Vehicle control method and device, computer device, storage medium and program product

Abstract

The application relates to a vehicle control method and device, computer equipment, a storage medium and a program product. The method comprises the following steps: acquiring the engine speed of a vehicle, the gear signal of the vehicle, the brake pressure of the vehicle, the throttle opening of the vehicle, the hand brake signal of the vehicle and the automatic parking signal of the vehicle; when the engine speed is greater than 0, the gear signal indicates that the vehicle is in a drivable gear, the brake pressure is less than a brake pressure threshold value, the throttle opening is less than a throttle opening threshold value, the hand brake signal is not activated and the automatic parking signal is not activated, acquiring the transmission coefficient efficiency, the wheel rolling radius, the asphalt road rolling resistance coefficient, the vehicle mass, the vehicle acceleration and the first-gear speed ratio of the vehicle; based on the transmission coefficient efficiency, the wheel rolling radius, the asphalt road rolling resistance coefficient, the vehicle mass, the vehicle acceleration and the first-gear speed ratio of the vehicle, calculating the vehicle load torque; and controlling the vehicle to run at low speed according to the vehicle load torque.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle technology, and in particular to a vehicle control method, device, computer equipment, storage medium, and program product. Background Technology

[0002] With the rapid development of the automotive industry and the continuous improvement of people's living standards, the number of cars on the road is increasing. The braking system of automobiles is also being upgraded accordingly, from the traditional hydraulic braking system based on the Electronic Stability Program (ESP) to the mechatronic brake-by-wire platform (IPB). Therefore, the low-speed control function of the transmission, as a key technology of automotive driving assistance systems, has received widespread attention regarding how to control low-speed driving.

[0003] In related technologies, when the transmission control unit (hereinafter referred to as the transmission control unit) performs low-speed control, it uses sensor signals such as brake switch signal, brake master cylinder pressure, and throttle opening signal to determine that the driver has released the brake and is not pressing the accelerator. It then controls the vehicle to creep at a low speed. During this process, the transmission control unit sends clutch load torque and target idle speed requests to the engine control unit (hereinafter referred to as the EMS). The EMS controls the engine torque and idle speed based on these two signals. If the driver needs to reduce the vehicle speed, they need to press the brake. The transmission control unit determines the driver's deceleration intention by checking the brake master cylinder pressure, reduces the torque request, and thus reduces the vehicle speed.

[0004] However, in the above schemes, the vehicle speed control method is relatively simple, and the vehicle control effect is poor. Summary of the Invention

[0005] This application provides a vehicle control method, apparatus, computer equipment, storage medium, and program product. The technical solution is as follows: On one hand, a vehicle control method is provided, the method being executed by the vehicle's transmission control unit, the method comprising: The vehicle's engine speed, gear position signal, brake pressure, throttle opening, handbrake signal, and auto hold signal are acquired. When the engine speed is greater than 0, the gear position signal indicates that the vehicle is in a drivable gear, the brake pressure is less than the brake pressure threshold, the throttle opening is less than the throttle opening threshold, the handbrake signal is not activated, and the automatic parking signal is not activated, the transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio of the vehicle are obtained. The vehicle load torque is calculated based on the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio. The vehicle is controlled to travel at low speed based on the total vehicle load torque.

[0006] On the other hand, a vehicle control device is provided, the device comprising: The information acquisition module is used to acquire the vehicle's engine speed, the vehicle's gear signal, the vehicle's brake pressure, the vehicle's throttle opening, the vehicle's handbrake signal, and the vehicle's automatic parking signal. The parameter acquisition module is used to acquire the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio when the engine speed is greater than 0, the gear signal indicates that the vehicle is in a drivable gear, the brake pressure is less than the brake pressure threshold, the throttle opening is less than the throttle opening threshold, the handbrake signal is not activated, and the automatic parking signal is not activated. The torque calculation module is used to calculate the vehicle load torque based on the vehicle's transmission coefficient efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio. The drivable gear is the gear that enables the vehicle to output forward or reverse power. The vehicle control module is used to control the vehicle to travel at low speed based on the total vehicle load torque.

[0007] In one possible implementation, the torque calculation module is used for, The transmission coefficient input torque is determined based on the transmission coefficient efficiency, the wheel rolling radius, the asphalt road rolling resistance coefficient, the vehicle mass, and the vehicle acceleration. The quotient of the input torque of the transmission system divided by the first gear ratio is used as the total vehicle load torque.

[0008] In one possible implementation, the torque calculation module is used for, Based on the transmission coefficient efficiency, the wheel rolling radius, the asphalt road rolling resistance coefficient, the vehicle mass, and the vehicle acceleration, the transmission coefficient input torque is determined using Formula 1, as follows: T input =η*[(f×m×g + m×a)*r] Formula 1 Where η is the transmission efficiency coefficient, r is the wheel rolling radius, f is the rolling resistance coefficient of the asphalt road surface, m is the vehicle mass, a is the vehicle acceleration, and T is the total acceleration. input is the transmission coefficient and input torque, and g is the acceleration due to gravity.

[0009] In one possible implementation, the device further includes: The control exit module is used to control the vehicle to exit low-speed driving when the engine speed is greater than 0, and when the gear signal indicates that the vehicle is in P or N gear, the brake pressure is not less than the brake pressure threshold, the throttle opening is not less than the throttle opening threshold, the handbrake signal is activated, or the automatic parking signal is activated.

[0010] In one possible implementation, the device further includes: The control submodule is used to activate the creep flag and control the torque of the clutch to increase to a target torque at a preset rate of increase before calculating the total vehicle load torque of the vehicle. The target torque is the torque required by the clutch when the vehicle is in a creeping state.

[0011] In one possible implementation, the brake pressure threshold is 5 bar and the throttle opening threshold is 2%.

[0012] In another aspect, a computer device is provided, the computer device comprising a processor and a memory, the memory storing at least one instruction, at least one program, code set or instruction set, the at least one instruction, the at least one program, the code set or instruction set being loaded and executed by the processor to implement the vehicle control method as described above.

[0013] In another aspect, a computer-readable storage medium is provided, wherein at least one instruction, at least one program, code set, or instruction set is stored therein, wherein the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by a processor to implement the vehicle control method described above.

[0014] In another aspect, a computer program product is provided, comprising a computer program stored in a computer-readable storage medium. A processor of a computer device reads the computer program from the computer-readable storage medium and executes the computer program, causing the computer device to perform the vehicle control method provided in the various alternative implementations described above.

[0015] The technical solution provided in this application may include the following beneficial effects: The vehicle's transmission control unit comprehensively judges engine speed, gear signal, brake pressure, throttle opening, handbrake and auto hold status. When the above parameters meet specific conditions, creep control is activated, effectively identifying low-speed driving scenarios where the driver has no intention to actively accelerate or decelerate. Based on this, multiple parameters such as transmission efficiency, rolling radius, rolling resistance coefficient, vehicle mass, acceleration and first gear ratio are introduced to calculate the vehicle load torque, so that the driving force output accurately matches the actual road load demand. This avoids the problem of fixed driving force in traditional idling creep, which can easily lead to jerking or rolling back, improves the smoothness of starting and responsiveness, and effectively improves the vehicle control effect.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] Figure 1 This is a system configuration diagram of a vehicle control method according to an embodiment of this application; Figure 2 This is a flowchart of a vehicle control method provided in one embodiment of this application; Figure 3 This is a flowchart of a vehicle control method provided in one embodiment of this application; Figure 4 This is a flowchart of a vehicle control method provided in one embodiment of this application; Figure 5 This is a flowchart of a vehicle low-speed control method provided in one embodiment of this application; Figure 6 This is a flowchart of a torque calculation method provided in one embodiment of this application; Figure 7 This is a timing diagram of a vehicle low-speed control method provided in one embodiment of this application; Figure 8 This is a correspondence between braking stroke and braking pressure provided in one embodiment of this application; Figure 9 This is an illustrative diagram of low-speed control provided in one embodiment of this application; Figure 10 A block diagram of a vehicle control device provided in an exemplary embodiment of this application; Figure 11 This is a schematic diagram of the structure of a computer device provided in an exemplary embodiment of this application. Detailed Implementation

[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0020] Figure 1 This is a system configuration diagram of a vehicle control method according to one embodiment of this application. Figure 1 As shown, the system includes a vehicle 120, and the vehicle 120 includes a transmission control unit 120a.

[0021] exist Figure 1 In the system shown, the transmission control unit 120a of vehicle 120 can acquire the vehicle's engine speed, gear position signal, brake pressure, throttle opening, handbrake signal, and auto hold signal. When the engine speed is greater than 0, the gear position signal indicates the vehicle is in a drivable gear, the brake pressure is less than the brake pressure threshold, the throttle opening is less than the throttle opening threshold, the handbrake signal is not activated, and the auto hold signal is not activated, it acquires the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio. Based on the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio, it calculates the vehicle load torque and controls the vehicle to travel at low speed according to the vehicle load torque.

[0022] Figure 2 This is a flowchart of a vehicle control method provided in one embodiment of this application. The vehicle control method may include steps 210, 220, 230, and 240. This method can be executed by the vehicle's transmission control unit 120a. The vehicle may be... Figure 1 In vehicle 120, the transmission control unit can be Figure 1 The specific implementation process of this method is as follows, using server 120a in the example.

[0023] Step 210: Obtain the vehicle's engine speed, gear position signal, brake pressure, throttle opening, handbrake signal, and auto hold signal.

[0024] In this embodiment, the transmission control unit can collect the vehicle's engine speed, gear position signal, brake pressure, throttle opening, handbrake signal, and automatic parking signal in real time through the vehicle's CAN (Controller Area Network) communication network.

[0025] The engine speed mentioned above refers to the crankshaft revolutions per minute (rpm) sent by the vehicle's engine management system, used to determine whether the engine is running (for example, an engine speed greater than 0 rpm indicates that it has been started).

[0026] The above gear position signals indicate the current gear of the vehicle, such as P, N, R, or D. They can also indicate whether the vehicle is in a drivable gear (a drivable gear is any gear other than P and N).

[0027] The aforementioned brake pressure refers to the actual hydraulic pressure value of the vehicle's master cylinder or wheel end, which is measured and transmitted by the braking system through sensors. Brake pressure can reflect the strength of the driver's braking intention.

[0028] The throttle opening mentioned above is a percentage signal (between 0% and 100%) output by the accelerator pedal position sensor, reflecting the driver's desired level of power.

[0029] The aforementioned handbrake signal is a status signal of the electronic parking brake system, indicating whether the handbrake has been activated (pulled up) and released.

[0030] The above automatic parking signal indicates whether the automatic parking function of the current vehicle is currently active, in standby, or off.

[0031] Step 220: When the engine speed is greater than 0, the gear signal indicates that the vehicle is in a drivable gear, the brake pressure is less than the brake pressure threshold, the throttle opening is less than the throttle opening threshold, the handbrake signal is not activated, and the automatic parking signal is not activated, obtain the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio.

[0032] The above-mentioned driving gears are those other than P and N.

[0033] The transmission efficiency of the aforementioned vehicle is the overall efficiency in the process of power being transmitted from the engine to the wheels. The transmission efficiency of a vehicle can be obtained through experimental calibration.

[0034] The aforementioned wheel rolling radius is the equivalent radius used when the wheel is rolling and there is no slippage between the tire and the ground. The vehicle's transmission efficiency can be determined through experimental calibration.

[0035] The rolling resistance coefficient of asphalt pavement mentioned above is the ratio of the rolling resistance generated by the contact between the tire and the road surface to the vertical load during vehicle operation. The rolling resistance coefficient of asphalt pavement can be obtained from road design specifications.

[0036] The above-mentioned vehicle weight refers to the weight of the vehicle itself. The vehicle weight is determined by testing before the vehicle leaves the factory, and different vehicle models have different vehicle weights.

[0037] The above-mentioned vehicle acceleration is the acceleration of the vehicle in the longitudinal direction (unit: m / s²), which is calculated by the vehicle body acceleration sensor or the wheel speed differential method.

[0038] The aforementioned first gear ratio is the speed ratio between the input shaft and the output shaft when the gearbox is in first gear. It is an inherent parameter of the gearbox and is stored in the parameter table inside the gearbox control unit. It can be obtained by looking up the table.

[0039] Step 230: Calculate the vehicle load torque based on the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio.

[0040] The aforementioned vehicle load torque refers to the total resistance torque that the output shaft of the transmission must overcome during vehicle operation.

[0041] Step 240: Control the vehicle to drive at low speed based on the total vehicle load torque.

[0042] The aforementioned control of vehicle speed refers to controlling the vehicle to travel at a speed lower than the normal cruising speed. The normal cruising speed is a relatively fixed speed that the vehicle can maintain without continuously pressing the accelerator. The normal cruising speed is determined by engineers through experiments, and different vehicle models correspond to different normal cruising speeds.

[0043] In some embodiments, after the vehicle's transmission control unit determines the vehicle's load torque, it sends a torque reduction command to the vehicle's motor control unit. The vehicle's motor control unit reduces the output torque of the drive motor to the target value and feeds back the actual torque. The vehicle's transmission control unit then uses the returned actual torque and the vehicle's required torque to look up a table or characteristic curve to calculate the most suitable gear ratio and controls the vehicle to travel at low speed according to the gear ratio.

[0044] In this embodiment, the vehicle's transmission control unit comprehensively judges engine speed, gear signal, brake pressure, throttle opening, handbrake and auto hold status. When the above parameters meet specific conditions, creep control is activated, effectively identifying low-speed driving scenarios where the driver has no intention to actively accelerate or decelerate. Based on this, multiple parameters such as transmission efficiency, rolling radius, rolling resistance coefficient, vehicle mass, acceleration and first gear ratio are introduced to calculate the vehicle load torque, so that the driving force output accurately matches the actual road load demand. This avoids the problem of fixed driving force in traditional idling creep, which can easily lead to jerking or slippage, improves the smoothness of starting and responsiveness, and effectively improves the vehicle control effect.

[0045] Based on the above Figure 2 Please refer to the solutions shown in one or more corresponding embodiments. Figure 3 , Figure 3 This is a flowchart of a vehicle control method provided in one embodiment of this application. Step 230 above can be implemented as steps 230a and 230b: Step 230a: Determine the input torque of the transmission coefficient based on the transmission coefficient efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, and vehicle acceleration.

[0046] The aforementioned transmission coefficient input torque refers to the amount of torque that the engine or motor must provide before the transmission coefficient (i.e., transmission efficiency) takes effect in order to overcome rolling resistance and achieve the required acceleration in the vehicle's power system.

[0047] Step 230b: Obtain the quotient of the input torque of the transmission system divided by the first gear ratio, which is used as the vehicle's total load torque.

[0048] In this embodiment, the vehicle's transmission control unit obtains the vehicle load torque by dividing the input torque of the transmission system by the first gear ratio. Since the first gear has the maximum reduction ratio, it is directly related to the torque amplification capability at low speeds. Therefore, by performing reverse calculation based on the first gear ratio, the minimum torque required at the transmission input can be accurately restored. The above method avoids the torque estimation deviation caused by ignoring the gear ratio and effectively improves the accuracy of the calculation of the vehicle's total load torque.

[0049] Based on the solutions shown in one or more of the above embodiments, in one possible implementation, step 230a can be implemented as follows: Based on the transmission coefficient efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, and vehicle acceleration, the transmission coefficient input torque is determined using Formula 1, as follows: T input =η*[(f×m×g + m×a)*r] Formula 1 Where η is the transmission efficiency coefficient, r is the wheel rolling radius, f is the rolling resistance coefficient of the asphalt road surface, m is the vehicle mass, a is the vehicle acceleration, and T is the total acceleration. input is the transmission coefficient and input torque, and g is the acceleration due to gravity.

[0050] In this embodiment, the formula above takes into account the requirements of rolling resistance (f×m×g) and inertial force (m×a) on driving force, and corrects energy loss through transmission efficiency η, so that the calculated transmission coefficient input torque is closer to the actual working conditions of the vehicle, which significantly improves the accuracy of transmission coefficient input torque calculation.

[0051] Based on the above Figure 2 Please refer to the solutions shown in one or more corresponding embodiments. Figure 4 , Figure 4 This is a flowchart of a vehicle control method provided in one embodiment of this application, the method further including step 250: Step 250: When the engine speed is greater than 0, if the gear signal indicates that the vehicle is in P or N gear, the brake pressure is not less than the brake pressure threshold, the throttle opening is not less than the throttle opening threshold, the handbrake signal is activated, or the auto hold signal is activated, control the vehicle to exit low-speed driving.

[0052] When the engine speed is greater than 0, it indicates that the engine is running and the vehicle is not stationary.

[0053] The above gear position signal indicates that the vehicle is in P or N gear, meaning that the vehicle does not have driving capability.

[0054] If the above-mentioned braking pressure is not less than the braking pressure threshold, it indicates that the driver has pressed the brake pedal and intends to stop or slow down.

[0055] If the throttle opening is not less than the throttle opening threshold, it means that the driver has actively pressed the accelerator and intends to accelerate.

[0056] The above handbrake signal indicates that the electronic parking brake has been activated and the vehicle should remain stationary.

[0057] The activation of the above automatic parking signal indicates that the automatic parking function has taken over the control of the vehicle's stationary position, and the transmission control unit no longer needs to maintain creeping.

[0058] In this embodiment, the above-mentioned scheme sets multiple trigger conditions for exiting low-speed driving. The trigger conditions cover key scenarios such as driver active intervention, parking intention, and non-driving state, ensuring that the crawl function will not continue to operate in inappropriate situations. Through the active exit mechanism, the safety hazards and mechanical wear caused by malfunctions are avoided, and the overall vehicle control effect is effectively improved.

[0059] Based on the solutions shown in one or more of the above embodiments, in one possible implementation, before calculating the vehicle's total load torque, the vehicle's transmission control unit activates the creep flag and controls the clutch torque to increase at a preset rate of increase to a target torque, which is the torque required by the clutch when the vehicle is in a creeping state.

[0060] The aforementioned creep flag is a Boolean state variable (e.g., 0 or 1). The creep flag is stored in the RAM (Random Access Memory) of the transmission control unit and is used to mark whether the current vehicle has entered the creep control mode.

[0061] In some embodiments, when the engine speed is greater than 0, the gear position signal indicates that the vehicle is in a drivable gear, the brake pressure is less than the brake pressure threshold, the throttle opening is less than the throttle opening threshold, the handbrake signal is not activated, and the automatic parking signal is not activated, the transmission control unit will set the creep flag to "1" to indicate that the creep function is enabled; otherwise, it will be set to "0".

[0062] In this embodiment, the preset rise rate refers to the torque transmission rate that the transmission control unit actively adjusts when the clutch gradually enters the engagement state from the disengaged state, based on the driving conditions and control strategy.

[0063] The above-mentioned control of the clutch torque to increase to the target torque at a preset rate of increase means that the transmission control unit controls the clutch torque to gradually increase at a preset rate of increase until the clutch torque reaches the target torque.

[0064] The target torque mentioned above is a calibrated torque.

[0065] After the vehicle's transmission control unit activates the creep flag, the transmission control unit starts the clutch control module and gradually increases the clutch clamping force according to the preset rising curve, so that the clutch slowly engages from the fully disengaged state, thereby smoothly transmitting engine power.

[0066] In this embodiment, the creep flag can be used to determine whether the vehicle has entered the creep state, preventing false triggering of the creep state. The preset ascent rate has been calibrated and optimized to achieve smooth power transmission and suppress shock and vibration. Before calculating the vehicle's total load torque, the above-mentioned phased control process is executed, which significantly improves the smoothness of low-speed creep start and the consistency of dynamic response, effectively improving the vehicle control effect.

[0067] Based on the scheme shown in one or more of the above embodiments, in one possible implementation, the brake pressure threshold is 5 bar and the throttle opening threshold is 2%.

[0068] When the above-mentioned brake pressure threshold is 5 bar, it means that when the brake system pressure is below 5 bar, the vehicle can enter crawl mode; if the brake pressure exceeds 5 bar, it indicates a clear braking intention, and the vehicle should exit crawl mode.

[0069] When the throttle opening threshold is 2%, it means that when the accelerator pedal opening is less than 2%, the driver has no intention to accelerate actively (close to idle speed), and creep control is allowed to intervene; if the throttle opening exceeds 2%, it means that the driver has requested power, and normal acceleration logic control should be given.

[0070] In this embodiment, specific brake pressure thresholds and throttle opening thresholds are defined. By defining specific brake pressure thresholds, it is possible to effectively distinguish between slight braking and a clear stopping intention, avoiding misjudgment that the vehicle has entered a crawling state due to slight pressure. By defining specific throttle opening thresholds, it is possible to ensure that the vehicle is controlled to enter the crawling mode after the throttle is completely released. The above scheme provides a quantitative basis for judging the driver's operating intention by setting brake pressure thresholds and throttle opening thresholds, thereby enhancing the judgment quality of the control logic.

[0071] For example, based on Figures 2 to 4 For any one or more embodiments, this application proposes a method for controlling the brake pressure of a brake-by-wire platform that supports mechatronics in a gearbox.

[0072] For example, please refer to Figure 5 , Figure 5 This is a flowchart of a vehicle low-speed control method provided in one embodiment of this application. This method is executed by the transmission control unit, such as... Figure 5 As shown, this solution includes steps S1 to S5, as detailed below.

[0073] Step S1: Start the engine.

[0074] In this step, the transmission control unit determines whether the engine is running based on the engine speed. If the engine speed is greater than 0, it determines that the engine is running.

[0075] Step S2: The gear is in D / R, and the electronic parking brake or auto hold is not activated.

[0076] In this step, the transmission control unit confirms the driver's intention to move forward or backward based on the gear position signal, and determines whether to engage the clutch torque based on the handbrake signal and the auto hold signal.

[0077] Step S3: The brake signal is released, and the brake pressure is less than a certain value.

[0078] In this step, the transmission control unit determines that the brake has been released and the brake pressure is less than 5 bar; the transmission control unit confirms the current vehicle speed based on the wheel speed or the transmission input shaft speed.

[0079] Step S4: Throttle opening is less than a certain value.

[0080] In this step, when the throttle opening is less than a certain value, the transmission control unit calculates the vehicle load torque and sends the load torque to the EMS. The EMS outputs the load torque accordingly, and at the same time, the transmission control unit controls the clutch to transmit and output this vehicle load torque. For example, if the throttle opening is less than 2%, it confirms that the driver has no intention of accelerating.

[0081] In this embodiment, the transmission control unit can calculate the torque required for static start-up based on Newton's second law and the principles of vehicle dynamics, i.e., the load calculation when the vehicle starts: 1. Assume basic parameters Total vehicle weight m = 1800 kg The acceleration due to gravity is g = 9.81 m / s². The rolling resistance coefficient of asphalt pavement is f=0.015 Assume the wheel rolling radius is r = 0.3m. The transmission system efficiency η = 0.9 First gear ratio R ratio = 17 Assume the vehicle starts with an acceleration of 0.3 m / s². 2. Driving force calculation Minimum driving force required to overcome rolling resistance: F roll =f×m×g=0.015×1800×9.81≈265N Considering the driving force of acceleration (assuming a starting acceleration of 0.3 m / s², which can be calibrated in practice): F accel =m×a=1800×0.3=540N Total driving force requirement: F total =F roll +F accel ≈805N 3. Drive torque calculation Wheel-side torque: T wheel =F total ×r = 805 × 0.3 ≈ 241.5 Nm Transmission system input torque (considering efficiency): T input =η*T wheel ≈0.9×241.5≈268.3Nm The torque required by the transmission, i.e., the load when the vehicle starts. T load torque=T input ÷R ratio =268.3÷17≈15.78Nm Tinput =η*T wheel T wheel =(f×m×g + m×a)×r For example, please refer to Table 1, which is a table of key parameters, as follows: Table 1 Key Parameters

[0082] Step S5: TCU enters low-speed control.

[0083] In this step, the TCU controls the clutch to open based on the brake pressure, reducing the output torque and keeping the vehicle at a low speed. Please refer to Figure 6 , Figure 6 This is a flowchart of a torque calculation method provided in one embodiment of this application.

[0084] When the driver applies the brakes, the current creep torque is frozen and multiplied by the attenuation coefficient found in the table, which is then used as the output creep torque. Please refer to Table 2, which shows the brake pressure corresponding to the attenuation coefficient, as follows: Table 2 Brake Pressure Corresponding Attenuation Coefficient

[0085] The data in Table 2 can be determined through calibration, and the braking pressure and actual braking performance differ for different items.

[0086] During calibration, the actual vehicle performance can be used as a reference. For example, when the brake pressure is 2 bar, the vehicle starts to brake. At this time, the brake pressure of 2 bar corresponds to a decay coefficient of 1, which means that when the brake pressure is greater than 2 bar, the TCU creep torque begins to decay. Simulate the force of a normal customer pressing the brake. After the customer presses the brake to stop, the brake pressure is maintained at 20 bar. At this time, the brake pressure of 20 bar corresponds to a decay coefficient of 0, which means that when the brake pressure is 20 bar, the TCU creep torque decays to 0 Nm.

[0087] For example, please refer to Figure 7 , Figure 7 This is a timing diagram of a vehicle low-speed control method provided in one embodiment of this application.

[0088] When the driver shifts the gear lever to R, D, or M, and releases the brake, the brake signal BrakePedalStsForTCU is 0. The vehicle then creeps at a speed of 5 km / h (which can be calibrated). During this process, the TCU sends the clutch load torque (IdleControlLoadTorque) and the target idle speed request (DesiredEngineIdleSpeed). The EMS should control the engine torque and idle speed based on these two signals, generally not exceeding 50 rpm.

[0089] The activation conditions for the TCU creep flag STAT_CreepingActive must all be met: a. EPB (Electronic Parking Brake) is not set, indicating that the electronic parking brake system is currently in the released state (ICM_1_HandBrakeSystemSts=Released). b. AVH (Auto Hold) is not activated (ABS_ESP_3_AVHSts=Off / Standby); c. Current gear determination: Engine started successfully (EngineStsForDCT= 0x3: Engine running) (indicating the engine is running) && drivetrain engaged (indicating the shift lever is not in P or N, i.e., the shift lever is in another gear, such as D, R, L) (shift lever is not in P or N GBPositoionDisplay!= 0x1: Display P or 0x3: Display N); d. Gas Pedal Position: The accelerator pedal is below a certain value (2%); this indicates that the driver has not pressed the pedal, or the vehicle is in a very low acceleration state. e. Brake pressure is effective and less than a certain value (5 bar). This indicates that the operating pressure of the braking system is controlled within a low and effective range.

[0090] The TCU creep flag STAT_CreepingActive exit condition must be met if any of the following conditions are satisfied: a. EPB (Electronic Parking Brake) is set and in the pulled-out state (ICM_1_HandBrakeSystemSts=Released). b. AVH activation (ABS_ESP_3_AVHSts=active); c. Current gear position determination: Engine start success (EngineStsForDCT= 0x1:stop) indicates that the engine is running && the transmission chain is open (meaning the shift lever is not in P or N, i.e., the shift lever is in other gears (e.g., D, R, L, etc.), (the shift lever is in P or N GBPositoionDisplay= 0x1: Display P or 0x3: Display N); d. GasPedalPosition: The accelerator pedal is greater than a certain value (2%); this indicates that the driver has not pressed the pedal, or the vehicle is in a very low acceleration state. e. The braking pressure is effective and greater than a certain value (5 bar). The operating pressure of the braking system is controlled within a low and effective range.

[0091] The TCU creep flag STAT_CreepingActive is reset to 0x0:Inactive, which requires the idle creep request torque IdleControlLoadTorque to drop to 0 Nm.

[0092] That is, when the TCU creep flag is reset to 0x0 (Inactive), the creep state ends when the idle creep request torque (IdleControlLoadTorque) drops to 0 Nm.

[0093] When the driver presses the accelerator to enter LAUNCH (start), the TCU IdleControlLoadTorque will gradually adjust the load torque from the current value ramp (i.e., idle ramp load torque) to 0 Nm (meaning zero torque, i.e., no torque output or torque effect). The ramp time (the time required to complete the adjustment from the current load torque to the target torque (0 Nm)) can be calibrated.

[0094] The TCU needs to work with the ECU to calibrate the engine torque characteristics at low throttle levels (below 2%-3%).

[0095] The "2%-3%" mentioned above refers to the percentage range of engine output torque under light throttle input (i.e., lightly pressing the accelerator). Specifically, this percentage refers to the torque range that the TCU and ECU need to jointly calibrate in the engine output torque calibration to ensure that the engine can output torque precisely to meet the vehicle's control requirements under low throttle input.

[0096] For example, please refer to Figure 8 , Figure 8 This is a correspondence between braking stroke and braking pressure provided in one embodiment of this application.

[0097] Pedal feel tuning involves the brake travel / distance between the start of the brake pedal movement and the start of the braking force generated by the braking system, as well as the coordination and matching relationship between brake pressure and vehicle acceleration.

[0098] For example, please refer to Figure 9 , Figure 9 This is an illustrative diagram of low-speed control provided in one embodiment of this application.

[0099] like Figure 9 As shown, low-speed control is divided into 3 stages, as detailed below: Low-speed control stage ①: After releasing the brake and the braking pressure is released, the vehicle is slowly accelerated by controlling the rate of clutch engagement, and the vehicle speed increases gradually.

[0100] Low-speed control stage ②: The stage where the vehicle begins to move slowly to reach the target speed; in this stage, because the clutch torque control is a PI closed-loop adjustment process based on the vehicle speed, as the vehicle speed approaches the target speed, the clutch torque gradually decreases, and eventually the vehicle will reach the target speed and stabilize within a reasonable range.

[0101] Low-speed control stage 3: When the brake is applied, the car begins to slowly decelerate until it stops. During this stage, the clutch torque is controlled by the brake pressure. As the brake pressure increases, the clutch torque gradually decreases, and the braking increases, thereby gradually reducing the vehicle speed until it stops.

[0102] Please refer to Figure 10 The diagram illustrates a block diagram of a vehicle control device provided in an exemplary embodiment of this application. This vehicle control device can be implemented as all or part of a computer device through hardware or a combination of hardware and software, to achieve the above-described... Figures 2 to 4 All or part of the steps in the illustrated embodiments. For example... Figure 10 As shown, the vehicle control device includes: The information acquisition module 1001 is used to acquire the vehicle's engine speed, vehicle gear signal, vehicle brake pressure, vehicle throttle opening, vehicle handbrake signal, and vehicle automatic parking signal. The parameter acquisition module 1002 is used to acquire the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio when the engine speed is greater than 0, the gear signal indicates that the vehicle is in a drivable gear, the brake pressure is less than the brake pressure threshold, the throttle opening is less than the throttle opening threshold, the handbrake signal is not activated, and the automatic parking signal is not activated. The torque calculation module 1003 is used to calculate the vehicle's total load torque based on the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio. The driving gear is the gear that enables the vehicle to output power forward or backward. The vehicle control module 1004 is used to control the vehicle's low-speed driving based on the vehicle's load torque.

[0103] In one possible implementation, the torque calculation module 1003 is used for, The input torque of the transmission coefficient is determined based on the transmission coefficient efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, and vehicle acceleration. The quotient of the input torque of the transmission system divided by the first gear ratio is used as the vehicle's total load torque.

[0104] In one possible implementation, the torque calculation module 1003 is used for, Based on the transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, and vehicle acceleration, the transmission input torque is determined using Formula 1, as follows: T input =η*[(f×m×g + m×a)*r] Formula 1 Where η is the transmission efficiency coefficient, r is the wheel rolling radius, f is the rolling resistance coefficient of the asphalt road surface, m is the vehicle mass, a is the vehicle acceleration, and T is the total acceleration. input is the transmission coefficient and input torque, and g is the acceleration due to gravity.

[0105] In one possible implementation, the device further includes: The control exit module is used to control the vehicle to exit low-speed driving when the engine speed is greater than 0, the gear position signal indicates that the vehicle is in P or N gear, the brake pressure is not less than the brake pressure threshold, the throttle opening is not less than the throttle opening threshold, the handbrake signal is activated, or the auto hold signal is activated.

[0106] In one possible implementation, the device further includes: The control submodule is used to activate the creep flag and control the clutch torque to increase to the target torque at a preset rate before calculating the vehicle's total load torque. The target torque is the torque required by the clutch when the vehicle is in a creeping state.

[0107] In one possible implementation, the brake pressure threshold is 5 bar and the throttle opening threshold is 2%.

[0108] Please refer to Figure 11 , Figure 11This is a schematic diagram of the structure of a computer device provided in an exemplary embodiment of this application. The computer device 1100 includes a Central Processing Unit (CPU) 1101, a system memory 1104 including Random Access Memory (RAM) 1102 and Read-Only Memory (ROM) 1103, and a system bus 1105 connecting the system memory 1104 and the CPU 1101. The computer device 1100 also includes a Basic Input / Output System (I / O System) 1106 to facilitate the transfer of information between various devices within the computer, and a mass storage device 1107 for storing the operating system 1113, application programs 1114, and other program modules 1115.

[0109] The basic input / output system 1106 includes a display 1108 for displaying information and an input device 1109 for user input, such as a mouse or keyboard. Both the display 1108 and the input device 1109 are connected to the central processing unit 1101 via an input / output controller 1110 connected to the system bus 1105. The basic input / output system 1106 may also include the input / output controller 1110 for receiving and processing input from multiple other devices such as a keyboard, mouse, or electronic stylus. Similarly, the input / output controller 1110 also provides output to a display screen, printer, or other types of output devices.

[0110] The mass storage device 1107 is connected to the central processing unit 1101 via a mass storage controller (not shown) connected to the system bus 1105. The mass storage device 1107 and its associated computer-readable media provide non-volatile storage for the computer device 1100. That is, the mass storage device 1107 may include computer-readable media (not shown) such as a hard disk or a CD-ROM (Compact Disc Read-Only Memory) drive.

[0111] Without loss of generality, the computer-readable medium may include computer storage media and communication media. Computer storage media include volatile and non-volatile, removable and non-removable media implemented using any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include RAM (Random Access Memory), ROM (Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory or other solid-state storage technologies, CD-ROM, DVD (Digital Video Disc), or other optical storage, magnetic tape cassettes, magnetic tape, disk storage, or other magnetic storage devices. Of course, those skilled in the art will recognize that the computer storage media are not limited to the above-mentioned types. The system memory 1104 and the mass storage device 1107 described above can be collectively referred to as memory.

[0112] Computer device 1100 can be connected to the Internet or other network devices via network interface unit 1111 connected to the system bus 1105.

[0113] The memory also includes one or more programs, which are stored in the memory, and the central processing unit 1101 implements these programs. Figures 2 to 4 All or some of the steps in the method shown.

[0114] In an exemplary embodiment, a chip is also provided, the chip including programmable logic circuitry and / or program instructions, which, when the chip is run on a computer device, are used to implement all or part of the steps of the methods shown in the above embodiments of this application.

[0115] In an exemplary embodiment, a computer program product is also provided, comprising computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions to implement all or part of the steps of the methods shown in the above embodiments of this application.

[0116] In an exemplary embodiment, a computer-readable storage medium is also provided, which stores a computer program that is loaded and executed by a processor to implement all or part of the steps of the methods shown in the above embodiments of this application.

[0117] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0118] Those skilled in the art will recognize that the functions described in the embodiments of this application in one or more of the above examples can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0119] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A vehicle control method, characterized in that, The method is executed by the vehicle's transmission control unit, and the method includes: The engine speed, gear position signal, brake pressure, throttle opening, handbrake signal, and automatic parking signal of the vehicle are acquired. When the engine speed is greater than 0, the gear position signal indicates that the vehicle is in a drivable gear, the brake pressure is less than the brake pressure threshold, the throttle opening is less than the throttle opening threshold, the handbrake signal is not activated, and the automatic parking signal is not activated, the transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio of the vehicle are obtained. The transmission coefficient and input torque are determined using Formula 1: T input =η [(f×m×g + m×a) Formula 1 Where η is the transmission efficiency coefficient, r is the wheel rolling radius, f is the asphalt road rolling resistance coefficient, m is the vehicle mass, a is the vehicle acceleration, and T is the total acceleration. input The input torque is the transmission coefficient, and g is the acceleration due to gravity. The quotient of the input torque of the transmission coefficient divided by the first gear ratio is used as the total vehicle load torque. The vehicle is controlled to travel at low speed based on the total vehicle load torque.

2. The method according to claim 1, characterized in that, The method further includes: When the engine speed is greater than 0, if the gear signal indicates that the vehicle is in P or N gear, the brake pressure is not less than the brake pressure threshold, the throttle opening is not less than the throttle opening threshold, the handbrake signal is activated, or the automatic parking signal is activated, the vehicle is controlled to exit low-speed driving.

3. The method according to claim 1, characterized in that, Before calculating the vehicle's total load torque, the method further includes: The creep flag is activated and the clutch torque is controlled to increase at a preset rate to a target torque, which is the torque required by the clutch when the vehicle is in a creeping state.

4. The method according to claim 1, characterized in that, The brake pressure threshold is 5 bar, and the throttle opening threshold is 2%.

5. A vehicle control device, characterized in that, The device includes: The information acquisition module is used to acquire the vehicle's engine speed, gear signal, brake pressure, throttle opening, handbrake signal, and automatic parking signal; The parameter acquisition module is used to acquire the vehicle's transmission efficiency, wheel rolling radius, asphalt road rolling resistance coefficient, vehicle mass, vehicle acceleration, and first gear ratio when the engine speed is greater than 0, the gear signal indicates that the vehicle is in a drivable gear, the brake pressure is less than the brake pressure threshold, the throttle opening is less than the throttle opening threshold, the handbrake signal is not activated, and the automatic parking signal is not activated. The torque calculation module is used to determine the input torque of the transmission coefficient using Formula 1: T input =η [(f×m×g + m×a) Formula 1 Where η is the transmission efficiency coefficient, r is the wheel rolling radius, f is the asphalt road rolling resistance coefficient, m is the vehicle mass, a is the vehicle acceleration, and T is the total acceleration. input The input torque is the transmission coefficient, and g is the acceleration due to gravity. The torque calculation module is also used to obtain the quotient of the input torque of the transmission coefficient divided by the first gear ratio, as the total vehicle load torque of the vehicle. The vehicle control module is used to control the vehicle to travel at low speed based on the total vehicle load torque.

6. A computer device, characterized in that, The computer device includes a processor and a memory, the memory storing instructions which are executed by the processor to implement the vehicle control method as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The storage medium stores instructions that are executed by a processor of a computer device to implement the vehicle control method as described in any one of claims 1 to 4.

8. A computer program product, characterized in that, The computer program product includes computer instructions stored in a computer-readable storage medium; the computer instructions are read and executed by a processor of a computer device to implement the vehicle control method as described in any one of claims 1 to 4.

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