, the hybrid control unit 805 stops the engine 10. For example, when the accelerator opening is relatively small, even if the accelerator opening becomes large after the engine 10 is stopped, only the output of the motor 20 can realize the minimum necessary acceleration at the start of vehicle 1 acceleration while starting the engine 10. More specifically, when the engine 10 is in an operating state, the hybrid ECU 80 outputs a stop command for the engine 10 to the engine ECU 15, or to the engine ECU 15 and the motor ECU 25. In this case, the hybrid ECU 80, the engine ECU 15, or the motor ECU 25 outputs a command (control current) to the clutch 45 to switch the clutch 45 from the connected state to the disengaged state. Then, the engine ECU 15 appropriately controls various actuators such as the injector and the fuel pump to stop the engine 10. Thereby, the engine 10 stops.

[0089] When the process of step S114 is completed, the hybrid ECU 80 ends the process of this flowchart.

[0090] <Second Example of Control Processing> FIG. 5 is a flowchart schematically showing a second example of the control processing of the hybrid ECU 80.

[0091] As shown in FIG. 5, steps S202, S204, S206, S208, and S210 are the same as the processes of steps S102, S104, S106, S108, and S110 in FIG. 4, so the description is omitted.

[0092] In step S210, when the required output Preq is greater than the maximum output Pmax, the hybrid control unit 805 proceeds to step S212, and when the required output Preq is less than or equal to the maximum output Pmax, it proceeds to step S214.

[0093] Since step S212 is the same as the process of step S112 in FIG. 4, the description is omitted.

[0094] When the process of step S212 is completed, the hybrid ECU 80 ends the process of the current flowchart.

[0095] On the other hand, in step S214, the hybrid control unit 805 determines whether the required output Preq is smaller than a value obtained by subtracting a predetermined value α (>0) (an example of a predetermined positive value) from the maximum output Pmax. The predetermined value α is set in advance as a value somewhat smaller than the maximum output Pmax, and data regarding the predetermined value α is stored in advance in a predetermined storage area of the auxiliary storage device 81, for example. When the required output Preq is smaller than the value obtained by subtracting the predetermined value α from the maximum output Pmax, the hybrid control unit 805 proceeds to step S216; otherwise, it proceeds to step S218. That is, when the required output Preq is less than or equal to the maximum output Pmax and greater than or equal to the value obtained by subtracting the predetermined value α from the maximum output Pmax, the hybrid control unit 805 proceeds to step S218.

[0096] Note that in step S214, the hybrid control unit 805 may determine whether the required output Preq is less than or equal to the value obtained by subtracting the predetermined value α from the maximum output Pmax. In this case, when the required output Preq is less than or equal to the maximum output Pmax, the hybrid control unit 805 proceeds to step S216; otherwise, it proceeds to step S218.

[0097] Since step S216 is the same as the process of step S114 in FIG. 4, the description thereof is omitted.

[0098] When the process of step S216 is completed, the hybrid ECU 80 ends the process of the current flowchart.

[0099] On the one hand, in step S218, the hybrid control unit 805 maintains the current operating state or stop state of the engine 10. That is, when the current engine 10 is in the operating state, the hybrid control unit 805 maintains the operating state of the engine 10, and when the current engine 10 is in the stop state, the hybrid control unit 805 maintains the stop state of the engine 10. Thereby, for example, even if the required output Preq exceeds the maximum output Pmax and immediately after the engine 10 transitions from the stop state to the operating state, the required output Preq drops below the maximum output Pmax, the engine 10 does not stop until it becomes smaller than the value obtained by subtracting the predetermined value α from the maximum output Pmax. Similarly, for example, even if the required output Preq becomes smaller than the value obtained by subtracting the predetermined value α from the maximum output Pmax and immediately after the engine 10 transitions from the operating state to the stop state, the required output Preq rises above the value obtained by subtracting the predetermined value α from the maximum output Pmax, the engine 10 does not start until it exceeds the maximum output Pmax. Therefore, the hybrid ECU 80 can suppress the occurrence of hunting in which the start and stop of the engine 10 are repeated.

[0100] When the process of step S218 is completed, the hybrid ECU 80 ends the process of the current flowchart.

[0101] [Second Example of Vehicle Configuration] Next, with reference to FIGS. 6 to 8, a second example of the configuration of the vehicle 1 according to the present embodiment will be described. Hereinafter, the description will focus on the parts different from the above-described first example (FIGS. 1 and 2).

[0102] FIG. 6 is a diagram showing a second example of the configuration of the vehicle 1. FIG. 7 is a functional block diagram showing a second example of the functional configuration of the hybrid ECU 80. FIG. 8 is a diagram showing the relationship between the rotational speed on the output side of the clutch 54 (the transmission 51 side) and the rotational speed of the motor 20 at the start of the engine 10.

[0103] As shown in FIGS. 6 and 7, the vehicle 1 according to this example is different from the first example described above in that the clutch 54 and the rotation speed sensor 75 are provided. Further, as shown in FIGS. 7 and 8, the vehicle 1 according to this example is different from the first example described above in the method of obtaining the rotation speed of the motor 20 at the start of the engine 10 by the required output acquisition unit 803.

[0104] The power transmission mechanism 50 includes a clutch 54 in addition to the transmission 51, the differential 52, and the drive shaft 53.

[0105] The clutch 54 is provided on the power transmission shaft between the motor 20 and the transmission 51, and switches between a connected state in which the power transmission shafts on the motor 20 side and the transmission 51 side are completely connected and a disconnected state in which they are blocked. Further, the clutch 54 has a slipping state in which power is transmitted while slipping between the power transmission shafts on the motor 20 side and the transmission 51 side. Thereby, in a part of the period from the start of starting of the engine 10 to the completion of starting, by switching the clutch 54 from the connected state to the disconnected state or the slipping state, the output of the motor 20 can be preferentially used for starting the engine 10. Specifically, one end of the clutch 54 may be connected to one end of the output shaft of the motor 20, and the other end may be connected to the input shaft of the transmission 51. The clutch 45 is, for example, an electromagnetic clutch that operates under the control of the engine ECU 15 or the hybrid ECU 80.

[0106] The vehicle state data output device 70 includes a rotation speed sensor 75 in addition to the accelerator sensor 71, the wheel speed sensor 72, the acceleration sensor 73, and the mode selector 74.

[0107] The rotation speed sensor 75 measures the rotation speed (rotation speed) of the power transmission shaft on the transmission 51 side (output side) of the clutch 54 and outputs data regarding the rotation speed of the power transmission shaft on the transmission 51 side of the clutch 54. Thereby, the hybrid ECU 80 can acquire the rotation speed of the power transmission shaft on the transmission 51 side of the clutch 54 based on the output of the rotation speed sensor 75.

[0108] The required output acquisition unit 803 acquires (calculates) the required output Preq of the motor 20 based on the required torque acquired by the required torque acquisition unit 802 and the rotational speed of the motor 20 at the time of starting the engine 10, similar to the case of the first example described above.

[0109] In this example, when starting the engine 10, the clutch 54 is switched from the connected state to the slipping state or the disconnected state. Therefore, the motor 20 rotates the engine 10 at a rotational speed higher than the current rotational speed when starting the engine 10. Thus, the required output acquisition unit 803 can predict the rotational speed of the motor 20 at the time of starting the engine 10 from the current rotational speed of the engine 10 and the rotational speed on the output side (transmission 51 side) of the clutch 54 using a predetermined map or relational expression.

[0110] For example, the required output acquisition unit 803 acquires (predicts) the rotational speed of the motor 20 at the time of starting (during starting) the engine 10 from the rotational speed on the output side of the clutch 54 using the map 800 in FIG. 8. The data of the map 800 is stored in advance in a predetermined storage area of the auxiliary storage device 81, for example.

[0111] The map 800 represents the relationship between the rotational speed on the output side of the clutch 54 and the rotational speed of the motor 20 at the time of starting the engine 10.

[0112] The map 800 represents that in the range where the rotational speed on the output side of the clutch 54 is equal to or lower than the threshold value Nth, that is, in the starting region where the speed of the vehicle 1 is relatively low, the rotational speed of the motor 20 is constant at the minimum rotational speed required to start the engine 10. The minimum rotational speed required to start the engine 10 is, for example, the idling rotational speed of the engine 10. Also, the map 800 represents that in the range where the rotational speed on the output side of the clutch 54 exceeds the threshold value Nth, the rotational speed of the motor 20 is a rotational speed that is a certain amount higher than the rotational speed on the output side of the clutch 54 (line 810).

[0113] The hybrid ECU 80 according to this example may perform the control processes shown in FIGS. 4 and 5 described above. At this time, in steps S106 and S206, as described above, the required output acquisition unit 803 may acquire (predict) the rotational speed of the motor 20 at the start of the engine 10 based on the rotational speed on the output side of the clutch 54 and the current rotational speed of the motor 20, thereby acquiring the required output Preq. Thereby, throughout the processes of FIGS. 4 and 5, the hybrid ECU 80 exhibits the same operations and effects as those of the first example described above.

[0114] [Third Example of Vehicle Configuration] Next, with reference to FIGS. 9 and 10, a third example of the configuration of the vehicle 1 according to the present embodiment will be described. Hereinafter, the description will focus on the parts different from the above-described first example (FIGS. 1 and 2) and second example (FIGS. 6 and 7).

[0115] FIG. 9 is a diagram showing a third example of the configuration of the vehicle 1. FIG. 10 is a functional block diagram showing a third example of the functional configuration of the hybrid ECU 80.

[0116] As shown in FIG. 9, the vehicle 1 according to this example is different from the above-described first example in that two motors 20, that is, motors 20A and 20B are provided. Further, as shown in FIG. 10, in this example, the required torque acquisition unit 802 is omitted, and the method for acquiring the required output Preq by the required output acquisition unit 803 is different from that of the above-described first example and second example.

[0117] In this example, the vehicle 1 is a hybrid vehicle capable of transmitting the power of only the motor 20A or the power of the engine 10 and the motor 20A to the drive wheels 60 through the power transmission mechanism 50 and traveling.

[0118] The motor 20A (an example of the first electric motor) is one of the power sources (prime movers) of the vehicle 1, similar to the motors 20 in the above-described first and second examples. One end of the output shaft of the motor 20A is connected to the power transmission mechanism 50, and power is transmitted to the drive wheels 60 through the power transmission mechanism 50. Further, when the vehicle 1 decelerates, the motor 20A is driven by the power (braking energy) from the drive wheels 60 through the power transmission mechanism 50, thereby performing regenerative power generation and charging the battery 30. On the other hand, different from the motors 20 in the above-described first and second examples, the motor 20A is not used for starting the engine 10, and when the engine 10 is started, the clutch 45 is in the disengaged state. That is, the motor 20A is a driving motor of the vehicle 1. The motor 20A is, for example, a motor generator driven by three-phase alternating current and is driven by the power supplied from the battery 30 through the power conversion device 40.

[0119] The motor 20B (an example of the second electric motor) has its rotating shaft connected to the output shaft (crankshaft) of the engine 10 in a power-transmittable manner. The motor 20B is a starting motor used for starting the engine 10. Further, the motor 20B may generate power using the power of the engine 10 and charge the battery 30 or supply power to the motor 20A through the power conversion device 40. The motor 20B is, for example, a motor generator driven by three-phase alternating current and is driven by the power supplied from the battery 30 through the power conversion device 40.

[0120] The required output acquisition unit 803 acquires the total required output Preq of the motors 20A and 20B when the above-described predetermined acceleration of the vehicle 1 and the start of the engine 10 are performed simultaneously by the power of only the motors 20A and 20B. Specifically, the required output acquisition unit 803 acquires the output (drive output) of the motor 20A required for the above-described predetermined acceleration of the vehicle 1 and the output (start output) of the motor 20B required for the start of the engine 10, respectively, and acquires the sum of the drive output and the start output as the required output Preq. More specifically, the required output acquisition unit 803 may acquire (calculate) the drive output based on the drive torque of the motor 20A acquired by the drive torque acquisition unit 801 and the current rotational speed of the motor 20A. Further, the required output acquisition unit 803 may acquire the start output based on a predetermined start torque of the motor 20B and the rotational speed of the engine 10 required for starting the engine 10 (for example, the idling rotational speed of the engine 10).

[0121] The hybrid ECU 80 according to this example may perform the control processes of FIGS. 4 and 5 described above. At this time, steps S104 and S204 are omitted, and in steps S106 and S206, the required output acquisition unit 803 may acquire the required output Preq by acquiring the drive output of the motor 20A and the start output of the motor 20B as described above. Thereby, throughout the entire process of FIGS. 4 and 5, the hybrid ECU 80 exhibits the same operations and effects as those of the first example described above.

[0122] [Fourth Example of Vehicle Configuration] Next, with reference to FIG. 11, a fourth example of the configuration of the vehicle 1 according to the present embodiment will be described. Hereinafter, the description will focus on the parts different from the above-described first example (FIGS. 1 and 2), second example (FIGS. 6 and 7), and third example (FIGS. 9 and 10).

[0123] FIG. 11 is a diagram showing a fourth example of the configuration of the vehicle 1.

[0124] Note that, since the functional configuration of the hybrid ECU 80 is the same as that of the third example (FIG. 10) described above, the illustration thereof is omitted.

[0125] As shown in FIG. 11, the vehicle 1 according to this example is different from the first and second examples described above in that two motors 20, that is, motors 20A and 20B are provided, and a power split mechanism 55 is provided instead of the transmission 51. Further, in this example, the required torque acquisition unit 802 is omitted, and the method for acquiring the required output Preq by the required output acquisition unit 803 is different from that in the first and second examples described above.

[0126] In this example, the vehicle 1 is a hybrid vehicle capable of transmitting the power of only the motor 20A or the power of the engine 10 and the motor 20A to the drive wheels 60 through the power transmission mechanism 50, similar to the case of the third example described above.

[0127] The motor 20A is one of the power sources (prime movers) of the vehicle 1, similar to the case of the third example described above. The motor 20A transmits power to the drive wheels 60 through the power transmission mechanism 50 (power split mechanism 55). Further, the motor 20B performs regenerative power generation by being driven by the power (braking energy) from the drive wheels 60 through the power transmission mechanism 50 when the vehicle 1 decelerates.

[0128] The motor 20B is used to start the engine 10, similar to the case of the third example described above. Further, the motor 20B is driven by the engine 10 through the power split mechanism 55 to generate power, supply power to the motor 20A, or charge the battery 30. Further, the motor 20B adjusts the gear ratio of the power split mechanism 55 with respect to the input from the engine 10 by adjusting the rotational speed.

[0129] The power transmission mechanism 50 includes a power split mechanism 55, a differential 52, and a drive shaft 53.

[0130] The power split mechanism 55 splits the power of the engine 10 into power for driving the drive wheels 60 and power for generating electricity with the motor 20B. Also, when starting the engine 10, the power of the motor 20B is transmitted to the engine 10. For example, the power split mechanism 55 may have a planetary gear mechanism, and the output shaft of the motor 20B, the output shaft of the engine 10, and the output shafts to the motor 20A and the differential 52 may be connected to the rotation shafts of the sun gear, the planetary carrier, and the ring gear, respectively.

[0131] The required output acquisition unit 803 acquires, in the same manner as in the above-described third example, the drive output of the motor 20A required for the above-described predetermined acceleration of the vehicle 1 and the starting output of the motor 20B required for starting the engine 10, and acquires the sum of the drive output and the starting output as the required output Preq. Specifically, the required output acquisition unit 803 may acquire (calculate) the drive output based on the drive torque of the motor 20A acquired by the drive torque acquisition unit 801 and the current rotational speed of the motor 20A. Also, the required output acquisition unit 803 may acquire the starting output based on the starting torque of the motor 20B and the rotational speed of the engine 10 required to start the engine 10. The gear ratio between the motor 20B and the engine 10 when starting the engine 10 via the power split mechanism 55 changes according to the running state of the vehicle 1 (the rotational speed of the motor 20A). Therefore, the required output acquisition unit 803 may acquire the starting torque of the motor 20B and the rotational speed of the motor 20B at the time of starting the engine 10 from the rotational speed of the motor 20A using a predetermined relational expression, a map, or the like.

[0132] The hybrid ECU 80 according to this example may perform the control processes of FIGS. 4 and 5 described above. At this time, in the same manner as in the above-described third example, steps S104 and S204 are omitted, and in steps S106 and S206, the required output acquisition unit 803 may acquire the required output Preq by acquiring the drive output of the motor 20A and the starting output of the motor 20B as described above. Thereby, throughout the entire process of FIGS. 4 and 5, the hybrid ECU 80 exhibits the same operations and effects as in the above-described first example.

[0133] [Operation] Next, the operation of the hybrid ECU 80 according to the present embodiment will also be described.

[0134] In the present embodiment, the drive torque acquisition unit 801 acquires the torque of the motor 20A required for the vehicle 1 to perform a predetermined acceleration with only the power of the motor 20A among the engine 10 and the motor 20A based on the state of the vehicle 1. Further, the required output acquisition unit 803 acquires the total required output Preq of the motors 20A and 20B when the vehicle 1 performs a predetermined acceleration and the engine 10 starts simultaneously, based on the drive torque of the motor 20A acquired by the drive torque acquisition unit 801 and the starting torque of the motor 20B required for starting the engine 10. Further, the maximum output acquisition unit 804 acquires the maximum output Pmax that the battery 30 can supply to the motors 20A and 20B based on the state of the battery 30. Then, when the required output Preq is greater than the maximum output Pmax, the hybrid control unit 805 starts the engine 10 in the stopped state or maintains the operation of the engine 10, and when the required output Preq is less than the maximum output Pmax, the hybrid control unit 805 stops the engine 10 in the operating state or maintains the stopped state of the engine 10.

[0135] Thereby, when the required output Preq considering the starting output of the motor 20B is greater than the maximum output Pmax corresponding to the state of the battery 30, the hybrid ECU 80 can bring the engine 10 into the operating state. Therefore, for example, when the available power of the motor 20A is limited due to a decrease in the maximum output of the battery 30 or the power used for starting the engine 10, stopping the engine 10 or maintaining the stopped state of the engine 10 is prohibited. Thus, the hybrid ECU 80 can suppress a deterioration in acceleration performance at the time of starting the engine 10 during the running of the vehicle 1.

[0136] Further, in the present embodiment, the drive torque acquisition unit 801 may acquire the drive torque of the motor 20A required for either one of the first acceleration state of the vehicle 1 requested by the driver of the vehicle 1 and the second acceleration state with the minimum acceleration required at the start of acceleration of the vehicle 1, where the acceleration is the same as or greater than the other.

[0137] Thereby, for example, when the accelerator opening is relatively large, the hybrid ECU 80 can acquire the drive torque for realizing the first acceleration state, and when the accelerator opening is relatively small, the hybrid ECU 80 can acquire the drive torque for realizing the second acceleration state. Therefore, for example, even when the accelerator opening is relatively small, the hybrid ECU 80 can consider the drive torque for realizing the acceleration state with the minimum acceleration required at the start of acceleration of the vehicle 1 after the accelerator opening increases. Thus, the hybrid ECU 80 can suppress the deterioration of the acceleration performance at the start of acceleration (re-acceleration) of the engine 10 during traveling.

[0138] Further, in the present embodiment, the drive torque acquisition unit 801 may vary the acceleration of the second acceleration state according to the speed of the vehicle 1.

[0139] Thereby, for example, in a situation where the accelerator opening is relatively small, the hybrid ECU 80 can acquire the drive torque for realizing an acceleration level that causes no dissatisfaction or discomfort to the driver at the start of acceleration of the vehicle 1 in accordance with the speed of the vehicle 1. Therefore, the deterioration of the acceleration performance at the start of acceleration of the vehicle 1 can be more appropriately suppressed.

[0140] Further, in the present embodiment, when the drive torque acquisition unit 801 determines that the degree of importance of the acceleration performance of the vehicle 1 by the driver of the vehicle 1 is relatively high based on the state of the vehicle 1, the drive torque acquisition unit 801 may increase the acceleration of the second acceleration state more than when it determines that the degree of importance is relatively low.

[0141] As a result, the hybrid ECU 80 can more appropriately suppress the deterioration of the acceleration performance at the start of acceleration of the vehicle 1 in accordance with the degree of importance attached to the acceleration performance of the driver of the vehicle 1.

[0142] Further, in the present embodiment, the drive torque acquisition unit 801 may determine the degree of importance attached to the acceleration performance by the driver of the vehicle 1 based on the selected driving mode among the plurality of driving modes of the vehicle 1.

[0143] As a result, the hybrid ECU 80 can specifically determine the degree of importance attached to the acceleration of the driver of the vehicle 1.

[0144] Further, in the present embodiment, the drive torque acquisition unit 801 may determine the degree of importance attached to the acceleration performance of the vehicle 1 by the driver of the vehicle 1 based on the history of the acceleration in the longitudinal and lateral directions of the vehicle 1.

[0145] As a result, the hybrid ECU 80 can specifically determine the degree of importance attached to the acceleration of the driver of the vehicle 1.

[0146] Further, in the present embodiment, the drive torque acquisition unit 801 acquires the torque of the motor 20A required for the first acceleration state according to the accelerator opening in the range of the accelerator opening where the torque of the motor 20A according to the accelerator opening is larger than the torque of the motor 20A according to the second acceleration state, and in the range of the accelerator opening where the torque of the motor 20A according to the accelerator opening is smaller than the torque of the motor 20A according to the second acceleration state, acquires the torque of the motor 20A required for the second acceleration state.

[0147] As a result, the hybrid ECU 80 can acquire the drive torque of the motor 20A in accordance with the accelerator opening.

[0148] Further, in the present embodiment, the drive torque acquisition unit 801 may acquire the torque of the motor 20A required for the second acceleration state in consideration of the running resistance according to the speed of the vehicle 1 and the gradient of the place where the vehicle 1 is running.

[0149] As a result, the hybrid ECU 80 can appropriately obtain the drive torque necessary to achieve the minimum acceleration required at the start of acceleration of the vehicle 1 in a situation where the accelerator opening is relatively small, according to the state of the vehicle 1.

[0150] Also, in the present embodiment, the motors 20A and 20B may be the same motor 20, that is, may be realized by a single motor 20.

[0151] As a result, the hybrid ECU 80 can correspond to a configuration in which one motor 20 outputs both the power for driving the drive wheels 60 and the power at the start of the engine 10.

[0152] Also, in the present embodiment, the clutch 54 may shift to a slipping state in which power is transmitted while slipping between the power transmission shaft of the motor 20A and the power transmission shaft on the drive wheel 60 side, or a state in which the power transmission path between the motor 20A and the drive wheel 60 is blocked, at the start of the engine 10 in the running state of the vehicle 1. Then, the required output acquisition unit 803 may predict the rotational speed of the motor 20A at the start of the engine 10 based on the rotational speed on the output side of the clutch 54, and calculate the required output Preq of the motor 20 based on the prediction result, the drive torque of the motor 20 acquired by the drive torque acquisition unit 801, and the starting torque of the motor 20 required for starting the engine 10.

[0153] As a result, the hybrid ECU 80 can appropriately obtain the required output Preq of the motor 20 according to the state of the clutch 54 at the start of the engine 10.

[0154] Also, in this embodiment, when the required output Preq is greater than the maximum output Pmax, the hybrid control unit 805 may start the engine 10 in the stopped state or maintain the operation of the engine 10. Further, when the required output Preq is less than the value obtained by subtracting a predetermined value α (>0) smaller than the maximum output Pmax from the maximum output, the hybrid control unit 805 may stop the engine 10 in the operating state or maintain the stopped state of the engine 10. And when the required output Preq is less than the maximum output Pmax and greater than the value obtained by subtracting the predetermined value α from the maximum output Pmax, the hybrid control unit 805 may maintain the stopped state or the operating state of the engine 10.

[0155] Thereby, the hybrid ECU 80 can suppress the occurrence of hunting in which the engine 10 is repeatedly started and stopped.

[0156] As described above, the embodiments have been described in detail, but the present disclosure is not limited to such specific embodiments, and various modifications and improvements are possible within the scope of the gist described in the claims.

Explanation of Signs

[0157] 1 Vehicle 10 Engine 15 Engine ECU 20 Motor (First electric motor, second electric motor) 20A Motor (First electric motor) 20B Motor (Second electric motor) 25 Motor ECU 30 Battery 35 Battery ECU 40 Power conversion device 45 Clutch 50 Power transmission mechanism 51 Transmission 52 Differential 53 Drive shaft 54 Clutch 55 Power split mechanism 60 Driving wheels 70 Vehicle state data output device 71 Accelerator sensor 72 Wheel speed sensor 73 Acceleration sensor 74 Mode selector 75 Rotation speed sensor 80 Hybrid ECU (control device) 81 Auxiliary storage device 82 Memory device 83 CPU 84 Interface 801 Driving torque acquisition unit (torque acquisition unit) 802 Required torque acquisition unit 803 Required output acquisition unit 804 Maximum output acquisition unit 805 Hybrid control unit (control unit) Pmax Maximum output Preq Required output α Predetermined value (predetermined positive value)

Claims

1. A control device for a vehicle having an engine, a first electric motor, a second electric motor capable of starting the engine, and a battery capable of supplying power to the first electric motor and the second electric motor, the vehicle being driven by the first electric motor, or the power transmitted from the engine and the first electric motor to rotate drive wheels, comprising: A torque acquisition unit that acquires the torque of the first electric motor necessary for the vehicle to perform a predetermined acceleration with only the power of the first electric motor among the engine and the first electric motor based on the state of the vehicle; A necessary output acquisition unit that acquires the total necessary output of the first electric motor and the second electric motor when the predetermined acceleration of the vehicle and the start of the engine are performed simultaneously based on the torque of the first electric motor acquired by the torque acquisition unit and the torque of the second electric motor necessary for starting the engine; A maximum output acquisition unit that acquires the maximum output that the battery can supply to the first electric motor and the second electric motor based on the state of the battery; A control unit that starts the engine in a stopped state or maintains the operation of the engine when the necessary output is greater than the maximum output, and stops the engine in an operating state or maintains the stopped state of the engine when the necessary output is less than the maximum output, The predetermined acceleration is either one of the first acceleration state of the vehicle requested by the driver of the vehicle and the second acceleration state with the minimum acceleration required at the start of the acceleration of the vehicle, where the acceleration is the same as or greater than the other; The torque acquisition unit acquires the torque of the first electric motor necessary for either one of the acceleration states, and varies the acceleration of the second acceleration state according to the speed of the vehicle. Control device. Claim 2. A control device for a vehicle having an engine, a first electric motor, a second electric motor capable of starting the engine, and a battery capable of supplying power to the first electric motor and the second electric motor, wherein the driving wheels are rotated by the power of the first electric motor, or the power transmitted from the engine and the first electric motor to cause the vehicle to travel, a torque acquisition unit that acquires the torque of the first electric motor necessary for the vehicle to perform a predetermined acceleration with only the power of the first electric motor among the engine and the first electric motor based on the state of the vehicle; a required output acquisition unit that acquires the total required output of the first electric motor and the second electric motor when the predetermined acceleration of the vehicle and the start of the engine are performed simultaneously based on the torque of the first electric motor acquired by the torque acquisition unit and the torque of the second electric motor necessary for starting the engine; a maximum output acquisition unit that acquires the maximum output that the battery can supply to the first electric motor and the second electric motor based on the state of the battery; a control unit that starts the engine in a stopped state or maintains the operation of the engine when the required output is greater than the maximum output, and stops the engine in an operating state or maintains the stopped state of the engine when the required output is less than the maximum output; the predetermined acceleration is either one of the first acceleration state of the vehicle requested by the driver of the vehicle and the second acceleration state with the minimum acceleration required at the start of the acceleration of the vehicle, where the acceleration is the same as or greater than the other; the torque acquisition unit acquires the torque of the first electric motor required for either one of the acceleration states, and when it is determined based on the state of the vehicle that the degree of importance of the acceleration performance of the vehicle by the driver of the vehicle is relatively high, increases the acceleration of the second acceleration state more than when it is determined to be relatively low; A control device. Claim 3. The torque acquisition unit varies the acceleration of the second acceleration state according to the speed of the vehicle. The control device according to claim 2.

4. When the torque acquisition unit determines that the degree of importance of the acceleration performance of the vehicle by the driver of the vehicle is relatively high based on the state of the vehicle, the acceleration of the second acceleration state is made larger than when it is determined to be relatively low. The control device according to claim 1.

5. The torque acquisition unit determines the degree of importance of the acceleration performance of the vehicle by the driver of the vehicle based on the selected driving mode among a plurality of driving modes of the vehicle. The control device according to any one of claims 2 to 4.

6. The torque acquisition unit determines the degree of importance of the acceleration performance of the vehicle by the driver of the vehicle based on the history of the acceleration in the longitudinal and lateral directions of the vehicle. The control device according to any one of claims 2 to 5.

7. In the range of the accelerator opening where the torque of the first electric motor according to the accelerator opening of the vehicle is larger than the torque of the first electric motor according to the second acceleration state, the torque of the first electric motor required for the first acceleration state according to the accelerator opening is acquired, and in the range of the accelerator opening where the torque of the first electric motor according to the accelerator opening of the vehicle is smaller than the torque of the first electric motor according to the second acceleration state, the torque of the first electric motor required for the second acceleration state is acquired. The control device according to any one of claims 1 to 6.

8. The torque acquisition unit acquires the torque of the first electric motor required for the second acceleration state in consideration of the running resistance according to the speed of the vehicle and the gradient of the place where the vehicle is running. The control device according to claim 7.

9. The functions of the first electric motor and the functions of the second electric motor are realized by one electric motor. The control device according to any one of claims 1 to 8.

10. The vehicle has a clutch provided in a power transmission path between the first electric motor and the drive wheels, When starting the engine in the running state of the vehicle, the clutch shifts to a slipping state in which power is transmitted while slipping between the power transmission shaft of the first electric motor and the power transmission shaft on the drive wheel side, or a blocking state in which the power transmission path is blocked. The required output acquisition unit predicts the rotation speed of the first electric motor at the start of the engine based on the rotation speed on the output side of the clutch, and based on the prediction result, the torque of the first electric motor acquired by the torque acquisition unit, and the torque of the second electric motor required for starting the engine, acquires the required output. The control device according to claim 9.

11. When the required output is greater than the maximum output, the control unit starts the engine in a stopped state or maintains the operation of the engine. When the required output is less than a value obtained by subtracting a predetermined positive value smaller than the maximum output from the maximum output, the control unit stops the engine in an operating state or maintains the stopped state of the engine. When the required output is less than the maximum output and greater than a value obtained by subtracting the predetermined positive value from the maximum output, the control unit maintains the stopped state or the operating state of the engine. The control device according to any one of claims 1 to 10.

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