An adaptive slope parking and starting method and device for a pure electric light truck
By pre-storing the hill-start torque corresponding to the load in the pure electric light truck and performing adaptive control, the problems of rollback and torque shudder during hill start are solved, improving driving stability and user experience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ANHUI JIANGHUAI AUTOMOBILE GRP CORP LTD
- Filing Date
- 2023-04-20
- Publication Date
- 2026-07-17
AI Technical Summary
When pure electric light trucks accelerate again after parking on a slope, they are prone to rolling backward and starting torque vibration, resulting in a poor driving experience and poor driving stability. The risk and degree of vibration vary under different load conditions.
The vehicle pre-stores the parking torque corresponding to the current load, and selects the larger one as the current parking torque when accelerating from a standstill. The motor torque is quickly controlled through the power control unit to prevent rollback and torque jitter. The pre-stored torque is also corrected according to changes in load to achieve adaptive control.
It improves the driving stability of pure electric light trucks under no-load, half-load and full-load conditions, prevents backward roll and torque vibration during hill start, and improves the user experience.
Smart Images
Figure CN116394942B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of intelligent driving technology for vehicles, and more specifically, to an adaptive hill-start and hill-start method and device for a pure electric light truck. Background Technology
[0002] Currently, intelligent braking systems are widely used in new energy passenger vehicles, but their application in commercial vehicles, especially pure electric light trucks, is relatively limited. In existing technologies, after a vehicle has stopped on a slope, it is prone to rolling backward and experiencing torque shuddering during acceleration, leading to reduced vehicle safety and a poor driving experience. Furthermore, the risk of rolling backward and the degree of torque shuddering vary depending on the load condition of the pure electric light truck, resulting in less stable driving performance. Summary of the Invention
[0003] This application provides an adaptive hill-start method and device for pure electric light trucks. The hill-start torque corresponding to the current load of the vehicle is pre-stored in the vehicle. When accelerating to start on a slope, the power control unit uses the larger of the pre-stored hill-start torque and the accelerator pedal torque as the current hill-start torque, realizing rapid control of the motor torque during the start-up process, preventing the vehicle from rolling backward and the start-up torque from jittering during the start-up process. Therefore, this application is applicable to hill-start and starting of pure electric light trucks under no-load, half-load and full-load conditions, improving the driving stability of pure electric light trucks.
[0004] This application provides a method for parking and starting a pure electric light truck on a slope, including:
[0005] When a pure electric light truck accelerates again while parked on a slope, it obtains the torque value from the accelerator pedal.
[0006] The larger of the pre-stored parking torque and the torque of the accelerator pedal is used as the current parking torque to prevent the vehicle from rolling backward, and is sent to the power control unit. The pre-stored parking torque corresponds to the current load of the pure electric light truck.
[0007] Preferably, the method for parking and starting a pure electric light truck on a slope also includes:
[0008] After the pure electric light truck completes the hill-climbing maneuver, compare the current hill-climbing torque with the pre-stored hill-climbing torque.
[0009] If the current holding torque is less than the pre-stored holding torque, then the pre-stored holding torque will be updated to the current holding torque.
[0010] Preferably, the method for parking and starting a pure electric light truck on a slope also includes:
[0011] If the overall weight of the pure electric light truck changes, the pre-stored parking torque will be corrected based on the correction factor and the change in overall weight.
[0012] Preferably, the ramp parking process for a pure electric light truck includes the following steps:
[0013] When a pure electric light truck enters a slope parking condition, the control power control unit adjusts the torque of the drive motor to balance the torque of the drive motor with the resistance torque, so that the vehicle can be parked smoothly on the slope.
[0014] Send a parking signal to the intelligent braking system to build up pressure and complete parking on the slope;
[0015] In response to the intelligent braking system completing hill parking, the power control unit unloads the torque of the drive motor;
[0016] After parking on a slope, the torque of the drive motor, which is balanced with the resistance torque, is stored as the pre-stored parking torque.
[0017] Preferably, the power control unit adjusts the torque of the drive motor by cyclically executing the following steps until the torque of the drive motor is balanced with the resistance torque:
[0018] It continuously receives the real-time torque of the drive motor transmitted by the power control unit and calculates the rate of change of the drive motor's speed.
[0019] The torque of the drive motor is adjusted based on the rate of change of rotational speed, and this torque is used as the first torque.
[0020] The second torque is determined based on the vehicle's driving status and the current speed of the drive motor, where the driving status includes creeping uphill parking and accelerating uphill parking.
[0021] The maximum value between the first torque and the second torque is taken as the current target torque, and a motor torque command is sent to the power control unit based on the current target torque.
[0022] Preferably, during the pressure build-up process of the intelligent braking system, if a signal is received that the intelligent braking system cannot perform pressure build-up, a clamping request is sent to the electronic parking brake system.
[0023] This application also provides a ramp parking and starting device for a pure electric light truck, including an accelerator pedal torque acquisition module and an anti-rollover torque determination module.
[0024] The accelerator pedal torque acquisition module is used to obtain the torque value of the accelerator pedal when a pure electric light truck accelerates again from a hilly position.
[0025] The anti-rollback torque determination module takes the larger of the pre-stored parking torque and the torque of the accelerator pedal as the current parking torque to prevent the vehicle from rolling backward and sends it to the power control unit. The pre-stored parking torque corresponds to the current load of the pure electric light truck.
[0026] Preferably, the ramp parking and starting device for the pure electric light truck further includes a first comparison module and an update module;
[0027] The first comparison module is used to compare the current parking torque with the pre-stored parking torque after the pure electric light truck has completed parking on the slope.
[0028] The update module is used to update the stored parking torque to the current parking torque when the current parking torque is less than the stored parking torque.
[0029] Preferably, the ramp parking and starting device of the pure electric light truck also includes a correction module, which is used to correct the pre-stored parking torque according to the correction factor and the change in the vehicle weight when the overall weight of the pure electric light truck changes.
[0030] Preferably, the ramp parking and starting device of the pure electric light truck also includes a ramp parking module, which includes a motor parking module, an automatic parking module, a torque unloading module, and a storage module.
[0031] The electric motor parking module is used to control the power control unit to adjust the torque of the drive motor after the pure electric light truck enters the slope parking condition, so that the torque of the drive motor is balanced with the resistance torque, and the vehicle is parked smoothly on the slope.
[0032] The automatic parking module is used to send a parking signal to the intelligent braking system, enabling the intelligent braking system to build up pressure and complete the parking on the slope.
[0033] The torque unloading module is used to respond to the intelligent braking system when parking on a slope by controlling the power control unit to unload the torque of the drive motor;
[0034] The storage module is used to store the torque of the drive motor that is balanced with the resistance torque after parking on a slope, as a pre-stored parking torque.
[0035] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description
[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.
[0037] Figure 1 A schematic diagram of the ramp parking and starting system of the pure electric light truck provided in this application;
[0038] Figure 2 A flowchart of the ramp parking process of the pure electric light truck provided in this application;
[0039] Figure 3 A flowchart of an embodiment of the ramp parking process of the pure electric light truck provided in this application;
[0040] Figure 4 The structural diagram of the ramp parking and starting device for the pure electric light truck provided in this application. Detailed Implementation
[0041] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the present application.
[0042] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.
[0043] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.
[0044] In all the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.
[0045] This application provides an adaptive hill-start method and device for a pure electric light truck. The vehicle has a pre-stored hill-start torque corresponding to its current load. When accelerating on a slope, the power control unit uses the larger of the pre-stored hill-start torque and the accelerator pedal torque as the current hill-start torque, achieving rapid control of the motor torque during start-up and preventing the vehicle from rolling backward and experiencing torque jitter. Therefore, this application is applicable to hill-starting and parking of pure electric light trucks under empty, half-load, and full-load conditions, improving the driving stability of the pure electric light truck. This application corrects the pre-stored hill-start torque based on weight changes during loading or unloading, ensuring that the pre-stored hill-start torque is consistent with the overall weight of the vehicle, thus guaranteeing smooth driving. Furthermore, this application adjusts the correction factor of the pre-stored hill-start torque under certain conditions, achieving self-learning of the pre-stored hill-start torque and enabling adaptive adjustment between the pre-stored hill-start torque and the vehicle's state.
[0046] like Figure 1As shown, the hill-start and parking system of the pure electric light truck of this application includes a vehicle control unit (VCU) 110, a power control unit (PCU) 120, an electronic parking brake (EPB) system 130, and an intelligent braking system (eBooster) 140. The hill-start and parking process is controlled by the VCU 110, with the PCU 120, eBooster 140, and EPB 130 serving as the actuators.
[0047] like Figure 2 As shown, the process of parking a pure electric light truck on a slope includes the following steps:
[0048] S210: After the pure electric light truck enters the hill parking condition, the VCU 110 controls the PCU 120 to adjust the torque of the drive motor so that the torque of the drive motor is balanced with the resistance torque, and the vehicle is parked smoothly on the hill, that is, motor parking.
[0049] Figure 3 An embodiment of the ramp parking process for a pure electric light truck is shown, such as... Figure 3 As shown, controlling the power control unit to adjust the torque of the drive motor includes the following steps:
[0050] S310: VCU 110 continuously receives the real-time torque of the drive motor transmitted by PCU 120.
[0051] S320: VCU 110 determines whether the real-time torque is the same as the resistance torque of the ramp, i.e. whether the two are balanced; if so, execute S370; otherwise, execute S330.
[0052] S330: VCU 110 calculates the rate of change of the drive motor speed based on the real-time torque received over a period of time.
[0053] S340: VCU 110 adjusts the torque of the drive motor based on the rate of change of speed, using it as the first torque.
[0054] Specifically, if the rate of change of speed exceeds a threshold, the torque of the drive motor needs to be reduced, i.e., torque reduction. If the rate of change of speed is below the threshold, the torque of the drive motor needs to be increased, i.e., torque increase.
[0055] As an example, the threshold is the torque value calibrated by a pure electric light truck under no-load conditions.
[0056] S350: VCU 110 determines the second torque based on the vehicle's driving status and the current speed of the drive motor.
[0057] The driving states include creeping uphill parking and accelerating uphill parking.
[0058] If the driver does not press the accelerator pedal, the vehicle will creep up the slope (i.e., be in a creeping uphill parking state). The VCU110 will then query the creep torque table to obtain the second torque corresponding to the current speed.
[0059] If the driver presses the accelerator pedal to enter the slope (i.e., in the state of accelerating uphill parking), the VCU 110 will query the acceleration torque table to obtain the second torque corresponding to the current speed.
[0060] S360: VCU 110 takes the maximum value of the first torque and the second torque as the current target torque, and sends a motor torque command to PCU 120 based on the current target torque, causing PCU 120 to control the drive motor to adjust the torque. Then it returns to S310.
[0061] S370: VCU 110 controls PCU 120 to maintain this real-time torque, so that the vehicle can be parked smoothly on the slope. The real-time torque at this time is the parking torque corresponding to the current load of the pure electric light truck.
[0062] If the vehicle slips during the parking process, VCU 110 controls PCU 120 to reverse the drive motor, thereby increasing the torque and stopping the vehicle.
[0063] S220: VCU 110 responds to the vehicle smoothly parking on a ramp by sending a parking signal to eBooster 140 (see below). Figure 3 In embodiment 380), the eBooster 140 builds pressure to achieve automatic parking, thus completing the hill-start assist. The eBooster builds pressure using existing technology, which will not be described in detail here. After the eBooster 140 completes the pressure build-up, it sends a parking completion indicator to the VCU 110.
[0064] Preferably, during the parking process of eBooster 140, if a system failure occurs that prevents eBooster 140 from continuing to park, eBooster 140 sends a parking failure (i.e., pressure build-up) signal to VCU 110 (see [link]). Figure 3 (Example 390). After receiving the signal, VCU 110 sends a clamping and parking request to EPB 130 (see...). Figure 3 In embodiment 3100), the EPB 130 performs clamping parking. If the VCU 110 does not receive this signal, the eBooster 140 performs automatic parking and sends a parking completion signal back to the VCU 110 (see [link]). Figure 3 Example 3110).
[0065] S230: In response to completing hill start parking, VCU 110 controls PCU 120 to unload the torque of the drive motor and cancel the parking enable signal (see [link]). Figure 3 Example 3120).
[0066] After completing the ramp parking maneuver, the torque of the drive motor that balances the resistance torque during this ramp parking maneuver is stored as the pre-stored ramp parking torque. Understandably, the torque of the drive motor that balances the resistance torque can be obtained in S210, therefore, storing the pre-stored ramp parking torque can be performed in S210, S220, or S230.
[0067] Preferably, after each successful hill-climbing maneuver, the pure electric light truck compares the current hill-climbing torque with the pre-stored hill-climbing torque. If the current hill-climbing torque is less than the pre-stored torque, the pre-stored torque is updated to the current torque, thus ensuring that the pre-stored torque is applicable to different vehicle weights (including unloaded, half-loaded, and fully loaded).
[0068] During the parking process on a slope, unloading or loading may occur. Based on this consideration, preferably, if the overall weight of the pure electric light truck changes, the pre-stored parking torque is corrected according to the correction factor φ and the change in overall weight. This avoids changes in overall weight during unloading or loading while parking on a slope, which could lead to a starting impact on the next start (parking condition). As an example, the pre-stored parking torque is corrected linearly. For example, if the overall weight under the original load condition is G1, the changed overall weight is G2, and the pre-stored parking torque before correction is N1, then the pre-stored parking torque after correction is N2.
[0069]
[0070] The factory correction factor φ is 1.
[0071] Among them, φ can be reported through a remote terminal to prevent abnormal values, and supports remote correction in the background.
[0072] By adjusting the pre-stored parking torque according to the load, this application can eliminate the impact of load changes caused by loading or unloading on starting on the slope.
[0073] Based on this, preferably, under certain conditions, the correction factor is adjusted. Adjustments are made to achieve self-learning of the parking torque.
[0074] As an example, the VCU 110 counts the proportion of motor speed feedback as reversing (or advancing) when torque fluctuation occurs after ramp release in a preset number of times (e.g., 100 times). If this proportion is greater than a preset proportion (e.g., 10%), then the correction factor is adjusted. Adjustments will be made:
[0075] φ′=φ*m
[0076] Where m is the adjustment parameter.
[0077] If the proportion of motor speed feedback as backward when torque fluctuation occurs after the slope is released in the preset number of times is greater than the preset proportion, then m > 1; if the proportion of motor speed feedback as forward when torque fluctuation occurs after the slope is released in the preset number of times is greater than the preset proportion, then m < 1.
[0078] Building upon the above, when a pure electric light truck accelerates again while parked on a slope, after the parking brake is released, the VCU110 obtains the torque value from the accelerator pedal and uses the larger of the pre-stored parking torque and the accelerator pedal torque as the current parking torque to prevent the vehicle from rolling backward, and sends it to the PCU120. Thus, the pre-stored parking torque allows the VCU to quickly control the motor torque, achieving a smooth transition of parking torque under no-load, half-load, and full-load conditions, preventing rollback when starting on a slope, preventing torque jitter during start-up, and improving the user experience.
[0079] Based on the above, this application also provides a ramp parking and starting device for a pure electric light truck. For example... Figure 4 As shown, the ramp parking and starting device includes a ramp parking module 410, an accelerator pedal torque acquisition module 420, and an anti-rollover torque determination module 430.
[0080] The ramp-holding module 410 is used to control the PCU, EPB, and eBooster to complete the ramp-holding process.
[0081] The accelerator pedal torque acquisition module 420 is used to obtain the torque value of the accelerator pedal when a pure electric light truck accelerates again from a hilly position.
[0082] The anti-rollback torque determination module 430 takes the larger of the pre-stored parking torque and the torque of the accelerator pedal as the current parking torque to prevent the vehicle from rolling backward and sends it to the power control unit. The pre-stored parking torque corresponds to the current load of the pure electric light truck.
[0083] Specifically, the ramp parking module 410 includes a motor parking module 4101, an automatic parking module 4102, a torque unloading module 4103, and a storage module 4104.
[0084] The motor parking module 4101 is used to control the power control unit to adjust the torque of the drive motor after the pure electric light truck enters the slope parking condition, so that the torque of the drive motor is balanced with the resistance torque, and the vehicle is parked smoothly on the slope.
[0085] The automatic parking module 4102 is used to send a parking signal to the intelligent braking system, so that the intelligent braking system can build up pressure and complete the parking on the slope.
[0086] The torque unloading module 4103 is used to control the power control unit to unload the torque of the drive motor in response to the intelligent braking system completing hill parking.
[0087] The storage module 4104 is used to store the torque of the drive motor that is balanced with the resistance torque after parking on a slope, as a pre-stored parking torque.
[0088] Preferably, the ramp parking and starting device further includes a first comparison module 440 and an update module 450.
[0089] The first comparison module 440 is used to compare the current parking torque with the pre-stored parking torque after the pure electric light truck has completed parking on the slope.
[0090] The update module 450 is used to update the stored parking torque to the current parking torque when the current parking torque is less than the stored parking torque.
[0091] Preferably, the ramp parking and starting device further includes a correction module 460, which is used to correct the pre-stored parking torque according to the correction factor and the change in the overall weight of the pure electric light truck when the overall weight of the vehicle changes.
[0092] Preferably, the ramp parking and starting device further includes an adjustment module 470, which is used to adjust the correction factor under certain conditions.
[0093] The control strategy of this invention fully considers the unique slope conditions of light trucks, and conducts a comprehensive analysis and optimization of the slope start strategy for light trucks, thereby improving the user experience of pure electric light truck users in slope start conditions.
[0094] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.
Claims
1. A method for parking and starting a pure electric light truck on a slope, characterized in that, include: When a pure electric light truck enters a slope parking condition, the torque of the drive motor is adjusted to balance the torque of the drive motor with the resistance torque, and the vehicle is parked smoothly on the slope. Store the torque of the drive motor that balances the resistance torque during this hill-start parking maneuver as the pre-stored hill-start torque; Send a parking signal to the eBooster to enable automatic parking by building up pressure, and unload the torque of the drive motor in response to completing hill parking. When accelerating and starting again while in a hilly parking state, the larger of the pre-stored parking torque and the torque of the accelerator pedal at the start is used as the current parking torque to prevent the vehicle from rolling backward, and is directly sent to the drive motor that has already unloaded the torque. The pre-stored parking torque corresponds to the current load of the pure electric light truck. The correspondence with the current load of the pure electric light truck includes at least the following: if the vehicle load changes during the current hill start, the pre-stored hill start torque is adjusted according to the load to eliminate the impact of the load change on the current hill start.
2. The method for parking and starting a pure electric light truck on a slope according to claim 1, characterized in that, Also includes: After the pure electric light truck completes the hill-climbing maneuver, compare the current hill-climbing torque with the pre-stored hill-climbing torque. If the current holding torque is less than the pre-stored holding torque, then the pre-stored holding torque will be updated to the current holding torque.
3. The method for parking and starting a pure electric light truck on a slope according to claim 1, characterized in that, The specific steps involved in parking a pure electric light truck on a slope are as follows: When a pure electric light truck enters a slope parking condition, the control power control unit adjusts the torque of the drive motor to balance the torque of the drive motor with the resistance torque, so that the vehicle can be parked smoothly on the slope. Send a parking signal to the intelligent braking system to build up pressure and complete parking on the slope; In response to the intelligent braking system completing hill parking, the power control unit unloads the torque of the drive motor; After parking on the slope, the torque of the drive motor that balances the resistance torque is stored as the pre-stored parking torque.
4. The method for parking and starting a pure electric light truck on a slope according to claim 3, characterized in that, The power control unit adjusts the torque of the drive motor by repeatedly executing the following steps until the torque of the drive motor is balanced with the resistance torque: It continuously receives the real-time torque of the drive motor transmitted by the power control unit and calculates the rate of change of the drive motor's speed. The torque of the drive motor is adjusted according to the aforementioned rate of change of rotational speed, and this torque is used as the first torque. The second torque is determined based on the vehicle's driving status and the current speed of the drive motor, wherein the driving status includes creeping uphill parking and accelerating uphill parking. The maximum value between the first torque and the second torque is taken as the current target torque, and a motor torque command is sent to the power control unit based on the current target torque.
5. The method for parking and starting a pure electric light truck on a slope according to claim 3, characterized in that, If a signal is received that the intelligent braking system cannot perform pressure build-up during the pressure build-up process, a clamping request is sent to the electronic parking brake system.