A hybrid vehicle drive system, control system and control method

Abstract

This invention belongs to the field of hybrid vehicle powertrain control technology, and discloses a hybrid vehicle drive system, control system, and control method. The engine crankshaft output is connected to the motor rotor shaft via a first clutch. The motor rotor shaft output is connected to the input shaft of a second clutch, and then to the transmission input shaft via the output shaft of the second clutch. The transmission output shaft transmits power to the wheels via the final drive and half-shafts to drive the vehicle. The control method includes the following steps: acquiring vehicle operating conditions; calculating the drive torque demand and engine speed for each gear based on the vehicle operating conditions; determining the operating mode based on the drive torque demand and engine speed for each gear; and outputting torque to the transmission mechanism in the corresponding operating mode. This invention minimizes the impact of vehicle driving conditions on engine operation, enabling the vehicle to achieve low emissions and ultra-low fuel consumption, achieving environmental protection and energy-saving effects.

Description

Technical Field

[0001] This invention belongs to the field of hybrid vehicle powertrain control technology, and particularly relates to a hybrid vehicle drive system, control system and control method. Background Technology

[0002] Currently, with social development, the ownership rate of automobiles is increasing, and at the same time, people's demands for energy conservation and environmental protection are becoming stronger. Regulations regarding vehicle emissions are becoming increasingly stringent, and against this backdrop, hybrid vehicles have become one of the main directions of automotive development.

[0003] The hybrid system of a hybrid vehicle consists of an engine, an electric motor, a transmission, a drive shaft, a main reducer, and drive half-shafts, and can be arranged in various ways depending on the operating mode of the hybrid system.

[0004] Based on the above analysis, the problems and defects of the existing technology are as follows: existing vehicles generally only consider two reference factors when making gear shifting decisions: the accelerator pedal opening and vehicle speed. This results in a limited assessment before gear shifting. Furthermore, in actual driving, gear shifting generally requires cutting off power transmission to complete the gear shifting operation, which leads to increased fuel consumption costs during gear shifting. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a hybrid vehicle drive system, control system, and control method.

[0006] The first aspect of this invention discloses a hybrid vehicle drive system, including an engine, an electric motor, a main reducer, half-shafts, and wheels;

[0007] The engine crankshaft output end is connected to the motor rotor shaft of the electric motor via a first clutch. The motor rotor shaft output end is connected to the input shaft of a second clutch and to the transmission input shaft via the output shaft of the second clutch. The transmission output shaft transmits power to the wheels via the main reducer and half shafts to drive the vehicle. The second clutch includes two input shafts and one output shaft.

[0008] A second aspect of this invention discloses a hybrid vehicle control method, comprising the following steps:

[0009] Obtain vehicle operating conditions and calculate drive torque requirements and engine speeds for each gear based on the vehicle operating conditions;

[0010] The operating mode is determined based on the driving torque requirement and the engine speed at each gear.

[0011] In the corresponding operating mode, the output torque is sent to the transmission mechanism.

[0012] Preferably, the operating modes include: motor drive mode, engine drive mode, hybrid drive mode, engine-driven battery pack charging mode, regenerative braking mode, and battery charging mode.

[0013] Preferably, in the motor drive mode;

[0014] When the SOC value of the battery is greater than the minimum set limit, or the engine speed is lower than the minimum stable speed, or the vehicle drive power is less than 30% of the engine rated power, the engine shuts off, the clutch K3 between the engine and the drive motor disengages, and only the electrode works to provide driving force.

[0015] Preferably, in the engine drive mode;

[0016] When the battery does not need to be charged, the SOC value is greater than the upper limit of the SOC control window, and the engine is in the optimal engine operating range set by the control system, the clutch K3 between the engine and the drive motor is engaged, the electrode is closed, and only the engine works to provide driving force.

[0017] Preferably, in hybrid drive mode;

[0018] When clutch K3 engages between the engine and the drive motor, and the vehicle is accelerating or operating at full load, if the drive power required for the vehicle to move is greater than the engine output power, the battery provides energy to participate in the drive.

[0019] Preferably, the method further includes: selecting either a power shift mode or an economy shift mode based on the vehicle speed, engine speed, and load.

[0020] Preferably, the power shift mode includes:

[0021] For engine-driven hybrid vehicles, when the engine speed is lower than the minimum stable speed, the vehicle shifts from a higher gear to a lower gear.

[0022] When the engine speed is higher than the set maximum shift speed, shift from a lower gear to a higher gear;

[0023] When the engine speed is between the maximum and minimum speeds, if the acceleration in a higher gear is greater than that in a lower gear, shift from a lower gear to a higher gear.

[0024] For hybrid vehicles driven by a drive motor, when the motor speed is higher than its set maximum shift speed, the vehicle will shift from a low gear to a high gear.

[0025] Preferably, the economical shifting mode includes:

[0026] When the acceleration of the hybrid vehicle is greater than zero, it is driven in a high gear; the engine fuel consumption rate is used as the basis for gear shifting, and the hybrid vehicle is controlled to drive in the gear with the lowest engine fuel consumption rate.

[0027] When the engine speed is lower than the minimum stable speed, shift from a higher gear to a lower gear.

[0028] When the engine speed is higher than its set maximum shift speed, shift from a lower gear to a higher gear.

[0029] When the engine speed is between its maximum and minimum speed, if the acceleration in the higher gear is greater than zero, shift from the lower gear to the higher gear.

[0030] When the driving resistance is greater than the traction force, if the engine speed is higher than the speed corresponding to the engine's maximum torque, do not shift gears; otherwise, shift to a lower gear.

[0031] A third aspect of this invention discloses a hybrid vehicle control system for implementing the hybrid vehicle control method, the hybrid vehicle control system comprising:

[0032] The parameter acquisition module is used to acquire the vehicle speed, engine speed, and load of the hybrid electric vehicle.

[0033] The shift mode determination module is used to select between a power shift mode and an economy shift mode based on the acquired parameters.

[0034] The shift control module is used to control the uninterrupted shifting of hybrid vehicles based on the selected shift mode.

[0035] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0036] In this invention, the crankshaft output end of the engine is connected to the rotor shaft of the drive motor via a clutch, and the engine driving force and the motor driving force are output coaxially, simplifying the drive system structure; the rotor shaft output end of the motor is connected to the transmission input shaft via a wet second clutch, and the second clutch transmission controls the two input shafts separately, achieving uninterrupted gear shifting control with one output shaft; the single output shaft structure simplifies the structure of the second clutch transmission system.

[0037] This invention employs a second clutch transmission to achieve uninterrupted power shifting control, which greatly improves the driving performance of the hybrid system. It can meet various driving conditions such as rapid start-stop, driving, and reversing of hybrid vehicles, effectively reducing the impact of vehicle driving conditions on engine operation, enabling the vehicle to achieve low emissions and ultra-low fuel consumption, thus achieving environmental protection and energy-saving effects.

[0038] In this invention, the hybrid vehicle transmission engagement adopts a wet second clutch structure. The advantage of the dual-clutch transmission is that it achieves higher transmission efficiency through a simple structure. By using the clutch as a coupling device, the mechanical energy loss generated by the clutch through sliding friction is much smaller than that of the hydraulic coupling.

[0039] This dual-clutch transmission system uses two sets of clutches and two power input shafts connected to clutches K1 and K2 respectively. Clutch K1 controls gears 1, 3, 5, and 7, while clutch K2 controls gears 2, 4, and 6.

[0040] Ordinary transmissions require disengaging the previous gear before shifting to the new gear, interrupting driving force and affecting vehicle performance. Dual-clutch transmissions, on the other hand, use two input drive shafts, eliminating the need to interrupt power during gear shifts. For example, when shifting from 3rd to 4th gear, if clutch K1 is engaged and the vehicle is driving in 3rd gear, and 4th gear is already engaged on the output shaft, simply disengaging clutch K1 and engaging clutch K2 completes the shift from 3rd to 4th gear. This also makes shift mode control easier to implement. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a hybrid vehicle powertrain system provided in an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the gear shifting mode of a hybrid vehicle provided in an embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram showing the matching relationship between the resistance characteristics of each gear in a hybrid vehicle and the universal characteristics of the engine, provided in an embodiment of the present invention.

[0044] Figure 4 This is a flowchart of the hybrid vehicle shift control method without power interruption provided in the embodiments of the present invention;

[0045] Figure 5 This is a schematic diagram of the multi-parameter shifting strategy for light vehicles under the WLTC cycle provided in an embodiment of the present invention;

[0046] In the diagram: 1. 1st gear; 2. 2nd gear; 3. 3rd gear; 4. 4th gear; 5. 5th gear; 6. 6th gear; 7. 7th gear; 8. Hybrid vehicle controller; 9. Engine controller; 91. Engine; 10. Clutch K3; 11. Motor; 111. Motor stator; 112. Motor rotor; 12. Second clutch transmission; 121. Clutch K2; 122. Clutch K1; 13. Main reducer. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] To enable those skilled in the art to fully understand how the present invention is specifically implemented, this section provides an explanatory description of the embodiments that expand upon the technical solutions of the claims.

[0049] like Figure 1 As shown, the hybrid vehicle drive system provided in this embodiment of the invention includes an engine 91, an electric motor 11, a main reducer 13, half shafts, and wheels;

[0050] The crankshaft output end of engine 91 is connected to the motor rotor shaft of motor 11 via a first clutch. The output end of motor rotor 112 is connected to the input shaft of second clutch and to the transmission input shaft via the output shaft of second clutch. The transmission output shaft transmits power to the wheels via the main reducer 13 and half shafts to drive the vehicle. The second clutch includes two input shafts and one output shaft.

[0051] like Figure 4 As shown, the hybrid vehicle control method provided in this embodiment of the invention includes the following steps:

[0052] S101: Obtain vehicle operating conditions and calculate drive torque requirements and engine speeds for each gear based on the vehicle operating conditions;

[0053] S102: Determine the working mode based on the driving torque requirement and the engine speed of each gear;

[0054] S103: Outputs torque to the transmission mechanism in the corresponding working mode.

[0055] In this invention, the operating modes include: motor drive mode, engine drive mode, hybrid drive mode, engine-driven battery pack charging mode, regenerative braking mode, and battery charging mode.

[0056] In this invention, under the motor drive mode;

[0057] When the SOC value of the battery is greater than the minimum set limit, or the engine speed is lower than the minimum stable speed, or the vehicle drive power is less than 30% of the engine rated power, the engine shuts off, the clutch K310 between the engine and the drive motor disengages, and only the electrode works to provide driving force.

[0058] In this invention, under the engine drive mode;

[0059] When the battery does not need to be charged, the SOC value is greater than the upper limit of the SOC control window, and the engine is in the optimal engine operating range set by the control system, the clutch K3 10 between the engine and the drive motor is engaged, the electrode is closed, and only the engine works to provide driving force.

[0060] In this invention, under hybrid driving mode;

[0061] Clutch K3 10 engages between the engine and the drive motor. When the vehicle is accelerating or operating under full load, and the driving power required for the vehicle is greater than the engine output power, the motor is powered by the battery to participate in the drive.

[0062] In this invention, the method further includes: selecting either a power shift mode or an economy shift mode based on the vehicle speed, engine speed, and load.

[0063] In this invention, the power shift mode includes:

[0064] For engine-driven hybrid vehicles, when the engine speed is lower than the minimum stable speed, the vehicle shifts from a higher gear to a lower gear.

[0065] When the engine speed is higher than the set maximum shift speed, shift from a lower gear to a higher gear;

[0066] When the engine speed is between the maximum and minimum speeds, if the acceleration in a higher gear is greater than that in a lower gear, shift from a lower gear to a higher gear.

[0067] For hybrid vehicles driven by a drive motor, when the motor speed is higher than its set maximum shift speed, the vehicle will shift from a low gear to a high gear.

[0068] In this invention, the economical shifting mode includes:

[0069] When the acceleration of the hybrid vehicle is greater than zero, it is driven in a high gear; the engine fuel consumption rate is used as the basis for gear shifting, and the hybrid vehicle is controlled to drive in the gear with the lowest engine fuel consumption rate.

[0070] When the engine speed is lower than the minimum stable speed, shift from a higher gear to a lower gear.

[0071] When the engine speed is higher than its set maximum shift speed, shift from a lower gear to a higher gear.

[0072] When the engine speed is between its maximum and minimum speed, if the acceleration in the higher gear is greater than zero, shift from the lower gear to the higher gear.

[0073] When the driving resistance is greater than the traction force, if the engine speed is higher than the speed corresponding to the engine's maximum torque, do not shift gears; otherwise, shift to a lower gear.

[0074] The hybrid vehicle control system provided in this embodiment of the invention is used to implement the hybrid vehicle control method. The hybrid vehicle control system includes:

[0075] The parameter acquisition module is used to acquire the vehicle speed, engine speed, and load of the hybrid electric vehicle.

[0076] The shift mode determination module is used to select between a power shift mode and an economy shift mode based on the acquired parameters.

[0077] The shift control module is used to control the uninterrupted shifting of hybrid vehicles based on the selected shift mode.

[0078] The hybrid power system described in this invention is a parallel hybrid electric vehicle (PHEV). Based on the driving power required for vehicle operation and the control requirements for battery SOC value, different driving modes are selected to operate, which not only meets the driving requirements but also ensures the efficient operation of the engine and battery.

[0079] The operating mode of the hybrid power system is as follows:

[0080] In a parallel hybrid system, the driving force can come from the engine 91 or the drive motor or a combination of both, so that the output power meets the vehicle's driving power requirements.

[0081] or or (1)

[0082] In the formula, Driven by power to meet vehicle driving requirements. For the output power of engine 91, This refers to the power output of the drive motor.

[0083] The hybrid vehicle hybrid system operation modes provided in this embodiment of the invention include: pure electric mode, engine-only drive mode, hybrid drive mode, engine-driven and battery-charging mode, regenerative braking mode, and battery charging mode.

[0084] The pure electric mode provided in this embodiment of the invention includes:

[0085] When the battery's SOC value exceeds the minimum set limit (e.g., 40%), and the vehicle starts or operates at low speeds, specifically when the engine 91's operating speed is below the minimum stable speed or the vehicle's drive power is less than 30% of the engine 91's rated power, the engine 91 shuts off, and the clutch K3 10 between the engine 91 and the drive motor disengages, with only the electrodes providing driving force. In pure electric mode, starting is smooth and there are no harmful exhaust emissions.

[0086] (2)

[0087] (3)

[0088] (4)

[0089] In the formula, The power provided to engine 91 For battery pack power, The power provided to the drive motor This refers to the working efficiency of motor 11.

[0090] Instantaneous current of the battery pack It can be calculated using the following formula:

[0091] (5)

[0092] In the formula, This refers to the instantaneous current of the battery pack. It is the open-circuit voltage of the battery pack.

[0093] Battery pack open circuit voltage It can be calculated by interpolation from a two-dimensional pulse spectrum lookup table of battery voltage, where the battery SOC and temperature are two-dimensional variables.

[0094] The instantaneous energy loss of the battery pack during discharge due to the internal resistance of the battery discharge is calculated by the following formula:

[0095] (6)

[0096] In the formula, It is the energy loss of the battery pack. This refers to the number of battery pack modules. This refers to the battery's internal discharge resistance. By using battery SOC and temperature as two-dimensional parameters The calculation is performed by interpolating the pulse spectrum table.

[0097] When the battery discharges, the battery's The value can be calculated using the following formula:

[0098] (7)

[0099] In the formula and Is the battery pack at all times? and SOC value, It is the initial total energy of the battery pack [unit: watt-second, W·s].

[0100] The engine-only drive mode includes:

[0101] When the battery does not need charging, i.e., the SOC value is greater than the upper limit of the SOC control window (e.g., 80%), and the engine 91 is in the optimal operating range set by the control system, the clutch K3 10 between the engine 91 and the drive motor is engaged, the electrode is closed, and only the engine 91 operates to provide driving force. That is,

[0102] (8)

[0103] (9)

[0104] 0 (10)

[0105] The engine 91 provides driving force to drive the vehicle. During this process, the shift strategy optimizes the control. By increasing the gear, the engine 91 switches from a high-speed, low-load condition to a low-speed, high-load condition along the constant power line, thereby reducing fuel consumption.

[0106] When the engine 91 cannot be operated within the optimal economic range through gear shifting control, the fuel supply to some cylinders is cut off by the engine 91 electronic control system to achieve cylinder deactivation control, thereby halving the number of working cylinders, increasing the single-cylinder load of the engine 91, and enabling the working cylinders of the engine 91 to operate within the optimal economic range, thus achieving the purpose of reducing fuel consumption.

[0107] The hybrid drive mode includes the following: In hybrid drive mode, the clutch K3 10 between the engine 91 and the drive motor engages. When the vehicle needs to accelerate or operate under full load, and the drive power required for vehicle movement exceeds the output power of the engine 91, the battery provides energy to participate in the drive. At this time, the output power of the vehicle drive system is the sum of the output power of the engine 91 and the output power of the motor 11. That is,

[0108] (11)

[0109] In this driving mode, the SOC value of the battery pack during the discharge process still needs to be calculated using formulas (4)-(7).

[0110] The engine-driven and battery-charging mode includes: during the engine 91's operating range, if the battery pack is in a rechargeable state, i.e., the SOC value is less than the upper limit of the SOC control window (e.g., 80%), the engine 91 can drive the vehicle while simultaneously using surplus power to drive the electric motor to generate electricity and charge the battery. By adjusting the power output of the electric motor 11, the engine 91 operates within its optimal economic range, thereby reducing fuel consumption. At this time,

[0111] (12)

[0112] In the formula, The driving power received by generator 11 from engine 91.

[0113] The power for charging the battery is

[0114] (13)

[0115] In the formula, The charging power of the battery, This refers to the generator efficiency.

[0116] Instantaneous current of the battery pack It can be calculated using the following formula:

[0117] (14)

[0118] In the formula, For the instantaneous conduction current of the battery pack, It is the open-circuit voltage of the battery pack, which is calculated by interpolation through a two-dimensional pulse spectrum lookup table of battery voltage. This pulse spectrum table uses battery SOC and temperature as two-dimensional variables.

[0119] The instantaneous energy loss during battery charging due to the battery's internal resistance is calculated using the following formula:

[0120] (15)

[0121] In the formula, For the instantaneous energy loss of the battery pack, This refers to the number of battery pack modules. Internal resistance during battery charging. Internal resistance during battery charging. By using battery SOC and temperature as two-dimensional parameters The calculation is performed by interpolating the pulse spectrum table.

[0122] The instantaneous SOC value of a battery during charging can be calculated using the following formula:

[0123] (16)

[0124] The regenerative braking mode includes: when the vehicle brakes, if it encounters deceleration or downhill conditions, the clutch between the engine 91 and the drive motor disengages, the engine 91 can be in an idling or stopped state, and the drive motor operates as a generator to recover braking energy to charge the battery pack. The battery SOC value is calculated using formulas (13)-(16).

[0125] The battery charging mode includes the following: When the battery needs charging, i.e., when the battery SOC value is less than the lower limit of the SOC control window (e.g., 40%), the vehicle can be parked, i.e., clutches K1 121 and K2 122 are disengaged, while clutch K3 10 between engine 91 and drive motor is engaged. Engine 91 drives the motor to operate as a generator to charge the battery pack. By adjusting the power output of motor 11, engine 91 can operate within its optimal economic range, thereby reducing fuel consumption.

[0126] In this operating mode:

[0127] (17)

[0128] (18)

[0129] (19)

[0130] In the formula, The engine has a power output of 91 kW. The charging power of the battery pack, This refers to the generator efficiency.

[0131] The instantaneous current I of the battery pack can be calculated using the following formula:

[0132] (20)

[0133] in, It is the open-circuit battery voltage, which is calculated by interpolation through a two-dimensional pulse spectrum lookup table of battery voltage. This pulse spectrum table uses battery SOC and temperature as two-dimensional variables.

[0134] The instantaneous energy loss of the battery pack due to the internal resistance of the battery is calculated by the following formula:

[0135] (twenty one)

[0136] In the formula, For the instantaneous energy loss of the battery pack, This refers to the number of battery pack modules. Internal resistance during battery charging. Internal resistance during battery charging. By using battery SOC and temperature as two-dimensional parameters The calculation is performed by interpolating the pulse spectrum table.

[0137] The instantaneous SOC value of a battery during charging can be calculated using the following formula:

[0138] (twenty two)

[0139] The hybrid vehicle shift control method without power interruption provided in this embodiment of the invention specifically includes:

[0140] 1) Optimal power shift pattern

[0141] In hybrid electric vehicle (HEV) performance simulation calculations, if an optimal performance shifting program is used, generally speaking, to ensure the HEV's performance, the vehicle should be driven in as low a gear as possible to guarantee higher drive torque. For example... Figure 2 As shown, in the simulation calculation, the optimal power shifting pattern specifies the driver's shifting operation as follows:

[0142] For engine 91 drive:

[0143] (1) When the engine speed is lower than its minimum stable speed, shift from high gear to low gear;

[0144] (2) When the engine speed is higher than its maximum speed, shift from a low gear to a high gear;

[0145] (3) When the engine speed is between the maximum and minimum speed, if the acceleration of the high gear is greater than that of the low gear, the engine should be shifted from the low gear to the high gear.

[0146] As for the drive motor: when the speed of motor 11 is higher than its maximum speed, it will switch from a low gear to a high gear;

[0147] 2) Optimal Economic Gear Shifting Pattern

[0148] The optimal fuel economy shifting pattern is primarily designed for engine 91 driving conditions. The fuel economy simulation calculations utilize shifting patterns that guarantee optimal fuel economy. There are two methods for determining this: one is to use higher gears whenever possible when the vehicle's acceleration is greater than zero; the other is to use the engine's 91 fuel consumption rate as the shifting basis, ensuring the vehicle always operates in the gear that minimizes the engine's fuel consumption.

[0149] In the simulation calculation of the shifting pattern under engine 91 driving conditions, the driver's shifting pattern is specified as follows:

[0150] (1) When the engine speed is lower than its minimum stable speed, shift from high gear to low gear;

[0151] (2) When the engine speed is higher than its maximum speed, shift from a low gear to a high gear;

[0152] (3) When the engine speed is between its maximum and minimum speed, if the acceleration in the high gear is greater than zero, the engine should be shifted from a low gear to a high gear.

[0153] (4) When the driving resistance is greater than the traction force, if the engine speed of 91 is higher than the speed corresponding to the maximum torque of engine 91, then do not shift gears; otherwise, shift to a lower gear. A schematic diagram showing the matching relationship between the resistance characteristics of each gear in a hybrid vehicle and the universal characteristics of engine 91 is shown below. Figure 3 As shown.

[0154] The hybrid vehicle shift control system without power interruption provided in this embodiment of the invention includes:

[0155] The parameter acquisition module is used to acquire the vehicle speed, engine speed, and load of the hybrid electric vehicle.

[0156] The shift mode determination module is used to select between a power shift mode and an economy shift mode based on the acquired parameters.

[0157] The shift control module is used to control the uninterrupted shifting of hybrid vehicles based on the selected shift mode.

[0158] Whether the driver needs to shift gears can be determined and calculated using a set of inequalities within the program. The gear shifting procedure flowchart is as follows: Figure 4 As shown.

[0159] The power-interruption-free gear shifting control method for hybrid vehicles provided in this invention can be applied to the simulation calculation of the power performance and fuel economy of hybrid vehicles. Figure 5 The figure shows the multi-parameter shifting strategy of a light vehicle under the WLTC (Worldwide harmonized Light vehicles Test Cycles) operating cycle. The numbers in the figure represent the transmission gears at the vehicle speed.

[0160] It should be noted that embodiments of the present invention can be implemented using hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented using hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or using software executed by various types of processors, or using a combination of the above-described hardware circuitry and software, such as firmware.

[0161] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A hybrid vehicle control method, characterized in that, Hybrid vehicles include an engine, an electric motor, a final drive, half-shafts, and wheels; The engine crankshaft output end is connected to the motor rotor shaft of the electric motor via a first clutch. The motor rotor shaft output end is connected to the input shaft of a second clutch and to the transmission input shaft via the output shaft of the second clutch. The transmission output shaft transmits power to the wheels via the final drive and half-shafts to drive the vehicle. The second clutch includes two input shafts and one output shaft. The hybrid vehicle control method includes the following steps: Obtain vehicle operating conditions and calculate drive torque requirements and engine speeds for each gear based on the vehicle operating conditions; The operating mode is determined based on the driving torque requirement and the engine speed at each gear. In the corresponding operating mode, torque is output to the transmission mechanism; The operating modes include: motor drive mode, engine drive mode, hybrid drive mode, engine-driven battery pack charging mode, regenerative braking mode, and battery charging mode. The method also includes: selecting either a power shift mode or an economy shift mode based on vehicle speed, engine speed, and load. The power shift modes include: For engine-driven hybrid vehicles, when the engine speed is below the minimum stable speed, shift from a high gear to a low gear. When the engine speed is higher than the set maximum shift speed, shift from a lower gear to a higher gear; When the engine speed is between the maximum and minimum speeds, if the acceleration in a higher gear is greater than that in a lower gear, shift from a lower gear to a higher gear. For hybrid vehicles driven by a drive motor, when the motor speed is higher than its set maximum shift speed, the vehicle will shift from a low gear to a high gear.

2. The control method as described in claim 1, characterized in that, In the motor drive mode; When the SOC value of the battery is greater than the minimum set limit, or the engine speed is lower than the minimum stable speed, or the vehicle drive power is less than 30% of the engine rated power, the engine shuts off, the clutch K3 between the engine and the drive motor disengages, and only the motor works to provide driving force.

3. The control method as described in claim 1, characterized in that, In the engine drive mode; When the battery does not need to be charged, the SOC value is greater than the upper limit of the SOC control window, and the engine is in the optimal engine operating range set by the control system, the clutch K3 between the engine and the drive motor engages, the motor shuts off, and only the engine works to provide driving force.

4. The control method as described in claim 1, characterized in that, In hybrid drive mode; When clutch K3 engages between the engine and the drive motor, and the vehicle is accelerating or operating at full load, if the driving power required for the vehicle to move is greater than the engine output power, the motor will be powered by the battery to participate in the drive.

5. The control method as described in claim 1, characterized in that, The economical shifting modes include: When the acceleration of the hybrid vehicle is greater than zero, it is driven in a high gear; the engine fuel consumption rate is used as the basis for gear shifting, and the hybrid vehicle is controlled to drive in the gear with the lowest engine fuel consumption rate. When the engine speed is lower than the minimum stable speed, shift from a higher gear to a lower gear. When the engine speed is higher than its set maximum shift speed, shift from a lower gear to a higher gear. When the engine speed is between its maximum and minimum speed, if the acceleration in the higher gear is greater than zero, shift from the lower gear to the higher gear. When the driving resistance is greater than the traction force, if the engine speed is higher than the speed corresponding to the engine's maximum torque, do not shift gears; otherwise, shift to a lower gear.

6. A hybrid vehicle control system, characterized in that, For implementing the hybrid vehicle control method as described in any one of claims 1-5, the hybrid vehicle control system includes: The parameter acquisition module is used to acquire the vehicle speed, engine speed, and load of the hybrid vehicle. The shift mode determination module is used to select between a power shift mode and an economy shift mode based on the acquired parameters. The shift control module is used to control the uninterrupted shifting of hybrid vehicles based on the selected shift mode.

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