Method and device for controlling ejection starting clutch and new energy automobile

Abstract

The invention relates to a launch starting clutch control method and device and a new energy automobile, and relates to the technical field of new energy automobiles. The method comprises the following steps: in response to activation of a launch control function of a vehicle, determining an engine request torque and a driving motor request torque based on a vehicle demand torque; in the clutch sliding friction stage, based on clutch sliding friction power and clutch sliding friction power, a target control coefficient is determined through a fuzzy control rule, then first clutch motor target voltage is determined based on the target control coefficient and engine rotating speed closed-loop control, and clutch pressure is adjusted based on the first clutch motor target voltage; and under the condition that the clutch combination condition is met, the second clutch motor target voltage is determined based on the actual engine torque and the vehicle speed, and the clutch pressure is adjusted based on the second clutch motor target voltage. Therefore, the fineness of clutch control in the vehicle starting process is improved, the engine also participates in vehicle ejection starting, and the vehicle ejection starting effect and driving experience are improved.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle technology, and in particular to a launch start clutch control method, device, and new energy vehicle. Background Technology

[0002] The dual-motor hybrid system has two different types 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 and drive motor, can provide high torque at low speeds and assist the engine in providing power at high speeds, thus covering different usage scenarios for consumers.

[0003] To provide consumers with more driving pleasure and stronger power output during the initial launch phase, launch control was developed. Currently, dual-motor hybrid systems on the market only allow the drive motor to output power during the launch phase, which greatly affects the power responsiveness and safety of the dual-motor hybrid system. Summary of the Invention

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

[0005] In a first aspect, this application provides a method for controlling a vehicle launch start clutch, the method comprising:

[0006] In response to the activation of the vehicle's launch control function, the engine requested torque and drive motor requested torque are determined based on the vehicle's required torque, and the output torque of the engine and drive motor are adjusted respectively based on the engine requested torque and drive motor requested torque.

[0007] During the clutch slippage stage, a corresponding target control coefficient is determined based on the vehicle's clutch slippage work and clutch slippage power; and based on the target control coefficient, the target voltage of the first clutch motor is determined through engine speed closed-loop control, and the clutch pressure is adjusted based on the first clutch motor target voltage.

[0008] When the clutch engagement conditions are met, the target voltage of the second clutch motor is determined based on the actual engine torque and vehicle speed, and the clutch pressure is adjusted based on the target voltage of the second clutch motor so that the output torque of the engine is transmitted to the wheel end, thereby realizing the vehicle launch start.

[0009] Secondly, this application provides a vehicle launch start clutch control device, comprising:

[0010] The torque distribution unit is used to determine the engine requested torque and drive motor requested torque based on the overall vehicle torque demand when the vehicle launch control function is activated, and to adjust the output torque of the engine and drive motor respectively based on the engine requested torque and drive motor requested torque.

[0011] The slippage control unit is used to determine a target control coefficient based on the vehicle's clutch slippage work and clutch slippage power during the clutch slippage phase; and based on the target control coefficient, to determine the target voltage of the first clutch motor through engine speed closed-loop control, and to adjust the clutch pressure based on the first clutch motor target voltage.

[0012] Combined with the control unit, it is used to determine the target voltage of the second clutch motor based on the actual engine torque and vehicle speed when the clutch engagement conditions are met, and to adjust the clutch pressure based on the target voltage of the second clutch motor, so that the output torque of the engine is transmitted to the wheel end, thereby realizing the vehicle launch start.

[0013] Thirdly, this application provides a new energy vehicle, including a memory and a hybrid power controller, wherein the memory stores a computer program, and the hybrid power controller executes the computer program to implement the steps of the method of any of the foregoing embodiments.

[0014] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method of any of the foregoing embodiments.

[0015] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the methods of any of the foregoing embodiments.

[0016] The aforementioned launch start clutch control method, device, computer equipment, storage medium, and computer program product, for hybrid vehicles, activate a preset launch start control function when the launch start control activation conditions are met. In response to the activation of the vehicle's launch start control function, the requested engine torque and drive motor torque are determined based on the vehicle's required torque, and the output torques of the engine and drive motor are adjusted accordingly. Simultaneously, during clutch slippage, a target control coefficient is determined based on the vehicle's clutch slippage work and clutch slippage power. Based on this target control coefficient, a first clutch motor target voltage is determined through closed-loop engine speed control. The clutch pressure is adjusted based on this first clutch motor target voltage to achieve refined clutch slippage control, thereby adjusting the engine load and avoiding significant pitching of the vehicle before launch caused by braking. When the clutch engagement conditions are met, unlike the slippage stage, a second clutch motor target voltage is determined based on the actual engine torque and vehicle speed for the clutch engagement stage. The clutch pressure is adjusted based on this second clutch motor target voltage to control clutch engagement, allowing the engine's output torque to be transmitted to the wheels, thus achieving launch start. With this solution, once the vehicle's launch control function is activated, the system analyzes the vehicle's required torque in real time. During the slippage phase, it monitors the clutch slippage work and clutch slippage power to control clutch slippage, complete torque reserve, and quickly determine the target voltage of the clutch motor to achieve precise clutch engagement control. This improves the precision of clutch control during vehicle start-up and allows the engine to participate in the launch start process, which is beneficial for improving the vehicle's launch start effect and driving experience. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an application environment diagram of the launch start clutch control method in one embodiment;

[0019] Figure 2 This is a flowchart illustrating the launch start clutch control method in one embodiment;

[0020] Figure 3 This is a flowchart illustrating the launch start clutch control method in another embodiment;

[0021] Figure 4This is a structural block diagram of the ejection start control device in one embodiment;

[0022] Figure 5 This is an internal structure diagram of a new energy vehicle in one embodiment. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0024] The launch start clutch control method provided in this application embodiment can be applied to, for example... Figure 1 The application environment shown. For example... Figure 1 As shown, the hybrid electric vehicle 100 includes a hybrid power controller 101 and a drive unit 102; wherein the drive unit 102 includes an engine 1021, a generator 1022, and a drive motor 1023, etc.

[0025] Among them, engine 1021 is a traditional power source used to provide driving force or generate electricity for the vehicle. Generator 1022 is usually located between the engine and the transmission of the vehicle, before the clutch, and is directly mounted on the engine crankshaft. Its functions are as follows: (1) connected in series with the engine to convert the mechanical energy of the engine into electrical energy, wherein the electrical energy can be converted into mechanical energy via drive motor 1023 to drive the vehicle; (2) recovering energy during braking or coasting, or generating electricity by engine drag; (3) outputting power in parallel with the engine to provide additional torque during rapid acceleration. Drive motor 1023 is located at the output end of the transmission or on the drive shaft, after the clutch, and is independent of the engine. Its functions are as follows: (1) driving the wheels alone in pure electric mode to enable the vehicle to start or drive; (2) outputting power in parallel with the engine to improve acceleration performance; (3) recovering energy during braking.

[0026] Dual-motor hybrid systems feature two different power sources to cover various consumer usage scenarios. To achieve stronger power coupling, multi-speed dual-motor hybrid systems have emerged, with two-speed systems being particularly popular. To fully recognize driver intentions, dual-motor hybrid systems deliver robust power regardless of driving conditions, especially during vehicle start-up.

[0027] In related technologies, dual-motor hybrid systems only allow the drive motor to output power during the start-up phase, and the engine cannot engage through the clutch, which greatly affects the power responsiveness and safety of the dual-motor hybrid system. This application aims to provide a launch start clutch control method. Based on driver operation information, vehicle driving status, and drive component operation information obtained by the hybrid system controller, it determines whether the activation conditions of the launch start control function are met. When the launch start control function is activated, it fully identifies the driving intention and road conditions to analyze the vehicle's required torque, monitors the clutch slippage work and clutch slippage power in real time, and uses fuzzy + closed-loop control to precisely control the clutch slippage to complete the drive torque reserve. Combined with precise clutch engagement control, it achieves the clutch slippage control target, enabling the hybrid system to stably output strong power under the simultaneous action of the engine, clutch, and drive motor, thus realizing the launch start of the vehicle.

[0028] In one exemplary embodiment, such as Figure 2 As shown, a launch start clutch control method is provided, which is applied to... Figure 1 Taking the hybrid control unit (HCU) as an example, the explanation includes the following steps S201 to S203. Wherein:

[0029] S201, in response to the activation of the vehicle's launch control function, determines the engine's requested torque and the drive motor's requested torque based on the vehicle's required torque, and adjusts the output torque of the engine and drive motor respectively based on the engine's requested torque and the drive motor's requested torque.

[0030] Launch control is a high-torque starting technology for vehicles. By precisely controlling engine speed, clutch engagement timing, and power output, the vehicle can achieve maximum acceleration at the moment of starting, realizing a rapid acceleration similar to "launching".

[0031] The vehicle described in this application can be pre-configured with a launch control function / logic, including activation conditions, completion conditions, and deactivation conditions. Activation conditions may include multiple factors, including but not limited to driving operation information (such as accelerator pedal opening, brake pedal opening, etc.), vehicle driving status information (such as the vehicle's current gear position), and drive component status information (such as transmission oil temperature, clutch plate temperature, etc.). Correspondingly, the hybrid power controller can activate or deactivate the launch control function / logic in response to the driver's operation information, vehicle driving status information, and drive component operating conditions meeting the corresponding activation conditions.

[0032] In some embodiments, during vehicle start-up, the hybrid power system control unit (HCU) can detect relevant information in real time and determine whether to activate the launch control function based on the detected information. The launch control function is activated in response to the following conditions being met: the actual gear is D; the actual operating mode of the hybrid power system is series; the battery SOC (State of Charge, representing the percentage of the battery's current remaining charge relative to its total capacity), brake pedal opening, brake master cylinder pressure, and accelerator pedal opening are all greater than their corresponding proportional values; the electronic parking brake (EPB) is released; the electronic stability program (ESP) is turned off; and the automatic vehicle hold (AVH) is not activated; the transmission oil temperature, clutch plate temperature, drive motor winding temperature, and engine coolant temperature all meet their corresponding temperature conditions; the clutch is not in a faulty state; and the vehicle has no preset launch start prohibition fault.

[0033] Based on the activation conditions described above, when the launch control function is activated, the driver has not yet released the brake, and both the accelerator and brake pedals are depressed, meaning the vehicle has not yet started moving. In a normal start-up process, torque request is not permitted under these conditions. However, in this embodiment, after the launch control function is activated, the engine and drive motor are allowed to pre-store torque. Through clutch slippage, the clutch pressure level is dynamically adjusted based on the speed difference between the clutch master and driven discs (at this time, the vehicle is stationary, so the clutch driven disc speed is 0 rpm; the speed difference between the clutch master and driven discs originates from the actual engine speed). This allows the actual engine speed to change in accordance with the target engine speed. By further adjusting the speed difference between the clutch master and driven discs based on the actual engine speed, the engine load is adjusted, avoiding the need for braking to adjust the vehicle's posture and causing significant pitch before start-up, thus preparing for launch control.

[0034] When the clutch slip control function is activated, driver operation information may include accelerator pedal operation information, brake pedal operation information, etc. Specifically, the opening degree of the driving pedals can be reflected in the driver's operation information to indicate the current acceleration intention. Therefore, in some embodiments, when the clutch slip control function is activated, the HCU can determine the vehicle's required torque based on the driver's operation information and vehicle driving status information, and distribute the torque of the drive components based on the required torque, so that the engine and drive motor pre-store the corresponding torque to better adapt to the driver's launch start requirements.

[0035] In this embodiment, the required torque of the whole vehicle is analyzed in real time, and the requested torque of the engine and the requested torque of the drive motor are obtained based on this. Only under this action can the clutch slippage be further determined.

[0036] S202, during the clutch slippage stage, the corresponding target control coefficient is determined based on the vehicle's clutch slippage work and clutch slippage power; and based on the target control coefficient, the target voltage of the first clutch motor is determined through engine speed closed-loop control, and the clutch pressure is adjusted based on the target voltage of the first clutch motor.

[0037] In this application, after the clutch is filled with oil, the clutch slippage control phase can be entered. Clutch slippage control spans the entire process from the clutch's "disengaged" state to the "slipping" state, and then gradually transitions to "fully engaged." During the clutch slippage phase, the vehicle is stationary, and the speed difference between the clutch's driving and driven plates originates from the engine's actual speed. Therefore, by controlling the clutch slippage, the actual engine speed can be dynamically adjusted, thereby adjusting the engine load and preventing the use of braking to adjust the vehicle's posture, which could cause significant pitching before starting and resulting in yaw instability. In practical implementation, the clutch motor target voltage can be dynamically adjusted, thereby dynamically adjusting the clutch pressure and controlling the clutch slippage.

[0038] The slip friction work characterizes the total energy consumed by the clutch due to friction during the slip friction phase, measured in joules (J) or kilojoules (kJ). It can be calculated based on the torque transmitted by the clutch, the speed difference between the driving and driven plates, and the duration of clutch slip friction. It reflects the total amount of energy converted into heat energy during clutch slip friction. The greater the slip friction work, the more heat is generated by friction, and the more significant the increase in clutch temperature. Therefore, it is also an indicator for evaluating the long-term durability of the clutch, and its cumulative amount needs to be controlled.

[0039] Slip friction power represents the energy consumed by slip friction per unit time, i.e., the instantaneous heat load, measured in watts (W) or kilowatts (kW). It can be calculated based on the torque transmitted by the clutch and the speed difference between the driving and driven discs. High slip friction power (e.g., greater than 5kW) can lead to localized hot spots, causing ablation of the friction material. Limiting slip friction power (e.g., dynamically adjusting the clamping force) protects the clutch. Therefore, it determines the instantaneous temperature rise rate of the clutch, reflects the instantaneous heat load, and affects the clutch's reliability.

[0040] In this embodiment of the application, during the clutch slippage control process, the clutch slippage work and slippage power are monitored in real time, which is equivalent to directly monitoring the clutch slippage situation. Friction generates heat, and monitoring the clutch slippage work and slippage power is more direct and effective than monitoring the clutch temperature.

[0041] In conventional clutch control, the clutch slippage phase is very short, so the slippage work and power are not considered during clutch engagement and disengagement. However, in this embodiment, the launch control function is activated, and the clutch is in the slippage phase for a longer period, generating heat through friction. To prevent clutch burnout and hardware damage, the slippage work and power need to be monitored during the slippage process, and the target voltage of the clutch motor is dynamically adjusted accordingly. This effectively ensures normal clutch operation during launch and also prevents the clutch from triggering over-temperature protection to a certain extent, resulting in no fault reports from the vehicle during launch.

[0042] Closed-loop control is a linear control algorithm. A representative example is PID control (Proportional-Integral-Derivative control), which adjusts system errors through a combination of proportional (P), integral (I), and derivative (D) components. The output of PID control consists of three parts: the proportional term (P), which quickly responds to errors and reduces steady-state errors. A larger proportional control coefficient results in a faster response but may lead to overshoot or oscillation. The integral term (I), which eliminates steady-state errors (such as small deviations in temperature control), may cause integral saturation if the integral control coefficient is too large, leading to system instability. The derivative term (D), which predicts error trends and suppresses overshoot. The derivative control coefficient can improve system damping but is sensitive to noise. Conventional closed-loop control has advantages such as simple structure, ease of implementation, few adjustment parameters, and high control accuracy under stable conditions, but its fixed parameters make it difficult to adapt to nonlinear systems.

[0043] S203, under the condition that the clutch engagement is met, determines the target voltage of the second clutch motor based on the actual engine torque and vehicle speed, and adjusts the clutch pressure based on the target voltage of the second clutch motor to realize the transmission of the engine's output torque to the wheel end, thereby realizing the vehicle launch start.

[0044] During launch control, the clutch engagement conditions directly affect the smoothness of power transmission, acceleration performance, and mechanical durability. Relevant clutch engagement conditions may include: engine / motor speed conditions, torque reserve and load matching conditions, clutch temperature and thermal load conditions, and vehicle status and system readiness conditions. For example, engine / motor speed conditions require the speed difference between the clutch's primary and driven discs to be controlled within a certain threshold to avoid vehicle shock and vibration. Torque reserve and load matching conditions require the engine and motor to output torque corresponding to the vehicle's required torque in advance, and the drive wheel slip ratio to be within a reasonable range to prevent wheel slippage after engagement. Clutch temperature and thermal load conditions require the clutch slippage energy to be less than a preset upper limit (e.g., 50 kJ) to prevent overheating and erosion of the friction materials. Vehicle status and system readiness conditions require the brake pedal to be fully released, the throttle opening to be greater than a set threshold (the set threshold can range from [50%, 100%]), the transmission oil temperature to be normal, and the battery SOC to be sufficient. In this embodiment, the clutch engagement conditions are not specifically limited.

[0045] In some embodiments, when the HCU detects that the clutch engagement conditions are met, it can determine the clutch motor target voltage (i.e., the second clutch motor target voltage) for the clutch engagement stage based on the current actual engine torque and vehicle speed, and adjust the clutch pressure based on the second clutch motor target voltage to precisely control the clutch engagement, so that the engine output torque is transmitted to the wheel end and drives the wheel together with the output torque of the drive motor to achieve vehicle launch start.

[0046] Through the above embodiments, during vehicle start-up, if the current driving operation information and vehicle driving status information are detected to meet the preset launch start control activation conditions, the launch start control function is activated. While analyzing the vehicle's required torque in real time, the system also monitors the clutch slippage work and clutch slippage power, and determines the clutch target voltage based on fuzzy control + closed-loop control to control clutch slippage, complete torque reserve, and quickly determine the clutch motor target voltage when the clutch engagement conditions are met, achieving precise clutch engagement control. By utilizing engine and clutch coordinated control and aiming at achieving refined control of launch start clutch slippage for the entire vehicle, the accuracy of clutch control during vehicle start-up is improved, the power requirements for launch start are met, and the driving experience during launch start is enhanced.

[0047] In one embodiment, the launch start clutch control method of this application further includes: in response to the activation of the launch start control function, performing pre-engaging of the maximum gear ratio of the transmission and clutch filling control; in response to the completion of clutch filling control, determining the vehicle's required torque based on driving operation information and road surface recognition information.

[0048] Among them, the dual motors (drive motor + generator) and the engine are linked through the clutch and gearbox to output driving force to the wheels. The transmission ratio is determined by the gearbox gear. For multi-gear gearboxes, the transmission ratio of 1st gear is usually greater than that of 2nd gear and then greater than that of 3rd gear. Therefore, when 1st gear is engaged, the transmission ratio of the gearbox is at its maximum, which is suitable for the torque requirements during the start-up phase.

[0049] The specific implementation of clutch oil filling control can include: setting the oil filling activation flag to True, and implementing the clutch oil filling control function through three stages: pulse, gradient, and hold; determining that the clutch oil filling function has been completed in response to the actual clutch pressure being greater than or equal to the clutch half-engagement point pressure value. The clutch half-engagement point pressure value can be predetermined through a clutch unit test.

[0050] 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 a large gear ratio, thereby providing strong driving force for the vehicle during start-up and enabling faster acceleration. Clutch lubrication control ensures smooth clutch engagement at the appropriate time, ensuring that engine torque is effectively transmitted to the transmission system, avoiding power loss, and further guaranteeing maximum torque output. On the other hand, pre-engaging the maximum gear ratio determines the gear ratio at start-up, providing a stable foundation for power transmission. Clutch lubrication control makes the clutch engagement process smoother, reducing the impact caused by sudden clutch engagement, allowing the vehicle to accelerate smoothly at start-up, improving ride comfort and handling stability. Furthermore, pre-engaging the maximum gear ratio ensures the transmission system is in a relatively reasonable operating state at start-up, avoiding insufficient engine power due to excessively high gears. Clutch lubrication control gradually increases friction during clutch engagement, reducing clutch disc wear and extending clutch life.

[0051] In some embodiments, during launch control, the driving operation information includes the accelerator pedal required torque and the brake pedal opening, and the road surface recognition information includes the road surface adhesion coefficient and slip ratio. Correspondingly, the method for determining the vehicle's required torque based on the driving operation information and road surface recognition information, as mentioned in the foregoing embodiments, includes: acquiring the vehicle's accelerator pedal required torque, road attenuation coefficient, and brake attenuation coefficient; and determining the vehicle's required torque based on the accelerator pedal required torque, road attenuation coefficient, and brake attenuation coefficient. The brake attenuation coefficient characterizes the degree of influence of the vehicle's master cylinder pressure on the attenuation of the accelerator pedal required torque; the road attenuation coefficient characterizes the degree of influence of the combination of the road surface adhesion coefficient and slip ratio on the attenuation of the accelerator pedal required torque; and the master cylinder pressure is correlated with the brake pedal opening.

[0052] Therefore, the HCU can analyze the vehicle's required torque in real time based on information such as the accelerator pedal torque demand, brake pedal opening, road surface adhesion coefficient, and slip ratio, and dynamically distribute torque based on this required torque. The basic principle is as follows:

[0053] (1)

[0054] In equation (1), The torque required for the entire vehicle (unit: Nm). Torque required for the accelerator pedal (unit: Nm). Road attenuation coefficient, This is the braking attenuation coefficient.

[0055] In equation (1), to avoid conflicts between the vehicle's drive and braking, a braking-priority control strategy is adopted, hence the introduction of a braking influence factor. In relevant embodiments, based on a preset real-vehicle scenario, historical vehicle data can be obtained, and the corresponding braking influence factor can be set according to the preset configuration rules of the braking influence factor to establish a mapping relationship between the brake master cylinder pressure and the torque attenuation required by the accelerator pedal. The configuration rules of the braking influence factor include a rule set with the goal that the higher the brake master cylinder pressure, the greater the torque attenuation required by the accelerator pedal. As an example, the configuration rules of the braking influence factor can be shown in Table 1. Based on this, during the vehicle launch start process, the HCU can quickly determine the current braking attenuation coefficient based on the brake master cylinder pressure and the relationship table.

[0056] Table 1: Relationship between brake master cylinder pressure and brake fade coefficient

[0057]

[0058] In equation (1), since the ESP system is off during the launch start adaptive control process, in order to avoid excessive torque demand from the vehicle and tire burnout during launch leading to vehicle instability, a road attenuation coefficient is introduced based on road surface recognition information and tire slippage. In relevant embodiments, historical vehicle data can be obtained based on a preset real-vehicle scenario, and the corresponding road attenuation coefficient can be set according to the preset road attenuation coefficient configuration rules. A mapping relationship between the road surface adhesion coefficient, slip ratio, and the attenuation of torque demand from the accelerator pedal can be established. The configuration rules for the road attenuation coefficient include a rule set with the goal of a larger road surface adhesion coefficient, a smaller slip ratio, and a smaller attenuation of torque demand from the accelerator pedal.

[0059] As an example, a two-dimensional table of road attenuation coefficients is shown in Table 2. Based on this, during vehicle launch, the HCU can quickly determine the current road attenuation coefficient based on the road surface adhesion coefficient, slip ratio, and this two-dimensional table.

[0060] Table 2: Two-dimensional table of road attenuation coefficients

[0061]

[0062] Based on the above embodiments, the HCU comprehensively considers multiple factors such as the accelerator pedal torque requirement, brake master cylinder pressure, road surface adhesion coefficient, gradient, slip ratio, and vehicle speed to jointly determine the vehicle's required torque. This improves the adaptability of the vehicle's required torque to the actual situation of the vehicle. Based on this, dynamic torque distribution is performed, while avoiding significant wear and tear on related components inside the vehicle and ensuring vehicle stability.

[0063] In one embodiment, the clutch slippage work mentioned in step S202 can be analyzed as follows: the HCU determines the clutch slippage work based on the monitored actual speed of the drive motor, the actual speed of the engine, the actual torque transmitted by the clutch, the clutch half-engagement point engagement time, and the clutch slippage time. For example:

[0064] (2)

[0065] (3)

[0066] In equations (2) and (3), The slip friction work of the clutch (unit: kJ). The speed difference between the clutch driving and driven plates (unit: ), This refers to the engine transmission ratio. The duration of engagement at the clutch half-engagement point (unit: seconds). Clutch slippage duration (unit: seconds). The actual torque transmitted by the clutch (unit: Nm). The actual engine speed (unit: ), The actual speed of the front drive motor (unit: ). This refers to the transmission speed ratio of the front drive motor.

[0067] Since the front drive motor is usually mechanically connected to the engine and clutch, while the rear drive motor is decoupled from the engine and clutch, if the rear wheel slips, the calculation results based on the rear drive motor will be distorted. Therefore, in this embodiment, the actual speed of the front drive motor is used to calculate the clutch slip friction work, so that the calculation results are more accurate.

[0068] In a related embodiment, when the oil filling activation flag is True, the HCU triggers the clutch oil filling timer, and when the actual clutch pressure signal is greater than or equal to the clutch half-engagement point pressure value, the clutch oil filling timer is frozen, thereby obtaining the clutch half-engagement point engagement time. The clutch half-engagement point pressure value is a clutch characteristic parameter determined through clutch unit testing.

[0069] In other related embodiments, when the speed difference between the clutch primary and driven plates is greater than or equal to 200 rpm, the HCU triggers the clutch slippage timer; when the speed difference between the clutch primary and driven plates is less than or equal to 20 rpm, the clutch oil filling timer is frozen, thereby obtaining the clutch slippage duration. The speed difference threshold is only one example and can be determined in advance through experiments. Furthermore, the threshold can be adjusted according to different vehicle models or operating conditions.

[0070] In one embodiment, the clutch slippage power mentioned in step S202 can be analyzed as follows: the HCU obtains the clutch slippage power based on the monitored actual transmitted torque of the clutch and the speed difference between the clutch driving and driven plates. For example:

[0071] (4)

[0072] In equation (4), Clutch slippage power (unit: kW). The actual torque transmitted by the clutch (unit: Nm). The speed difference between the clutch driving and driven plates (unit: ).

[0073] In this embodiment of the application, during the analysis of clutch slippage work and clutch slippage power, in order to calculate effectively, the actual engine speed and the clutch driving and driven plate speeds are measured in units of... Converted to .

[0074] By using the analysis method for clutch slippage work and clutch slippage power in the above embodiments, based on the actual operating conditions of the vehicle's drive components, the corresponding clutch slippage work and clutch slippage power can be analyzed in real time. This serves as an important basis for clutch slippage control, ensuring that clutch slippage control is more matched with the state of each drive component in the vehicle, thereby improving the effectiveness of clutch slippage control.

[0075] In some embodiments, based on the clutch slippage work and clutch slippage power already obtained by the HCU, the process mentioned in step S202 of determining the corresponding target control coefficients based on the vehicle's clutch slippage work and clutch slippage power includes: during the clutch slippage stage, determining the corresponding coefficient correction value through a preset fuzzy control rule based on the vehicle's clutch slippage work and clutch slippage power, and obtaining the target control coefficients based on the coefficient correction value and the original control coefficients. The target control coefficients and the original control coefficients can be the three control coefficients of PID control.

[0076] Among them, fuzzy control is an intelligent control method based on fuzzy logic, which imitates the human decision-making process and is suitable for nonlinear and highly uncertain systems. It does not rely on precise mathematical models, but rather reasoning through empirical rules. The idea of ​​fuzzy control is to achieve nonlinear mapping through fuzzy rules defined by expert experience. The main steps of fuzzy control include: (1) Fuzzification, converting precise inputs into fuzzy linguistic variables (such as "positive large PB" and "negative small NS"). Membership functions (such as triangles and trapezoids) are used to describe the degree of fuzziness of variables. (2) Fuzzy rule base, formulating "IF-THEN" rules based on expert experience, for example: IF error is "positive large" AND error change rate is "negative small" THEN output "increases". (3) Fuzzy reasoning, calculating the output fuzzy set according to the input and fuzzy rule base. (4) Defuzzification, converting fuzzy outputs into precise control quantities. Fuzzy control has the advantages of not requiring precise mathematical models, being suitable for nonlinear systems, having strong robustness, and good anti-interference ability.

[0077] As a specific embodiment, the implementation process of step S202 includes:

[0078] (1) The clutch slip friction work and clutch slip friction power are used as input variables of fuzzy control, and the coefficient correction value of the control coefficient of PID control is used as the output variable of fuzzy control.

[0079] For example, the input variable for fuzzy control can be defined as: the HCU will input the clutch slippage work. and clutch slip power This serves as the input variable for the fuzzy controller. In some embodiments, the clutch slip friction work can also be set. The value range is 0~10 (kJ); clutch slippage power The value range is 0~50 (kW).

[0080] In one embodiment, the method for determining the range of values ​​for clutch slip friction work and clutch slip friction power includes: assuming that the speed difference between the clutch driving plate and the driven plate is 1500 rpm (the speed difference is generally less than or equal to 1500 rpm), and the actual clutch torque is 75 Nm (the engine end torque is less than or equal to 50 Nm in actual request process, and the actual transmission torque of the clutch should be less than or equal to 75 Nm according to the conventional 20% gain torque calculation), substituting into the above formulas (2) to (4), and taking values ​​within a certain range below the calculation results, the optimal range of values ​​for clutch slip friction work and clutch slip friction power can be obtained.

[0081] In other embodiments, the optimal range of values ​​for clutch slippage work and clutch slippage power can be determined based on empirical data or parameters provided by the clutch supplier.

[0082] For example, the HCU defines the output variable of fuzzy control as the proportional control coefficient correction value of PID control. Integral control coefficient correction value and differential control coefficient correction value In some embodiments, to avoid excessive overshoot of the incremental PID controller, which could lead to clutch burnout or an unexpected increase in engine speed, a setting can also be made. , , The value range is [-5, 5].

[0083] (2) Determine the membership functions corresponding to the input variables and the output variables, and the fuzzy control rules corresponding to each membership function.

[0084] For example, the HCU can determine the fuzzy subset and the fundamental universe of discourse for clutch slip work and clutch slip power as follows.

[0085] The clutch slip friction work is divided into five fuzzy subsets {ZO, VS, S, B, VB}, with the basic universe of discourse [0, 1], meaning that all possible values ​​of the variable are between 0 and 1, including 0 and 1 themselves. The membership function adopts a triangular distribution. The input membership function of the clutch slip friction work is shown in Table 3.

[0086] Table 3 Membership function of input variable: clutch slippage work

[0087]

[0088] Among them, the clutch slip friction work corresponds to five fuzzy subsets. Fuzzy subset ZO can represent that the clutch slip friction work is "zero" or "close to zero". Fuzzy subset VS represents the case where the clutch slip friction work is "very small" but greater than ZO. Fuzzy subset S represents that the clutch slip friction work is "small". Compared with VS, the value represented by S is larger, but still within a small range. Fuzzy subset B represents that the clutch slip friction work is "large". It is used to describe that the clutch slip friction work has reached a large value or degree. Fuzzy subset VB represents that the clutch slip friction work is "very large". It is a larger degree than B.

[0089] The clutch slip power is divided into five fuzzy subsets {ZO, VS, S, B, VB}, with the basic universe of discourse being [0, 4]. That is, all possible values ​​of the variable are between 0 and 4, including 0 and 4 themselves. The membership function adopts a triangular distribution. The clutch slip power input membership function is shown in Table 4.

[0090] Table 4: Membership function of input variable clutch slip power

[0091]

[0092] Among them, the five subsets corresponding to clutch slip power are as follows: fuzzy subset ZO can represent clutch slip power as "zero" or "close to zero"; fuzzy subset VS represents clutch slip power as "very small" but greater than ZO; fuzzy subset S represents clutch slip power as "small", which is larger than VS but still within a small range; fuzzy subset B represents clutch slip power as "large", used to describe clutch slip power reaching a large value or degree; and fuzzy subset VB represents clutch slip power as "very large", which is greater than B.

[0093] Furthermore, the HCU can determine the fuzzy subset and fundamental universe of discourse of the output variable (the correction value of the PID control coefficient) according to the following example.

[0094] Among them, the correction value of the PID control coefficient , , It can be divided into five fuzzy subsets {NB, NS, ZO, PS, PB}, with a universe of discourse of [-1, 1], meaning that all possible values ​​of the variable are between -1 and 1, including -1 and 1 itself. The membership function adopts a triangular distribution, and the output quantity is corrected. , , The membership functions are shown in Table 5.

[0095] Table 5: Membership function of coefficient correction values

[0096]

[0097] Among them, the correction values ​​of the PID control coefficients are divided into five subsets: fuzzy subset NB represents a correction value that is "large in the negative direction", which describes a large value or degree of correction value in the negative direction; fuzzy subset NS represents a correction value that is "small in the negative direction", which means that the correction value has a small value or degree in the negative direction; fuzzy subset ZO can represent a correction value that is "zero" or "close to zero"; fuzzy subset PS represents a correction value that is "small in the positive direction", which means that the correction value has a small value or degree in the positive direction; and fuzzy subset PB represents a correction value that is "large in the positive direction", which describes a correction value that reaches a large value or degree in the positive direction.

[0098] Furthermore, fuzzy control rules can be determined based on expert experience. In one embodiment, based on expert experience and combined with the launch start clutch slip control process, the HCU determines five fuzzy control rules corresponding to the input membership function and the output membership function based on desktop simulation and bench simulation tests, as shown below:

[0099] ①If the clutch slips... VB value or clutch slip power When it is a VB value, Take NB value, Get NS value Get the NS value;

[0100] ②If the clutch slips... B value or clutch slippage power When it is the value of B, Take NB value, Get NS value Get the ZO value;

[0101] ③ If the clutch slips... S value or clutch slip power When it is the value of S, Get the ZO value, Get the ZO value, Get the ZO value;

[0102] ④ If the clutch slips... VS value or clutch slip power When it is the VS value, Get PS value Get PS value Get the ZO value.

[0103] ⑤ If the clutch slips... ZO value or clutch slip power When the value is ZO, Take PB value Take PB value Get the PS value.

[0104] (3) Based on the aforementioned membership function and the corresponding fuzzy control rules, determine the coefficient correction value.

[0105] For example, the output variable is defuzzified, the defuzzified output quantity is inversely mapped to the corresponding actual value based on the membership function, and fuzzy inference is performed using the corresponding fuzzy control rules to obtain the coefficient correction value of the PID controller.

[0106] For example, a weighted average method can be used for the output variables. , , Defuzzification, based on membership function, output variables , , The inverse mapping is converted to the actual value.

[0107] (4) Based on the coefficient correction value, the original control coefficient is corrected to obtain the optimized (or corrected) control coefficient, i.e. the target control coefficient.

[0108] Specifically, the original control coefficients of the PID controller can be corrected based on the coefficient correction value to obtain optimized (or corrected) PID control coefficients as target control coefficients. The original control coefficients can be obtained based on the vehicle's transmission fluid and a first correspondence relationship, which includes multiple sets of correspondences between transmission fluid and PID control coefficients. For example, this first correspondence relationship can be a one-dimensional table, and the original control coefficients of the PID controller can be obtained by looking up the table based on the vehicle's transmission fluid.

[0109] In one embodiment, the optimized control coefficients at time k include proportional control coefficients, integral control coefficients, and derivative control coefficients, and their calculation formulas are as follows:

[0110] (5)

[0111] In equation (5), To optimize the proportional control coefficient at time k, To optimize the integral control coefficient at time k, To optimize the differential control coefficients at time k, The original coefficients for proportional control at time k. The integral control coefficients at time k are the original coefficients. The differential control original coefficients at time k. This is the correction value for the proportional control coefficient at time k. Let k be the correction value of the integral control coefficient at time k. The value of the differential control coefficient correction at time k is given.

[0112] In other related embodiments, the HCU can obtain the original coefficients by looking up a one-dimensional table based on the transmission oil temperature. , , This is a one-dimensional table that can be pre-determined through bench testing and real-vehicle calibration regarding the mapping relationship between transmission oil temperature and PID control coefficients. For example, the original coefficients... , , The corresponding one-dimensional tables are shown in Tables 6, 7, and 8. This method determines the original PID control coefficients, fully considering the changes in transmission oil temperature during the clutch slippage control process, making the determined original PID control coefficients more closely match the vehicle's state.

[0113] Table 6: Transmission oil temperature and One-dimensional table

[0114]

[0115] Table 7: Transmission oil temperature and One-dimensional table

[0116]

[0117] Table 8: Transmission oil temperature and One-dimensional table

[0118]

[0119] Through the above embodiments, on the one hand, the changes in transmission oil temperature during the clutch slippage control process are fully considered, making the determined original PID control coefficients more compatible with the vehicle's state; on the other hand, the clutch slippage work and slippage power during the slippage control process are combined with fuzzy control to dynamically determine the correction value of the PID control coefficients in a nonlinear manner. Based on this correction value, the original PID control coefficients are optimized, making the optimized PID control coefficients more compatible with the current working state of the clutch and transmission. This allows for a more accurate target control coefficient for PID control while ensuring clutch reliability and durability. Based on this optimized PID control coefficient, combined with engine speed closed-loop control, a clutch target voltage that is more compatible with normal driving conditions can be analyzed. In other words, based on the clutch slippage work and clutch slippage power, combining the advantages of fuzzy control and PID control, it is beneficial to improve the accuracy of clutch slippage control during launch control.

[0120] In one embodiment, the process of determining the target voltage of the first clutch motor based on the target control coefficient and the engine speed closed-loop control mentioned in step S202 above may include: obtaining the difference between the target engine speed and the actual engine speed of the vehicle; and determining the target voltage of the first clutch motor based on the target control coefficient, the difference between the target engine speed and the actual engine speed parsed from the above embodiment.

[0121] The actual engine speed can be obtained based on relevant sensors. The method for obtaining the vehicle's target engine speed may include: determining the initial value of the target engine speed based on the vehicle's accelerator pedal opening, brake pedal opening, and a second correspondence; the second correspondence includes multiple sets of correspondences between the combination of accelerator pedal opening and brake pedal opening and engine speed; obtaining the vehicle's engine idle speed; and obtaining the target engine speed based on the engine idle speed and the initial value of the target engine speed.

[0122] For example, the process by which the HCU analyzes the target engine speed of the clutch is as follows:

[0123] (6)

[0124] In equation (6), The target engine speed (unit: rpm). This represents the initial target engine speed (in rpm). Engine idle speed (unit: rpm).

[0125] Engine idle speed refers to the minimum stable speed at which a vehicle maintains its own operation when in neutral (or P / N) gear and without load (such as when the air conditioning / headlights are off). Its basic functions are to ensure that the engine does not stall, maintain the operation of basic accessories (such as the oil pump and water pump), and provide a buffer speed for starting or power switching. For example, the vehicle's engine idle speed can be tested in advance and saved to the HCU.

[0126] In one relevant embodiment, the second correspondence can be a two-dimensional table. Based on a preset real-vehicle scenario, historical vehicle data can be obtained, and a corresponding initial target engine speed value can be set according to preset configuration rules. A two-dimensional table is established that includes a mapping relationship between the combination of accelerator pedal opening and brake pedal opening and the initial target engine speed value. The configuration rules include: when the brake pedal opening is not zero, a rule is set where a larger accelerator pedal opening corresponds to a larger brake pedal opening, and consequently, a larger initial target engine speed value. For example, the configuration rules for engine speed can be shown in Table 9 below. Based on this, the HCU can quickly determine the initial target engine speed value according to the current accelerator pedal opening, brake pedal opening, and this mapping relationship.

[0127] Table 9: Two-dimensional table of initial engine target speed values

[0128]

[0129] Once the target engine speed is obtained, the HCU can determine the target voltage of the first clutch motor based on the actual engine speed it monitors, using the difference between the target and actual engine speeds as the input variable for PID control and the target voltage of the first clutch motor as the output variable. This is done in conjunction with the target control coefficients derived from the clutch slip friction work and slip friction power. The process may include:

[0130] Define the input variable for PID control: The HCU sets the difference e(k) between the engine target speed and the actual engine speed at time k as the input variable for PID control. Here, time k is a point in time during the vehicle's start-up process. The difference between the engine target speed and the actual engine speed at time k can be represented as:

[0131] (7)

[0132] In equation (7), Let k be the target engine speed (in rpm). The actual engine speed at time k (in rpm). Let k be the difference between the target engine speed and the actual engine speed at time k.

[0133] In some embodiments, the HCU can also set the difference between the target engine speed and the actual engine speed. The value range is [-3000, 3000] rpm.

[0134] To avoid noise and vibration from excessively high engine speeds affecting the driving experience, the actual engine speed needs to be within a certain range. While ensuring a good driving experience, the range of actual engine speeds and a generalized maximum target engine speed can be obtained based on empirical data. Then, based on this range and the generalized maximum target engine speed, the difference between the target engine speed and the actual engine speed can be set. The range of values ​​for .

[0135] Define the output variable for PID control: The HCU sets the clutch motor target voltage at time k as the output variable for PID control. In some embodiments, the clutch motor target voltage can also be set to... The value range is [0, 15]V. This range can be determined based on the maximum and minimum voltages that the clutch motor can request.

[0136] Furthermore, based on the PID target control coefficients analyzed in the above embodiments, the target voltage of the clutch motor at time k can be calculated as follows:

[0137] (8)

[0138] In equation (8), Let k be the target voltage of the clutch motor at time k. To optimize the proportional control coefficient at time k, To optimize the integral control coefficient at time k, To optimize the differential control coefficients at time k, Let be the difference between the target engine speed and the actual engine speed at time k. Let be the difference between the target engine speed and the actual engine speed at time k-1. Let be the difference between the target engine speed and the actual engine speed at time k-2. It should be noted that equation (8) is not a conventional physical equation, but rather the principle equation of incremental PID, and is dimensionless.

[0139] The target voltage of the clutch motor during the clutch slippage stage can be obtained by analyzing the above formula (8). The clutch pressure can be adjusted by adjusting the clutch motor target voltage to achieve precise clutch slippage control and torque reserve.

[0140] In this application, the advantages of fuzzy control and PID control are combined in the clutch slip control process. This can better adapt to the complex vehicle conditions during the launch start phase, and can also determine the target voltage of the clutch generator simply and efficiently. At the same time, it can ensure the power for launch start, which is conducive to improving the driving experience during the launch start phase of the vehicle.

[0141] In one embodiment, the aforementioned step S203, which involves determining the target voltage of the second clutch motor based on the actual engine torque and vehicle speed when the clutch engagement conditions are met, may specifically include: determining the target clutch pressure by looking up a table based on the actual engine torque and vehicle speed when the clutch engagement conditions are met; and then determining the target voltage of the second clutch motor by looking up a table based on the target clutch pressure and the vehicle's transmission oil temperature.

[0142] To distinguish them, in this embodiment of the application, the clutch motor target voltage analyzed during the clutch slippage stage is referred to as the first clutch motor target voltage; and the clutch motor target voltage analyzed during the clutch engagement stage is referred to as the second clutch motor target voltage.

[0143] In one relevant embodiment, the HCU can deduce the clutch target pressure from a two-dimensional table based on the actual engine torque and vehicle speed. This two-dimensional table can be a table of the relationship between the actual engine torque, vehicle speed, and clutch target pressure determined through actual vehicle calibration. The configuration rule includes: when both the actual engine torque and vehicle speed are not zero, the greater the actual engine torque and the higher the vehicle speed, the greater the clutch target pressure. For example, the two-dimensional table of configuration rules for clutch target pressure can be shown in Table 10 below. The configuration rules represent an overall trend and do not necessarily mean that an increase in actual engine torque or vehicle speed will immediately increase the clutch target pressure.

[0144] Table 10: Two-Dimensional Table of Clutch Target Pressure

[0145]

[0146] In another related embodiment, the HCU uses a two-dimensional table to determine the target voltage of the clutch motor based on the target clutch pressure and transmission oil temperature. This two-dimensional table can be a table showing the relationship between the target clutch pressure, transmission oil temperature, and target clutch motor voltage determined through bench testing. The configuration rules include rules set with the objective that a higher target clutch pressure corresponds to a higher transmission oil temperature and a higher target clutch motor voltage. For example, the two-dimensional table of configuration rules for the target clutch motor voltage can be shown in Table 11 below.

[0147] Table 11: Two-dimensional table of target voltage for clutch motor

[0148]

[0149] By using two pre-built two-dimensional tables, the HCU can quickly analyze the target voltage of the second clutch motor in the clutch engagement control stage based on the actual engine torque, vehicle speed, and transmission oil temperature. This eliminates the need to determine the clutch motor target voltage based on fuzzy control + PID control, thus avoiding the delay in clutch engagement control and enabling the clutch engagement control to adapt to the vehicle's operating conditions, thereby improving the accuracy of clutch engagement control.

[0150] Figure 3 This is a flowchart illustrating the implementation of a launch start clutch control method as an example of another embodiment. (Combined with...) Figure 3 As shown, the method is applied to the hybrid power system control unit (HCU) as an example for illustration. The specific implementation process includes:

[0151] Step S11: Input signal acquisition and analysis.

[0152] For example, the dual-motor hybrid system control unit (HCU) collects and analyzes accelerator pedal opening, actual gear position, brake pedal opening, transmission oil temperature, and actual clutch pressure signals in real time; the HCU obtains vehicle speed, battery SOC value, EPB system status, ESP system status, AVH status, brake master cylinder pressure, engine actual torque, engine actual speed, drive motor actual speed, and drive motor winding temperature signals through the controller area network; the HCU obtains the actual operating mode of the hybrid system, accelerator pedal torque demand, clutch actual transmitted torque, road adhesion coefficient, and slip ratio signals from relevant internal modules.

[0153] Step S12: Determine the activation conditions for launch start clutch slip control (i.e., the aforementioned launch start control function).

[0154] In one embodiment, the actual gear is D, the actual operating mode of the hybrid system is series, the remaining battery charge is ≥50% (ensuring sufficient charge and large discharge power during launch control to ensure normal launch control), the brake pedal opening is ≥30% and the brake master cylinder pressure is ≥20 bar (ensuring the vehicle remains stationary during the torque reserve phase of braking force), the accelerator pedal opening is >10% (ensuring the driver has acceleration needs for starting), the EPB system is released, the ESP system is off, and the AVH system is inactive (also used to ensure the vehicle remains stationary during the torque reserve phase of braking force), the transmission oil temperature signal is <80℃ (ensuring clutch lubrication and cooling to avoid clutch burning), the drive motor winding temperature is <100℃ (avoiding power degradation due to excessive drive motor winding temperature, which would prevent the torque requirement for launch control from being met), 80℃≤engine coolant temperature≤100℃ (avoiding engine function degradation due to excessively high or low engine coolant temperature, which would limit engine output torque), the clutch is not in a fault state, and the vehicle has no preset fault prohibiting launch control. When all the above conditions are met, the HCU sets the launch control function to True (activated). When any condition is not met, the HCU sets the launch control function to False (frozen). It should be noted that the hybrid power controller can also adjust or set other thresholds for the above conditions based on the actual situation of the vehicle; this is not limited here.

[0155] In other embodiments, when the launch control function is identified as True, the HCU also performs pre-engaging of first gear and then sets the oil filling activation flag to True. It then implements the clutch oil filling control function through three stages: pulse, gradient, and hold, thereby quickly eliminating the clutch piston free travel and enabling the clutch to respond quickly during the launch phase.

[0156] Correspondingly, when the actual clutch pressure signal is greater than or equal to the clutch half-engagement point pressure value, the HCU determines that the clutch oil filling function has been completed and jumps to step S13.

[0157] The clutch half-engagement point pressure value is a clutch characteristic parameter determined through individual clutch tests. When the oil filling activation flag is True, the HCU triggers the clutch oil filling timer, and when the actual clutch pressure signal is greater than or equal to the clutch half-engagement point pressure value, the clutch oil filling timer is frozen, and the clutch half-engagement point engagement time is output.

[0158] Step S13: Analyze the required torque for the entire vehicle.

[0159] In one embodiment, the HCU can analyze the vehicle's required torque based on the accelerator pedal torque demand, brake pedal opening, road surface adhesion coefficient, and slip ratio.

[0160] To avoid conflicts between the vehicle's drive and braking systems, a braking-priority control strategy is adopted. Therefore, a braking influence factor is introduced when analyzing the vehicle's required torque. Since the ESP system is off during launch control, to prevent excessive vehicle torque demand and potential tire burnout leading to vehicle instability, a road attenuation coefficient is also introduced based on road surface recognition information and tire slippage when analyzing the required torque. Specific implementation details can be found in the aforementioned embodiments.

[0161] Step S14: Clutch slippage control during launch start process.

[0162] As an example, the HCU analyzes the clutch slippage work and clutch slippage power in real time based on the actual speed of the drive motor, the actual speed of the engine, the actual torque transmitted by the clutch, the clutch half-engagement time, and the clutch slippage time. Furthermore, based on the accelerator pedal opening, brake pedal opening, actual engine torque, actual engine speed, and transmission oil temperature, it analyzes the clutch motor target voltage during the clutch slippage control stage using fuzzy control and an incremental PID controller to achieve the preset control target. The main process includes:

[0163] 1. Analysis of clutch slip friction work and clutch slip friction power.

[0164] In one embodiment, the clutch slippage work can be determined based on the actual speed of the drive motor, the actual speed of the engine, the actual torque transmitted by the clutch, the engagement time of the clutch half-engagement point, and the clutch slippage time. The calculation method can be referred to the description of the foregoing embodiment.

[0165] In one embodiment, the HCU can calculate the clutch slip power based on the actual transmitted torque of the clutch and the speed difference between the clutch driving and driven plates. The calculation method can be referred to the description of the foregoing embodiment.

[0166] Furthermore, in another embodiment, to avoid the risk of clutch burnout, in response to the vehicle's clutch slippage work exceeding a predetermined slippage work threshold or clutch slippage power exceeding a predetermined slippage power threshold, the launch control function is switched to a frozen state and forcibly exited. After exiting the launch control function, the clutch disengagement logic can be executed, i.e., the clutch target pressure is set to 0 bar with no gradient limit, and the clutch pressure is unloaded through a one-way relief valve.

[0167] For example, when the clutch slippage work > 12kJ or the clutch slippage power > 55kW, the HCU can set the launch control function to False (frozen state) and forcibly exit the launch control function / logic. The threshold values ​​for slippage work and slippage power are merely examples and can be determined in advance through experiments, and can also be adjusted according to the vehicle model and operating conditions. This can avoid or reduce the risk of unexpected clutch wear.

[0168] 2. Incremental PID control coefficient optimization.

[0169] In one embodiment, the HCU can utilize fuzzy control and optimize the PID control coefficients based on the clutch slip work and clutch slip power to obtain optimized PID control coefficients. The main steps may include:

[0170] (1) Define input variables: The HCU uses the clutch slip friction work and clutch slip friction power as input variables for fuzzy control. The range of clutch slip friction work can be set to 0~10 (kJ) and the range of clutch slip friction power can be set to 0~50 (kW). When the value exceeds the range, the upper limit of the range is used as the input.

[0171] (2) Define the output variable: Set the proportional control coefficient correction value for PID control. Integral control coefficient correction value The correction value of the differential control coefficient is For output variables.

[0172] In one embodiment, to avoid excessive overshoot in the incremental PID controller, which could lead to clutch burnout or an unexpected increase in engine speed, the correction values ​​for the three PID control coefficients can be set to a range of [-5, 5], i.e., the final output... , , It does not exceed the range of values.

[0173] (3) Fuzzification: Determine the membership functions of the input and output variables.

[0174] In this embodiment, clutch slippage work and clutch slippage power are used as input variables of the fuzzy controller, and the correction values ​​of the three PID control coefficients are used as output variables of the fuzzy controller. The fuzzy subsets and basic universes of discourse of clutch slippage work and clutch slippage power, as well as the fuzzy subsets and basic universes of discourse of the output variables, can be referred to the description of the foregoing embodiments, and will not be repeated here.

[0175] (4) Determine fuzzy control rules based on expert experience.

[0176] In one embodiment, the HCU can determine the fuzzy control rules corresponding to the input and output membership functions based on desktop simulation and bench simulation tests, as detailed in the description of the foregoing embodiments.

[0177] (5) Defuzzification.

[0178] In one embodiment, a weighted average method can be used to defuzzify the output variable (the correction values ​​of the three PID control coefficients), and the fuzzy output variable can be inversely mapped into the actual value based on the membership function.

[0179] (6) Use fuzzy control rules to perform fuzzy reasoning, and after defuzzification, calculate the optimized incremental PID parameters.

[0180] In this embodiment, the optimized PID control coefficient at time k includes the optimized proportional control coefficient. Integral control coefficient Differential control coefficient It outputs fuzzy variables at time k. , , For the corresponding PID control original coefficients , , The results obtained after adjustments. Among them, the original coefficients of the PID control... , , The relationship between transmission oil temperature and the original control coefficients can be determined by referring to a table. Correspondingly, a one-dimensional table of the relationship between transmission oil temperature and control coefficients can be determined by bench testing and actual vehicle calibration to fully consider the transmission oil temperature changes during the clutch slip control process.

[0181] 3. PID control based on engine speed closed loop: The HCU controls clutch slippage based on accelerator pedal opening, brake pedal opening, actual engine torque, actual engine speed, and transmission oil temperature, using a closed-loop system. The main process can be summarized as follows:

[0182] (1) The HCU analyzes the initial value of the target engine speed based on the accelerator pedal opening and the brake pedal opening, and then analyzes the target engine speed of the clutch. The specific method can be referred to the aforementioned embodiment.

[0183] (2) Define the input variable: The HCU sets the difference e(k) between the engine target speed and the engine actual speed at time k as the input variable. In one embodiment, the difference between the engine target speed and the engine actual speed can also be set. The value range is [-3000, 3000] rpm, when the actual difference If the value is outside the range, the nearest endpoint value within the range can be used as the input.

[0184] (3) Define the output variable: The HCU sets the clutch motor target voltage at time k (i.e., the first clutch motor target voltage in the aforementioned embodiment) as the output variable. The clutch motor target voltage can also be set to a range of [0, 15] V, so that the final output clutch motor target voltage falls within this range.

[0185] (4) PID controller: The target voltage of the clutch motor at time k is calculated based on the optimized PID control coefficients. The principle is the same as described in the previous embodiment.

[0186] Step S15: Clutch engagement control.

[0187] Under the condition of satisfying clutch engagement control, the HCU can analyze the target voltage of the clutch motor during the clutch engagement control stage based on the actual engine torque, vehicle speed, and transmission oil temperature. For example, the target clutch pressure can be analyzed by looking up a two-dimensional table based on the actual engine torque and vehicle speed; in this table, the higher the actual engine torque and the higher the vehicle speed, the higher the target clutch pressure. Furthermore, the HCU can analyze the target clutch motor voltage by looking up another two-dimensional table based on the target clutch pressure and transmission oil temperature; in this other two-dimensional table, the higher the target clutch pressure and the higher the transmission oil temperature, the higher the target clutch motor voltage.

[0188] This yields the target voltage of the clutch motor during the clutch engagement phase. Based on this target voltage, the clutch engagement is precisely controlled to transmit the reserve torque of the engine and generator to the vehicle, providing powerful acceleration for launch control.

[0189] Step S16: Determine the completion conditions for the launch start clutch slip control function (i.e., the aforementioned launch start control function).

[0190] In one embodiment, 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 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 sum of the output torques of the drive motor and the engine being equal to the required torque of the vehicle, the launch control function is switched to "complete". Afterwards, the clutch torque following control logic can be entered, that is, while the clutch is engaged, the clutch pressure level is dynamically adjusted according to the torque at the engine flywheel end to ensure the normal driving process of the vehicle.

[0191] For example, when the actual clutch pressure is ≥10 bar, the speed difference between the clutch primary and driven plates is ≤20 rpm, the vehicle speed is ≥10 km / h, and the engine can simultaneously output the torque required by the vehicle through the clutch and drive motor, the HCU sets the launch control state to complete. Therefore, by judging the launch control completion conditions in real time, the dual-motor hybrid system can stably output strong power under the simultaneous action of the engine, clutch, and drive motor, ensuring the effectiveness of launch control.

[0192] The launch start clutch control method described in the foregoing embodiments, during vehicle start-up, fully identifies the operating status of the drive components based on the driver's intention, road information, and clutch slippage, and utilizes coordinated control of the engine and clutch to ensure the vehicle achieves the launch start clutch slippage control target, thereby meeting the driver's power needs. Furthermore, by real-time judgment of the launch start clutch slippage control completion conditions, the dual-motor hybrid system achieves stable and strong power output under the simultaneous action of the engine, clutch, and drive motor, providing a superior driving experience.

[0193] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0194] Based on the same inventive concept, this application also provides a launch start control device for implementing the launch start clutch control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more launch start control device embodiments provided below can be found in the limitations of the launch start clutch control method described above, and will not be repeated here.

[0195] In one exemplary embodiment, such as Figure 4 As shown, a launch start clutch control device is provided, comprising:

[0196] The torque distribution unit 401 is used to determine the engine requested torque and the drive motor requested torque based on the overall vehicle torque demand when the vehicle launch control function is activated, and to adjust the output torque of the engine and the drive motor respectively based on the engine requested torque and the drive motor requested torque.

[0197] The slippage control unit 402 is used to determine the corresponding target control coefficient based on the vehicle's clutch slippage work and clutch slippage power through a preset fuzzy control rule during the clutch slippage stage; and based on the target control coefficient, determine the target voltage of the first clutch motor through engine speed closed-loop control, and adjust the clutch pressure based on the first clutch motor target voltage.

[0198] Combined with the control unit 403, it is used to determine the target voltage of the second clutch motor based on the actual engine torque and vehicle speed when the clutch engagement conditions are met, and to adjust the clutch pressure based on the target voltage of the second clutch motor, so that the output torque of the engine is transmitted to the wheel end, thereby realizing the vehicle launch start.

[0199] Through the launch start clutch control device of this application embodiment, after the launch start control function or control logic of the vehicle is activated, while the torque distribution unit 401 analyzes the torque required by the whole vehicle in real time, the slip control unit 402 determines the corresponding target control coefficient by monitoring the clutch slip work and clutch slip power, and determines the target voltage of the clutch motor based on the target control coefficient and the engine speed closed-loop control, thereby controlling the clutch slip and completing the torque reserve. In addition, by combining with the control unit 403, the target voltage of the clutch motor is quickly determined when the clutch engagement conditions are met, so as to achieve precise clutch engagement control. Thus, by using the coordinated control of the engine and the clutch, the whole vehicle can achieve the goal of fine control of launch start clutch slip and meet the power requirements of launch start.

[0200] In one embodiment, the torque distribution unit 401 is further configured to: in response to the activation of the launch control function, pre-engage the gearbox to the maximum gear ratio and perform clutch filling control; and in response to the completion of the clutch filling control, determine the required torque of the vehicle based on driving operation information and road surface recognition information.

[0201] In one embodiment, the driving operation information includes accelerator pedal required torque and brake pedal opening, and the road surface identification information includes road surface adhesion coefficient and slip ratio; wherein determining the vehicle required torque based on the driving operation information and road surface identification information includes: acquiring the vehicle's accelerator pedal required torque, road attenuation coefficient, and brake attenuation coefficient; the brake attenuation coefficient characterizes the degree of influence of the vehicle's brake master cylinder pressure on the attenuation of accelerator pedal required torque; the road attenuation coefficient characterizes the degree of influence of the combination of road surface adhesion coefficient and slip ratio on the attenuation of accelerator pedal required torque; the brake master cylinder pressure is correlated with the brake pedal opening; and the vehicle required torque is determined based on the accelerator pedal required torque, road attenuation coefficient, and brake attenuation coefficient.

[0202] In one embodiment, the slip control unit 402 is specifically configured to: use the clutch slip work and the clutch slip power as input variables for fuzzy control, and use the coefficient correction value of the closed-loop control coefficient as the output variable for fuzzy control; determine the membership functions corresponding to the input variables and the output variables, and the fuzzy control rules corresponding to each membership function; obtain the coefficient correction value based on the membership function and the corresponding fuzzy control rule; and correct the original control coefficient of the closed-loop control based on the coefficient correction value to obtain the target control coefficient; wherein the original control coefficient is obtained by looking up the vehicle's transmission oil level in a table.

[0203] In one embodiment, the launch start clutch control device further includes a slip friction work and slip friction power analysis unit, used to: determine the clutch slip friction work based on the actual speed of the drive motor, the actual speed of the engine, the speed difference between the clutch driving plate and the driven plate, the actual torque transmitted by the clutch, the clutch half-engagement point engagement time and the clutch slip friction time; and determine the clutch slip friction power based on the speed difference between the clutch driving plate and the driven plate and the actual torque transmitted by the clutch.

[0204] In one embodiment, the slip control unit 402 is further configured to: acquire the target engine speed and the actual engine speed of the vehicle; and determine the target voltage of the first clutch motor based on the target control coefficient, the difference between the target engine speed and the actual engine speed.

[0205] In one embodiment, the method for obtaining the target engine speed of a vehicle includes: determining the corresponding initial value of the target engine speed by looking up a table based on the accelerator pedal opening and brake pedal opening of the vehicle; the third mapping relationship is the mapping relationship between the combination of accelerator pedal opening and brake pedal opening and the initial value of the target engine speed; obtaining the engine idle speed of the vehicle; and obtaining the target engine speed based on the engine idle speed and the initial value of the target engine speed.

[0206] In one embodiment, in conjunction with the control unit 403, the specific functions are: determining the clutch target pressure by looking up a table based on the actual engine torque and vehicle speed of the vehicle; and determining the second clutch motor target voltage by looking up a table based on the clutch target pressure and transmission oil temperature.

[0207] In one embodiment, the launch start clutch control device further includes a state control unit, configured to: switch the launch start control state to complete in response to the following: 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 sum of the output torques of the drive motor and the engine being equal to the required torque of the vehicle.

[0208] In one embodiment, the state control unit is further configured to: switch the state of the launch control to a frozen state and forcibly exit the launch control logic in response to the clutch slip work of the vehicle being greater than a predetermined slip work threshold or the clutch slip power being greater than a predetermined slip power threshold.

[0209] In one embodiment, the state control unit is further configured to: activate the ejection start control function in response to the following conditions being met:

[0210] The vehicle is in Drive (D) gear; the hybrid system operates in series mode; the battery SOC, brake pedal opening, brake master cylinder pressure, and accelerator pedal opening are all greater than their respective proportional values; the electronic parking brake (EPB) is released, the electronic stability program (ESP) is off, and the automatic parking brake (AVH) is inactive; the transmission oil temperature, clutch disc temperature, drive motor winding temperature, and engine coolant temperature all meet their respective temperature requirements; the clutch is not faulty; and the vehicle does not have a preset launch prevention malfunction.

[0211] The modules in the aforementioned catapult launch control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the new energy vehicle in hardware form or independent of it, 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.

[0212] In one exemplary embodiment, a new energy vehicle is provided, which may include a hybrid power system. For example... Figure 5 As shown, the new energy vehicle includes a processor (e.g., a hybrid power controller), a memory, an input / output interface (I / O), and a communication interface. The processor, memory, and I / O are connected via a system bus, and the communication interface is also connected to the system bus via the I / O. The hybrid power controller provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores relevant vehicle data. The I / O interface is used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements the launch start clutch control method of any of the above embodiments.

[0213] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0214] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0215] 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.

[0216] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, 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 many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0217] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0218] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A launch start clutch control method, characterized in that, The method includes: In response to the activation of the vehicle's launch control function, the engine requested torque and drive motor requested torque are determined based on the vehicle's required torque, and the output torque of the engine and drive motor are adjusted respectively based on the engine requested torque and drive motor requested torque. During the clutch slippage phase, a corresponding target control coefficient is determined based on the vehicle's clutch slippage work and clutch slippage power; and based on the target control coefficient, the target voltage of the first clutch motor is determined through engine speed closed-loop control, and the clutch pressure is adjusted based on the first clutch motor target voltage. When the clutch engagement conditions are met, the target voltage of the second clutch motor is determined based on the actual engine torque and vehicle speed, and the clutch pressure is adjusted based on the target voltage of the second clutch motor so that the output torque of the engine is transmitted to the wheel end, thereby realizing the vehicle launch start.

2. The method according to claim 1, characterized in that, The method further includes: In response to the activation of the launch control function, the maximum gear ratio of the transmission is pre-engaged, and clutch oil filling control is performed; In response to the completion of the clutch filling control, the required torque of the vehicle is determined based on driving operation information and road surface recognition information.

3. The method according to claim 2, characterized in that, The driving operation information includes the accelerator pedal torque requirement and the brake pedal opening; the road surface recognition information includes the road surface adhesion coefficient and slip ratio. The determination of the vehicle's required torque based on driving operation information and road surface recognition information includes: The vehicle's accelerator pedal required torque, road attenuation coefficient, and brake attenuation coefficient are obtained; the brake attenuation coefficient characterizes the degree of influence of the vehicle's master cylinder pressure on the attenuation of the accelerator pedal required torque; the road attenuation coefficient characterizes the degree of influence of the combination of road surface adhesion coefficient and slip ratio on the attenuation of the accelerator pedal required torque; the master cylinder pressure is related to the brake pedal opening. The required torque of the whole vehicle is determined based on the accelerator pedal torque requirement, the road attenuation coefficient, and the brake attenuation coefficient.

4. The method according to claim 1, characterized in that, The method further includes: The clutch slippage work is determined based on the actual speed of the drive motor, the actual speed of the engine, the speed difference between the clutch driving plate and the driven plate, the actual torque transmitted by the clutch, the engagement time of the clutch half-engagement point, and the clutch slippage time. The clutch slip power is determined based on the speed difference between the clutch driving plate and the driven plate and the actual torque transmitted by the clutch.

5. The method according to claim 1, wherein Based on the vehicle's clutch slip work and clutch slip power, the corresponding target control coefficients are determined, including: Based on the clutch slip friction work and the clutch slip friction power, as well as the preset fuzzy control rules, the corresponding coefficient correction values ​​are obtained; The original control coefficients are corrected based on the coefficient correction values ​​to obtain the target control coefficients; wherein, the original control coefficients are obtained based on the vehicle's transmission fluid and a first correspondence; the first correspondence includes multiple sets of correspondences between transmission fluid and control coefficients.

6. The method according to claim 1, characterized in that, The step of determining the target voltage of the first clutch motor through closed-loop control of engine speed based on the target control coefficient includes: Obtain the difference between the target engine speed and the actual engine speed of the vehicle; Based on the target control coefficient and the difference between the target engine speed and the actual engine speed, the target voltage of the first clutch motor is determined through closed-loop control.

7. The method according to claim 6, characterized in that, Obtaining the target engine speed of the vehicle includes: Based on the accelerator pedal opening, brake pedal opening, and the second correspondence, the corresponding initial value of the engine target speed is determined; the second correspondence includes multiple sets of correspondences between the combination of accelerator pedal opening and brake pedal opening and the initial value of the engine target speed. Obtain the engine idle speed of the vehicle; The target engine speed is obtained based on the engine idle speed and the initial value of the engine target speed.

8. The method according to any one of claims 1-7, characterized in that, The method 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 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 sum of the output torques of the drive motor and the engine being equal to the required torque of the vehicle, the launch start control function is switched to complete.

9. A launch start clutch control device, characterized in that, include: The torque distribution unit is used to determine the engine requested torque and drive motor requested torque based on the overall vehicle torque demand when the vehicle launch control function is activated, and to adjust the output torque of the engine and drive motor respectively based on the engine requested torque and drive motor requested torque. The slip control unit is used to determine the corresponding target control coefficient based on the vehicle's clutch slip work and clutch slip power during the clutch slip phase. Based on the target control coefficient, the target voltage of the first clutch motor is determined through closed-loop control of engine speed, and the clutch pressure is adjusted based on the target voltage of the first clutch motor. Combined with the control unit, it determines the target voltage of the second clutch motor based on the actual engine torque and vehicle speed when the clutch engagement conditions are met, and adjusts the clutch pressure based on the target voltage of the second clutch motor, so that the output torque of the engine is transmitted to the wheel end, thereby realizing the vehicle launch start.

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 power controller executes the computer program, it implements the steps of the method according to any one of claims 1 to 8.

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