Driving control system for hybrid vehicles

Abstract

This travel control device for a hybrid vehicle comprises a motor rotation synchronization start determination unit that: when a battery output determination unit has determined that the maximum battery output of a drive battery has been exceeded and a requested output determination unit has determined that the maximum output of an engine has been exceeded during engine travel in which driving wheels are driven by the engine while a motor clutch cuts off the power of a driving motor, causes an assist control unit to assist the generator with driving power until the output value of the generator reaches a generator assist output target value; and causes a synchronization control unit to synchronize the rotation of the driving motor with the rotation of the driving wheels after the output value of the generator has reached the generator assist output target value.

Description

Technical Field

[0001] The present disclosure relates to a driving control device for a hybrid vehicle.

Background Art

[0002] Patent Document 1 discloses a driving control device for a hybrid vehicle equipped with an engine, a driving motor, and a generator, which individually transmits the power of the engine and the power of the driving motor to drive wheels from different power transmission paths, and also transmits the power of the engine to the generator for power generation. In the hybrid vehicle, a motor clutch is provided on the power transmission path for transmitting the power of the driving motor to the drive wheels. The driving control device calculates the required driving force for the hybrid vehicle, and when shifting the motor clutch from the disengaged state to the engaged state in engine driving where the drive wheels are driven by the engine with the power of the driving motor cut off, the generator is made to perform power running to transmit the power of the generator to the drive wheels.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when shifting the motor clutch from the disengaged state to the engaged state in engine driving where the drive wheels are driven by the engine with the power of the driving motor cut off, it is necessary to synchronize the rotational speed of the driving motor with the rotational speed of the drive wheels at the motor clutch (clutch shaft). When shifting the motor clutch from the disengaged state to the engaged state, it is necessary to supply electricity from the driving battery to the generator and the driving motor.

[0005] However, if the drive battery's output is insufficient to supply power to both the generator and the drive motor simultaneously, the drive motor will take priority over the generator. This could result in the hybrid vehicle accelerating slowly because the drive battery may not supply enough power to the generator.

[0006] In view of the above circumstances, at least one embodiment of the present invention aims to provide a driving control device for a hybrid vehicle that can suppress the slow acceleration of the hybrid vehicle even when, in engine-driven driving where the engine drives the drive wheels with the motor clutch disconnecting the power of the drive motor, there is insufficient capacity in the battery output of the drive battery to simultaneously supply electricity to the generator and the drive motor. [Means for solving the problem]

[0007] (1) A driving control device for a hybrid vehicle according to at least one embodiment of the present invention is a driving control device for a hybrid vehicle that drives the drive wheels by at least one of a drive motor or an engine, wherein the hybrid vehicle comprises a drive battery that supplies electricity to the drive motor, a generator that is driven by the engine to generate electricity and assists the driving force with electricity supplied from the drive battery, and a motor clutch that transmits or disconnects the power of the drive motor on a motor clutch shaft provided between the drive motor and the drive wheel, wherein the driving control device comprises an assist control unit that causes the generator to assist the driving force when the motor clutch disconnects the power of the drive motor, a synchronization control unit that synchronizes the rotation of the drive motor with the rotation of the drive wheel on the motor clutch shaft when the motor clutch disconnects the power of the drive motor, and when the output required for the hybrid vehicle exceeds the maximum output of the engine The system includes: a request output determination unit that determines whether or not; a battery output determination unit that determines whether or not the sum of a generator assist output target value necessary for the generator to assist the driving force and a motor rotation synchronization output upper limit value necessary for synchronizing the rotation of the drive motor with the rotation of the drive wheels exceeds the maximum battery output value of the drive battery; and, in engine-driven driving where the engine drives the drive wheels with the motor clutch disconnected from the power of the drive motor, if the request output determination unit determines that the engine's maximum output is exceeded and the battery output determination unit determines that the maximum battery output of the drive battery is exceeded, the system includes: an assist control unit that causes the generator to assist the driving force until the generator's output value becomes the generator assist output target value, and a motor rotation synchronization start determination unit that causes the synchronization control unit to synchronize the rotation of the drive motor with the rotation of the drive wheels after the generator's output value becomes the generator assist output target value.

[0008] According to the configuration described in (1) above, in engine-driven operation where the engine drives the drive wheels with the motor clutch disconnecting the power to the drive motor, if the output required for the hybrid vehicle exceeds the maximum output of the engine, and the sum of the generator assist output target value and the motor rotation synchronous output upper limit exceeds the maximum output of the drive battery, then there is no capacity to supply electricity to the generator and the drive motor simultaneously. Therefore, the generator is made to assist the driving force until the generator's output value reaches the generator assist output target value. As a result, the battery output of the drive battery is used to assist the generator in providing driving force until the generator's output value reaches the generator assist output target value. This prevents the acceleration of the hybrid vehicle from becoming sluggish until the generator's output value reaches the generator assist target value.

[0009] When the generator output reaches the generator assist output target value, the rotation of the drive motor is synchronized with the rotation of the drive wheels. As a result, the battery output of the drive battery is used to synchronize the rotation of the drive motor with the rotation of the drive wheels, but in this operation, the battery output for generator assist and the battery output for synchronizing the rotation of the drive motor with the rotation of the drive wheels are not used simultaneously. Instead, the battery output is used only for generator assist, so the acceleration rises more smoothly once generator assist becomes necessary. This helps to prevent the acceleration of the hybrid vehicle from becoming sluggish even when the battery output of the drive battery does not have enough capacity to supply electricity to both the generator and the drive motor simultaneously during engine-driven driving with the motor clutch disconnecting the power to the drive motor.

[0010] (2) In some embodiments, the configuration of (1) above is further provided with a motor control unit for controlling the drive motor, the synchronous control unit includes a motor torque calculation unit for calculating the rotational synchronous torque of the drive motor, the motor control unit controls the drive motor by the rotational synchronous torque calculated by the motor torque calculation unit, and the motor torque calculation unit has a rate of change limiting unit for limiting the rate of change of the rotational synchronous torque.

[0011] According to the configuration described in (2) above, the rate of change of rotational synchronous torque is limited, thereby suppressing the decrease in the amount of electricity supplied from the drive battery to the generator by synchronizing the rotational speed of the drive motor with the rotational speed of the drive wheels. This makes it possible to suppress the drop in acceleration of the hybrid vehicle caused by the decrease in the amount of electricity supplied from the drive battery to the generator.

[0012] (3) In some embodiments, in the configuration of (1) above, the hybrid vehicle includes a speed sensor for measuring the speed of the hybrid vehicle and an accelerator position sensor for detecting the accelerator opening, and the driving control device has a request output calculation unit that calculates the output required for the hybrid vehicle based on the speed measured by the speed sensor and the accelerator opening detected by the accelerator position sensor.

[0013] According to the configuration described in (3) above, the output required for the hybrid vehicle is calculated based on the speed measured by the speed sensor and the accelerator opening detected by the accelerator position sensor. This allows for accurate calculation of the output required for the hybrid vehicle.

[0014] (4) In some embodiments, in the configuration of (3) above, the driving control device has a generator assist output target value calculation unit that calculates the generator assist output target value based on the output required for the hybrid vehicle calculated by the request output calculation unit and the maximum torque of the engine.

[0015] According to the configuration described in (4) above, the generator assist output target value is calculated based on the output required for the hybrid vehicle and the maximum torque of the engine. This allows for accurate calculation of the generator assist output target value. [Effects of the Invention]

[0016] According to at least one embodiment of the present invention, in engine-driven driving where the engine drives the drive wheels with the motor clutch disconnecting the power of the drive motor, even when the battery output of the drive battery does not have enough capacity to supply electricity to the generator and the drive motor simultaneously, it is possible to suppress the sluggish acceleration of the hybrid vehicle. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram showing a hybrid vehicle according to Embodiment 1. [Figure 2] This diagram schematically shows the configuration of the hybrid vehicle shown in Figure 1. [Figure 3] This block diagram schematically shows the control configuration of the hybrid vehicle shown in Figure 2. [Figure 4] Figure 3 is a block diagram illustrating the schematic configuration of the driving control system for the hybrid vehicle shown. [Figure 5] Figure 4 is a flowchart illustrating the control system of the hybrid vehicle's driving control device. [Figure 6] This figure shows the battery output for the generator that assists the engine of the hybrid vehicle according to Embodiment 1, and the battery output for motor rotation synchronization of the drive motor. [Figure 7] This is a block diagram showing the configuration of the driving control device for a hybrid vehicle according to Embodiment 2. [Figure 8] (a) This figure compares the battery output of the drive battery according to Embodiment 1 with (b) the battery output of the drive battery according to Embodiment 2. [Figure 9]It is a block diagram showing the configuration of a running control device for a hybrid vehicle according to Embodiment 3. [Figure 10] It is a block diagram showing the configuration of a running control device for a hybrid vehicle according to Embodiment 4.

Embodiments for Carrying out the Invention

[0018] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. For example, expressions indicating relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" not only strictly represent such arrangements, but also represent a state of being relatively displaced with tolerances or angles and distances that can obtain the same function. Also, for example, expressions indicating shapes such as a rectangular shape or a cylindrical shape not only represent the shapes such as a rectangular shape or a cylindrical shape in a geometrically strict sense, but also represent shapes including concave and convex portions, chamfered portions, etc. within a range where the same effect can be obtained. On the other hand, the expressions "comprising", "having", "including", or "possessing" a component are not exclusive expressions that exclude the existence of other components.

[0019] [Embodiment 1] [Hybrid Vehicle] Figure 1 is a schematic diagram showing a hybrid vehicle 1 according to Embodiment 1. As shown in Figure 1, the hybrid vehicle 1 according to Embodiment 1 is a hybrid vehicle that drives the drive wheels 14 by at least one of a drive motor 10 or an engine 12. The hybrid vehicle 1 according to Embodiment 1 is a plug-in hybrid vehicle (PHEV) that can be charged from an external device (e.g., a fast charger) while stationary ("external charging") and can supply power to an external source (e.g., a general household) while stationary ("external power supply"), but is not limited to this. Furthermore, the hybrid vehicle 1 according to Embodiment 1 is a hybrid vehicle that drives the two front wheels, but it may also be a hybrid vehicle that drives four wheels.

[0020] [Hybrid Vehicle Configuration] Figure 2 is a schematic diagram showing the configuration of the hybrid vehicle 1 shown in Figure 1. As shown in Figure 2, the hybrid vehicle 1 according to Embodiment 1 includes, in addition to the drive motor 10 and engine 12 described above, a drive battery 16 that supplies electricity to the drive motor 10, a generator 18 that is driven by the engine 12 to generate electricity and assists the driving force with electricity supplied from the drive motor 10, and a motor clutch 22 that transmits or interrupts the power of the drive motor 10 on a motor clutch shaft 20 provided between the drive motor 10 and the drive wheel 14.

[0021] The motor clutch 22 is connectable and disconnectable. When the clutch is disconnected, power transmission from the drive motor 10 is interrupted, and when the clutch is connected, power from the drive motor 10 is transmitted. As a result, the hybrid vehicle 1 according to Embodiment 1 is capable of engine-driven driving, in which the engine 12 drives the drive wheels 14 with the motor clutch 22 interrupting the power from the drive motor 10, and parallel driving (hereinafter referred to as "PR driving"), in which the engine 12 drives the drive wheels 14 and the drive motor 10 assists the driving force with the motor clutch 22 transmitting power from the drive motor 10.

[0022] Furthermore, the hybrid vehicle 1 according to Embodiment 1 is further equipped with an engine clutch 26 on an engine clutch shaft 24 provided between the engine 12 and the drive shaft, which transmits or disconnects power from the engine 12. The engine clutch 26 is connectable and disconnectable; when the clutch is disconnected, power transmission from the engine 12 is interrupted, and when the clutch is connected, power from the engine 12 is transmitted. As a result, in addition to the engine driving and PR driving described above, the hybrid vehicle 1 according to Embodiment 1 is capable of motor driving (hereinafter referred to as "EV driving") in which the drive motor 10 drives the drive wheels 14 with electricity supplied from the drive battery 16, while the engine clutch 26 disconnects power from the engine 12 and transmits power from the drive motor 10, and series driving (hereinafter referred to as "SR driving") in which the drive motor drives the drive wheels 14 with electricity supplied from the generator 18 driven by the engine 12.

[0023] The hybrid vehicle 1 according to Embodiment 1 is provided with a transaxle 28 that incorporates the motor clutch shaft 20 and engine clutch shaft 24 described above. In addition to the drive motor 10 and engine 12 described above, a drive shaft 30 that drives the drive wheels (front wheels) 14 described above is connected to the transaxle 28. The transaxle 28 is provided with a final gear 32 on the drive shaft 30, a motor gear 34 on the output shaft of the drive motor 10, a first gear 36 provided on one side of the motor clutch shaft 20 that meshes with the motor gear 34, a second gear 38 provided on the other side of the motor clutch shaft 20 that meshes with the final gear 32, an engine gear 40 provided on the output shaft (crankshaft) of the engine 12, a third gear 42 provided on one side of the engine clutch shaft 24 that meshes with the engine gear 40, a fourth gear 44 provided on the other side of the engine clutch shaft 24 that meshes with the final gear 32, and a generator gear 46 provided on the input shaft (output shaft) of the generator 18 that meshes with the engine gear 40. As a result, the power of the drive motor 10 is transmitted to the drive shaft 30 (drive wheels 14) via the motor gear 34, first gear 36, second gear 38, and final gear 32, and the power of the engine 12 is transmitted to the drive shaft 30 (drive wheels 14) via the engine gear 40, third gear 42, fourth gear 44, and final gear 32. In addition, the power of the engine 12 is transmitted to the generator 18 via the engine gear 40 and generator gear 46 and used for generating electricity in the generator 18, while the power of the generator 18, which is driven by electricity supplied from the drive battery 16, is transmitted to the engine gear 40 via the generator gear 46 and assists the rotation of the drive shaft 30.

[0024] [Control configuration for hybrid vehicles] Figure 3 is a block diagram schematically showing the control configuration of the hybrid vehicle 1 shown in Figure 2. As shown in Figure 3, a motor control unit 48 (hereinafter referred to as "motor ECU 48") is electrically connected to the drive motor 10 described above, and the drive motor 10 is electrically controlled by the motor ECU 48.

[0025] A fuel tank 50 (see Figure 1) is connected to the engine 12 described above, and fuel is supplied to the engine 12 from the fuel tank 50. In addition, an engine control unit 52 (hereinafter referred to as "engine ECU 52") is electrically connected to the engine 12, and the engine 12 is electrically controlled by the engine ECU 52.

[0026] A battery control unit 54 (hereinafter referred to as "battery ECU 54") is electrically connected to the aforementioned drive battery 16, and the charge level (SOC (State of Charge)), battery temperature, maximum battery output, etc. of the drive battery 16 are electrically managed by the battery ECU 54.

[0027] A generator control unit 56 (hereinafter referred to as "generator ECU 56") is electrically connected to the generator 18 described above, and the generator 18 is electrically controlled by the generator ECU 56.

[0028] A transaxle control unit 58 (hereinafter referred to as "transaxle ECU 58") is electrically connected to the motor clutch 22 and engine clutch 26 built into the transaxle 28 described above, and the opening and closing of the motor clutch 22 and engine clutch 26 are electrically controlled by the transaxle ECU 58.

[0029] The motor ECU48, engine ECU52, battery ECU54, generator ECU56, and transaxle ECU58 are each composed of a processor consisting of an arithmetic unit, registers for storing instructions and information, and peripheral circuits, memory such as ROM (Read Only Memory) and RAM (Random Access Memory), and an input interface.

[0030] The motor ECU 48, engine ECU 52, battery ECU 54, generator ECU 56, and transaxle ECU 58 are electrically connected to the vehicle control device 60 (hereinafter referred to as "HEV-ECU 60") via an in-vehicle network (CAN (Controll Area Network)). As a result, the motor ECU 48, engine ECU 52, generator ECU 56, and transaxle ECU 58 are managed by the HEV-ECU 60, and based on commands from the HEV-ECU 60, the motor ECU 48, engine ECU 52, battery ECU 54, generator ECU 56, and transaxle ECU 58 control the drive motor 10, engine 12, drive battery 16, generator 18, and transaxle 28. For example, the motor ECU 48 controls the drive motor 10 so that it is driven by the torque (rotational torque, rotational synchronous torque, etc.) input to the motor ECU 48 from the HEV-ECU 60.

[0031] Furthermore, the HEV-ECU60 is connected to a chassis control unit 62 (hereinafter referred to as "chassis ECU62") via CAN. The chassis ECU62 consists of a processor comprising an arithmetic unit, registers for storing instructions and information, and peripheral circuits, as well as memory such as ROM (Read Only Memory) and RAM (Random Access Memory), and an input interface.

[0032] For example, a speed sensor 64 is electrically connected to the chassis system ECU 62, and the information (vehicle speed) from the speed sensor 64 is input to the chassis system ECU 62, and the vehicle speed is input from the chassis system ECU 62 to the HEV-ECU 60.

[0033] Furthermore, an accelerator position sensor 66 (hereinafter referred to as "APS66") is connected to the HEV-ECU60, and the accelerator opening angle is input from the APS66 to the HEV-ECU60.

[0034] [Configuration of the driving control system] Figure 4 is a schematic block diagram showing the configuration of the driving control device 68 of the hybrid vehicle 1 shown in Figure 3. As shown in Figure 4, the HEV-ECU 60 of the hybrid vehicle 1 according to Embodiment 1 constitutes the driving control device 68. The driving control device 68 includes an assist control unit 70, a synchronization control unit 72, a request output determination unit 74, a battery output determination unit 76, and a motor rotation synchronization start determination unit 78.

[0035] The assist control unit 70 is the part that causes the generator 18 to assist the rotation of the drive shaft 30 when the motor clutch 22 has cut off the power to the drive motor 10. When the motor clutch 22 has cut off the power to the drive motor 10 and the engine 12 is driving the drive wheels 14, the assist control unit 70 determines that the sum of the generator assist output target value required for the generator 18 to assist the rotation of the drive shaft 30 and the motor rotation synchronization output upper limit value required to synchronize the rotation of the drive motor 10 with the rotation of the drive wheels 14 is less than or equal to the maximum output value of the drive battery 16, and when it is determined that the output required for the hybrid vehicle 1 exceeds the maximum output of the engine 12, the assist control unit 70 causes the generator 18 to assist the rotation of the drive shaft 30. For example, the assist control unit 70 includes a generator torque calculation unit 80 that calculates the assist torque of the generator 18, and the assist torque of the generator 18 calculated by the generator torque calculation unit 80 is output to the generator ECU 56. As a result, the generator ECU 56 controls the generator 18 so that it is driven by the assist torque calculated by the assist control unit 70 (generator torque calculation unit 80).

[0036] The synchronous control unit 72 is the part that synchronizes the rotation of the drive motor 10 with the rotation of the drive wheel 14 on the motor clutch shaft 20 when the motor clutch 22 has cut off the power to the drive motor 10. For example, the synchronous control unit 72 includes a motor torque calculation unit 82 that calculates the rotational synchronous torque of the drive motor 10, and the rotational synchronous torque of the drive motor 10 calculated by the motor torque calculation unit 82 is output to the motor ECU 48. As a result, the motor ECU 48 controls the drive motor 10 so that it is driven by the rotational synchronous torque calculated by the synchronous control unit 72 (motor torque calculation unit 82).

[0037] The requested output determination unit 74 is responsible for determining whether the output required for the hybrid vehicle 1 exceeds the maximum output of the engine 12. For example, the output required for the hybrid vehicle 1 is calculated based on the vehicle speed input from the chassis system ECU 62 to the HEV-ECU 60 and the accelerator opening input from the APS 66 to the HEV-ECU 60, and the maximum output of the engine 12 is set to a value (fixed value) determined in advance through experiments or the like.

[0038] The battery output determination unit 76 is responsible for determining whether the sum of the generator assist output target value required for the generator 18 to assist the rotation of the drive shaft 30 and the motor rotation synchronization output upper limit value required to synchronize the rotation of the drive motor 10 with the rotation of the drive wheels 14 exceeds the maximum battery output value of the drive battery 16.

[0039] The motor rotation synchronization start determination unit 78 is the part that, in engine-driven driving where the engine 12 drives the drive wheels 14 with the motor clutch 22 disconnecting the power to the drive motor 10, when the battery output determination unit 76 determines that the output required for the hybrid vehicle 1 exceeds the maximum output of the drive battery 16, and the required output determination unit 74 determines that the output required for the hybrid vehicle 1 exceeds the maximum output of the engine 12, instructs the assist control unit 70 to have the generator 18 assist the rotation of the drive shaft 30 until the output value of the generator 18 reaches the generator assist output target value, and after the output value of the generator 18 reaches the generator assist output target value, instructs the synchronization control unit 72 to synchronize the rotation of the drive motor 10 with the rotation of the drive wheels 14.

[0040] The driving control device 68 of the hybrid vehicle 1 according to Embodiment 1 further includes a motor clutch control unit 84. The motor clutch control unit 84 is the part of the motor clutch 22 (motor clutch shaft 20) that connects the motor clutch 22 when the rotational speed of the drive motor 10 is synchronized with the rotational speed of the drive wheels 14. For example, when the rotational speed of the drive motor 10 is synchronized with the rotational speed of the drive wheels 14, the motor clutch control unit 84 outputs a connection instruction for the motor clutch 22 to the transaxle ECU 58. As a result, the transaxle ECU 58 controls the motor clutch 22 so that the motor clutch 22 is connected. Note that in the motor clutch 22 (motor clutch shaft 20), it is necessary to synchronize the rotational speed of the drive motor 10 with the rotational speed of the drive wheels 14, so the rotational speed of the drive motor 10 is converted to the rotational speed at the motor clutch 22 (motor clutch shaft 20), and the rotational speed of the drive wheels 14 is converted to the rotational speed at the motor clutch 22 (motor clutch shaft 20).

[0041] [Driving control system control] Figure 5 is a flowchart illustrating the control contents of the driving control device 68 of the hybrid vehicle 1 shown in Figure 4. As shown in Figure 5, in the hybrid vehicle 1 according to Embodiment 1, the motor rotation synchronization start determination unit 78 determines whether or not the motor clutch 22 has cut off the power to the drive motor 10 (step S11).

[0042] If the motor clutch 22 is disconnecting the power to the drive motor 10 (clutch: disengaged) (step S11: Yes), then the vehicle is running on the engine, and the requested output determination unit 74 determines whether the output required for the hybrid vehicle 1 exceeds the maximum output of the engine 12 (step S12). If the output required for the hybrid vehicle 1 exceeds the maximum output of the engine 12 (step S12: Yes), then the output required for the hybrid vehicle 1 cannot be met by engine running, and the battery output determination unit 76 determines whether the sum of the generator assist output target value required for the generator 18 to assist the rotation of the drive shaft 30 and the motor rotation synchronization output upper limit value required to synchronize the rotation of the drive motor 10 with the rotation of the drive wheels 14 exceeds the maximum battery output value of the drive battery 16 (step S13).

[0043] If the sum of the generator assist output target value and the motor rotation synchronization output upper limit value exceeds the maximum battery output value of the drive battery 16 (step S13: Yes), the drive battery 16 does not have enough capacity to supply electricity to the generator 18 and the drive motor 10 simultaneously, so the system switches to PR driving (generator assist), in which the generator 18 assists the rotation of the drive shaft 30 (step S14). Then, when the output value of the generator 18 reaches the generator assist output target value (step S15: Yes), rotation synchronization of the drive motor 10 is started (step S16).

[0044] In the motor clutch 22 (motor clutch shaft 20), when the rotation of the drive motor 10 synchronizes with the rotation of the drive wheel 14 (step S17: Yes), the motor clutch 22 can be engaged, and the motor clutch control unit 84 engages the motor clutch 22 (step S18). This allows the power of the drive motor 10 to be transmitted to the drive wheel 14, and the system switches from generator assist to motor assist (step S19).

[0045] On the other hand, if the sum of the generator assist output target value and the motor rotation synchronization output upper limit value exceeds the maximum battery output value of the drive battery 16 (step S13: No), the system switches to PR driving (generator assist) in which the generator 18 assists the rotation of the drive shaft 30 (step S20), and the rotation synchronization of the drive motor 10 is started (step S16).

[0046] [Effects of the driving control system] Figure 6 shows the battery output for the generator that assists the rotation of the drive shaft 30 and the battery output for motor rotation synchronization of the drive motor 10 in the hybrid vehicle 1 according to Embodiment 1. In the hybrid vehicle 1 according to Embodiment 1, when the motor clutch 22 disconnects the power to the drive motor 10 and the engine 12 drives the drive wheels 14, if the output required for the hybrid vehicle 1 exceeds the maximum output of the engine 12, and the sum of the generator assist output target value and the motor rotation synchronization output upper limit value exceeds the maximum battery output of the drive battery 16, there is no capacity to supply electricity to the generator 18 and the drive motor 10 simultaneously. Therefore, the driving control device 68 of the hybrid vehicle 1 according to Embodiment 1 causes the generator 18 to assist the rotation of the drive shaft 30 until the output value of the generator 18 reaches the generator assist output target value. As a result, as shown as "generator assist portion" in Figure 6, the battery output of the drive battery 16 is used to assist the generator 18 in rotating the drive shaft 30 until the output value of the generator 18 reaches the generator assist target value. This makes it possible to suppress the slow acceleration of the hybrid vehicle 1 until the output value of the generator 18 reaches the generator assist target value.

[0047] When the output value of the generator 18 reaches the generator assist target value, the rotation speed of the drive motor 10 is synchronized with the rotation speed of the drive wheel 14. As a result, as shown in Figure 6 as "motor rotation synchronization component", the battery output of the drive battery 16 is also used to synchronize the rotation of the drive motor 10 with the rotation of the drive wheel 14. However, in the operation up to this point, the battery output is used only for generator assist, without using both the battery output for generator assist and the battery output for synchronizing the rotation of the drive motor 10 with the rotation of the drive wheel 14 simultaneously. Therefore, the acceleration rise after generator assist becomes necessary is improved. When the sum of the generator assist output target value and the motor rotation synchronization output upper limit value exceeds the maximum battery output value of the drive battery 16, the battery output used by the generator 18 to assist the rotation of the drive shaft 30 (hereinafter referred to as "battery output for generator assist") decreases, but the acceleration rise after generator assist becomes necessary is improved. As a result, even when the motor clutch 22 has cut off power to the drive motor 10 and the engine 12 is driving the drive wheels 14, if the battery output of the drive battery 16 does not have enough capacity to supply electricity to the generator 18 and the drive motor 10 simultaneously, it is possible to suppress the acceleration of the hybrid vehicle 1 from becoming sluggish.

[0048] [Embodiment 2] [Configuration of the driving control system] Figure 7 is a block diagram showing the configuration of the driving control device 68 of the hybrid vehicle 1 according to Embodiment 2. The hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 2 have the same configuration as the hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 1, except for the synchronous control unit 72. Therefore, the explanation of the same configuration as the hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 1 will be omitted.

[0049] As shown in Figure 7, in the driving control device 68 of the hybrid vehicle 1 according to Embodiment 2, the synchronous control unit 72 includes a motor torque calculation unit 82 that calculates the rotational synchronous torque of the drive motor 10, and the motor ECU 48 controls the drive motor 10 by the synchronous torque calculated by the motor torque calculation unit 82, while the motor torque calculation unit 82 has a change rate limiting unit 86 that limits the rate of change of the rotational synchronous torque.

[0050] [Driving control system control] In the driving control device 68 of the hybrid vehicle 1 according to Embodiment 2, the drive motor 10 is controlled by the synchronous torque calculated by the motor torque calculation unit 82. However, the rate of change of the synchronous torque is limited by the rate of change limiting unit 86, so large fluctuations in the synchronous torque are suppressed.

[0051] As described in Embodiment 1, after the output value of the generator 18 reaches the generator assist target value, the battery output of the drive battery 16 is used not only to assist the rotation of the drive shaft 30 by the generator 18, but also to synchronize the rotation of the drive motor 10 with the rotation of the drive wheels 14. Therefore, when the battery output of the drive battery 16 synchronizes the rotation of the drive motor 10 with the rotation of the drive wheels 14, and the sum of the generator assist output target value and the motor rotation synchronization output upper limit value exceeds the maximum battery output value of the drive battery 16, the battery output used by the generator 18 to assist the rotation of the drive shaft 30 (hereinafter referred to as "battery output for generator assist") decreases, but this decrease is suppressed by the rate of change limiting unit 86 which limits the rate of change of the synchronous torque.

[0052] [Effects of the driving control system] Figure 8 is a diagram comparing the battery output of the drive battery 16 according to (a) Embodiment 1 and the battery output of the drive battery 16 according to (b) Embodiment 2. As shown in Figure 8(a), in Embodiment 1, after the output value of the generator 18 reaches the generator assist target value, the battery output used to synchronize the rotation of the drive motor 10 with the rotation of the drive wheels 14 (hereinafter referred to as "battery output for motor rotation synchronization") gradually increases, and when the sum of the battery output for generator assist and the battery output for motor rotation synchronization reaches the maximum battery output value, the battery output for motor rotation synchronization gradually decreases the battery output for generator assist.

[0053] On the other hand, as shown in Figure 8(b), the battery output of the drive battery 16 in Embodiment 1 also increases gradually after the output value of the generator 18 reaches the generator assist target value. When the sum of the battery output for generator assist and the battery output for motor rotation synchronization reaches the maximum battery output value, the battery output for motor rotation synchronization gradually decreases the battery output for generator assist. However, the rate of change limiting unit 86 limits the rate of change of the synchronous torque, so the amount of decrease is limited. As a result, the hybrid vehicle 1 according to Embodiment 2 can suppress the sluggish acceleration compared to the hybrid vehicle 1 according to Embodiment 1.

[0054] [Embodiment 3] [Driving control device] Figure 9 is a block diagram showing the configuration of the driving control device 68 of the hybrid vehicle 1 according to Embodiment 3. The hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 3 have the same configuration as the hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 1, except for the request output calculation unit 88. Therefore, the explanation of the same configuration as the hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 1 will be omitted.

[0055] As shown in Figure 9, the driving control device 68 of the hybrid vehicle 1 according to Embodiment 3 has a request output calculation unit 88 that calculates the output required for the hybrid vehicle 1 based on the vehicle speed measured by the speed sensor 64 and the accelerator opening detected by the APS 66.

[0056] [Driving control system control] Regardless of whether it is a hybrid vehicle 1 or not, the vehicle speed fluctuates sequentially. Since the output required for the vehicle is calculated based on the sequentially fluctuating vehicle speed and the accelerator opening detected by the APS66, the requested output calculation unit 88 calculates the vehicle speed in a feedforward manner.

[0057] [Effects of the driving control system] According to the driving control device 68 of the hybrid vehicle 1 in Embodiment 3, the output required for the hybrid vehicle 1 is calculated based on the speed measured by the speed sensor 64 and the accelerator opening detected by the APS 66. This makes it possible to accurately calculate the output required for the hybrid vehicle 1.

[0058] [Embodiment 4] [Driving control device] Figure 10 is a block diagram showing the configuration of the driving control device 68 of the hybrid vehicle 1 according to Embodiment 4. The hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 4 have the same configuration as the hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 3, except for the generator assist output target calculation unit. Therefore, the explanation of the configuration which is the same as the hybrid vehicle 1 and the driving control device 68 of the hybrid vehicle 1 according to Embodiment 3 will be omitted.

[0059] As shown in Figure 10, the driving control device 68 of the hybrid vehicle 1 according to Embodiment 4 has a generator assist output target value calculation unit 90 that calculates a generator assist output target value based on the output required for the hybrid vehicle 1 calculated by the request output calculation unit 88 and the maximum torque of the engine 12. In the example shown in Figure 10, the assist torque output target value is calculated from the generator assist torque obtained from the requested torque calculated by the request output calculation unit 88 and the maximum torque of the engine 12. The requested torque calculated by the request output calculation unit 88 is, for example, the requested torque to be requested from the generator 18, but the requested torque to be requested from the drive wheels 14 may be converted to the torque to be requested from the generator 18 by the generator torque calculation unit 80. The generator assist torque is the difference between the requested torque calculated by the request output calculation unit 88 and the maximum torque of the engine 12, and the torque to be requested from the generator 18 is calculated.

[0060] The generator assist output target value is the insufficient output obtained by subtracting the maximum engine output from the output required for the hybrid vehicle 1 (required output). In the generator assist output target value calculation unit 90 according to Embodiment 4, the generator assist output target value is determined by converting the generator assist torque into output.

[0061] [Effects of the driving control system] According to the driving control device 68 of the hybrid vehicle 1 in Embodiment 4, the generator assist output target value is calculated based on the output required for the hybrid vehicle 1 and the maximum torque of the engine 12. This makes it possible to accurately calculate the generator assist output target value.

[0062] The present invention is not limited to the embodiments described above, and also includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate. [Explanation of symbols]

[0063] 1. Hybrid vehicle 10 Drive motor 12 Engines 14 drive wheels 16 Power Battery 18 Generators 20 Motor clutch shaft 22 Motor Clutch 24 Engine clutch shaft 26 Engine Clutch 28 transaxle 30 Drive shaft 32 Final Gear 34 Motor Gears 36 First Gear 38. Second gear 40 Engine Gear 42 Third Gear 44th gear 46 Generator Gear 48 Motor control unit (motor ECU) 50 Fuel Tank 52 Engine Control Unit (Engine ECU) 54 Battery Control Unit (Battery ECU) 56. Generator Control Unit (Generator ECU) 58 Transaxle Control Unit (Transaxle ECU) 60. Vehicle control unit (HEV-ECU) 62 Chassis Control Unit (Chassis ECU) 64 Speed ​​Sensor 66. Accelerator Position Sensor (APS) 68. Driving control device 70 Assist Control Unit 72 Synchronization Control Unit 74 Requested output judgment section 76 Battery output determination unit 78 Motor rotation synchronization start determination unit 80 Generator Torque Calculation Unit 82 Motor Torque Calculation Unit 84 Motor Clutch Control Unit 86 Change Rate Limiting Unit 88 Request output calculation section 90 Generator assist output target value calculation unit

Claims

1. A driving control device for a hybrid vehicle that drives the drive wheels with at least one of a drive motor or an engine, The aforementioned hybrid vehicle is A drive battery that supplies electricity to the drive motor, A generator that is driven by the engine to generate electricity, while assisting the driving force with electricity supplied from the drive battery, A motor clutch shaft provided between the drive motor and the drive wheel includes a motor clutch that transmits or interrupts the power of the drive motor, Equipped with, The aforementioned travel control device is The motor clutch, while the drive motor's power is cut off, provides an assist control unit that assists the generator in providing driving force, With the motor clutch disconnecting the power to the drive motor, the motor clutch shaft includes a synchronization control unit that synchronizes the rotation of the drive motor with the rotation of the drive wheel, A request output determination unit that determines whether the output required for the hybrid vehicle exceeds the maximum output of the engine, A battery output determination unit determines whether the sum of the generator assist output target value required for the generator to assist the driving force and the motor rotation synchronization output upper limit value required to synchronize the rotation of the drive motor with the rotation of the drive wheel exceeds the maximum battery output value of the drive battery. When the motor clutch disconnects the power to the drive motor, and the engine drives the drive wheels, the requested output determination unit determines that the engine's maximum output is exceeded, and the battery output determination unit determines that the battery's maximum output is exceeded, the assist control unit instructs the generator to assist the generator with driving force until the generator's output value reaches the generator assist output target value, and after the generator's output value reaches the generator assist output target value, the synchronization control unit instructs the motor rotation synchronization start determination unit to synchronize the rotation of the drive motor with the rotation of the drive wheels. A driving control system for hybrid vehicles equipped with the following features.

2. The unit includes a motor control unit that controls the aforementioned drive motor, The synchronization control unit includes a motor torque calculation unit that calculates the rotational synchronous torque of the drive motor, The motor control unit controls the drive motor using the rotational synchronous torque calculated by the motor torque calculation unit, The motor torque calculation unit has a rate of change limiting unit that limits the rate of change of the rotational synchronous torque. A driving control device for a hybrid vehicle according to claim 1.

3. The aforementioned hybrid vehicle is A speed sensor for measuring the speed of the aforementioned hybrid vehicle, An accelerator position sensor that detects the accelerator pedal opening, Equipped with, The aforementioned travel control device is A driving control device for a hybrid vehicle according to claim 1, comprising a request output calculation unit that calculates the output required for the hybrid vehicle based on the speed measured by the speed sensor and the accelerator opening detected by the accelerator position sensor.

4. The aforementioned travel control device is The driving control device for a hybrid vehicle according to claim 3, further comprising a generator assist output target value calculation unit that calculates the generator assist output target value based on the output required for the hybrid vehicle calculated by the request output calculation unit and the maximum torque of the engine.