Vehicle ejection starting control method and device and new energy vehicle

Abstract

The invention relates to a vehicle ejection starting control method and device and a new energy vehicle, and relates to the technical field of new energy vehicles. The method comprises the steps that under the condition that launch control activation conditions are met, a preset launch control function is activated, the whole vehicle required torque in the torque recovery stage is determined, and torque dynamic distribution in the torque recovery stage is carried out; and in addition, the clutch is controlled to accurately slip, the whole vehicle required torque in the rotating speed synchronization stage is determined along with loosening of the brake pedal, and dynamic torque distribution in the rotating speed synchronization stage is carried out. Therefore, through cooperation of torque distribution in the torque recovery stage, clutch sliding friction control and torque dynamic distribution of rotating speed synchronization, the dynamic property of the hybrid power system in the starting stage is improved, ejection starting of the vehicle is achieved, meanwhile, the hybrid power system better adapts to the operation intention of a vehicle driver, and unexpected loss of vehicle parts in the ejection starting process is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and in particular to a vehicle launch control method and device and a new energy vehicle. Background Art

[0002] The dual-motor hybrid system has two different forms of power sources. One of the power sources, the engine, can provide power under high-speed or high-load conditions. The other power source, the generator motor and drive motor, can provide high torque at low speed and assist the engine in providing power at high speed, thus covering different usage scenarios for consumers.

[0003] To achieve stronger power coupling in dual-motor hybrid systems, multi-gear dual-motor hybrid systems have emerged. However, the quality of a dual-motor hybrid system's launch control strategy directly impacts the vehicle's overall power and stability, easily triggering vehicle malfunctions and resulting in a poor driver experience. Related technologies for vehicle launch control have focused primarily on launch power, failing to fully consider the overall effectiveness of the launch control strategy. Summary of the Invention

[0004] Based on this, it is necessary to provide a vehicle launch control method, device, new energy vehicle, computer-readable storage medium and computer program product to address the above technical problems.

[0005] In a first aspect, the present application provides a vehicle launch control method, the method comprising:

[0006] When the vehicle's launch control function is activated, determining the vehicle's required torque during a torque recovery phase based on driver operation information and the upper limit of the hybrid system's driving capability, and adjusting the output torques of the engine and the drive motor, respectively, according to the vehicle's required torque during the torque recovery phase;

[0007] During the clutch slip phase, determining a clutch motor target voltage, and adjusting the clutch pressure based on the clutch motor target voltage;

[0008] In response to the release of the brake pedal, the vehicle's required torque in the speed synchronization phase is determined based on driver operation information, vehicle condition information and road surface information, and the output torque of the engine and drive motor are adjusted respectively according to the vehicle's required torque in the speed synchronization phase to achieve the vehicle's launch.

[0009] In one embodiment, in response to activation of the launch control function of the vehicle, determining the vehicle required torque during the torque recovery phase based on driver operation information and an upper limit of the driving capability of the hybrid power system includes:

[0010] In response to activation of the launch control function of the vehicle, executing a maximum gear ratio of the pre-engaged transmission and performing clutch oil filling control;

[0011] In response to the clutch oil filling control being completed, a vehicle required torque in a torque recovery phase is determined based on driver operation information and an upper limit of a driving capability of the hybrid power system.

[0012] In one embodiment, the driver operation information includes accelerator pedal opening information, and the driving capability upper limit of the hybrid system includes the driving capability upper limit of the engine and the driving capability upper limit of the drive motor;

[0013] The determining of the vehicle required torque in the torque recovery phase based on the driver operation information and the upper limit of the driving capability of the hybrid power system includes:

[0014] Obtaining the sum of the upper limit of the driving capability of the engine and the upper limit of the driving capability of the drive motor;

[0015] In response to the accelerator pedal required torque being less than or equal to the sum, determining a vehicle required torque in a torque recovery phase based on the accelerator pedal required torque and an attenuation coefficient;

[0016] In response to the accelerator pedal required torque being greater than the sum, determining the vehicle required torque in the torque recovery phase based on the sum and a damping coefficient;

[0017] The accelerator pedal required torque is determined based on the accelerator pedal opening, and the attenuation coefficient represents the influence of the drive motor winding temperature and the engine water temperature on the vehicle required torque.

[0018] In one embodiment, adjusting the output torques of the engine and the drive motor according to the vehicle required torque in the torque recovery phase includes: determining the transmittable torque of the first clutch based on the actual clutch pressure in the torque recovery phase and a pre-obtained clutch characteristic mapping relationship; and determining the engine request torque and the drive motor request torque in the torque recovery phase according to the vehicle required torque and the first clutch transmittable torque, and adjusting the output torques of the engine and the drive motor according to the engine request torque and the drive motor request torque in the torque recovery phase;

[0019] The method of adjusting the output torques of the engine and the drive motor according to the vehicle torque requirement during the speed synchronization phase includes: determining a second clutch transmittable torque based on an actual clutch pressure during the speed synchronization phase and a pre-obtained clutch characteristic mapping relationship; determining the engine request torque and the drive motor request torque during the speed synchronization phase according to the vehicle torque requirement during the speed synchronization phase and the second clutch transmittable torque; and adjusting the output torques of the engine and the drive motor according to the engine request torque and the drive motor request torque during the speed synchronization phase;

[0020] The clutch characteristic mapping relationship includes a mapping relationship between clutch pressure and clutch transmittable torque.

[0021] In one embodiment, determining the clutch motor target voltage includes: determining the clutch target base voltage based on the actual engine torque, the transmission oil temperature, and a first correspondence relationship; the first correspondence relationship includes multiple sets of correspondences between combinations of the actual engine torque and the transmission oil temperature and the clutch base voltage;

[0022] determining a corresponding control coefficient according to a difference between an engine target speed and an actual engine speed; and determining a clutch speed compensation voltage through closed-loop control based on the control coefficient;

[0023] The clutch target base voltage is corrected based on the clutch speed compensation voltage to obtain a clutch motor target voltage.

[0024] In one embodiment, a method for obtaining the target engine speed includes:

[0025] determining an initial value of the target engine speed based on the accelerator pedal opening, the brake pedal opening, and a second correspondence relationship, wherein the second correspondence relationship includes multiple sets of correspondence relationships between combinations of the accelerator pedal opening and the brake pedal opening and the initial value of the engine speed;

[0026] Obtaining a temperature influence factor; the temperature influence factor reflects the degree of attenuation of the clutch plate temperature on the initial value of the engine target speed;

[0027] The initial value of the engine target speed is adjusted based on the temperature influence factor to obtain the engine target speed.

[0028] In one embodiment, the driver operation information includes an accelerator pedal opening, the vehicle condition information includes a master brake cylinder pressure, longitudinal acceleration, and slip rate of the vehicle, and the road surface information includes a road slope and a road adhesion coefficient;

[0029] The step of determining the vehicle required torque in the speed synchronization phase based on driver operation information, vehicle condition information, and road surface information in response to the brake pedal being released includes:

[0030] In response to the brake pedal being released, a current accelerator pedal required torque, a braking influence factor, a road influence factor, and an acceleration influence factor are obtained; the accelerator pedal required torque is determined based on the accelerator pedal opening; the braking influence factor represents the degree of influence of the brake master cylinder pressure on the attenuation of the accelerator pedal required torque; the road influence factor represents the degree of influence of the combination of the road adhesion coefficient and the slip ratio on the attenuation of the accelerator pedal required torque; and the acceleration influence factor represents the degree of influence of the combination of the road grade and the longitudinal acceleration of the vehicle on the accelerator pedal required torque;

[0031] Based on the current braking influence factor, road influence factor, acceleration influence factor and accelerator pedal required torque, the vehicle required torque during the speed synchronization phase is determined.

[0032] In one embodiment, the method further comprises:

[0033] In response to the actual clutch pressure being greater than or equal to a preset pressure threshold, the speed difference between the clutch driving plate and the driven plate being less than or equal to a preset speed difference threshold, the vehicle speed being greater than or equal to a preset vehicle speed threshold, the slip ratio being less than or equal to a preset slip ratio threshold, and the difference between the output torque of the drive motor and the engine and the required torque of the entire vehicle being less than or equal to a preset torque threshold, the state of the launch control function is switched to completed.

[0034] In one embodiment, the method further comprises:

[0035] In response to the transmission oil temperature being greater than a preset first temperature threshold, the clutch plate temperature being greater than a preset second temperature threshold, the drive motor winding temperature being greater than a preset third temperature threshold, or the engine water temperature being greater than a preset fourth temperature threshold, the launch control function is exited.

[0036] In a second aspect, a vehicle launch control device is provided, comprising:

[0037] a first torque distribution unit for determining, when the launch control function of the vehicle is activated, a vehicle torque requirement during a torque recovery phase based on driver operation information and an upper limit of a driving capability of the hybrid power system, and adjusting the output torques of the engine and the drive motor, respectively, according to the vehicle torque requirement during the torque recovery phase;

[0038] a slip control unit, configured to determine a clutch motor target voltage during a clutch slip phase and adjust the clutch pressure based on the clutch motor target voltage;

[0039] The second torque distribution unit is used to determine the vehicle's required torque in the speed synchronization phase in response to the release of the brake pedal based on driver operation information, vehicle condition information and road surface information, and adjust the output torque of the engine and drive motor respectively according to the vehicle's required torque in the speed synchronization phase to achieve the vehicle's launch.

[0040] In a third aspect, a new energy vehicle is provided, comprising a memory and a hybrid power controller, wherein the memory stores a computer program, and the hybrid power controller implements the steps of the method described in any one of the above embodiments when executing the computer program.

[0041] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the methods described above are implemented.

[0042] In a fifth aspect, a computer program product is provided, comprising a computer program, which implements the steps of any of the above methods when executed by a processor.

[0043] The launch control method, device, new energy vehicle, storage medium, and computer program product are designed for hybrid vehicles. When launch control activation conditions are met, a preset launch control function is activated. In response to the launch control function activation, the method determines the vehicle's required torque during the torque recovery phase based on driver operation information and the hybrid system's upper limit of drive capability, and dynamically distributes torque during the torque recovery phase. This ensures that the vehicle can preload a portion of the accelerator pedal's required torque while meeting driver intent, while avoiding overload of drive and transmission components during the torque recovery phase. Furthermore, the method precisely controls clutch slippage and adjusts clutch pressure based on the clutch motor's target voltage to ensure that power reserve during the torque recovery phase is maintained during the slip control phase, thereby avoiding unexpected engine speed spikes. Furthermore, as the brake pedal is released, the method determines the vehicle's required torque during the speed synchronization phase based on driver operation information, vehicle condition information, and road surface information, and dynamically distributes torque during the speed synchronization phase to avoid excessive vehicle torque demand during the speed synchronization phase, which could cause burnout and vehicle instability. Through the launch control method of the present application, the torque distribution in the torque recovery phase, the clutch slip control and the torque dynamic distribution with speed synchronization are coordinated to improve the power of the hybrid system in the starting phase, realize the launch start of the vehicle, and better adapt to the driver's operating intentions and road conditions, and avoid unexpected damage to vehicle components caused by the launch start process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 A diagram illustrating an application environment of a launch control method according to an embodiment;

[0046] Figure 2 1 is a flow chart of a launch control method according to an embodiment;

[0047] Figure 3 is a flow chart of a launch control method according to another embodiment;

[0048] Figure 4 is a structural block diagram of a launch control device in one embodiment;

[0049] Figure 5 1 is a diagram of the internal structure of a new energy vehicle in one embodiment. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0051] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0052] The launch control method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Figure 1 As shown, the hybrid vehicle 100 includes a hybrid controller 101 and a driving component 102 ; the driving component 102 includes an engine 1021 , a generator 1022 , and a driving motor 1023 .

[0053] Among them, the engine 1021 is a traditional power source used to provide driving force for the vehicle or generate electricity.

[0054] The generator 1022 is typically located between the vehicle's engine and transmission, before the clutch, and is mounted directly on the engine crankshaft. Its functions are as follows: (1) connected in series with the engine to convert the engine's mechanical energy into electrical energy, where the electrical energy can be converted into mechanical energy via the drive motor 1023 to drive the vehicle; (2) recovering energy during braking or coasting, or generating electricity by dragging the engine; and (3) outputting power in parallel with the engine to provide additional torque during rapid acceleration.

[0055] The drive motor 1023 is located at the output end of the gearbox or on the drive shaft, after the clutch. It is independent of the engine and has the following functions: (1) driving the wheels alone in pure electric mode to enable the vehicle to start or move; (2) output power in parallel with the engine to improve acceleration performance; (3) recover energy during braking.

[0056] The dual-motor hybrid system features two distinct power sources, catering to diverse consumer scenarios. To achieve enhanced power coupling, a multi-speed dual-motor hybrid system has emerged, with the two-speed dual-motor hybrid system being particularly popular. To fully recognize the driver's intent, the dual-motor hybrid system delivers robust power regardless of driving conditions, particularly during vehicle launch.

[0057] In related technologies, the quality of the launch control strategy of a dual-motor hybrid system directly affects the vehicle's power and stability, and can easily trigger vehicle driving function failures, resulting in a poor driver experience. This application aims to provide a launch control method that determines whether the launch control activation conditions are currently met based on driver operation information, vehicle driving status, and drive component operation status obtained by the hybrid controller. When the launch control activation conditions are met, the method calculates the vehicle's required torque in real time based on driver operation information and road surface information, analyzes the hybrid system's driving capability boundaries, and dynamically distributes the driving torque and precisely slips the clutch. Through torque recovery, slip control, and speed synchronization, the vehicle's launch is achieved, and the launch control exit conditions are determined in real time, thereby improving the hybrid system's power during the starting phase and providing consumers with a high-quality driving experience.

[0058] In an exemplary embodiment, Figure 2 As shown, a launch control method is provided, which is described by taking the method applied to a hybrid system control unit HCU (Hybrid Control Unit) in a vehicle as an example, and includes the following steps S201 to S203. Among them:

[0059] S201, when the vehicle's launch control function is activated, the vehicle's required torque in the torque recovery phase is determined based on the driver's operating information and the upper limit of the hybrid system's driving capability, and the output torques of the engine and the drive motor are adjusted respectively according to the vehicle's required torque in the torque recovery phase.

[0060] In some embodiments, the engine request torque and the drive motor request torque in the torque recovery phase are first determined according to the vehicle demand torque in the torque recovery phase, and then the output torques of the engine and the drive motor are adjusted respectively based on the engine request torque and the drive motor request torque in the torque recovery phase.

[0061] Among them, launch control is a high-torque starting technology for vehicles. By precisely controlling the engine speed, clutch engagement timing and power output, the vehicle can achieve maximum acceleration at the moment of starting, achieving rapid acceleration similar to "launching".

[0062] The vehicle of this application may be pre-configured with a launch control function, including activation conditions, control logic, completion conditions, and exit conditions. When activated, this function can replace the traditional launch control method that requires manual driver control (such as speed limit and clutch engagement timing). The launch control activation conditions may include multiple conditions, including but not limited to driving operation information (such as accelerator pedal position, brake pedal position), vehicle driving status information (such as the current gear position), and drive component status information (such as transmission oil temperature and clutch plate temperature).

[0063] In some embodiments, during the vehicle starting process, the hybrid system control unit HCU can determine whether the launch control function is currently activated based on the relevant information it detects, and activate the launch control function in response to the following conditions being met: the vehicle's gear is D gear; the vehicle's hybrid system operating mode is series mode; the battery SOC value (State of Charge, indicating the percentage of the battery's current remaining power to its total capacity), brake pedal opening, brake master cylinder pressure, and accelerator pedal opening are all greater than corresponding proportional values; the electronic parking brake system EPB (Electronic Park Brake) status is released, the electronic stability system ESP (Electronic Stability Program) status is off, and the automatic parking system AVH (Auto Vehicle Hold) status is inactive; the transmission oil temperature, clutch plate temperature, drive motor winding temperature, and engine water temperature all meet corresponding temperature conditions; and the vehicle does not have a preset fault that prohibits launch control.

[0064] The torque recovery phase is the initial stage of launch control. Because the vehicle's actual output torque during launch is greater than that during a conventional launch, reserve power can be unleashed during launch. The vehicle is stationary during the torque recovery phase, and the control objective is to rapidly increase the powertrain's output torque to a level sufficient to propel the vehicle from launch with optimal acceleration.

[0065] During the torque recovery phase, driver operation information can include accelerator pedal operation information, brake pedal operation information, and more. Specifically, the degree of opening of the driving pedal, for example, can reflect the current acceleration intention. Therefore, the required vehicle drive power determined based on this driver operation information can better meet the driver's launch requirements.

[0066] The hybrid system's driving capability boundary can be understood as the sum of the maximum driving torques that each drive component in the vehicle can provide under current circumstances. Specifically, when a vehicle is in different driving modes, the driving components involved in driving the vehicle may differ. For example, in some driving modes, the engine or the drive motor may drive the vehicle alone. In this case, the hybrid system's driving capability boundary can be understood as the maximum driving torque that the engine or the drive motor can provide under current circumstances. In other driving modes, the engine and the drive motor (or the engine, generator, and drive motor) may jointly drive the vehicle. In this case, the hybrid system's driving capability boundary can be understood as the sum of the maximum driving torques that the engine and the drive motor (or the engine, generator, and drive motor) can provide under current circumstances.

[0067] In combination with the above description, in order to avoid overloading of the driving and transmission components during the torque recovery phase and to ensure that the entire vehicle can pre-load a portion of the accelerator pedal demand torque while meeting the driving intention, the HCU determines the vehicle demand torque during the torque recovery phase based on the driver's operating information and the upper limit of the hybrid system's driving capability. This can both adapt to the driver's acceleration intention and avoid overloading of the vehicle's driving and transmission components during the torque recovery phase. Power is distributed through the vehicle demand torque during the torque recovery phase, and the determined engine request torque and drive motor request torque during the torque recovery phase can also better adapt to the driver's starting needs and current vehicle conditions.

[0068] S202 , during the clutch slip phase, determining a clutch motor target voltage, and adjusting the clutch pressure based on the clutch motor target voltage.

[0069] In this application, clutch slip control encompasses the entire process of the clutch transitioning from "disengaged" to "slipping" and then to "fully locked." During the clutch slip phase, the vehicle is currently stationary, and the speed difference between the clutch master and slave plates is derived from the actual engine speed. Therefore, by controlling clutch slip, the actual engine speed can be dynamically adjusted, thereby adjusting the speed difference between the clutch master and slave plates and adjusting the engine load. This avoids using brakes to adjust the vehicle's posture before departure, which could cause significant pitching and yaw instability. In specific implementations, clutch slip can be controlled by dynamically adjusting the clutch motor target voltage, thereby dynamically adjusting the clutch pressure.

[0070] In some embodiments, the clutch motor target voltage can be determined by looking up a table based on the actual engine torque and transmission oil temperature during the clutch slip control process, and the clutch pressure can be adjusted based on the clutch motor target voltage to maintain the power reserve in the torque recovery phase.

[0071] S203, in response to the release of the brake pedal, determining the vehicle's required torque in the speed synchronization phase based on the driver's operation information, vehicle condition information, and road surface information, and adjusting the output torques of the engine and the drive motor respectively according to the vehicle's required torque in the speed synchronization phase to achieve a launch control of the vehicle.

[0072] Among them, the execution timing of S203 can be understood as that the driver previously stepped on the brake pedal and did not move, and at this moment the driver began to release the brake pedal, and then in response to the release of the brake pedal, the vehicle's required torque in the speed synchronization stage was determined based on the driver's operation information, vehicle condition information and road surface information.

[0073] In some embodiments, the engine request torque and the drive motor request torque in the speed synchronization stage can be determined first according to the vehicle's required torque in the speed synchronization stage, and then the output torques of the engine and the drive motor are adjusted respectively based on the engine request torque and the drive motor request torque in the speed synchronization stage to achieve the vehicle's launch.

[0074] Among them, the speed synchronization stage can be understood as the stage of controlling the smooth closure of the clutch. At the end of the slip control stage, by precisely matching the speed of the engine / motor and the transmission system, the clutch is fully locked, entering the rigid power transmission stage, and maximizing power efficiency.

[0075] The vehicle's required torque during the speed synchronization phase can be determined based on a combination of driver input, vehicle condition, and road surface information. Driver input can include accelerator pedal position and brake pedal position, specifically the accelerator pedal's required torque. Vehicle condition information can include master cylinder pressure, vehicle speed, and vehicle slip ratio. Road surface information can include road adhesion coefficient and / or slope. Determining the vehicle's required torque during the speed synchronization phase in this manner can better adapt to driver input, varying road conditions, and vehicle conditions, while also preventing excessive vehicle torque requirements from causing burnout and vehicle instability. The engine's requested torque and the drive motor's requested torque during the speed synchronization phase are then determined based on the vehicle's required torque. The output torques of the engine and drive motor are then adjusted based on these respective torques to achieve a launch-start.

[0076] Based on the launch control method of the above embodiment, for a hybrid vehicle, a preset launch control function is activated when launch control activation conditions are met. In response to the launch control function activation, the vehicle's required torque during the torque recovery phase is determined based on driver operation information and the hybrid system's upper limit of drive capability, and torque is dynamically distributed during the torque recovery phase. This ensures that the vehicle can preload a portion of the accelerator pedal's required torque while meeting the driver's intent, while avoiding overload of the drive and transmission components during the torque recovery phase. Furthermore, the method precisely controls clutch slippage and adjusts clutch pressure based on the clutch motor's target voltage to ensure that power reserve during the torque recovery phase is maintained during the slip control phase, thereby avoiding unexpected engine speed increases. Furthermore, during the clutch slip control process, as the brake pedal is released, the vehicle's required torque during the speed synchronization phase is determined based on driver operation information, vehicle condition information, and road surface information, and torque is dynamically distributed during the speed synchronization phase. This avoids excessive vehicle torque demand during the speed synchronization phase, which could cause burnout and vehicle instability. Through the launch control method of the present application, the torque reserve in the torque recovery phase, the clutch slip control and the torque dynamic distribution with speed synchronization are coordinated to improve the power of the hybrid system in the starting phase, realize the launch start of the vehicle, and better adapt to the driver's operating intentions and road conditions, and avoid unexpected damage to vehicle components caused by the launch start process.

[0077] In one embodiment, determining the vehicle required torque during the torque recovery phase based on the driver operation information and the upper limit of the hybrid power system's driving capability in step S201 may specifically include: in response to activation of a launch control function of the vehicle, executing a maximum gear ratio of the pre-engagement transmission and performing clutch oil filling control; and in response to completion of the clutch oil filling control, determining the vehicle required torque during the torque recovery phase based on the driver operation information and the upper limit of the hybrid power system's driving capability.

[0078] Among them, the dual motors (drive motor + generator) and the engine are linked through the clutch and gearbox to output driving force to the wheel end. The transmission ratio is determined by the gear of the gearbox. For multi-gear gearboxes, generally speaking, the gear ratio of 1st gear is greater than the gear ratio of 2nd gear and greater than the gear ratio of 3rd gear. Therefore, the 1st gear is pre-engaged and the gearbox has the largest gear ratio, which is suitable for the torque requirements in the starting stage.

[0079] The clutch oil filling control can be specifically implemented by setting an oil filling activation flag to True and implementing the clutch oil filling control function through three stages: pulse, gradient, and hold. In response to the actual clutch pressure being greater than or equal to the clutch half-engagement point pressure value, the clutch oil filling function is determined to be complete. The clutch half-engagement point pressure value can be predetermined through a clutch unit test.

[0080] Based on this embodiment, on the one hand, by pre-engaging the maximum gear ratio of the transmission, the engine torque is amplified and transmitted to the wheels using the large gear ratio, thereby providing a strong driving force for the vehicle at the start stage and enabling faster acceleration. Clutch oil filling control allows the clutch to be smoothly engaged at the appropriate time, ensuring that the engine torque can be effectively transmitted to the transmission system, avoiding power loss and further ensuring the output of maximum torque. On the other hand, the maximum gear ratio of the pre-engaging transmission determines the transmission ratio at the start, providing a stable basis for power transmission. Clutch oil filling control can make the clutch engagement process smoother, reducing the impact caused by sudden clutch engagement, allowing the vehicle to accelerate smoothly at the start moment, and improving driving comfort and handling stability. On the other hand, by pre-engaging the maximum gear ratio of the transmission, the transmission system can be in a relatively reasonable working state at the start, avoiding insufficient engine power due to excessive gear. Clutch oil filling control can gradually increase the friction of the clutch during the engagement process, reducing clutch plate wear and extending the service life of the clutch.

[0081] In one exemplary embodiment, the driver operation information mentioned in the aforementioned embodiment includes accelerator pedal opening information, and the hybrid system's driving capability upper limit includes the engine's driving capability upper limit and the drive motor's driving capability upper limit. The engine's driving capability upper limit can be derived based on the engine's maximum torque and the engine's maximum transmission speed ratio, while the drive motor's driving capability upper limit can be derived based on the drive motor's maximum allowable torque and the drive motor's transmission speed ratio.

[0082] Correspondingly, the specific implementation of determining the vehicle required torque in the torque recovery phase based on the driver operation information and the upper limit of the driving capability of the hybrid power system in the aforementioned step S201 may include:

[0083] Obtain the sum of the upper limit of the driving capacity of the engine and the upper limit of the driving capacity of the drive motor; in response to the accelerator pedal required torque being less than or equal to the sum of the upper limit of the driving capacity of the engine and the upper limit of the driving capacity of the drive motor, determine the vehicle required torque in the torque recovery stage based on the accelerator pedal required torque and the attenuation coefficient; in response to the accelerator pedal required torque being greater than the sum of the upper limit of the driving capacity of the engine and the upper limit of the driving capacity of the drive motor, determine the vehicle required torque in the torque recovery stage based on the sum of the upper limit of the driving capacity of the engine and the upper limit of the driving capacity of the drive motor and the attenuation coefficient; wherein, the accelerator pedal required torque can be determined based on the accelerator pedal opening, and the attenuation coefficient can be determined based on the vehicle's drive motor winding temperature and the engine water temperature, characterizing the degree of influence of the drive motor winding temperature and the engine water temperature on the vehicle's required torque.

[0084] As a specific example, the calculation principle of the vehicle's required torque during the torque recovery phase is as follows:

[0085] (1)

[0086] In formula (1), is the vehicle required torque in the torque recovery phase (unit: Nm), is the accelerator pedal torque (unit: Nm), is the maximum engine torque (unit: Nm), The transmission ratio for the engine is 1st gear. The maximum torque allowed for the drive motor (unit: Nm) To transmit the speed ratio for the drive motor, is the attenuation coefficient.

[0087] In order to avoid excessive preselected torque loading during the torque recovery phase, which could lead to engine overheating and overload, and the risk of stalled motor overheating and power degradation, an attenuation coefficient is introduced into Equation (1). Based on a preset test scenario, the vehicle's historical data can be obtained, and the corresponding attenuation coefficient can be set according to the preset configuration rules for the vehicle's required torque attenuation coefficient. A mapping relationship between the combination of the drive motor winding temperature and the engine water temperature and the vehicle's required torque optimization can be established. The attenuation coefficient configuration rules can include rules that target a higher attenuation of the vehicle's required torque as the drive motor winding temperature and the engine water temperature increase. As an example, the attenuation coefficient configuration table can be shown in Table 1 below.

[0088] Table 1 Configuration table of attenuation coefficient

[0089]

[0090] Based on the approach of the above-described embodiment, in the process of calculating the vehicle's required torque during the torque recovery phase, the driving operation information and the driving capability limit of the drive system are combined, as well as the influence of the drive system's temperature. The vehicle's required torque during the torque recovery phase thus analyzed can adapt to the driver's driving intention and the vehicle's current operating conditions, while avoiding overload of the drive and transmission components during the torque recovery phase, thereby providing a basis for vehicle launch control.

[0091] In one embodiment, the engine request torque and the drive motor request torque in the torque recovery phase are determined based on the vehicle demand torque in the torque recovery phase, including: determining the first clutch transmittable torque based on the actual clutch pressure in the torque recovery phase and a pre-obtained clutch characteristic mapping relationship; and determining the engine request torque and the drive motor request torque in the torque recovery phase respectively based on the vehicle demand torque in the torque recovery phase and the first clutch transmittable torque; wherein the clutch characteristic mapping relationship includes a mapping relationship between the clutch pressure and the clutch transmittable torque. As an example, the clutch characteristic mapping relationship can be a pre-obtained clutch pressure-torque characteristic curve.

[0092] Based on this, during the torque recovery phase, the HCU interprets the engine's rapid torque request and the drive motor's torque request signals based on the clutch's transmittable torque and the vehicle's required torque. Based on the actual clutch pressure, the HCU uses a pre-determined clutch PT (pressure-torque) characteristic curve, determined through clutch load testing, to determine the clutch's transmittable torque. This allows for precise torque distribution between the engine and drive motor based on the vehicle's required torque during the torque recovery phase.

[0093] It should also be noted that the distribution of vehicle torque requirements during the speed synchronization phase can be modeled after the torque recovery phase. Specifically, the second clutch's transmittable torque is determined based on the actual clutch pressure and clutch characteristic mapping during the speed synchronization phase. The engine and drive motor torque requirements are then determined based on the vehicle torque requirements and the second clutch's transmittable torque. This approach allows for precise torque distribution between the engine and drive motor based on the vehicle torque requirements during the speed synchronization phase.

[0094] In one embodiment, determining the clutch motor target voltage in the aforementioned step S202 includes: determining the clutch target base voltage based on the actual engine torque, the transmission oil temperature, and a first correspondence; the first correspondence includes multiple sets of correspondences between the combination of the actual engine torque and the transmission oil temperature and the clutch base voltage; determining a corresponding control coefficient based on the difference between the engine target speed and the actual engine speed; and determining the clutch speed compensation voltage through closed-loop control based on the control coefficient; and correcting the clutch target base voltage based on the clutch speed compensation voltage to obtain the clutch motor target voltage.

[0095] For example, based on the actual engine torque and transmission oil temperature at time k, a table is used to determine the corresponding clutch target base voltage. The incremental PID control coefficient at time k is determined based on the difference between the target engine speed and the actual engine speed at time k, the difference between the target engine speed and the actual engine speed at time k-1, and the difference between the target engine speed and the actual engine speed at time k-2. The incremental PID control coefficient includes a proportional control coefficient, an integral control coefficient, and a differential control coefficient. The clutch speed compensation voltage at time k is determined based on the incremental PID control coefficient. The clutch target base voltage is then corrected based on the clutch speed compensation voltage to obtain the clutch motor target voltage at time k. Time k can be a point in time during a launch control process.

[0096] Based on the above embodiment, the HCU can implement clutch slip control based on the closed-loop system according to the actual engine torque, the target engine speed, the actual engine speed and the transmission oil temperature.

[0097] To more clearly illustrate the clutch slip control, as a specific example, the process may include:

[0098] ① Analyze the clutch target base voltage: The HCU analyzes the clutch target base voltage based on the actual engine torque and transmission oil temperature by looking up a two-dimensional table.

[0099] Based on a preset test scenario, historical test bench data is obtained, and the corresponding clutch target base voltage is set according to the preset clutch target base voltage configuration rules. A mapping relationship between the actual engine torque and transmission oil temperature and the clutch target base voltage is established to generate a corresponding two-dimensional table. The clutch target base voltage configuration rules include a rule that targets a higher clutch target base voltage as the actual engine torque and transmission oil temperature increase. As an example, the two-dimensional table corresponding to the clutch target base voltage may be shown in Table 2 below.

[0100] Table 2 Two-dimensional table corresponding to clutch target basic voltage

[0101]

[0102] ②Define input variables: The HCU sets the difference between the target engine speed and the actual engine speed at time k to e(k).

[0103] (2)

[0104] In formula (2), is the target engine speed at time k (unit: rpm), is the actual engine speed at time k (unit: rpm), is the difference between the target engine speed and the actual engine speed at time k.

[0105] In one embodiment, the difference between the target engine speed and the actual engine speed can be set The value range of is [-2500, 2500] rpm. If the actual difference exceeds this range, it will be replaced by the value closest to the actual difference within this range. If the value range is set too large, it is very easy to cause the clutch temperature to be too high and thus cause clutch burning; and the lowest engine speed is the idle speed (about 800rpm) and the highest speed is about 6000rpm. Therefore, the value range of the difference between the engine target speed and the actual engine speed can be determined based on the empirical data of the idle speed, the maximum engine speed and the clutch performance.

[0106] ③Define output variables: HCU sets the clutch speed compensation voltage at time k to is the output variable of PID control.

[0107] In one embodiment, the clutch speed compensation voltage can be set The value range of is [-10,10]V, so that the resolved clutch speed compensation voltage is within a suitable range, which is beneficial to the stability of clutch voltage regulation.

[0108] ④ Determine the incremental PID control parameters: To improve the real-time responsiveness of the clutch during slippage and avoid overshoot in the incremental PID control, which may cause large fluctuations in engine speed, the HCU can determine the incremental PID control coefficients based on the transmission oil temperature and engine water temperature by looking up a one-dimensional table. 、 、 The one-dimensional table can be constructed by using virtual bench testing and real-vehicle calibration to construct a one-dimensional table of the relationship between transmission oil temperature, engine water temperature, and incremental PID control coefficients. As an example, the one-dimensional table corresponding to the PID control coefficients can be shown in Tables 3 to 5 below.

[0109] Table 3: PID control coefficients The corresponding one-dimensional table

[0110]

[0111] Table 4: PID control coefficients The corresponding one-dimensional table

[0112]

[0113] Table 5: PID control coefficients The corresponding one-dimensional table

[0114]

[0115] ⑤ Incremental PID controller: Calculate the clutch speed compensation voltage at time k based on the incremental PID control coefficient analyzed above , which can be calculated according to the following formula:

[0116] (3)

[0117] In formula (3), is the proportional control coefficient of incremental PID control, is the integral control coefficient of incremental PID control, is the differential control coefficient of incremental PID control, is the difference between the target engine speed and the actual engine speed at time k, is the difference between the target engine speed and the actual engine speed at time k-1, is the difference between the target engine speed and the actual engine speed at time k-2.

[0118] ⑥ Clutch motor target voltage: Use clutch speed compensation voltage as , the clutch target basic voltage at time k Correction is performed to obtain the clutch motor target voltage at time k after compensation , which can be calculated according to the following formula:

[0119] (4)

[0120] In formula (4), is the clutch target voltage at time k after compensation (unit: v), is the clutch target base voltage at time k (unit: V), is the clutch speed compensation voltage at time k (unit: V).

[0121] Through the above method, the clutch speed compensation voltage is determined based on the incremental closed-loop PID method, and the clutch target base voltage is finely adjusted based on this. The clutch pressure is thereby adjusted to achieve fine clutch slip control, ensure the torque reserve effect, and ensure vehicle stability.

[0122] In one embodiment, a method for obtaining the target engine speed used in the aforementioned formula (2) includes: determining a corresponding initial value of the target engine speed based on an accelerator pedal opening, a brake pedal opening, and a second corresponding relationship, wherein the second corresponding relationship includes multiple sets of corresponding relationships between a combination of the accelerator pedal opening and the brake pedal opening and the initial value of the engine speed; determining a temperature influence factor; the temperature influence factor reflects the degree of attenuation of the clutch plate temperature on the initial value of the target engine speed; and adjusting the initial value of the target engine speed based on the temperature influence factor to obtain the target engine speed.

[0123] In one embodiment, the HCU can determine the initial target engine speed value by consulting a two-dimensional table based on the accelerator pedal opening and brake pedal opening. For example, based on a preset real-world vehicle scenario, historical vehicle data can be obtained, and the corresponding initial target engine speed value can be set according to the preset configuration rules for the initial target engine speed value. Multiple combinations of accelerator pedal opening and brake pedal opening can be established, as well as mapping relationships between these combinations and the initial target engine speed value. The configuration rules for the initial target engine speed value include a rule that sets the goal that the larger the accelerator pedal opening and the smaller the brake pedal opening, the larger the corresponding initial target engine speed value. As an example, the two-dimensional table corresponding to the initial target engine speed value is shown in Table 6 below.

[0124] Table 6: Two-dimensional table corresponding to the initial value of engine speed

[0125]

[0126] In one embodiment, the HCU analyzes the temperature impact factor based on the clutch slip work and clutch slip power, as well as a pre-established corresponding mapping relationship. For example, based on a preset test scenario, historical data of the test bench can be obtained, and the corresponding temperature impact factor can be set according to the preset temperature impact factor configuration rules corresponding to the clutch slip work and clutch slip power, and a one-dimensional table corresponding to the temperature impact factor can be established. Among them, the temperature impact factor configuration rules corresponding to the clutch slip work and its power include: a rule set with the goal that the higher the clutch plate temperature, the greater the attenuation of the initial value of the engine target speed. As an example, the one-dimensional table corresponding to the temperature impact factor can be shown in Table 7 below.

[0127] Table 7: One-dimensional table corresponding to temperature influence factors

[0128]

[0129] Furthermore, the target engine speed can be calculated as follows:

[0130] (5)

[0131] In formula (5), is the target engine speed (unit: rpm), is the initial value of the target engine speed (unit: rpm), is the temperature influence factor, is the engine idle speed (unit: rpm). The engine idle speed is the lowest speed at which the engine maintains stable operation when unloaded (e.g., when the vehicle is stationary and the transmission is in Neutral or P). At this point, the engine only needs to overcome its own internal frictional resistance and does not output any effective power.

[0132] In one embodiment, to prevent excessive clutch friction and power during this process, which could shorten the clutch lifespan due to excessive friction, the HCU can set the engine target speed to a maximum of 2500 rpm. If the calculated engine target speed is greater than 2500 rpm, it is replaced with 2500 rpm.

[0133] Through this embodiment, the HCU can analyze the initial value of the engine target speed based on the accelerator pedal opening and the brake pedal opening, determine the temperature influence factor based on the clutch slip work and slip power, and dynamically adjust the clutch engine target speed through the temperature influence factor. The clutch engine target speed that matches the driver's operation information and the current vehicle condition can be obtained, which is conducive to analyzing the clutch target voltage that is adapted to the driver's operation information, while avoiding overheating and damage to the clutch.

[0134] In one embodiment, the driver operation information in step S203 includes accelerator pedal opening, the vehicle condition information includes the vehicle's master cylinder pressure, longitudinal acceleration, and slip ratio, and the road surface information includes road slope and road adhesion coefficient. Accordingly, upon release of the brake pedal, the required vehicle torque during the speed synchronization phase is determined based on the driver operation information, vehicle condition information, and road surface information, including:

[0135] As the brake pedal is released, the accelerator pedal demand torque during the speed synchronization phase, as well as the current braking influence factor, road influence factor, and acceleration influence factor, are obtained. The vehicle demand torque during the speed synchronization phase is determined based on the current braking influence factor, road influence factor, acceleration influence factor, and the accelerator pedal demand torque during the speed synchronization phase. The accelerator pedal demand torque can be determined based on the accelerator pedal opening; the braking influence factor can be determined based on the brake master cylinder pressure and represents the degree of attenuation of the brake master cylinder pressure on the accelerator pedal demand torque; the road influence factor can be determined based on the road adhesion coefficient and slip ratio and represents the degree of attenuation of the accelerator pedal demand torque by the combination of the road adhesion coefficient and slip ratio; and the acceleration influence factor can be determined based on the road grade and the vehicle's longitudinal acceleration and represents the degree of influence of the combination of the road grade and the vehicle's longitudinal acceleration on the accelerator pedal demand torque.

[0136] For example, the calculation method of the vehicle required torque in the speed synchronization stage can be as follows:

[0137] (6)

[0138] In formula (6), is the vehicle required torque during the speed synchronization phase (unit: Nm), is the accelerator pedal torque (unit: Nm), is the braking influence factor, is the road impact factor, is the acceleration impact factor.

[0139] In formula (6), a braking influence factor is introduced to avoid conflicts between vehicle driving and braking, adhering to the braking priority control strategy. This braking influence factor can be determined based on a pre-established mapping relationship. This mapping relationship is constructed by obtaining historical vehicle data based on a preset real-world scenario, setting a corresponding braking influence factor according to a preset braking influence factor configuration rule, and establishing a mapping relationship between the brake master cylinder pressure and the accelerator pedal required torque attenuation. The braking influence factor configuration rule includes a rule that targets a higher brake master cylinder pressure, resulting in a greater accelerator pedal required torque attenuation. As an example, the braking influence factor configuration rule can be shown in Table 8.

[0140] Table 8: Relationship between brake master cylinder pressure and brake influencing factors

[0141]

[0142] In Equation (6), since the ESP system is disabled during launch, a road influence factor is introduced based on road surface identification information and tire slip to prevent excessive vehicle torque demand, which could result in burnout and vehicle instability. This road influence factor can also be determined based on a pre-established mapping relationship. This mapping relationship is constructed by obtaining historical vehicle data based on a preset real-world scenario, setting corresponding road influence factors according to preset road influence factor configuration rules, and establishing multiple combinations of road adhesion coefficients and slip rates, mapping each combination to the accelerator pedal demand torque attenuation. The road influence factor configuration rules include a rule that targets a greater road adhesion coefficient and a smaller slip rate, resulting in a smaller accelerator pedal demand torque attenuation. As an example, the road influence factor configuration rules are shown in Table 9.

[0143] Table 9: Two-dimensional table corresponding to road impact factors

[0144]

[0145] In formula (6), an acceleration influence factor is introduced to adapt to different slopes, suppress excessive acceleration at start-up, and improve the vehicle's slope adaptability and comfort. This acceleration influence factor can also be determined based on a pre-established mapping relationship. The mapping relationship is constructed by obtaining historical vehicle data based on a preset real-world scenario, setting the corresponding acceleration influence factor according to the preset acceleration influence factor configuration rules, and establishing a mapping relationship between slope, longitudinal acceleration, and the influence on the accelerator pedal required torque. The acceleration influence factor configuration rules include: the larger the slope, the smaller the longitudinal acceleration, and the stronger the accelerator pedal required torque gain, or the smaller the slope, the smaller the longitudinal acceleration, and the greater the accelerator pedal required torque attenuation. As the longitudinal acceleration used in this analysis, a corresponding analytical method can be: the HCU can obtain the longitudinal acceleration based on the vehicle speed through first-order differential and low-pass filter analysis.

[0146] Furthermore, in step S203, the engine requested torque and the drive motor requested torque during the speed synchronization phase may be determined based on the vehicle's required torque during the speed synchronization phase. The drive component torques are then adjusted based on the engine requested torque and the drive motor requested torque. Specifically, this may include: determining the engine's rapid torque request and the drive motor requested torque signals during the speed synchronization phase based on the vehicle's required torque and the clutch's transmittable torque during the speed synchronization phase; and determining the clutch's transmittable torque during the speed synchronization phase based on the actual clutch pressure during the speed synchronization phase and a pre-determined clutch pressure-torque characteristic curve. The clutch pressure-torque characteristic curve can be pre-determined with reference to the description of the previous embodiment and is not further described.

[0147] Based on the above embodiment, the HCU comprehensively considers multiple factors such as the accelerator pedal required torque, brake master cylinder pressure, road adhesion coefficient, slope, slip rate, and vehicle speed to jointly determine the vehicle's required torque during the speed synchronization stage. This improves the adaptability of the vehicle's required torque during the speed synchronization stage to the vehicle's current actual conditions. Based on this, dynamic torque distribution is performed during the speed synchronization stage, allowing the engine and drive motor to coordinately drive the vehicle to launch, while avoiding significant damage to related components in the vehicle and taking into account vehicle stability.

[0148] In one embodiment, the vehicle launch control method of the present application further includes: in response to the actual clutch pressure being greater than or equal to a preset pressure threshold, the speed difference between the clutch driving plate and the driven plate being less than or equal to a preset speed difference threshold, the vehicle speed being greater than or equal to a preset vehicle speed threshold, the slip ratio being less than or equal to a preset slip ratio threshold, and the output torque of the drive motor and the engine being highly close to the required vehicle torque (for example, reaching more than 98% of the required vehicle torque), switching the state of the launch control function to completed.

[0149] As an example, the HCU switches the state of the launch control function to completed in response to the actual clutch pressure being ≥10 bar, the speed difference between the clutch active plate and the driven plate being ≤20 rpm, the vehicle speed being ≥10 km / h, the slip ratio being ≤8%, and the output torque of the drive motor and the engine being equal to the required torque of the vehicle.

[0150] Through this embodiment, the HCU performs real-time launch control exit condition determination. When it is determined that the launch control exit condition is met, the launch control logic is promptly exited and switched to the normal driving control logic to ensure driving safety.

[0151] In another embodiment, the vehicle launch control method of the present application further includes: freezing the launch control function, or forcibly exiting the launch control function, in response to the transmission oil temperature being greater than a preset first temperature threshold, the clutch plate temperature being greater than a preset second temperature threshold, the drive motor winding temperature being greater than a preset third temperature threshold, or the engine water temperature being greater than a preset fourth temperature threshold.

[0152] As an example, the HCU will forcibly exit the launch control logic when the transmission oil temperature signal exceeds 120°C, the clutch plate temperature exceeds 200°C, the drive motor winding temperature exceeds 150°C, or the engine water temperature exceeds 125°C. This prevents the drive and transmission system from overheating and causing irreversible hardware failures in the hybrid system. It is understood that the temperature thresholds mentioned are only examples and can be set to other values ​​based on specific vehicle conditions.

[0153] Figure 3 FIG1 is a flowchart of a launch control method according to another embodiment. Figure 3 As shown, the launch control method is applied to the hybrid power system control unit HCU as an example for description. The specific implementation process includes:

[0154] Step S11: input signal acquisition and analysis.

[0155] The hybrid system control unit HCU collects and analyzes the accelerator pedal opening, actual gear position, brake pedal opening, transmission oil temperature, and actual clutch pressure signals in real time; in addition, the HCU can also obtain vehicle speed, battery SOC value, EPB system status, ESP system status, AVH status, brake master cylinder pressure, engine actual torque, engine water temperature, engine maximum torque, drive motor maximum available torque and drive motor winding temperature signals through the controller local area network; in addition, the HCU can also obtain the actual hybrid system operating mode, accelerator pedal required torque, clutch plate temperature, clutch master and driven plate speed difference, road adhesion coefficient, slope and slip rate signals from internal related modules.

[0156] Step S12: Launch control activation condition determination and preprocessing.

[0157] As an example, the activation conditions of the launch control include: the actual gear is D gear, the actual operation mode of the hybrid system is series, the battery SOC value is ≥50% (to ensure that the battery has sufficient power and large discharge power during the launch start to ensure normal launch start), the brake pedal opening is ≥50% and the brake master cylinder pressure is ≥20bar (to ensure that the braking force ensures that the vehicle remains stationary during the torque reserve phase), the accelerator pedal opening is greater than 10% (to ensure that the driver has a starting demand), the EPB system status is released, the ESP system status is off and the AVH status is not activated (also used To ensure the braking force and keep the vehicle stationary during the torque reserve stage, the transmission oil temperature signal is less than 80℃ (to ensure clutch lubrication and cooling to avoid clutch burning), the clutch plate temperature is less than 150℃ (to avoid clutch burning), the drive motor winding temperature is less than 100℃ (to avoid power degradation due to excessive drive motor winding temperature, which makes it impossible to meet the torque requirement corresponding to the launch), 80℃≤engine water temperature≤100℃ (to avoid engine function degradation due to excessive or low engine water temperature, which leads to engine output torque being limited), and there are no other faults that prohibit launch.

[0158] When all of the above conditions are met, the HCU sets the launch control function status to True (activated state); when any of the above conditions is not met, the HCU sets the launch control function status to False (frozen state).

[0159] Furthermore, when the launch control function is detected as True, the HCU pre-engages first gear, sets the oil filling activation flag to True, and implements clutch oil filling control through three stages: pulse, ramp, and hold. This quickly eliminates clutch piston idle travel and enables quick clutch response during the launch phase. When the clutch actual pressure signal ≥ the clutch half-engagement pressure value, the HCU determines that the clutch oil filling function is complete and jumps to step S13.

[0160] Step S13: Torque recovery phase.

[0161] During the torque recovery phase, the HCU analyzes the vehicle's required torque, engine quick torque request, and drive motor torque request signals based on the accelerator pedal's required torque, the engine's maximum torque, the drive motor's maximum available torque, the clutch's master and slave plate speed difference, and the engine's water temperature. This phase includes:

[0162] 1. Analyzing the vehicle's required torque: To avoid overloading the drive and transmission components during the torque recovery phase and to ensure that the vehicle can preload a portion of the accelerator pedal's required torque while satisfying driving intent, the HCU analyzes the vehicle's required torque based on the accelerator pedal's required torque, the engine's maximum torque, the drive motor's maximum allowable torque, the drive motor's winding temperature, and the clutch plate temperature. The basic principles are similar to those of the previous embodiment and are not detailed here.

[0163] 2. During the torque recovery phase, the HCU can parse the engine torque request and the drive motor torque request based on the clutch's transmittable torque and the vehicle's required torque. The clutch's transmittable torque can be derived from the clutch's actual pressure using the clutch's PT (pressure-torque) characteristic curve. For detailed implementation details, refer to the previous embodiment and are omitted here.

[0164] Step S14: Sliding friction control stage.

[0165] Clutch slip control is crucial to ensure that the torque recovery phase maintains power reserves during slip control and prevents unexpected engine speed spikes. The HCU uses an incremental PID controller to determine the clutch motor target voltage based on actual engine torque, engine speed, accelerator pedal position, brake pedal position, clutch plate temperature, and engine water temperature. This process is described in detail in the previous embodiment and will not be repeated here.

[0166] Step S15: Speed ​​synchronization stage.

[0167] During clutch slip control, as the driver releases the brake pedal (which can be understood as the driver releasing the brake pedal while holding it), the engine transmits power to the wheels via the clutch and drive motor, enabling a launch. Specifically, the HCU generates the vehicle's required torque, engine quick torque request, and drive motor torque request signals for the speed synchronization phase based on the accelerator pedal's required torque, master cylinder pressure, road adhesion, grade, slip ratio, and vehicle speed.

[0168] The method for determining the vehicle's required torque may be: the HCU calculates the vehicle's required torque during the speed synchronization phase based on driving operation information, vehicle condition information, and road conditions. Driving operation information may include accelerator pedal position, vehicle condition information may include master cylinder pressure and vehicle speed, and road conditions may include road adhesion coefficient, slope, slip ratio, etc. The specific calculation method can be referred to in the previous embodiment and will not be repeated here.

[0169] In some embodiments, during the speed synchronization phase, the HCU may also perform torque distribution according to the same processing method as step S13 to obtain the engine rapid torque request and the drive motor request torque signal.

[0170] Step S16: Determine whether the launch control is completed.

[0171] In one embodiment, when the actual clutch pressure is ≥10 bar, the clutch master and slave plate speed difference is ≤20 rpm, the vehicle speed is ≥10 km / h, the slip ratio is ≤8%, and the drive motor and engine are capable of normally outputting the required vehicle torque, the HCU sets the launch control function to "complete." It is understood that these thresholds can be adaptively adjusted based on different vehicle models or conditions. The clutch torque following control logic then enters. This dynamically adjusts the clutch pressure level based on the engine flywheel torque when the clutch is engaged, ensuring normal vehicle operation.

[0172] In this embodiment, on the basis of satisfying the driver's intention, the road surface information is fully identified, and the engine, clutch and drive motor are coordinated and controlled to ensure that the entire vehicle achieves a launch start, thereby meeting the driver's power needs.

[0173] The launch control method for a dual-motor hybrid system in the above-mentioned embodiment determines whether launch control activation conditions are currently met based on driver operation information, vehicle driving status, and drive component operating conditions obtained by the dual-motor hybrid controller. If the launch control activation conditions are met, the method analyzes the drive capability boundaries of the dual-motor hybrid system, calculates the vehicle's required torque in real time based on the driver operation, drive capability boundaries, and road surface information, and dynamically distributes the drive torque and precisely slips the clutch. Launch control is achieved through torque recovery, slip control, and speed synchronization. In addition, during the launch control process, launch control exit conditions are determined in real time, taking into account different usage scenarios such as different road surfaces and slopes, thereby improving the power and stability of the dual-motor hybrid system during the launch phase and providing users with a high-quality driving experience.

[0174] It should be understood that, although the steps in the flowcharts of the above embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts of the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily to be performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0175] Based on the same inventive concept, embodiments of the present application also provide a launch control device for implementing the aforementioned launch control method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more launch control device embodiments provided below can be found in the aforementioned limitations of the launch control method and will not be further elaborated here.

[0176] In an exemplary embodiment, Figure 4 As shown, a vehicle launch control device is provided, comprising:

[0177] a first torque distribution unit 401 for determining, when the launch control function of the vehicle is activated, a vehicle torque requirement during a torque recovery phase based on driver operation information and an upper limit of the hybrid power system's driving capability, and adjusting the output torques of the engine and the drive motor, respectively, according to the vehicle torque requirement during the torque recovery phase;

[0178] a slip control unit 402 for determining a clutch motor target voltage during a clutch slip phase and adjusting the clutch pressure based on the clutch motor target voltage;

[0179] The second torque distribution unit 403 is used to determine the vehicle's required torque during the speed synchronization phase in response to the release of the brake pedal based on driver operation information, vehicle condition information, and road surface information, and adjust the output torque of the engine and the drive motor respectively according to the vehicle's required torque during the speed synchronization phase to achieve a launch operation of the vehicle.

[0180] The vehicle launch control device of the embodiment of the present application can activate a preset launch control function for a hybrid vehicle when launch control activation conditions are met. The first torque distribution unit can, in response to the activation of the launch control function, determine the vehicle's required torque during the torque recovery phase based on driver operation information and the hybrid system's upper limit of driving capability, and dynamically distribute torque during the torque recovery phase. This ensures that the vehicle can preload a portion of the accelerator pedal's required torque while meeting the driver's intention, while avoiding overload of the drive and transmission components during the torque recovery phase. The slip control unit can control the clutch to precisely slip, ensuring that the power reserve during the torque recovery phase is maintained during the slip control phase, thereby avoiding an unexpected increase in engine speed. The second torque distribution unit can, when the driver releases the brake pedal, determine the vehicle's required torque during the speed synchronization phase based on driver operation information, vehicle condition information, and road surface information, and dynamically distribute torque during the speed synchronization phase. This avoids excessive vehicle torque demand during the speed synchronization phase, which could cause burnout and vehicle instability. Therefore, through the coordination of torque distribution in the torque recovery phase, clutch slip control and torque dynamic distribution with speed synchronization, the power of the hybrid system in the starting phase is improved, the vehicle's launch start is realized, and unexpected damage to vehicle components caused by the launch start process is avoided.

[0181] In one embodiment, the first torque distribution unit 401 is further used to: in response to activation of the vehicle's launch control function, execute the maximum gear ratio of the pre-engagement transmission and perform clutch oil filling control; in response to completion of the clutch oil filling control, determine the vehicle's required torque in the torque recovery phase based on driver operation information and the upper limit of the driving capability of the hybrid power system.

[0182] In one embodiment, the driver operation information includes accelerator pedal opening information, and the upper limit of the driving capability of the hybrid system includes the upper limit of the driving capability of the engine and the upper limit of the driving capability of the drive motor; accordingly, the first torque distribution unit 401 includes a first torque determination module for:

[0183] Obtain the sum of the upper limit of the driving capacity of the engine and the upper limit of the driving capacity of the drive motor; in response to the accelerator pedal demand torque being less than or equal to the sum, determine the vehicle demand torque in the torque recovery stage based on the accelerator pedal demand torque and the attenuation coefficient; in response to the accelerator pedal demand torque being greater than the sum, determine the vehicle demand torque in the torque recovery stage based on the sum and the attenuation coefficient; wherein, the accelerator pedal demand torque is determined based on the accelerator pedal opening, and the attenuation coefficient represents the degree of influence of the drive motor winding temperature and the engine water temperature on the vehicle demand torque.

[0184] In one embodiment, the first torque distribution unit 401 is further configured to: determine the clutch transmittable torque based on the actual clutch pressure and a pre-determined clutch characteristic mapping relationship; and determine the engine request torque and the drive motor request torque during the torque recovery phase based on the vehicle's required torque during the torque recovery phase and the clutch transmittable torque. The clutch characteristic mapping relationship includes a mapping relationship between clutch pressure and clutch transmittable torque.

[0185] In one embodiment, the sliding friction control unit 402 includes a clutch target voltage analysis module, which is used to: determine the clutch target base voltage based on the actual engine torque, the transmission oil temperature and a first correspondence; the first correspondence includes multiple groups of correspondences between the combination of the actual engine torque and the transmission oil temperature and the clutch base voltage; determine the corresponding control coefficient based on the difference between the engine target speed and the actual engine speed; and determine the clutch speed compensation voltage through closed-loop control based on the control coefficient; and correct the clutch target base voltage based on the clutch speed compensation voltage to obtain the clutch motor target voltage.

[0186] In one embodiment, the device also includes an engine target speed analysis unit, which is used to determine the initial value of the engine target speed based on the accelerator pedal opening, the brake pedal opening and a second corresponding relationship; the second corresponding relationship includes multiple groups of corresponding relationships between the combination of the accelerator pedal opening and the brake pedal opening and the initial value of the engine speed; obtain a temperature influence factor; the temperature influence factor characterizes the degree of attenuation of the clutch plate temperature on the initial value of the engine target speed; adjust the initial value of the engine target speed based on the temperature influence factor to obtain the engine target speed.

[0187] In one embodiment, the driver operation information includes an accelerator pedal opening, the vehicle condition information includes a master brake cylinder pressure, longitudinal acceleration, and slip ratio of the vehicle, and the road surface information includes a road slope and a road adhesion coefficient. Correspondingly, the second torque distribution unit 403 includes a second torque analysis module, specifically configured to:

[0188] In response to further releasing the brake pedal, the current accelerator pedal required torque, braking influence factor, road influence factor and acceleration influence factor are obtained; the accelerator pedal required torque is determined based on the accelerator pedal opening, the braking influence factor characterizes the degree of attenuation influence of the brake master cylinder pressure on the accelerator pedal required torque, the road influence factor characterizes the degree of attenuation influence of the combination of road adhesion coefficient and slip rate on the accelerator pedal required torque, and the acceleration influence factor characterizes the degree of influence of the combination of road slope and vehicle longitudinal acceleration on the accelerator pedal required torque; based on the current braking influence factor, road influence factor, acceleration influence factor and accelerator pedal required torque, the vehicle required torque in the speed synchronization stage is determined.

[0189] In one embodiment, the device further includes a launch control state switching unit, configured to:

[0190] In response to the actual clutch pressure being greater than or equal to a preset pressure threshold, the speed difference between the clutch driving plate and the driven plate being less than or equal to a preset speed difference threshold, the vehicle speed being greater than or equal to a preset vehicle speed threshold, the slip ratio being less than or equal to a preset slip ratio threshold, and the difference between the output torque of the drive motor and the engine and the required torque of the entire vehicle being less than or equal to a preset torque threshold, the state of the launch control function is switched to completed.

[0191] In one embodiment, the launch control state switching unit can also be used to: exit the control logic of the launch control in response to the transmission oil temperature being greater than a preset first temperature threshold, the clutch plate temperature being greater than a preset second temperature threshold, the drive motor winding temperature being greater than a preset third temperature threshold, or the engine water temperature being greater than a preset fourth temperature threshold.

[0192] In one embodiment, the launch control state switching unit may be further configured to activate the launch control function in response to the following conditions being met:

[0193] The vehicle's gear position is D; the vehicle's hybrid system operating mode is series mode; the battery SOC value, brake pedal opening, brake master cylinder pressure, and accelerator pedal opening are all greater than the corresponding proportional values; the electronic parking brake system EPB status is released, the body electronic stability system ESP status is off, and the automatic parking system AVH status is not activated; the transmission oil temperature, clutch plate temperature, drive motor winding temperature, and engine water temperature all meet the corresponding temperature conditions; the vehicle does not have a preset fault that prohibits launch control.

[0194] Each module in the launch control device described above can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of the processor in the new energy vehicle in hardware form, or stored in the memory of the new energy vehicle in software form, so that the processor can call and execute the corresponding operations of each module.

[0195] In an exemplary embodiment, a new energy vehicle is provided, which may include a hybrid power system. Figure 5 As shown. The new energy vehicle includes a processor (such as a hybrid power controller), a memory, an input / output interface (Input / Output, abbreviated as I / O) and a communication interface. The processor, memory and input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The hybrid power controller is used to provide computing and control capabilities. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database is used to store data such as preset reference videos, shot videos, preset editing templates, etc. The input / output interface is used to exchange information between the processor and an external device. The communication interface is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a launch control method is implemented.

[0196] Those skilled in the art will understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of the present application, and does not constitute a limitation on the new energy vehicle to which the scheme of the present application is applied. The specific new energy vehicle may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0197] In an exemplary embodiment, a new energy vehicle is provided. The new energy vehicle includes a hybrid power system and a hybrid power controller. The hybrid power controller is used to implement the steps in the above-mentioned launch control method embodiments.

[0198] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0199] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0200] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0201] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0202] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A vehicle launch control method, characterized in that: The method comprises: When the vehicle's launch control function is activated, determining the vehicle's required torque during a torque recovery phase based on driver operation information and the upper limit of the hybrid system's driving capability, and adjusting the output torques of the engine and the drive motor, respectively, according to the vehicle's required torque during the torque recovery phase; During the clutch slip phase, determining a clutch motor target voltage, and adjusting the clutch pressure based on the clutch motor target voltage; In response to the release of the brake pedal, the vehicle's required torque in the speed synchronization phase is determined based on driver operation information, vehicle condition information and road surface information, and the output torque of the engine and drive motor are adjusted respectively according to the vehicle's required torque in the speed synchronization phase to achieve the vehicle's launch.

2. The vehicle launch control method according to claim 1, wherein: The driver operation information includes accelerator pedal opening information, and the driving capability upper limit of the hybrid system includes the driving capability upper limit of the engine and the driving capability upper limit of the drive motor; The determining of the vehicle required torque in the torque recovery phase based on the driver operation information and the upper limit of the driving capability of the hybrid power system includes: Obtaining the sum of the upper limit of the driving capability of the engine and the upper limit of the driving capability of the drive motor; In response to the accelerator pedal required torque being less than or equal to the sum, determining a vehicle required torque in a torque recovery phase based on the accelerator pedal required torque and an attenuation coefficient; In response to the accelerator pedal required torque being greater than the sum, determining the vehicle required torque in the torque recovery phase based on the sum and a damping coefficient; The accelerator pedal required torque is determined based on the accelerator pedal opening, and the attenuation coefficient represents the influence of the drive motor winding temperature and the engine water temperature on the vehicle required torque.

3. The vehicle launch control method according to claim 1, wherein: The step of adjusting the output torques of the engine and the drive motor according to the vehicle required torque in the torque recovery phase includes: determining a transmittable torque of the first clutch based on an actual clutch pressure during the torque recovery phase and a pre-obtained clutch characteristic mapping relationship; determining an engine request torque and a drive motor request torque during the torque recovery phase based on the vehicle required torque during the torque recovery phase and the transmittable torque of the first clutch, and adjusting the output torques of the engine and the drive motor based on the engine request torque and the drive motor request torque during the torque recovery phase; The step of adjusting the output torques of the engine and the drive motor respectively according to the vehicle required torque in the speed synchronization stage includes: determining a transmittable torque of the second clutch based on an actual clutch pressure during the speed synchronization phase and a pre-obtained clutch characteristic mapping relationship; determining an engine request torque and a drive motor request torque during the speed synchronization phase based on the vehicle required torque during the speed synchronization phase and the transmittable torque of the second clutch, and adjusting the output torques of the engine and the drive motor based on the engine request torque and the drive motor request torque during the speed synchronization phase; The clutch characteristic mapping relationship includes a mapping relationship between clutch pressure and clutch transmittable torque.

4. The vehicle launch control method according to claim 1, wherein: Determining the clutch motor target voltage includes: determining a clutch target base voltage based on a first correspondence between the actual engine torque and the transmission oil temperature; wherein the first correspondence includes multiple correspondences between combinations of the actual engine torque and the transmission oil temperature and the clutch base voltage; determining a corresponding control coefficient according to a difference between an engine target speed and an actual engine speed; and determining a clutch speed compensation voltage through closed-loop control based on the control coefficient; The clutch target base voltage is corrected based on the clutch speed compensation voltage to obtain a clutch motor target voltage.

5. The vehicle launch control method according to claim 4, wherein: in, The method for obtaining the target engine speed includes: determining an initial value of the target engine speed based on the accelerator pedal opening, the brake pedal opening, and a second correspondence relationship, wherein the second correspondence relationship includes multiple sets of correspondence relationships between combinations of the accelerator pedal opening and the brake pedal opening and the initial value of the engine speed; Obtaining a temperature influence factor; the temperature influence factor represents the degree of attenuation of the clutch plate temperature on the initial value of the engine target speed; The initial value of the engine target speed is adjusted based on the temperature influence factor to obtain the engine target speed.

6. The vehicle launch control method according to claim 1, wherein: The driver operation information includes the accelerator pedal opening, the vehicle condition information includes the vehicle's brake master cylinder pressure, longitudinal acceleration and slip rate, and the road surface information includes the road surface gradient and road surface adhesion coefficient; The step of determining the vehicle required torque in the speed synchronization phase based on driver operation information, vehicle condition information, and road surface information in response to the brake pedal being released includes: In response to the brake pedal being released, a current accelerator pedal required torque, a braking influence factor, a road influence factor, and an acceleration influence factor are obtained; the accelerator pedal required torque is determined based on the accelerator pedal opening; the braking influence factor represents the degree of influence of the brake master cylinder pressure on the attenuation of the accelerator pedal required torque; the road influence factor represents the degree of influence of the combination of the road adhesion coefficient and the slip ratio on the attenuation of the accelerator pedal required torque; and the acceleration influence factor represents the degree of influence of the combination of the road grade and the longitudinal acceleration of the vehicle on the accelerator pedal required torque; Based on the current braking influence factor, road influence factor, acceleration influence factor and accelerator pedal required torque, the vehicle required torque during the speed synchronization phase is determined.

7. The vehicle launch control method according to any one of claims 1 to 6, characterized in that: The method further comprises: In response to the actual clutch pressure being greater than or equal to a preset pressure threshold, the speed difference between the clutch driving plate and the driven plate being less than or equal to a preset speed difference threshold, the vehicle speed being greater than or equal to a preset vehicle speed threshold, the slip ratio being less than or equal to a preset slip ratio threshold, and the difference between the output torque of the drive motor and the engine and the required torque of the entire vehicle being less than or equal to a preset torque threshold, the state of the launch control function is switched to completed.

8. The vehicle launch control method according to any one of claims 1 to 6, characterized in that: The method further comprises: In response to the transmission oil temperature being greater than a preset first temperature threshold, the clutch plate temperature being greater than a preset second temperature threshold, the drive motor winding temperature being greater than a preset third temperature threshold, or the engine water temperature being greater than a preset fourth temperature threshold, the launch control function is exited.

9. A vehicle launch control device, characterized in that: include: a first torque distribution unit for determining, when the launch control function of the vehicle is activated, a vehicle required torque during a torque recovery phase based on driver operation information and an upper limit of a driving capability of the hybrid power system, and adjusting the output torques of the engine and the drive motor respectively according to the vehicle required torque during the torque recovery phase; a slip control unit, configured to determine a clutch motor target voltage during a clutch slip phase and adjust the clutch pressure based on the clutch motor target voltage; The second torque distribution unit is used to determine the vehicle's required torque in the speed synchronization stage in response to the release of the brake pedal based on driver operation information, vehicle condition information and road surface information, and adjust the output torque of the engine and drive motor respectively according to the vehicle's required torque in the speed synchronization stage to achieve the vehicle's launch.

10. A new energy vehicle, comprising a memory and a hybrid power controller, wherein the memory stores a computer program, characterized in that: When the hybrid controller executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

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