Power control method and system for hybrid vehicle

Abstract

The present disclosure provides a power control method and system for a hybrid vehicle. The method comprises: in response to a first driving mode switching request, acquiring current working condition information of an engine in a hybrid vehicle; on the basis of the current working condition information, determining a target rotating speed of the engine when the engine is started; and on the basis of the target rotating speed, controlling the engine in the hybrid vehicle to be started so as to communicate the engine with a connecting device, and controlling the connecting device in the hybrid vehicle to operate, so that the engine in the hybrid vehicle operates according to the target rotating speed, wherein the connecting device comprises a clutch and a conjunction gear. According to the present disclosure, combined speed regulation of the engine is realized, and the torque is transmitted by the clutch and the conjunction gear of the connecting device, so that the rotating speed of the engine reaches a target rotating speed, and thus control over the power connection process when the engine in the hybrid vehicle participates in driving is realized, thereby improving the stability of power control of the hybrid vehicle.

Description

Power control method and power control system of hybrid vehicle

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202410009063.7, filed with the State Intellectual Property Office of China on January 4, 2024, entitled “Power Control Method and Power Control System for Hybrid Vehicles,” the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The present disclosure relates to the field of control technology, and in particular to a power control method and a power control system for a hybrid vehicle. Background Art

[0004] Existing hybrid vehicle powertrain control methods are mostly based on the motor, transmission, engine, and clutch. During powertrain control, torque transmission relies entirely on the clutch, which not only requires the clutch to have slipping capabilities but also places high demands on the clutch's torque capacity. Furthermore, since engine starting relies on the motor, some of the motor's power is diverted during engine startup, compromising the smoothness of hybrid vehicle engine power control.

[0005] Therefore, how to improve the smoothness of engine power control of hybrid vehicles is an urgent problem to be solved in this field.

[0006] Application Contents

[0007] The purpose of the present disclosure is to address the deficiencies in the above-mentioned related technologies and provide a power control method and a power control system for a hybrid vehicle, so as to solve the problem of stability of engine power control of a hybrid vehicle in the related technologies.

[0008] To achieve the above objectives, the technical solution adopted in an optional embodiment of the present disclosure is as follows:

[0009] In a first aspect, an optional embodiment of the present disclosure provides a power control method for a hybrid vehicle, which is applied to a power control system in a hybrid vehicle. The method includes:

[0010] acquiring current operating condition information of an engine in the hybrid vehicle in response to a first driving mode switching request, wherein the first driving mode switching request is used to request the hybrid vehicle to operate in a hybrid driving mode;

[0011] determining a target speed of the engine after starting based on the current operating condition information;

[0012] According to the target speed, the engine in the hybrid vehicle is controlled to start to connect the engine with the connecting device, and the connecting device in the hybrid vehicle is controlled to operate so that the engine in the hybrid vehicle operates according to the target speed, wherein the connecting device includes: a clutch and a coupling tooth.

[0013] As an optional implementation, determining the target speed of the engine after starting based on the current operating condition information includes:

[0014] determining, based on the current operating condition information and a preset driving mode switching time, vehicle speed change information of the hybrid vehicle within the driving mode switching time, wherein the driving mode switching time is the time from the start of the driving mode switching to the completion of the switching;

[0015] The target speed is determined according to the vehicle speed change information, a preset transmission output speed and vehicle speed conversion ratio coefficient, and a preset current transmission power transmission gear ratio.

[0016] As an optional implementation, determining the vehicle speed change information of the hybrid vehicle within the driving mode switching time based on the current operating condition information and a preset driving mode switching time includes:

[0017] determining a current acceleration of the hybrid vehicle according to a current driving force of the vehicle and a current resistance of the vehicle in the current operating condition information;

[0018] The vehicle speed change information is determined according to a current acceleration of the hybrid vehicle, the driving mode switching time, and a current vehicle speed in the current operating condition information.

[0019] As an optional implementation, controlling the engine in the hybrid vehicle to start so as to connect the engine to the connection device includes:

[0020] Starting a starter in the hybrid vehicle by an engine control unit in the power control system, the starter being arranged on the engine;

[0021] The engine is started by the starter, so that the engine is connected to the connecting device.

[0022] As an optional implementation, controlling the connection device in the hybrid vehicle to operate so that the engine in the hybrid vehicle operates according to the target speed includes:

[0023] According to the target speed, the opening and closing degree of the clutch and the meshing degree of the coupling teeth are adjusted so that the engine in the hybrid vehicle operates according to the target speed.

[0024] As an optional implementation, adjusting the opening and closing degree of the clutch and the meshing degree of the coupling teeth according to the target speed so that the engine in the hybrid vehicle operates at the target speed includes:

[0025] Adjusting the clutch opening / closing degree to a first opening / closing degree so that the engine speed reaches a first preset speed;

[0026] According to the speed difference between the target speed and the first preset speed, the meshing degree of the coupling teeth is adjusted to a first meshing degree so that the engine in the hybrid vehicle operates at the target speed.

[0027] As an optional implementation, adjusting the clutch opening / closing degree to a first opening / closing degree includes:

[0028] According to a preset first current increase value, power is supplied to the electromagnetic coil corresponding to the clutch in a current increasing manner until the opening and closing degree of the clutch is adjusted to the first opening and closing degree.

[0029] As an optional implementation, adjusting the meshing degree of the coupling teeth to a first meshing degree according to a speed difference between the target speed and the first preset speed includes:

[0030] According to the preset second current increase value, power is supplied to the electromagnetic coil corresponding to the coupling tooth in an increasing current manner, pushing the active end and the driven end of the coupling tooth to engage until the meshing degree of the coupling tooth is adjusted to the first meshing degree.

[0031] As an optional implementation, the method further includes:

[0032] In response to a second driving mode switching request, controlling the engine to reduce torque to a zero torque output state, wherein the second driving mode switching request is used to request the hybrid vehicle to operate in a pure electric driving mode;

[0033] A connection device in the hybrid vehicle is controlled to be disconnected from the engine.

[0034] As an optional implementation, the controlling the connection device in the hybrid vehicle to be disconnected from the engine includes:

[0035] According to a preset first current reduction value, the current value of the electromagnetic coil corresponding to the clutch is reduced in a current decreasing manner until the clutch is in a disengaged state;

[0036] According to the preset second current reduction value, the current value of the electromagnetic coil corresponding to the coupling tooth is reduced in a current decreasing manner until the coupling tooth exits the meshing position.

[0037] In a second aspect, another optional embodiment of the present disclosure provides a power control system, the power control system including a hybrid power control unit, an engine control unit, a motor control unit, a transmission control unit, and a controller;

[0038] The hybrid power control unit is connected to the engine control unit, the motor control unit, the transmission control unit, and the controller respectively through a preset communication protocol; the hybrid power control unit is used to send a first driving mode switching request to the controller, wherein the first driving mode switching request is used to request the hybrid vehicle to operate in a hybrid driving mode;

[0039] The controller is connected to a connection device of the hybrid vehicle, and is configured to respond to the first driving mode switching request, obtain current operating condition information of an engine in the hybrid vehicle, and determine a target speed of the engine after starting based on the current operating condition information;

[0040] The engine control unit is connected to the engine of the hybrid vehicle, and the engine control unit is used to control the start of the engine in the hybrid vehicle to connect the engine to the connection device;

[0041] The controller is further configured to control the operation of a connection device in the hybrid vehicle so that the engine in the hybrid vehicle operates according to the target speed;

[0042] The motor control unit is connected to the hybrid drive motor of the hybrid vehicle, and the motor control unit is used to control the hybrid drive motor;

[0043] The transmission control unit is connected to a transmission of the hybrid vehicle, and is configured to control the transmission.

[0044] In the third aspect, another optional embodiment of the present disclosure provides a hybrid vehicle, comprising: a processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor. When the hybrid vehicle is running, the processor communicates with the storage medium via the bus, and the processor executes the machine-readable instructions to perform the steps of the power control method of the hybrid vehicle as described in any of the first aspects above.

[0045] In a fourth aspect, another optional embodiment of the present disclosure provides a storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the power control method for a hybrid vehicle as described in any one of the first aspects above are executed.

[0046] According to a hybrid vehicle power control method and control system according to an embodiment of the present disclosure, in response to a first drive mode switch request, current operating condition information of the hybrid vehicle's engine is obtained. Based on the current operating condition information, a target speed after engine startup is determined. Based on the target speed, the method controls engine startup in the hybrid vehicle to connect the engine to a connecting device, and controls the operation of the connecting device in the hybrid vehicle so that the engine in the hybrid vehicle operates at the target speed. Based on the power control system provided in an optional embodiment of the present disclosure, engine-coordinated speed regulation is adopted, and torque is transmitted through a clutch and coupling gear in the connecting device to achieve the target speed. This method controls the power connection process of the hybrid vehicle's engine when it is driving, thereby improving the smoothness of the hybrid vehicle's power control. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0048] FIG1 shows a schematic diagram of the architecture of a power system of a hybrid vehicle provided by an optional embodiment of the present disclosure;

[0049] FIG2 shows a schematic diagram of the architecture of a power control system of a hybrid vehicle provided by an optional embodiment of the present disclosure;

[0050] FIG3 is a schematic flow chart showing a power control method for a hybrid vehicle provided in an optional embodiment of the present disclosure;

[0051] FIG4 shows a flow chart of a method for determining a target rotational speed according to an optional embodiment of the present disclosure;

[0052] FIG5 shows a schematic flow chart of an engine speed control method provided in an optional embodiment of the present disclosure;

[0053] FIG6 shows a schematic diagram of an engine power access control provided by an optional embodiment of the present disclosure;

[0054] FIG7 shows a schematic flow chart of another engine power access control process provided by an optional embodiment of the present disclosure;

[0055] FIG8 is a flow chart showing another method for controlling power of a hybrid vehicle according to an optional embodiment of the present disclosure;

[0056] FIG9 shows a schematic diagram of an engine power exit control provided by an optional embodiment of the present disclosure;

[0057] FIG10 shows a schematic flow chart of another engine power exit control method provided by an optional embodiment of the present disclosure;

[0058] FIG11 shows a schematic structural diagram of a hybrid vehicle provided in an optional embodiment of the present disclosure. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. It should be understood that the drawings in the present disclosure are only for the purpose of illustration and description and are not used to limit the scope of protection of the present disclosure. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present disclosure illustrate operations implemented according to some embodiments of the present disclosure. It should be understood that the operations of the flowchart can be implemented out of sequence, and steps that do not have a logical context relationship can be reversed in order or implemented simultaneously. In addition, those skilled in the art, guided by the contents of the present disclosure, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0060] In addition, the described embodiments are only a portion of the embodiments of the present disclosure, rather than all of the embodiments. The components of the embodiments of the present disclosure generally described and shown in the drawings herein can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the disclosure claimed for protection, but merely represents selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present disclosure.

[0061] To enable those skilled in the art to utilize this disclosure, the following embodiments are provided with reference to the specific application scenario of a hybrid vehicle. Those skilled in the art will appreciate that the general principles defined herein can be applied to other embodiments and application scenarios without departing from the spirit and scope of this disclosure. While this disclosure primarily describes a power control method for a hybrid vehicle, it should be understood that this is merely an exemplary embodiment.

[0062] It should be noted that the term “comprising” will be used in the embodiments of the present disclosure to indicate the existence of the features claimed thereafter, but does not exclude the addition of other features.

[0063] For single-motor hybrid systems, based on the position of the motor relative to the traditional powertrain, single-motor hybrid solutions can be divided into five categories, namely P0, P1, P2, P3, and P4. Among them, P0 mode means that the motor is placed before the gearbox, and the motor is an integrated motor that uses a belt drive to take care of both starting and power generation. The P0 mode hybrid integrates the function of the starter, making the entire engine more compact. Combined with a larger battery, it can drive the mechanical compressor of the air conditioner when the engine is stopped, such as when waiting at a traffic light, thereby achieving a certain degree of fuel saving. However, since the belt is a flexible connection, the power of the engine for both boosting and recovering kinetic energy is limited. Moreover, due to the limitation of the belt drive, the engine and belt must keep pace with each other, so it cannot operate independently to provide a pure electric form.

[0064] The P1 mode means that the motor is placed in front of the gearbox and installed on the engine crankshaft. Since the motor and the engine are rigidly connected, the P1 mode can achieve power assistance, allowing the vehicle to maintain a high balance between power output and fuel economy. However, since the motor needs to have a relatively large torque and volume, and also needs to be made relatively thin so that the motor can be placed in the original flywheel position, the implementation cost is relatively high.

[0065] P2 mode places the electric motor at the input of the transmission, after the clutch. This allows the vehicle to drive the wheels independently, while also disconnecting from the engine for kinetic energy recovery. The gear ratio between the motor and the shaft reduces torque requirements, reducing costs and motor size. However, the motor cannot simultaneously regenerate electrical energy while driving the vehicle.

[0066] P3 mode means that the motor is placed at the output end of the gearbox, sharing the same shaft and the same output as the engine. As a result, the vehicle's pure electric drive is more direct and efficient, and the efficiency of kinetic energy recovery is higher. However, since the motor must be connected to the axle in P3 mode, the motor cannot be used to start the engine, and the motor cannot be integrated with the transmission or engine, and requires additional volume.

[0067] P4 mode places the electric motor behind the transmission, separated from the engine's output shaft. Wheel-drive also falls under P4 mode. Because P4 mode places the electric motor on the drive axle, it can directly drive the wheels, resulting in better cornering performance. Furthermore, because the motor and engine don't drive the same shaft in P4 mode, the vehicle can achieve four-wheel drive, but it can't switch between pure electric and pure engine drive at will, which is detrimental to vehicle handling and comfort.

[0068] It should be noted that the power control method for a hybrid vehicle provided in an optional embodiment of the present disclosure is used for a hybrid vehicle in the above-mentioned P2 mode, and is intended to solve the power connection process control of the engine of the hybrid vehicle when it participates in driving. It adopts engine joint speed regulation and transmits torque through the clutch and coupling teeth in the connecting device to make the engine speed reach the target speed, thereby achieving smooth engine power access without noise, vibration and sound roughness (NVH) and other comprehensive problems.

[0069] FIG1 shows a schematic diagram of the architecture of a power system of a hybrid vehicle provided by an optional embodiment of the present disclosure. Referring to FIG1 , the power system of the hybrid vehicle includes an engine 11, a starter 12, a connecting device 13, a hybrid drive motor 14 and a transmission 15. When the hybrid vehicle is driving in pure electric mode, the hybrid drive motor 14 drives the vehicle, the connecting device 13 disconnects the power connection, and the engine 11 is shut down and the speed drops to zero. When the pure electric mode is switched to the parallel drive mode, the starter 12 drives the engine 11 to start successfully, and then relies on the speed regulation function of the engine 11 to adjust the speed of the engine 11 to the target speed. When the speed of the hybrid drive motor 14 and the speed difference are met, the connecting device 13 performs a closing action to connect the power of the engine 11, and together with the hybrid drive motor 14, drives the hybrid vehicle to travel.

[0070] Based on this, compared with the power system of traditional vehicles, the engine is started by the starter, and the power of the hybrid drive motor is driven without shunt loss, ensuring good vehicle smoothness.

[0071] FIG2 shows a schematic diagram of the architecture of a power control system for a hybrid vehicle provided by an optional embodiment of the present disclosure. Referring to FIG2 , the power control system includes a hybrid control unit 21 (HCU), an engine control unit 22 (ECU), a controller 23, a motor control unit 24 (MCU), and a transmission control unit 25 (TCU). For example, as shown in FIG1 and FIG2 , the hybrid control unit 21 is connected to the engine control unit 22, the controller 23, the motor control unit 24, and the transmission control unit 25 via a CAN bus. The engine control unit 22 is connected to the engine 11 and the starter 12 in the hybrid vehicle via a control harness. The controller 23 is connected to the connection device 13 in the hybrid vehicle via a control harness. The motor control unit 24 is connected to the hybrid drive motor 14 in the hybrid vehicle via a control harness. The transmission control unit 25 is connected to the transmission 15 in the hybrid vehicle via a control harness.

[0072] The hybrid control unit 21 is primarily responsible for monitoring the hybrid vehicle's driving mode and power requirements, determining the switching and power distribution between the internal combustion engine and the hybrid drive motor 14 to achieve excellent fuel economy and emissions control. The engine control unit 22 is primarily responsible for managing and controlling the operation of the engine 11. It uses sensors to obtain various engine 11 data, such as speed, temperature, and oxygen content, and adjusts parameters such as fuel injection, ignition timing, and valve opening and closing based on this data to ensure efficient and stable engine 11 operation. The motor control unit 24 is primarily responsible for managing and controlling the hybrid drive motor 14. It receives data from the battery and the hybrid drive motor 14 and controls the speed and torque output of the hybrid drive motor 14 based on the hybrid vehicle's requirements and driver input, thereby enabling the hybrid vehicle's acceleration, braking, and driving functions. The transmission control unit 25 collects information from various sensors and the engine 11 to determine when and how the transmission should shift gears, thereby improving the hybrid vehicle's performance, ensuring smooth shifting, and conserving fuel.

[0073] According to a power control system provided by an optional embodiment of the present disclosure, based on the various control units of the power control system, the connection relationship between the control units, and the connection relationship between the control units and the various components in the hybrid vehicle, the working status of the engine 11, such as starting, idling, current speed, combustion torque, torque loss, etc., sent by the engine control unit 22 is collected through the CAN communication protocol, and the engine 11 is controlled accordingly, such as starting, speed control, torque control, shutdown, etc., and then the working status of the hybrid drive motor 14, such as speed, torque, and the output end speed calculated according to the internal gear structure of the transmission controlled by the transmission control unit 25, is collected through the motor control unit 24, and the controller 23 is combined to control the connection device 13 to disconnect or perform connection, so as to realize power control of the hybrid vehicle.

[0074] A power control method for a hybrid vehicle provided by an optional embodiment of the present disclosure is described in detail below in conjunction with the contents described in the power system of the hybrid vehicle shown in FIG1 and the power control system of the hybrid vehicle shown in FIG2 .

[0075] FIG3 shows a flow chart of a power control method for a hybrid vehicle provided by an optional embodiment of the present disclosure, which is applied to a power control system in a hybrid vehicle. Referring to FIG3 , the method specifically includes the following steps:

[0076] S301 . Respond to a first driving mode switching request and obtain current operating condition information of an engine in a hybrid vehicle, wherein the first driving mode switching request is used to request the hybrid vehicle to operate in a hybrid driving mode.

[0077] Optionally, the first drive mode switch request is used to request the hybrid vehicle to operate in the hybrid drive mode, i.e., the process of connecting the power of the engine 11. The hybrid control unit 21 determines whether to initiate the hybrid drive mode switch based on factors such as the vehicle power demand, the battery state of charge (SOC), and the driver's torque demand.

[0078] Optionally, when it is necessary to switch the driving mode of the hybrid vehicle from a pure electric driving mode to a hybrid driving mode, the hybrid control unit 21 issues a first driving mode switching request, and the controller 23 responds to the first driving mode switching request issued by the hybrid control unit 21, and collects the current operating condition information of the engine 11 in the hybrid vehicle through the CAN bus. For example, the current operating condition information includes the current gear, the current speed of the vehicle, the speed of the hybrid drive motor, the driving torque, the transmission oil temperature, the current driving force of the vehicle, the current resistance of the vehicle, etc.

[0079] S302: Determine a target speed after the engine is started based on current operating condition information.

[0080] Optionally, after obtaining current operating condition information of the hybrid vehicle's engine 11, the controller 23 calculates a target speed for the engine 11 based on the current operating condition information. This target speed is the operating speed of the hybrid vehicle when the drive mode is successfully switched to the hybrid drive mode after the engine 11 is started. Specifically, determining the target speed of the engine 11 requires determining the acceleration of the hybrid vehicle based on the vehicle's driving dynamics equations, and determining the vehicle speed after the drive mode switch is completed based on the drive mode switch time from the start of the drive mode switch to the completion of the drive mode switch, thereby determining the target speed of the engine 11 after starting.

[0081] S303. According to the target speed, control the engine start of the hybrid vehicle to connect the engine to the connecting device, and control the connecting device in the hybrid vehicle to operate so that the engine in the hybrid vehicle operates at the target speed, wherein the connecting device includes: a clutch and a coupling tooth.

[0082] Optionally, after determining the target speed for engine 11 after starting, controller 23 sends a control command and a speed adjustment command to engine control unit 22 via the CAN bus. Engine control unit 22 responds to the control command, controls starter 12 in the hybrid vehicle to start engine 11, and responds to the speed adjustment command to adjust the speed of engine 11 to the target speed. Furthermore, when the speed of engine 11 reaches the target speed, engine 11 enters torque control mode, i.e., a zero torque output state.

[0083] Optionally, the controller 23 controls the engine 11 to start and simultaneously connect the engine 11 to the connecting device 13 based on the control command, thereby controlling the operation of the connecting device 13 so that the engine 11 in the hybrid vehicle operates at a target speed. The connecting device 13 includes a clutch and engaging teeth. During the process of adjusting the speed of the engine 11 to the target speed, the clutch first partially adjusts the speed. When the speed of the engine 11 is synchronized to a certain range through clutch slip, the engaging teeth re-engage, driving the sliding gear sleeve in the hybrid vehicle to quickly engage, achieving full torque transmission. As the torque of the engine 11 increases, the hybrid vehicle begins to drive.

[0084] In addition, when the sliding gear sleeve in the hybrid vehicle is engaged, the controller 23 feeds back the engagement status of the hybrid vehicle to the hybrid control unit 21. When the hybrid control unit 21 receives the engagement status signal of the hybrid vehicle sent by the controller 23, it controls the engine 11 to enter the hybrid drive mode. At this point, the drive mode switching of the hybrid vehicle is completed, specifically switching from the pure electric drive mode to the hybrid drive mode.

[0085] Therefore, according to a hybrid vehicle power control method provided in an optional embodiment of the present disclosure, in response to a first drive mode switch request, current operating condition information of the hybrid vehicle's engine is obtained. Based on the current operating condition information, a target speed for the engine after starting is determined. Based on the target speed, the hybrid vehicle's engine is started to connect the engine to a connecting device, and the connecting device is controlled to operate so that the hybrid vehicle's engine operates at the target speed. Based on the power control system provided in an optional embodiment of the present disclosure, engine-coordinated speed regulation is employed, and torque is transmitted through a clutch and coupling gear in the connecting device to achieve the target speed. This achieves control of the hybrid vehicle's engine power connection process when the hybrid vehicle is driving, thereby improving the smoothness of the hybrid vehicle's power control.

[0086] As an optional implementation, as shown in FIG3 and FIG4 , the above-mentioned S302 determines the target speed of the engine after starting based on the current operating condition information, and specifically includes the following steps:

[0087] S401 : Determine vehicle speed change information of the hybrid vehicle within a driving mode switching time according to current operating condition information and a preset driving mode switching time, where the driving mode switching time is the time from the start of driving mode switching to the completion of the switching.

[0088] Optionally, the current acceleration of the hybrid vehicle is determined based on the current driving force and current resistance of the vehicle in the current operating condition information; the vehicle speed change information is determined based on the current acceleration, driving mode switching time and current speed of the hybrid vehicle in the current operating condition information.

[0089] For example, the current acceleration of the hybrid vehicle is determined based on the vehicle driving dynamics equation and in combination with the vehicle current driving force and vehicle current resistance in the current working condition information. The vehicle driving dynamics equation is shown in the following formula (1):

[0090] F t =F f +F w +F i +F j (1)

[0091] Among them, Ft Indicates the driving mode switching time, F f Indicates rolling resistance, F w Indicates air resistance, F i Indicates slope resistance, F j Indicates the acceleration resistance.

[0092] For example, the above-mentioned automobile driving dynamics equation is visualized to obtain the following formula (2), and the current acceleration of the vehicle is determined based on the formula (2).

[0093] Among them, T tq Indicates the engine output torque, i g represents the transmission ratio, i o Indicates the final reducer transmission ratio, represents the mechanical efficiency of the transmission system, r represents the wheel rolling radius, G represents the vehicle weight, f represents the rolling resistance coefficient, i represents the road slope, C d represents the air resistance coefficient, A represents the frontal area, u a represents the vehicle speed, δ represents the vehicle rotation mass conversion coefficient, m represents the vehicle mass, Indicates the current acceleration of the vehicle.

[0094] Exemplarily, after determining the current acceleration of the hybrid vehicle based on the above formula (2), the vehicle speed change information is determined based on the following formula (3), as well as the driving mode switching time and the current vehicle speed in the current operating condition information.

[0095] v=v0+at (3)

[0096] Wherein, v represents the vehicle speed change information, v0 represents the current vehicle speed, a represents the current acceleration of the hybrid vehicle, and t represents the driving mode switching time.

[0097] S402: Determine a target speed based on vehicle speed change information, a preset transmission output speed and vehicle speed conversion ratio coefficient, and a preset current transmission power transmission gear ratio.

[0098] For example, after the vehicle speed change information of the hybrid vehicle is determined based on the above formula (3), the target speed of the engine 11 is determined according to the following formula (4).

[0099] w=K·i·v (4)

[0100] Among them, w represents the target speed of the engine, K represents the conversion ratio coefficient between the transmission output speed and the vehicle speed, i represents the current transmission power gear ratio, and v represents the vehicle speed change information.

[0101] The transmission output speed to vehicle speed conversion ratio coefficient K can be calculated based on the rear-wheel drive speed ratio and tire rolling radius of the hybrid vehicle.

[0102] Based on this, the current operating condition information of the hybrid vehicle collected by the controller is specifically based on the vehicle driving dynamics equation, combined with the current driving force and current resistance of the vehicle in the current operating condition information to determine the current acceleration of the hybrid vehicle, and then the current acceleration of the hybrid vehicle is used to determine the target speed of the engine, and the engine speed is adjusted to the target speed through the engine control unit to switch the driving mode of the hybrid vehicle from pure electric driving mode to hybrid driving mode.

[0103] As an optional implementation, the above step S303 of controlling the engine start-up in the hybrid vehicle to connect the engine to the connection device includes:

[0104] The starter in the hybrid vehicle is started by the engine control unit in the power control system. The starter is arranged on the engine. The engine is started by the starter so that the engine is connected to the connection device.

[0105] For example, as shown in conjunction with Figures 2 and 3 , the engine 11 in the disclosed embodiment is not started directly by the electric motor. Instead, the engine 11 is started by the starter 12 in the hybrid vehicle, thereby driving the engine 11 to operate at a target speed. Specifically, after determining the target speed after the engine 11 is started, the controller 23 provides feedback to the hybrid control unit 21, which then issues a control instruction to the engine control unit 22. In response to the control instruction issued by the hybrid control unit 21, the engine control unit 22 first controls the starter 12 in the hybrid vehicle to start, and then the starter 12 drives the engine 11 to start. Simultaneously, the engine 11 is controlled to communicate with the connection device 13.

[0106] Traditionally, when the engine is started by an electric motor, some of the motor's power is diverted to the engine, affecting the smoothness of the vehicle's power control. However, in the disclosed embodiment, the engine is started not by the hybrid drive motor, but by the starter. This eliminates power diversion losses to the hybrid drive motor and improves the smoothness of the hybrid vehicle's power control.

[0107] As an optional implementation, step S303 controls the operation of the connection device in the hybrid vehicle so that the engine in the hybrid vehicle operates at the target speed, including:

[0108] According to the target speed, the opening and closing degree of the clutch and the meshing degree of the engaging teeth are adjusted so that the engine in the hybrid vehicle operates at the target speed.

[0109] Optionally, as shown in FIG1 , when adjusting the speed of the engine 11 to the target speed, compared to the conventional method of relying solely on the clutch, the disclosed embodiment first adjusts the clutch and then adjusts the speed of the engine 11 based on the engaging teeth. Specifically, when the speed of the engine 11 is synchronized to a certain range through clutch slip, the engaging teeth re-engage, prompting the sliding gear sleeve in the hybrid vehicle to quickly engage.

[0110] For example, with reference to FIG3 and FIG5 , the above steps adjust the clutch opening and closing degree and the meshing degree of the coupling teeth according to the target speed so that the engine in the hybrid vehicle operates at the target speed, and specifically include the following steps:

[0111] S501: Adjust the clutch opening / closing degree to a first opening / closing degree so that the engine speed reaches a first preset speed.

[0112] Optionally, according to a preset first current increase value, power is supplied to the electromagnetic coil corresponding to the clutch in an increasing current manner until the opening and closing degree of the clutch is adjusted to a first opening and closing degree.

[0113] For example, the connection device 13 in a hybrid vehicle includes not only a clutch and engaging teeth, but also an electromagnetic coil control device. When the engine 11 is connected to the connection device 13, the electromagnetic coil control device is also activated for power transmission. Specifically, the clutch and engaging teeth each correspond to a corresponding electromagnetic coil. The controller 23 controls the clutch opening and closing degree and the engagement degree of the engaging teeth by controlling the current values ​​of the electromagnetic coils. The clutch only acts by slipping to reduce the speed difference. Considering the rotational inertia and speed difference of the engine 11, and the clutch slippage time is very short, it can meet the needs of high-torque engines, such as hybrid system designs with torques greater than 800 Nm. This also solves the problem of the lack of 800 Nm multi-plate clutch resources in traditional power control systems.

[0114] Specifically, the controller 23 supplies power to the electromagnetic coil corresponding to the clutch in an increasing current manner according to the preset first current increase value l1, adjusts the opening and closing degree of the clutch to the first opening and closing degree, and at the same time, synchronizes the speed of the engine 11 through clutch slippage, so that the speed of the engine 11 reaches the first preset speed.

[0115] S502 : According to a speed difference between the target speed and a first preset speed, adjust the meshing degree of the coupling teeth to a first meshing degree, so that the engine in the hybrid vehicle runs at the target speed.

[0116] Optionally, according to a preset second current increase value, power is supplied to the electromagnetic coil corresponding to the coupling tooth in an increasing current manner to push the active end and the driven end of the coupling tooth to engage until the meshing degree of the coupling tooth is adjusted to the first meshing degree.

[0117] For example, when the speed of the engine 11 reaches a first preset speed through clutch slip, the controller 23 can adjust the meshing degree of the coupling teeth to the first meshing degree by controlling the current value of the electromagnetic coil corresponding to the coupling teeth.

[0118] Specifically, a second current increase value l2 is determined based on the speed difference between the target speed and the first preset speed, and power is supplied to the electromagnetic coil corresponding to the coupling tooth in an increasing manner. The electromagnetic coil corresponding to the coupling tooth engages the driving end and the driven end of the coupling tooth, thereby adjusting the meshing degree of the coupling tooth to the first meshing degree, thereby enabling the sliding gear sleeve in the hybrid vehicle to quickly engage. As shown in conjunction with Figures 1 and 6, after the sliding gear sleeve in the hybrid vehicle quickly engages, the power access control process of the engine 11 is completed.

[0119] In addition, as shown in Figure 2, after the sliding gear sleeve is engaged, the controller 23 feeds back the engagement status of the hybrid vehicle to the hybrid control unit 21. After receiving the engagement status signal sent by the controller 23, the hybrid control unit 21 sends an instruction to the engine control unit 22, and the engine control unit 22 controls the engine 11 to enter the hybrid drive mode, thereby completing the switching of the drive mode of the hybrid vehicle, that is, realizing the power access control of the engine 11.

[0120] For example, FIG7 shows a flowchart of another engine power access control provided by an optional embodiment of the present disclosure, wherein the implementation process of each step is the same as that described above and will not be repeated here.

[0121] Based on this, by estimating the target engine speed, smooth power connection to the hybrid vehicle can be ensured after engine power is connected. Furthermore, the disclosed embodiment uses a clutch and engaging gear to adjust the engine speed, overcoming the disadvantage of poor engine speed regulation accuracy. This allows engine speed regulation even with relatively large speed differences, with clutch slippage completing speed adjustment. Furthermore, clutch speed regulation does not require complete speed synchronization, allowing a small speed difference to be used for speed regulation based on the engaging gear, ensuring smooth engagement of the sliding gear sleeve in the hybrid vehicle. During this process, CAN bus communication and monitoring are used, eliminating the need for additional sensors.

[0122] As an optional implementation, FIG8 shows a flow chart of another hybrid vehicle power control method provided by an optional embodiment of the present disclosure. As shown in FIG8, the method further includes:

[0123] S801 . Respond to a second driving mode switching request by controlling the engine to reduce torque to a zero torque output state, wherein the second driving mode switching request is used to request the hybrid vehicle to operate in a pure electric driving mode.

[0124] Optionally, the second drive mode switching request is used to request the hybrid vehicle to operate in a pure electric drive mode, that is, the control process of the engine 11 power withdrawal as shown in FIG9 . Referring to FIG9 , the process between dotted lines 1, 2, and 3 represents the power exchange process during the power withdrawal process of the engine 11, dotted line 4 represents that the engine speed will eventually drop to 0 during the power withdrawal process, dotted line 5 represents that the engine torque will eventually drop to 0 during the power withdrawal process, dotted line 6 represents that the hybrid drive motor torque will eventually drop to 0 during the power withdrawal process, and dotted line 7 represents that the control current will eventually drop to 0 during the power withdrawal process. Furthermore, in conjunction with FIG2 , the hybrid control unit 21 determines to start switching the hybrid vehicle to a pure electric drive mode based on factors such as the vehicle power demand, the battery state of charge (SOC), and the driver's torque demand.

[0125] For example, when it is necessary to switch the driving mode of the hybrid vehicle from the hybrid driving mode to the pure electric driving mode, as shown in Figure 2, the hybrid control unit 21 issues a second driving mode switching request, and the controller 23 responds to the second driving mode switching request issued by the hybrid control unit 21, and issues a torque reduction instruction to the engine control unit 22 through the CAN bus, and the engine control unit 22 controls the engine 11 to reduce the torque to a zero torque output state.

[0126] S802: Control the connection device in the hybrid vehicle to disconnect from the engine.

[0127] Optionally, according to a preset first current reduction value, the current value of the electromagnetic coil corresponding to the clutch is reduced in a current decreasing manner until the clutch is in a disengaged state; according to a preset second current reduction value, the current value of the electromagnetic coil corresponding to the coupling tooth is reduced in a current decreasing manner until the coupling tooth exits the meshing position.

[0128] For example, as shown in FIG2 , controller 23 decreases the current of the electromagnetic coil corresponding to the clutch in a decreasing manner according to a preset first current reduction value, thereby maintaining the clutch in a disengaged state. Simultaneously, controller 23 decreases the current of the electromagnetic coil corresponding to the coupling tooth in a decreasing manner according to a preset second current reduction value, thereby causing the sliding gear sleeve in the hybrid vehicle to slide out of the meshing position under the action of the spring force, thereby also causing the coupling tooth to exit the meshing position.

[0129] In addition, in combination with what is shown in FIG2 , the controller 23 feeds back the disconnected working status of the connecting device 13 to the hybrid power control unit 21. After the hybrid power control unit 21 receives the working status information of the connecting device 13 fed back by the controller 23, it sends a shutdown command to the engine control unit 22. The engine control unit 22 responds to the shutdown command sent by the hybrid power control unit 21, controls the engine 11 to cut off the fuel and shut down, so that the mode of the hybrid vehicle is switched from the hybrid drive mode to the pure electric drive mode, and the power exit control of the engine 11 is completed.

[0130] For example, FIG10 shows a flow chart of an engine power exit control provided by an optional embodiment of the present disclosure, wherein the implementation process of each step is the same as that described above and will not be repeated here.

[0131] Based on this, the engine power disengagement process can be performed without requiring a rapid response. The response spring stiffness and preload are reduced, reducing the electromagnetic coil operating current and, in turn, lowering the energy consumption of the hybrid vehicle's powertrain. Furthermore, the power control system provided in an optional embodiment of the present disclosure utilizes CAN communication speed signals, ensuring sufficient control accuracy without requiring additional hardware or electrical equipment.

[0132] The present disclosure also provides a hybrid vehicle, as shown in FIG11 , which is a schematic structural diagram of a hybrid vehicle 1100 according to an optional embodiment of the present disclosure, including a processor 1101, a memory 1102, and optionally, a bus 1103. The memory 1102 stores machine-readable instructions executable by the processor 1101. When the hybrid vehicle 1100 is operating, the processor 1101 communicates with the memory 1102 via the bus 1103. When the machine-readable instructions are executed by the processor 1101, the steps of any of the above hybrid vehicle power control methods are performed.

[0133] An embodiment of the present disclosure further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of any of the above methods for controlling the power of a hybrid vehicle are executed.

[0134] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working processes of the systems and devices described above can refer to the corresponding processes in the method embodiments, and will not be repeated in this disclosure. In the several embodiments provided in the present disclosure, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0135] In addition, the functional units in the various embodiments of the present disclosure can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the relevant technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

[0136] The above are only specific implementation methods of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this disclosure, which should be covered by the protection scope of the present disclosure.

Claims

1. A power control method for a hybrid vehicle, applied to a power control system in the hybrid vehicle. The power control method for the hybrid vehicle includes: Responding to a first drive mode switching request, obtaining current operating condition information of an engine in the hybrid vehicle, where the first drive mode switching request is used to request the hybrid vehicle to operate in a hybrid drive mode; Determining a target speed after the engine starts based on the current operating condition information; According to the target speed, controlling the engine in the hybrid vehicle to start to connect the engine with a connecting device, and controlling the connecting device in the hybrid vehicle to operate so that the engine in the hybrid vehicle operates at the target speed, where the connecting device includes: a clutch and engaging teeth.

2. The power control method for a hybrid vehicle according to claim 1, wherein, The determining the target speed after the engine starts based on the current operating condition information includes: Determining vehicle speed change information of the hybrid vehicle within a drive mode switching time according to the current operating condition information and a preset drive mode switching time, where the drive mode switching time is the time from the start of drive mode switching to the completion of switching; Determining the target speed according to the vehicle speed change information, a preset conversion ratio coefficient between the output speed of the transmission and the vehicle speed, and a preset speed ratio of the current transmission gear for power transmission.

3. The power control method of a hybrid vehicle according to claim 2, wherein, The determining the vehicle speed change information of the hybrid vehicle within the drive mode switching time according to the current operating condition information and the preset drive mode switching time includes: Determining a current acceleration of the hybrid vehicle according to the current driving force of the vehicle and the current resistance of the vehicle in the current operating condition information; Determining the vehicle speed change information according to the current acceleration of the hybrid vehicle, the drive mode switching time, and the current vehicle speed in the current operating condition information.

4. The power control method of a hybrid vehicle according to claim 1, wherein, The controlling the engine in the hybrid vehicle to start to connect the engine with the connecting device includes: Starting a starter in the hybrid vehicle through an engine control unit in the power control system, where the starter is arranged on the engine; Driving the engine to start through the starter so that the engine is connected with the connecting device.

5. The power control method of a hybrid vehicle according to claim 1, wherein, The controlling the connecting device in the hybrid vehicle to operate so that the engine in the hybrid vehicle operates at the target speed includes: Adjusting the opening and closing degree of the clutch and the meshing degree of the engaging teeth according to the target speed so that the engine in the hybrid vehicle operates at the target speed.

6. The power control method for a hybrid vehicle according to claim 5, wherein, The adjusting the opening and closing degree of the clutch and the meshing degree of the engaging teeth according to the target speed so that the engine in the hybrid vehicle operates at the target speed includes: Adjusting the opening and closing degree of the clutch to a first opening and closing degree so that the speed of the engine reaches a first preset speed; Adjusting the meshing degree of the engaging teeth to a first meshing degree according to the speed difference between the target speed and the first preset speed so that the engine in the hybrid vehicle operates at the target speed.

7. The power control method of a hybrid vehicle according to claim 6, wherein, Adjusting the opening and closing degree of the clutch to the first opening and closing degree includes: Supplying power to the electromagnetic coil corresponding to the clutch in an increasing current manner according to a preset first current increase value, until the opening and closing degree of the clutch is adjusted to the first opening and closing degree.

8. The power control method for a hybrid vehicle according to claim 6, wherein, Adjusting the meshing degree of the engaging teeth to the first meshing degree according to the rotational speed difference between the target rotational speed and the first preset rotational speed includes: Supplying power to the electromagnetic coil corresponding to the engaging teeth in an increasing current manner according to a preset second current increase value, and pushing the driving end and the driven end of the engaging teeth to engage until the meshing degree of the engaging teeth is adjusted to the first meshing degree.

9. The power control method of a hybrid vehicle according to claim 1, wherein, The power control method of the hybrid vehicle further includes: Responding to a second driving mode switching request, controlling the engine to reduce torque to a zero torque output state, where the second driving mode switching request is used to request the hybrid vehicle to operate in a pure electric driving mode; Controlling the disconnecting of the connecting device in the hybrid vehicle from the engine.

10. The power control method for a hybrid vehicle according to claim 9, wherein, Controlling the disconnecting of the connecting device in the hybrid vehicle from the engine includes: Reducing the current value of the electromagnetic coil corresponding to the clutch in a decreasing current manner according to a preset first current decrease value until the clutch is in a disengaged state; Reducing the current value of the electromagnetic coil corresponding to the engaging teeth in a decreasing current manner according to a preset second current decrease value until the engaging teeth withdraw from the meshing position.

11. A power control system, the power control system includes a hybrid control unit, an engine control unit, a motor control unit, a transmission control unit, and a controller; The hybrid control unit is connected to the engine control unit, the motor control unit, the transmission control unit, and the controller respectively through a preset communication protocol. The hybrid control unit is used to send a first driving mode switching request to the controller, and the first driving mode switching request is used to request the hybrid vehicle to operate in a hybrid driving mode; The controller is connected to the connecting device of the hybrid vehicle. The controller is used to respond to the first driving mode switching request, obtain the current working condition information of the engine in the hybrid vehicle, and determine the target rotational speed after the engine starts based on the current working condition information; The engine control unit is connected to the engine of the hybrid vehicle. The engine control unit is used to control the engine in the hybrid vehicle to start to connect the engine to the connecting device; The controller is further used to control the operation of the connecting device in the hybrid vehicle so that the engine in the hybrid vehicle operates at the target rotational speed; The motor control unit is connected to the hybrid drive motor of the hybrid vehicle. The motor control unit is used to control the hybrid drive motor; The transmission control unit is connected to the transmission of the hybrid vehicle. The transmission control unit is used to control the transmission.

12. A hybrid vehicle, comprising: A processor and a memory, the memory storing machine-readable instructions executable by the processor, and when the hybrid vehicle is operating, the processor executes the machine-readable instructions to perform the steps of the power control method of the hybrid vehicle according to any one of claims 1 to 10.

13. A computer-readable storage medium having a computer program stored thereon, and when the computer program is run by a processor, it executes the steps of the power control method of the hybrid vehicle according to any one of claims 1 to 10.

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