Vehicle slope parking auxiliary control method and device, electronic equipment and storage equipment

Abstract

The invention discloses a vehicle slope parking auxiliary control method and device, electronic equipment and storage equipment. The method comprises the steps of obtaining vehicle condition data of a vehicle and condition data of a road where the vehicle is located; in response to the situation that the vehicle enters the slope parking scene, rear axle slope parking auxiliary control torque is determined based on the vehicle condition data and the road condition data, and the rear axle slope parking auxiliary control torque is used for controlling a rear axle driving motor of the vehicle to operate to generate torque so as to assist the vehicle in slope parking; and based on the rear axle hill-holding auxiliary control torque, a rear axle driving motor is controlled to operate. According to the invention, the technical problems of high cost and high complexity of realizing vehicle slope parking auxiliary control in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically, to a method, device, electronic equipment, and storage device for assisting vehicle parking on slopes. Background Technology

[0002] In the field of vehicle technology, implementing hill-start assist is a significant technical challenge. To park a vehicle on an incline, related technologies primarily employ the following methods: increasing the diameter of the rear axle brake calipers to improve braking force, but this increases manufacturing costs; or introducing an inter-axle differential lock to transfer the braking torque from the front axle to the rear axle, improving overall parking performance, which similarly leads to increased costs and system complexity, introduces new reliability risks, and raises vehicle maintenance costs. Therefore, implementing hill-start assist control for vehicles in related technologies is both costly and complex.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This invention provides a method, apparatus, electronic device, and storage device for assisting vehicle parking on a slope, in order to at least solve the technical problems of high cost and complexity in implementing assisting vehicle parking on a slope in related technologies.

[0005] According to one aspect of the present invention, a vehicle hill-start assist control method is provided, comprising: acquiring vehicle status data and road condition data of the vehicle; in response to the vehicle entering a hill-start parking scenario, determining a rear axle hill-start assist control torque based on the vehicle status data and the road condition data, wherein the rear axle hill-start assist control torque is used to control the operation of the rear axle drive motor of the vehicle to generate torque to assist the vehicle in hill-start parking; and controlling the operation of the rear axle drive motor based on the rear axle hill-start assist control torque.

[0006] In this embodiment of the invention, determining the rear axle hill-holding assist control torque based on vehicle condition data and road condition data includes: determining the vehicle's feedforward torque parameters and closed-loop control torque parameters based on the vehicle condition data and road condition data, wherein the feedforward torque parameters represent the predicted desired torque control parameters required by the rear axle drive motor, and the closed-loop control torque parameters represent the control parameters that require torque compensation for the rear axle drive motor; and determining the rear axle hill-holding assist control torque based on the feedforward torque parameters and the closed-loop control torque parameters.

[0007] In this embodiment of the invention, the vehicle status data includes at least first vehicle status data and second vehicle status data; based on the vehicle status data and road status data, determining the vehicle's feedforward torque parameters and closed-loop control torque control parameters includes: acquiring the first vehicle status data corresponding to the vehicle at a first moment; determining the feedforward torque parameters based on the first vehicle status data and road status data; controlling the operation of the rear axle drive motor based on the feedforward torque parameters, and acquiring the second vehicle status data corresponding to the vehicle at a second moment; and determining the closed-loop control torque control parameters based on the second vehicle status data and road status data.

[0008] In this embodiment of the invention, the feedforward torque parameters of the vehicle are determined based on first vehicle condition data and road condition data, including: acquiring the vehicle weight, tire radius, front axle mechanical braking torque, and rear axle mechanical braking torque from the first vehicle condition data, and acquiring the road slope and adhesion coefficient from the road condition data, wherein the adhesion coefficient is used to represent the friction coefficient between the road and the tire; determining the rear axle adhesion torque and front axle adhesion torque of the vehicle based on the vehicle weight, tire radius, road slope, and adhesion coefficient; and determining the feedforward torque parameters based on the rear axle adhesion torque, front axle adhesion torque, front axle mechanical braking torque, and rear axle mechanical braking torque.

[0009] In this embodiment of the invention, the feedforward torque parameters are determined based on the rear axle adhesion torque, front axle adhesion torque, front axle mechanical braking torque, and rear axle mechanical braking torque, including: determining the effective mechanical braking torque of the vehicle based on the rear axle adhesion torque, front axle adhesion torque, front axle mechanical braking torque, and rear axle mechanical braking torque; and determining the feedforward torque parameters based on the effective mechanical braking torque, vehicle weight, and road gradient.

[0010] In this embodiment of the invention, the feedforward torque parameters are determined based on the effective mechanical braking torque, vehicle weight, and road slope, including: determining the vehicle weight's downward sliding torque along the slope based on the vehicle weight and road slope; and determining the feedforward torque parameters based on the vehicle weight's downward sliding torque along the slope and the effective mechanical braking torque.

[0011] In this embodiment of the invention, the closed-loop control torque control parameters are determined based on the second vehicle condition data and road condition data, including: obtaining the rear axle drive motor speed from the second vehicle condition data and obtaining the road slope from the road condition data; determining the target difference between the rear axle drive motor speed and the preset vehicle parking motor speed; and determining the closed-loop control torque control parameters based on the target difference and the road slope.

[0012] In this embodiment of the invention, obtaining the road slope from road condition data includes: obtaining vehicle speed parameters and acceleration parameters from vehicle condition data, and obtaining the initial road slope from the road condition data; determining the slope update magnitude based on the vehicle speed parameters and / or acceleration parameters, wherein the slope update magnitude is positively correlated with the vehicle speed parameters and negatively correlated with the acceleration parameters; and updating the initial road slope based on the slope update magnitude to obtain the road slope.

[0013] In this embodiment of the invention, the method further includes: obtaining preset rear axle hill-start assist activation conditions and preset rear axle hill-start assist deactivation conditions; determining that the vehicle enters a hill-start parking scenario when the vehicle status data and road status data meet the preset rear axle hill-start assist activation conditions; and determining that the vehicle exits the hill-start parking scenario when the vehicle status data and road status data meet the preset rear axle hill-start assist deactivation conditions.

[0014] According to another aspect of the present invention, a vehicle hill-start assist control device is also provided, comprising: an acquisition module for acquiring vehicle status data and road condition data of the vehicle; a determination module for determining a rear axle hill-start assist control torque based on the vehicle status data and road condition data in response to the vehicle entering a hill-start parking scenario, wherein the rear axle hill-start assist control torque is used to control the operation of the rear axle drive motor of the vehicle to generate torque to assist the vehicle in hill-start parking; and a control module for controlling the operation of the rear axle drive motor based on the rear axle hill-start assist control torque.

[0015] According to another aspect of the present invention, an electronic device is also provided, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods of various embodiments of the present invention during runtime.

[0016] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is executed, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of the present invention.

[0017] According to another aspect of the present invention, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of the present invention.

[0018] According to another aspect of the present invention, a computer program product is also provided, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods of various embodiments of the present invention.

[0019] According to another aspect of the present invention, a computer program is also provided, which, when executed by a processor, implements the methods of the various embodiments of the present invention.

[0020] In this embodiment of the invention, firstly, vehicle status data and road condition data are acquired. In response to the vehicle entering a hillside parking scenario, a rear axle hill-start assist control torque is determined based on the vehicle status data and road condition data. This torque is used to control the operation of the rear axle drive motor to generate torque, assisting the vehicle in hillside parking. Finally, the rear axle drive motor is controlled to operate based on the rear axle hill-start assist control torque. Acquiring vehicle status data and road condition data helps to accurately assess the vehicle's real-time condition and environmental conditions, facilitating the development of a reasonable assist control torque strategy. By determining the rear axle hill-start assist control torque based on the vehicle status data and road condition data, and by controlling the operation of the rear axle drive motor to apply accurate assist control torque, the vehicle can effectively prevent rollback due to gravity or insufficient road surface adhesion when parked on a slope, enhancing parking safety and stability. In the parking state, the torque generated by the rear axle drive motor helps the vehicle start smoothly on a slope, avoiding driving discomfort or safety hazards caused by sudden acceleration or rollback. This method eliminates the need to increase hardware costs such as brake caliper diameter or inter-axle differential lock devices. It utilizes vehicle electronic control system and sensor data to implement hill-start assist through software algorithms, achieving cost savings and reducing the complexity of implementing vehicle hill-start assist. This solves the technical problems of high cost and complexity in implementing vehicle hill-start assist control in related technologies. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0022] Figure 1 This is a flowchart of a vehicle hill-start assist control method according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of an optional vehicle hill-start assist control technology framework according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of a vehicle hill-start assist control device according to an embodiment of the present invention. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] According to one aspect of the present invention, a vehicle hill-start assist control method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0028] Figure 1 This is a flowchart of a vehicle hill-start assist control method according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0029] Step S102: Obtain vehicle status data and road condition data where the vehicle is located.

[0030] The vehicle status data mentioned above refers to the vehicle's status data at a certain moment, which can be used to determine whether the vehicle is in a hilly parking scenario and how to control the vehicle. Vehicle status data may include, but is not limited to: vehicle weight, tire radius, acceleration parameters, gear position, and sensor signals.

[0031] The aforementioned road condition data can refer to information about the vehicle's environment, specifically road conditions, which helps in calculating the vehicle's response under specific conditions. Road condition data may include road gradient, coefficient of friction, etc.

[0032] In one optional embodiment, acquiring vehicle status data and road condition data can involve the collaborative work of multiple sensors and onboard systems to collect and analyze information in real time, ensuring the control system can make appropriate decisions based on the current vehicle status and environmental conditions. Vehicle status data may include, but is not limited to, vehicle speed, throttle opening, gear information, motor speed, and vehicle weight distribution. This data can be captured in real time by various sensors installed on the vehicle, such as wheel speed sensors, acceleration sensors, and throttle position sensors, and transmitted to the processor or corresponding control module via the onboard network. For example, a vehicle speed sensor can monitor the vehicle's instantaneous speed, a throttle position sensor can record the driver's operating force, and a motor speed sensor can track the motor's operating status; this information collectively constitutes a real-time overview of the vehicle's operation. Road condition data may include road gradient and road surface adhesion coefficient. Gradient information can be calculated using an acceleration sensor in conjunction with the vehicle's tilt angle, and the adhesion coefficient can be estimated based on historical data of road surface type and weather conditions, or measured in real time through small vibrations between the tires and the ground. Road condition data is crucial for assessing the vehicle's stability in the current terrain.

[0033] In the above process, by acquiring and analyzing vehicle status data and road condition data in real time, the hill-start assist control system can accurately assess the vehicle's immediate operating status and the environmental conditions it is in, which helps to formulate a reasonable assist torque strategy.

[0034] Step S104: In response to the vehicle entering a hillside parking scenario, determine the rear axle hill-start assist control torque based on vehicle condition data and road condition data.

[0035] Among them, the rear axle hill-start assist control torque is used to control the operation of the vehicle's rear axle drive motor to generate torque, so as to assist the vehicle in parking on slopes.

[0036] The aforementioned hill-start parking scenario refers to a situation where a vehicle needs to remain stationary on a slope. In this scenario, the vehicle needs to overcome the tendency to slide due to the slope to prevent it from rolling or moving unexpectedly. A hill-start parking scenario can be triggered by the following conditions: the vehicle is on a relatively steep slope, requiring additional braking force to maintain stability; the vehicle speed decreases below a preset threshold, and the vehicle is in the process of stopping or is preparing to stop; the driver intends to park, for example, the driver shifts the gear to drive, while the throttle opening is less than a preset value, and the master cylinder pressure is greater than a preset value.

[0037] The aforementioned rear axle hill-start assist control torque refers to the additional torque generated by the vehicle's rear axle drive motor in hill-dwelling scenarios. This torque assists in stabilizing the vehicle and preventing it from rolling away. The rear axle hill-start assist control torque aims to add a drive torque to the vehicle's rear axle mechanical braking torque, ensuring stable parking on slopes without increasing the hardware cost of the braking system. The specific calculation of the rear axle hill-start assist control torque can consider factors such as vehicle weight, slope, and mechanical braking torque, and can be achieved through both feedforward torque and closed-loop control torque.

[0038] In one optional embodiment, when the vehicle detects a parking scenario on a slope, the control system can respond by analyzing current vehicle status data, such as vehicle speed, gear position, throttle opening, and master cylinder pressure, as well as road condition data, such as slope and coefficient of friction. This response process can collect real-time information through multiple vehicle sensors and send it to a processor or control module for analysis. When preset rear axle parking assist activation conditions are met, such as vehicle speed, gear position, and slope, the required auxiliary control torque for the rear axle can be calculated. This calculation can be based on a series of formulas, including considerations of vehicle weight, tire radius, mechanical braking torque, and coefficient of friction, to determine the effective mechanical braking torque and feedforward torque parameters. Simultaneously, based on changes in motor speed and slope information, the torque parameters can be adjusted through closed-loop control to ensure the vehicle remains stable on the slope.

[0039] In the above process, by applying precise auxiliary control torque, the vehicle can effectively prevent rolling backwards on a slope due to gravity or insufficient road surface adhesion when parked, thus enhancing parking safety and stability. In the parking state, the auxiliary control torque adaptively adjusts, helping the vehicle to start smoothly on a slope and avoiding driving discomfort or safety hazards caused by sudden acceleration or rolling backwards. This method eliminates the need to increase hardware costs such as brake caliper diameter or inter-axle differential lock devices. Instead, it utilizes existing vehicle electronic control systems and sensor data, optimizing hill-start assist through software algorithms, achieving cost savings.

[0040] Step S106: Based on the rear axle parking slope auxiliary control torque, control the operation of the rear axle drive motor.

[0041] The aforementioned rear axle drive motor refers to the electric motor in a vehicle used to drive the rear axle wheels. The rear axle drive motor provides forward power to the vehicle and can also generate additional driving torque in parking scenarios on slopes, assisting in stable parking. The torque and speed of the rear axle drive motor can be adjusted by an electronic control system to adapt to different parking needs and road conditions.

[0042] In one optional embodiment, after determining the rear axle hill-start assist control torque, the rear axle hill-start assist control torque can be converted into an actual operating control signal for the motor to assist the vehicle in parking on slopes. This process can be implemented by the vehicle's motor controller, and the specific flow is as follows: The motor controller can receive a torque command signal from the processor or control module. The torque command signal can contain the magnitude and direction information of the rear axle hill-start assist control torque calculated based on vehicle and road conditions. The torque command signal is decoded and converted into specific control commands that the motor controller can interpret. According to the received control commands, the motor controller can adjust the current input of the rear axle drive motor and control the operating speed and direction of the rear axle drive motor. If it is necessary to provide assist torque to prevent slippage, the rear axle drive motor can be controlled to rotate in the reverse direction to generate a reverse torque; if it is necessary to assist starting on a slope, the rear axle drive motor can rotate in the forward direction to provide forward power. During the operation of the rear axle drive motor, the motor controller can also monitor the motor's operating status in real time, such as actual torque and speed, and continuously adjust the operating parameters of the rear axle drive motor through a closed-loop control mechanism to ensure that the actual output torque matches the commanded torque, thereby achieving accurate control of the vehicle's hill-start assist.

[0043] In the above process, through precise control of the motor controller, the auxiliary torque calculated by software is converted into the physical action of the motor, thereby affecting the vehicle's hill-holding ability. Real-time response and precise execution of auxiliary torque commands ensure that the vehicle can quickly obtain the necessary assistance on slopes, enhancing the safety and stability of hill-holding and hill starts. Since the generation of auxiliary torque does not rely on the enhancement of traditional mechanical braking or the addition of additional hardware, this motor control strategy reduces the overall cost of the vehicle while achieving equivalent hill-holding performance.

[0044] In this embodiment of the invention, firstly, vehicle status data and road condition data are acquired. In response to the vehicle entering a hillside parking scenario, a rear axle hill-start assist control torque is determined based on the vehicle status data and road condition data. This torque is used to control the operation of the rear axle drive motor to generate torque, assisting the vehicle in hillside parking. Finally, the rear axle drive motor is controlled to operate based on the rear axle hill-start assist control torque. Acquiring vehicle status data and road condition data helps to accurately assess the vehicle's real-time condition and environmental conditions, facilitating the development of a reasonable assist control torque strategy. By determining the rear axle hill-start assist control torque based on the vehicle status data and road condition data, and by controlling the operation of the rear axle drive motor to apply accurate assist control torque, the vehicle can effectively prevent rollback due to gravity or insufficient road surface adhesion when parked on a slope, enhancing parking safety and stability. In the parking state, the torque generated by the rear axle drive motor helps the vehicle start smoothly on a slope, avoiding driving discomfort or safety hazards caused by sudden acceleration or rollback. This method eliminates the need to increase hardware costs such as brake caliper diameter or inter-axle differential lock devices. It utilizes vehicle electronic control system and sensor data to implement hill-start assist through software algorithms, achieving cost savings and reducing the complexity of implementing vehicle hill-start assist. This solves the technical problems of high cost and complexity in implementing vehicle hill-start assist control in related technologies.

[0045] In this embodiment of the invention, determining the rear axle hill-holding assist control torque based on vehicle condition data and road condition data includes: determining the vehicle's feedforward torque parameters and closed-loop control torque parameters based on the vehicle condition data and road condition data, wherein the feedforward torque parameters represent the predicted desired torque control parameters required by the rear axle drive motor, and the closed-loop control torque parameters represent the control parameters that require torque compensation for the rear axle drive motor; and determining the rear axle hill-holding assist control torque based on the feedforward torque parameters and the closed-loop control torque parameters.

[0046] The aforementioned feedforward torque parameter can refer to the control parameter used to control the rear axle drive motor of the vehicle to generate the desired torque, which is predicted based on vehicle condition data and road condition data. It can be a pre-calculated torque value that helps the rear axle drive motor generate the necessary driving force in advance to counteract or mitigate the downward trend caused by the slope and the vehicle's own weight.

[0047] The aforementioned closed-loop control torque control parameters refer to the control parameters used to adjust the torque of the rear axle drive motor in real time. These parameters are calculated based on the deviation between the vehicle's actual dynamic performance, such as motor speed and vehicle speed changes, and the expected target, ensuring the vehicle can dynamically maintain a stable state when parked on an incline. Closed-loop control primarily focuses on feedback; that is, by monitoring the actual operating state of the rear axle drive motor, such as motor speed, and the difference between it and the ideal state, it dynamically adjusts the torque to correct these differences, suppressing potential rollback or acceleration tendencies, thus keeping the vehicle stable on inclines and ensuring stable parking and safe starts even in complex or changing environmental conditions.

[0048] In one alternative embodiment, the required feedforward torque parameters for the rear axle drive motor can be predicted using a preset mathematical model or algorithm based on vehicle dynamic parameters, such as vehicle speed and acceleration, and road conditions, such as gradient and coefficient of adhesion. The feedforward torque parameters can be predictive calculations based on anticipated vehicle behavior, aiming to provide the necessary torque in advance to overcome gravity and prevent vehicle rollback. Closed-loop control can be based on a real-time feedback dynamic adjustment mechanism, monitoring the actual torque output of the rear axle drive motor and changes in vehicle speed. A proportional-integral control algorithm calculates the torque difference that needs adjustment to compensate for insufficient or excessive torque caused by vehicle dynamic changes or prediction errors, ensuring vehicle stability. Finally, the feedforward torque parameters can be added to the closed-loop control torque parameters to obtain the rear axle hill-start assist control torque. The feedforward torque provides anticipated torque support, while the closed-loop control enables real-time adjustments, ensuring the torque output of the rear axle drive motor and adapting to the instantaneous needs of the vehicle on inclines.

[0049] In the above process, the feedforward torque parameter predicts future torque demand, while the closed-loop control parameter corrects deviations in real time, ensuring the stability and safety of the vehicle when parking on an incline. The combination of the feedforward torque parameter and the closed-loop control torque parameter improves the response speed to dynamic changes in the vehicle and reduces control errors caused by delays.

[0050] In this embodiment of the invention, the vehicle status data includes at least first vehicle status data and second vehicle status data; based on the vehicle status data and road status data, determining the vehicle's feedforward torque parameters and closed-loop control torque control parameters includes: acquiring the first vehicle status data corresponding to the vehicle at a first moment; determining the feedforward torque parameters based on the first vehicle status data and road status data; controlling the operation of the rear axle drive motor based on the feedforward torque parameters, and acquiring the second vehicle status data corresponding to the vehicle at a second moment; and determining the closed-loop control torque control parameters based on the second vehicle status data and road status data.

[0051] The aforementioned first vehicle condition data can refer to the vehicle operating status data collected at the first moment. The first vehicle condition data may include, but is not limited to, the vehicle's weight, tire radius, mechanical braking torque of the front and rear axles, master cylinder pressure, vehicle speed, acceleration, and gear information.

[0052] The aforementioned second vehicle status data can refer to the vehicle operating status data collected again at a second moment after the rear axle drive motor starts running according to the feedforward torque parameters. This data may include more accurate motor speed, vehicle speed, and updated master cylinder pressure.

[0053] In one optional embodiment, during the hill-start assist control process, a set of first vehicle status data can be acquired at a first moment, which may include, but is not limited to, vehicle speed, gear position, master cylinder pressure, throttle opening, etc., while road condition data, such as gradient and coefficient of adhesion, are simultaneously read. Based on the above data, a feedforward torque parameter is calculated by an algorithm, which is the estimated theoretical torque value required by the rear axle motor to overcome the influence of gravity on the slope. Subsequently, the rear axle drive motor can be instructed to operate according to the feedforward torque parameter to assist the vehicle in hill-start assist control. Next, second vehicle status data can be collected again at a second moment, which may include motor speed, actual vehicle speed, etc., and used together with the road condition data to adjust the closed-loop control torque control parameters, that is, to adjust the motor torque through real-time feedback to ensure that the actual vehicle state meets the expected hill-start requirements.

[0054] In the above process, the feedforward torque parameter is based on prediction, while the closed-loop control torque parameter is based on real-time feedback. This allows for more precise control of the rear axle drive motor torque, ensuring stable vehicle parking on slopes. Closed-loop control relies on real-time data, enabling rapid response to changes in vehicle status and timely torque adjustment. When starting on a slope, it can quickly prevent rollback.

[0055] In this embodiment of the invention, the feedforward torque parameters of the vehicle are determined based on first vehicle condition data and road condition data, including: acquiring the vehicle weight, tire radius, front axle mechanical braking torque, and rear axle mechanical braking torque from the first vehicle condition data, and acquiring the road slope and adhesion coefficient from the road condition data, wherein the adhesion coefficient is used to represent the friction coefficient between the road and the tire; determining the rear axle adhesion torque and front axle adhesion torque of the vehicle based on the vehicle weight, tire radius, road slope, and adhesion coefficient; and determining the feedforward torque parameters based on the rear axle adhesion torque, front axle adhesion torque, front axle mechanical braking torque, and rear axle mechanical braking torque.

[0056] The aforementioned front axle mechanical braking torque can refer to the braking force generated by the braking system of the vehicle's front axle, which applies pressure to the brake disc or brake drum through the brake caliper, thereby converting it into a torque that prevents the vehicle from moving forward or backward.

[0057] The aforementioned rear axle mechanical braking torque refers to the torque generated by the vehicle's rear axle braking system, which is used to prevent the rear of the vehicle from moving. Rear axle braking torque is particularly important when parking on a slope. When a vehicle is parked on a slope, the center of gravity shifts towards the rear axle, increasing the braking demand on the rear axle.

[0058] The aforementioned coefficient of adhesion refers to the ratio of the maximum frictional force that can be provided on the contact surface between the vehicle tire and the road surface to the load perpendicularly pressing on the tire. It reflects the vehicle tire's grip ability on a specific road surface and can affect the vehicle's braking force and traction on slopes.

[0059] The aforementioned rear axle adhesion torque refers to the torque that prevents the rear wheels from slipping, generated by the friction between the vehicle's rear wheels and the road surface under given slope and road conditions. Rear axle adhesion torque can be related to the vehicle weight on the rear axle, the road surface's coefficient of adhesion, and the tire radius.

[0060] The aforementioned front axle adhesion torque refers to the torque generated by the friction between the front wheels and the road surface, which resists front wheel slippage. In control strategies, the front axle adhesion torque, along with the front axle mechanical braking torque, is used to calculate the effective parking torque at the front of the vehicle. The calculation of the front axle adhesion torque ensures the stability of the entire vehicle on slopes; however, the front axle braking force is more important when descending slopes.

[0061] In one optional embodiment, when determining the feedforward torque parameters, first vehicle condition data can be obtained from a sensor network, which may include the vehicle's static and dynamic attributes, such as vehicle weight, tire radius, and current mechanical braking torque of the front and rear axles. Simultaneously, road condition data can be read, including road gradient and coefficient of friction, which reflects the friction between the tires and the road surface. Based on this data, the front and rear axle adhesion torques of the vehicle at the current gradient can be calculated, representing the upper limit of the friction torque that the tire-ground contact point can withstand. Then, using the vehicle weight, gradient, adhesion torque, and current mechanical braking torque, the feedforward torque parameters can be calculated. These parameters can predict the additional torque required by the rear axle motor to ensure that the vehicle does not roll away when parked on a slope.

[0062] In the above process, by quantifying vehicle and road data, the required torque can be accurately predicted, improving control accuracy. The calculation of feedforward torque parameters takes into account the dynamic changes in slope and adhesion coefficient, adapting to different slope and road conditions, providing suitable auxiliary torque, and enhancing the vehicle's hill-start assist performance.

[0063] In this embodiment of the invention, the feedforward torque parameters are determined based on the rear axle adhesion torque, front axle adhesion torque, front axle mechanical braking torque, and rear axle mechanical braking torque, including: determining the effective mechanical braking torque of the vehicle based on the rear axle adhesion torque, front axle adhesion torque, front axle mechanical braking torque, and rear axle mechanical braking torque; and determining the feedforward torque parameters based on the effective mechanical braking torque, vehicle weight, and road gradient.

[0064] The aforementioned effective mechanical braking torque refers to the total torque at which the vehicle's braking system can actually stop the vehicle from moving. During hill-start assist control, the effective mechanical braking torque, taking into account the mechanical braking torques of the front and rear axles and the corresponding adhesion torque between the tires and the road, is a measure of the total braking force that the vehicle can effectively apply to the road surface. It integrates the performance of the vehicle's braking system itself and the tire grip on the road surface, reflecting the actual ability of the braking system to overcome the downward tendency due to gravity when the vehicle is parked on a slope.

[0065] In one alternative embodiment, to determine the feedforward torque parameters, the effective mechanical braking torque can be calculated based on the adhesion torque and mechanical braking torque of the front and rear axles of the vehicle. This calculation may include comparing the mechanical braking torque of the front and rear axles with their respective adhesion torques, selecting the smaller one as the effective contribution; braking torque exceeding the adhesion torque will be ineffective, causing tire slippage. Next, the vehicle's tendency to slide downhill can be assessed using a physical model based on the vehicle weight, road gradient, and the calculated effective mechanical braking torque. Finally, the feedforward torque parameters can be determined by analyzing the component of the vehicle weight along the slope, the effective mechanical braking torque, and the slope characteristics to predict the auxiliary motor torque, compensating for insufficient mechanical braking and ensuring the vehicle remains firmly stationary.

[0066] In the above process, the feedforward torque parameters are adjusted according to changes in vehicle weight, gradient, and effective mechanical braking torque, enhancing flexibility and adaptability to different environments. This method avoids adding hardware or over-designing the braking system to cope with possible sloping road conditions, achieving a balance between cost control and performance improvement through software improvements. The process of determining the feedforward torque parameters based on the rear axle adhesion torque, front axle adhesion torque, and front and rear axle mechanical braking torques enables accurate control of braking force, enhancing vehicle stability in sloping environments.

[0067] In this embodiment of the invention, the feedforward torque parameters are determined based on the effective mechanical braking torque, vehicle weight, and road slope, including: determining the vehicle weight's downward sliding torque along the slope based on the vehicle weight and road slope; and determining the feedforward torque parameters based on the vehicle weight's downward sliding torque along the slope and the effective mechanical braking torque.

[0068] The aforementioned vehicle weight sliding downhill moment refers to the downward tendency moment of a vehicle on a slope due to gravity. In slope parking assist control methods, the vehicle weight sliding downhill moment is related to whether the vehicle can be stably parked on the slope and avoid spontaneously sliding downhill due to gravity.

[0069] In one optional embodiment, when determining the feedforward torque parameters, the vehicle weight's downward sliding moment along the slope can be calculated. This downward sliding moment can be considered as the vehicle's tendency to slide down the slope due to gravity. Based on the vehicle weight's downward sliding moment and the effective mechanical braking torque, the feedforward torque parameters are determined. This process ensures that the rear axle motor can promptly provide the necessary auxiliary torque to overcome the effects of gravity and achieve slope parking when the vehicle enters a parking scenario on a slope.

[0070] In the above process, by quantifying the impact of vehicle weight, road slope, and tire radius on the roll-off moment, accurate feedforward torque can be calculated in advance, effectively suppressing the vehicle's tendency to roll off the slope when parked. The calculation of the feedforward torque parameter targets the roll-off moment, ensuring the vehicle remains firmly parked on the slope, significantly improving the safety of hill-start assist and reducing the risk of accidental roll-off. Simultaneously considering the roll-off moment and effective mechanical braking torque allows for intelligent allocation of motor torque and mechanical braking force, avoiding the cost and performance bottlenecks associated with relying solely on mechanical braking.

[0071] In this embodiment of the invention, the closed-loop control torque control parameters are determined based on the second vehicle condition data and road condition data, including: obtaining the rear axle drive motor speed from the second vehicle condition data and obtaining the road slope from the road condition data; determining the target difference between the rear axle drive motor speed and the preset vehicle parking motor speed; and determining the closed-loop control torque control parameters based on the target difference and the road slope.

[0072] The aforementioned preset vehicle parking motor speed refers to the ideal speed that the rear axle drive motor needs to achieve to maintain stability and safety when the vehicle is parked. The preset vehicle parking motor speed can be zero or close to zero, reflecting that the rear axle drive motor should keep the vehicle stationary.

[0073] The aforementioned target difference refers to the difference between the actual speed of the rear axle drive motor and the preset speed of the vehicle parking motor. This target difference can serve as a feedback signal in the closed-loop control system, indicating the deviation between the motor's operating state and the desired state. Within the control system, the target difference can be used to adjust the motor torque to ensure that the motor's operating state responds quickly and reaches the preset parking motor speed requirement.

[0074] In one optional embodiment, during the closed-loop control phase, the rear axle drive motor speed from the second vehicle status data can be acquired in real time, and the road gradient from the current road status data can be read. Subsequently, the motor speed can be compared with a preset vehicle parking motor speed to determine a target difference between the rear axle drive motor speed and the preset vehicle parking motor speed. This target difference reflects the degree of deviation of the motor speed from the ideal parking state, serving as the basis for adjusting the closed-loop control torque. Next, based on the target difference and the road gradient, the closed-loop control torque control parameters can be calculated using a lookup table or control algorithm; that is, the control value used to adjust the motor torque to achieve the target difference. The closed-loop control torque control parameters can be dynamic, adjusting in real time according to changes in motor speed and gradient to ensure stable parking of the vehicle on a slope.

[0075] In the above process, the closed-loop control mechanism ensures real-time matching between the motor speed and the preset parking speed, enabling rapid response and maintaining vehicle stability even under changes in gradient or load fluctuations. By combining the motor speed difference with gradient information, the closed-loop control can accurately calculate the adjustment amount of the motor torque, preventing the vehicle from rolling backward or moving unexpectedly due to improper speed control, thus enhancing the safety of parking and starting on slopes. The smooth adjustment characteristics of the closed-loop control reduce vehicle vibration and impact on slopes, providing the driver with a more comfortable driving experience. When starting from a standstill, the transition is smooth, avoiding abrupt movements.

[0076] In this embodiment of the invention, obtaining the road slope from road condition data includes: obtaining vehicle speed parameters and acceleration parameters from vehicle condition data, and obtaining the initial road slope from the road condition data; determining the slope update magnitude based on the vehicle speed parameters and / or acceleration parameters, wherein the slope update magnitude is positively correlated with the vehicle speed parameters and negatively correlated with the acceleration parameters; and updating the initial road slope based on the slope update magnitude to obtain the road slope.

[0077] The initial road gradient mentioned above refers to the road gradient angle initially identified or preset when a vehicle is driving on a slope. The initial road gradient can be used in the vehicle's hill-start assist control system as the starting point for calculating torque-assisted control, roll torque, and other parameters. The initial road gradient can be obtained through sensors, such as accelerometers, or it can be estimated based on the vehicle's driving conditions, such as speed and acceleration.

[0078] The aforementioned slope update range refers to the range or increment of the road slope identification value adjusted in real time based on vehicle speed and acceleration parameters during vehicle operation. The slope update range reflects the sensitivity and response speed to changes in road slope. The slope update range is positively correlated with vehicle speed parameters; the faster the vehicle speed, the larger the allowable range for road slope updates. Simultaneously, the slope update range is negatively correlated with acceleration parameters; that is, the greater the change in vehicle acceleration, the smaller the allowable range for road slope updates, to prevent excessive fluctuations in slope estimation caused by acceleration changes, such as acceleration or deceleration of the vehicle on a slope.

[0079] In one optional embodiment, vehicle speed and acceleration parameters can be read from vehicle condition data, and the initial road gradient can be obtained from road condition data. Then, the gradient update magnitude can be calculated based on the real-time changes in the vehicle speed and acceleration parameters. The gradient update magnitude can be set according to the following logic: as vehicle speed increases, the gradient update magnitude also increases, while an increase in acceleration leads to a decrease in the gradient update magnitude. This logic design allows for faster adaptation to changes in road gradient when the vehicle is traveling at high speeds, and avoids vehicle control instability caused by excessively rapid gradient updates during vehicle acceleration or deceleration. Finally, the initial road gradient can be updated based on the calculated gradient update magnitude, thereby obtaining more accurate road gradient information in the actual operating environment of the vehicle.

[0080] In the above process, the positive correlation between vehicle speed and gradient update magnitude ensures rapid capture and response to gradient changes during high-speed driving, improving the vehicle's adaptability to road condition changes. The negative correlation between acceleration and gradient update magnitude prevents control instability caused by excessively frequent gradient updates during vehicle acceleration or deceleration, avoiding misoperation at the moment of vehicle start-up or stopping. By dynamically adjusting the sensitivity of gradient sensing, the vehicle's current gradient environment can be more accurately determined, thereby improving the regulation of auxiliary torque and enhancing the safety of driving on slopes.

[0081] In this embodiment of the invention, the method further includes: obtaining preset rear axle hill-start assist activation conditions and preset rear axle hill-start assist deactivation conditions; determining that the vehicle enters a hill-start parking scenario when the vehicle status data and road status data meet the preset rear axle hill-start assist activation conditions; and determining that the vehicle exits the hill-start parking scenario when the vehicle status data and road status data meet the preset rear axle hill-start assist deactivation conditions.

[0082] The aforementioned preset rear axle hill-start assist activation conditions refer to a set of pre-defined conditions. When these conditions are met during vehicle operation, a signal is triggered to activate the rear axle hill-start assist control system, which can intervene and provide additional torque assistance to enhance the vehicle's ability to park on slopes. Preset rear axle hill-start assist activation conditions may include, but are not limited to: the vehicle being in off-road mode; the vehicle's electronic control unit being set to handle more complex road conditions and challenges, such as steep slopes, mud, or rocks; the gear being set to drive; the vehicle being ready for or in the process of moving forward; the slope being greater than the preset slope; the vehicle being driven on a steep slope, requiring hill-start assist to prevent rolling back; the master cylinder pressure being greater than the preset master cylinder pressure; the braking system being at a high pressure level, meaning the driver has applied significant braking force through the brake pedal; the vehicle speed being between 2 km / h and -5 km / h, i.e., the vehicle approaching a stop or traveling at a low speed, as this is when hill-start assist is needed; and the throttle opening being less than the preset throttle opening, excluding situations where the driver attempts to overcome the slope by increasing the throttle. Relevant sensors, including master cylinder pressure sensor, vehicle speed sensor, motor speed sensor, and acceleration sensor, need to return valid data to ensure that the control system can accurately assess vehicle and road conditions.

[0083] The aforementioned preset rear axle hill-start assist disengagement conditions refer to a pre-set set of conditions used to determine when to stop providing assist torque while the rear axle hill-start assist system is running. When any disengagement condition is met, the control system can begin to reduce or stop the torque assist to the rear axle, allowing the vehicle to return to normal driving mode or respond to different driving needs. Preset rear axle hill-start assist disengagement conditions may include: the vehicle changing from a drive gear to a non-drive gear; when the slope is small, high-intensity hill-start assist is no longer needed; the master cylinder pressure decreasing and remaining so for several seconds, indicating the driver has released the brake pedal and begun actively controlling the vehicle; the vehicle speed reaching or falling above 5 km / h or below -10 km / h, indicating the vehicle is no longer in the hill-start parking phase; a large throttle opening, and the driver's torque demand exceeding the hill-start assist control torque, indicating the driver's intention to accelerate or climb, allowing intervention to cease in response to the driver's actions; and a sudden failure of sensor signals, such as master cylinder pressure, vehicle speed, motor speed, and acceleration, necessitating safe disengagement of assist control to avoid potential risks.

[0084] In one optional embodiment, preset activation and deactivation conditions for rear axle hill-start assist can be read from memory or a configuration file. Activation conditions may include, but are not limited to, driving mode being off-road mode and gear being drive; deactivation conditions may include gear changes, calculated gradient reduction, and master cylinder pressure reduction. Then, vehicle status data, such as vehicle speed, throttle opening, and master cylinder pressure, and road condition data, such as gradient and coefficient of friction, can be monitored in real time. When these data meet the activation conditions, it can be determined that the vehicle has entered a hill-start parking scenario, activating the hill-start assist function and implementing feedforward and closed-loop torque control. When the data meets the deactivation conditions, it can be determined that the vehicle has exited the hill-start parking scenario, gradually reducing the assist torque until the function is deactivated, ensuring a smooth transition to normal driving.

[0085] By setting clear activation and deactivation conditions, the system can accurately determine when hill start assist needs to be activated, avoiding unnecessary resource consumption and function activation. Ensuring the assist function is activated in hill start parking scenarios reduces control failures or excessive intervention due to misjudgments, effectively improving driving safety. When vehicle conditions and road conditions no longer meet the assistance requirements, the assist function deactivates promptly, preventing interference with normal driving operations and providing a more natural and smooth driving experience.

[0086] The technical solution proposed in this application will be described below with reference to an optional embodiment. This application proposes a slope braking assist control method. For the slope parking function of current pure electric vehicles, a slope parking drive torque assist control method is proposed. When braking on a slope, a certain driving torque is superimposed on the mechanical braking torque of the rear axle to assist the vehicle in parking. In this way, the same performance can be achieved without increasing the diameter of the rear axle brake caliper or adding an inter-axle differential lock device. Moreover, when starting from parking, even if the brake pedal is released, the applied assist driving torque can be adaptively adjusted to prevent the vehicle from rolling. This can reduce the pressure holding performance requirements of the automatic parking brake system, and also save research and development and manufacturing costs.

[0087] Hill Start Assist Control can be divided into several parts: gradient calculation, function enablement, and torque control. The gradient calculation involves adjusting the slope based on vehicle speed and the rate of change of acceleration. The higher the absolute value of the vehicle speed, the larger the gradient can be calculated, using a speed-based lookup table. For example, when the vehicle speed is ≥15 km / h, the gradient is ±20 pptps; when 15 km / h ≥ 10 km / h, the gradient is ±10 pptps; when 10 km / h ≥ 5 km / h, the gradient is ±5 pptps; and when 5 km / h ≥ 2 km / h, the gradient is ±2 pptps. When the vehicle is stationary, if the absolute speed is ≤1 km / h and there is a 5-second delay, the gradient can be locked. When the vehicle is out of a stationary state, if the absolute speed is ≥3 km / h and there is a 1-second delay, the gradient will resume calculation as described above. The purpose of this processing is to ensure that at higher vehicle speeds, the calculated gradient changes more quickly to keep up with actual road conditions. At this speed, the parking assist function is not activated, so even if the calculated gradient fluctuates significantly, it's acceptable. At lower vehicle speeds, the actual road conditions change more slowly, and the parking assist function is about to activate. To reduce fluctuations in the calculated gradient, the gradient is slowed down. This prevents the calculated gradient from being difficult to accurately reflect when the vehicle is about to stop and the parking assist function is activated. When the absolute value of the acceleration change rate (ActAx) from the accelerometer is greater than 10 mps³, or the absolute value of the acceleration change rate (CalAx) calculated from the vehicle speed is greater than 10 mps³, the slope of the calculated gradient can be reduced. A slope can be created using a lookup table of the ActAx / CalAx acceleration change rates. For example, if the absolute value of the acceleration change rate is ≥30 mps³, the slope is ±1 pctps; 30 mps³ ≥ 20 mps³, the slope is ±2 pctps; 20 mps³ ≥ 10 mps³, the slope is ±5 pctps; 10 mps³ ≥ 5 mps³, the slope is ±10 pctps; 5 mps³ ≥ 2 mps³, the slope is ±15 pctps; and 2 mps³ ≥ the absolute value of the acceleration change rate, the slope is ±20 pctps.

[0088] Function enable conditions: Driving mode is off-road mode, gear is drive, calculated gradient is greater than 40%, master cylinder pressure is greater than 45 bar, vehicle speed is ≥2 km / h ≥ -5 km / h, throttle is less than 10%, relevant sensor signals are valid, master cylinder pressure, vehicle speed, motor speed, and acceleration are all valid. Exit conditions: Gear is non-drive mode, calculated gradient is less than 30%, master cylinder pressure is less than 40 bar with a 2-second delay to prevent the vehicle from rolling back when the driver releases the brake pedal to start; vehicle speed is ≥5 km / h or ≤-10 km / h, throttle opening is greater than 20% and the driver's required torque is greater than the hill-start assist control torque, relevant sensor signals are invalid, master cylinder pressure, vehicle speed, motor speed, or acceleration are all valid.

[0089] Torque control: When the hill brake assist control function is not activated or is deactivated, the calculated rear axle hill-hold assist control torque is zero; when the hill brake assist control function is activated, the calculated rear axle hill-hold assist control torque is as follows:

[0090] Rear axle hill-start assist control torque T = feedforward torque parameter Tpre + closed-loop control torque control parameter TPI;

[0091] Feedforward torque parameter Tpre=Min (rear axle mechanical braking torque) Safety factor (feedforward torque limit);

[0092] Among them, the feedforward torque parameter is not allowed to exceed the mechanical braking torque of the rear axle, and the safety factor can be taken as 0.7~0.8.

[0093] Rear axle mechanical braking torque = brake hydraulic clamping force Brake friction coefficient Caliper effective radius;

[0094] The feedforward torque limit is mainly designed to prevent the calculated feedforward value from being too large, ensuring it adapts to the current slope. The feedforward torque limit can be obtained by calculating the two-dimensional mapping relationship between the slope and the master cylinder pressure. The specific calculation process is as follows: Rear axle adhesion torque = Vehicle weight vertical component along the slope. Equivalent Axle Load Distribution Factor Adhesion coefficient Tire radius; Front axle adhesion torque = vertical component of vehicle weight along the slope (1 - equivalent axle load distribution factor) Adhesion coefficient Tire radius; Effective mechanical braking torque = [Min(Front axle mechanical braking torque, Front axle adhesion torque) + Min(Rear axle mechanical braking torque, Rear axle adhesion torque)]; Feedforward torque limit = (Vehicle weight rolling downhill torque - Effective mechanical braking torque) Redundancy coefficient + slope delay compensation value; where the redundancy coefficient is 1.1~1.2.

[0095] The feedforward torque limit calculation is divided into two stages. In the first stage, within the first 3 seconds after the function is activated, there is a delay in calculating the slope. The actual slope value is calculated, but it takes 2 seconds of uphill climbing for the calculated value to catch up with the actual value. Therefore, the slope delay compensation value in the feedforward torque limit is increased as the master cylinder pressure increases. For example, if the master cylinder pressure is ≥100 bar, the slope delay compensation value is 2000 Nm; if the master cylinder pressure is ≥80 bar, the slope delay compensation value is 1500 Nm; if the master cylinder pressure is ≥60 bar, the slope delay compensation value is 1000 Nm; and if the master cylinder pressure is ≥40 bar, the slope delay compensation value is 500 Nm. In the second stage, after 3 seconds of function activation, the calculated slope is close to the actual slope. At this time, the slope delay compensation value in the feedforward torque limit needs to be reset to zero with a certain slope.

[0096] After calculating the closed-loop control torque TPI and activating the hill-start assist control function, based on the rear axle feedforward torque, proportional-integral closed-loop control can be performed according to the rear axle motor speed fluctuations to suppress potential rollback and unexpected acceleration tendencies and keep the vehicle stable on the slope. When the vehicle comes to a standstill (i.e., the absolute speed ≤ 1 km / h with a 5-second delay), the I-term control parameter can be latched; when the rear motor speed comes to a standstill (i.e., the absolute speed ≤ 10 rpm with a 5-second delay), the I-term control parameter can also be latched. The P / I-term control parameter can be mapped based on the two-dimensional relationship between the target difference of the rear axle motor speed and the calculated slope. The larger the target speed difference or the larger the calculated slope, the larger the control parameter will be. The principle for determining the P / I-term control parameter is: when the vehicle is parked on a slope and shows a tendency to roll backward or accelerate forward, the closed-loop control torque TPI can suppress this tendency within 1 second to avoid driver panic and unexpected situations.

[0097] When the hill start assist control function is disengaged, the hill start assist torque reset process for the rear axle can be controlled in two ways: First, if the function is abnormally disengaged, such as when the sensor signal is invalid and the master cylinder pressure is still greater than 45 bar, the torque reset slope needs to be reduced to a smaller angle, such as 500 Nmps, to mitigate the tendency to roll backward after the function is disengaged. Second, if the function is normally disengaged, such as when starting on a slope with the throttle opening ≥20% and the driver's torque demand is greater than the hill start assist torque, the torque reset slope needs to be increased to a larger angle, such as 2000 Nmps, to prevent interference with normal driving conditions. Regardless of which function is disengaged, if the vehicle speed exceeds 5 km / h during the torque reset process, the torque reset slope needs to be increased to 5000 Nmps to prevent unexpected acceleration of the vehicle.

[0098] For example, given a vehicle weight of 3200kg, wheelbase of 2.7m, load factor of 0.45, center of gravity height of 0.68m, rolling radius of 0.402m, current slope of 100%, and brake master cylinder pressure of 100bar, calculate the corresponding torque parameters: the downhill component of the vehicle weight is 22174N, and the downhill component of the vehicle weight is mg. sinα, where m is the vehicle weight and α is the slope angle; the vertical component of the vehicle weight along the slope is 22174 N, and the vertical component of the vehicle weight along the slope is mg. cosα, where m is the vehicle weight and α is the slope angle; equivalent axle load distribution factor = 0.198, equivalent axle load distribution factor = b / Lh / L tanα, where b / L is the load factor and α is the slope angle; the front axle mechanical braking torque is 11600 Nm, the front axle adhesion torque is 1768 Nm, the front axle effective mechanical braking torque is Min(11600, 1768) Nm, the rear axle mechanical braking torque is 4900 Nm, the rear axle adhesion torque is 7155 Nm, the rear axle effective mechanical braking torque is Min(4900, 7155) Nm, the effective mechanical braking torque is 6668 Nm, [Min(11600, 1768) + Min(4900, 7155)], the feedforward torque limit is 2470 Nm, the feedforward torque limit = (mg sinα r-Fb) γ, where r is the rolling radius, Fb is the effective mechanical braking torque, and γ is the redundancy coefficient, taken as 1.1. The feedforward torque value is equal to 2470 Nm, Min(4900 0.8, 2470).

[0099] Figure 2 This is a schematic diagram of an optional vehicle hill-start assist control technology framework according to an embodiment of the present invention, such as... Figure 2 As shown, the system acquires vehicle status data and road condition data; if the vehicle status data and road condition data meet the preset rear axle hill-start assist activation conditions, it determines that the vehicle has entered a hill-start parking scenario; based on the vehicle status data and road condition data, it determines the rear axle hill-start assist control torque; and based on the rear axle hill-start assist control torque, it controls the operation of the rear axle drive motor.

[0100] According to another aspect of the present invention, a vehicle hill-start assist control device is also provided. This device can execute the vehicle hill-start assist control method of the above embodiments. The specific implementation method and preferred application scenarios are the same as those of the above embodiments, and will not be repeated here.

[0101] Figure 3 This is a schematic diagram of a vehicle hill-start assist control device according to an embodiment of this application, such as... Figure 3 As shown, the device includes the following: an acquisition module 302, a determination module 304, and a control module 306.

[0102] The acquisition module 302 is used to acquire vehicle status data and road condition data of the vehicle; the determination module 304 is used to determine the rear axle parking assist control torque based on the vehicle status data and road condition data in response to the vehicle entering a slope parking scenario, wherein the rear axle parking assist control torque is used to control the operation of the rear axle drive motor of the vehicle to generate torque to assist the vehicle in parking on a slope; the control module 306 is used to control the operation of the rear axle drive motor based on the rear axle parking assist control torque.

[0103] The determination module is also used to determine the vehicle's feedforward torque parameters and closed-loop control torque parameters based on vehicle condition data and road condition data. The feedforward torque parameters represent the expected torque control parameters required by the predicted rear axle drive motor, and the closed-loop control torque parameters represent the control parameters that need to be used to compensate the torque of the rear axle drive motor. Based on the feedforward torque parameters and closed-loop control torque parameters, the rear axle hill-climbing auxiliary control torque is determined.

[0104] The vehicle status data includes at least first vehicle status data and second vehicle status data; the determination module is also used to acquire the first vehicle status data corresponding to the vehicle at the first moment; determine the feedforward torque parameters based on the first vehicle status data and road status data; control the operation of the rear axle drive motor based on the feedforward torque parameters, and acquire the second vehicle status data corresponding to the vehicle at the second moment; and determine the closed-loop control torque control parameters based on the second vehicle status data and road status data.

[0105] The determination module is further used to acquire vehicle weight, tire radius, front axle mechanical braking torque, and rear axle mechanical braking torque from the first vehicle condition data, and to acquire road slope and adhesion coefficient from the road condition data, wherein the adhesion coefficient is used to represent the friction coefficient between the road and the tire; based on vehicle weight, tire radius, road slope, and adhesion coefficient, the rear axle adhesion torque and front axle adhesion torque of the vehicle are determined; based on the rear axle adhesion torque, front axle adhesion torque, front axle mechanical braking torque, and rear axle mechanical braking torque, the feedforward torque parameter is determined.

[0106] The determination module is also used to determine the effective mechanical braking torque of the vehicle based on the rear axle adhesion torque, front axle adhesion torque, front axle mechanical braking torque, and rear axle mechanical braking torque; and to determine the feedforward torque parameters based on the effective mechanical braking torque, vehicle weight, and road slope.

[0107] The determination module is also used to determine the downhill sliding moment of the vehicle weight along the slope based on the vehicle weight and the road gradient; and to determine the feedforward torque parameters based on the downhill sliding moment of the vehicle weight and the effective mechanical braking torque.

[0108] The determination module is also used to obtain the rear axle drive motor speed from the second vehicle condition data and the road slope from the road condition data; determine the target difference between the rear axle drive motor speed and the preset vehicle parking motor speed; and determine the closed-loop control torque control parameters based on the target difference and the road slope.

[0109] The determination module is also used to obtain vehicle speed parameters and acceleration parameters from vehicle condition data, and to obtain the initial road slope from road condition data; based on the vehicle speed parameters and / or acceleration parameters, it determines the slope update range, wherein the slope update range is positively correlated with the vehicle speed parameters and negatively correlated with the acceleration parameters; based on the slope update range, it updates the initial road slope to obtain the road slope.

[0110] The determination module is also used to obtain preset rear axle hill-start assist activation conditions and preset rear axle hill-start assist deactivation conditions; when the vehicle condition data and road condition data meet the preset rear axle hill-start assist activation conditions, it determines that the vehicle has entered the hill-start parking scenario; when the vehicle condition data and road condition data meet the preset rear axle hill-start assist deactivation conditions, it determines that the vehicle has exited the hill-start parking scenario.

[0111] According to another aspect of the present invention, an electronic device is also provided, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods of various embodiments of the present invention during runtime.

[0112] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is executed, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of the present invention.

[0113] According to another aspect of the present invention, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of the present invention.

[0114] According to another aspect of the present invention, a computer program product is also provided, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods of various embodiments of the present invention.

[0115] According to another aspect of the present invention, a computer program is also provided, which, when executed by a processor, implements the methods of the various embodiments of the present invention.

[0116] Embodiments of this application also provide an electronic device, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of the present invention during runtime.

[0117] The aforementioned memory can refer to devices inside a computer used to store data and programs, including RAM, hard disks, etc. RAM can be used to temporarily store running programs and data, while hard disks can be used to store programs and data long-term. Memory enables the computer to read and write data and execute programs. The aforementioned processor is responsible for executing instructions in computer programs and performing data processing. It can also be responsible for controlling and executing various operations, including arithmetic operations, logical operations, and data transmission.

[0118] Embodiments of this application also provide a computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of the present invention.

[0119] The aforementioned computer storage media can refer to the media used in computer memory to store certain discontinuous physical quantities. Computer storage media mainly include semiconductors, magnetic cores, magnetic drums, magnetic tapes, laser discs, etc. Computer-readable storage media include stored programs, which can be a set of instructions that a computer can recognize and execute, running on an electronic computer to meet certain information needs.

[0120] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the methods of various embodiments of the present invention.

[0121] The aforementioned computer program products can refer to software programs that have been written, tested, and released, and can run on computers or other devices. Computer program products can include application programs, operating systems, utility software, etc., used to achieve specific functions or solve specific problems.

[0122] Embodiments of this application also provide a computer program product, including a non-volatile computer-readable storage medium for storing a computer program that, when executed by a processor, implements the methods in various embodiments of the present invention.

[0123] The aforementioned non-volatile computer-readable storage medium can refer to a medium for storing data. Non-volatile computer-readable storage media can retain data without loss when power is off and can be used to store long-term data, such as operating systems, applications, and user files. Non-volatile storage media can include hard disk drives, solid-state drives, optical disks, and flash memory storage devices, etc.

[0124] Embodiments of this application also provide a computer program that, when executed by a processor, implements the methods described in the various embodiments of the present invention.

[0125] The aforementioned computer program can refer to a set of instructions used to tell the computer to perform specific tasks or operations. Computer programs can be written by programmers using specific programming languages ​​and can include algorithms, data structures, logic, and control flow. Computer programs can be used for a variety of purposes, including application software, operating systems, etc.

[0126] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0127] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection can be through some interfaces; the indirect coupling or communication connection between units or modules can be electrical or other forms.

[0128] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0129] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0130] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0131] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for assisting vehicle parking on slopes, characterized in that, include: Obtain vehicle status data and road condition data where the vehicle is located; In response to the vehicle entering a hillside parking scenario, based on the vehicle status data and the road status data, a rear axle hillside parking assist control torque is determined, wherein the rear axle hillside parking assist control torque is used to control the operation of the vehicle's rear axle drive motor to generate torque to assist the vehicle in hillside parking. The rear axle drive motor is controlled to operate based on the rear axle hill-climbing auxiliary control torque.

2. The vehicle slope parking assist control method according to claim 1, characterized in that, Based on the vehicle condition data and the road condition data, the rear axle hill-start assist control torque is determined, including: Based on the vehicle condition data and the road condition data, the feedforward torque parameter and the closed-loop control torque parameter of the vehicle are determined. The feedforward torque parameter is used to represent the expected torque control parameter required by the predicted rear axle drive motor, and the closed-loop control torque parameter is used to represent the control parameter that needs to be torque compensated for the rear axle drive motor. Based on the feedforward torque parameters and the closed-loop control torque parameters, the rear axle hill-holding auxiliary control torque is determined.

3. The vehicle slope parking assist control method according to claim 2, characterized in that, The vehicle status data includes at least first vehicle status data and second vehicle status data; Based on the vehicle condition data and the road condition data, the feedforward torque parameters and closed-loop control torque control parameters of the vehicle are determined, including: Obtain the first vehicle status data corresponding to the vehicle at the first moment; The feedforward torque parameter is determined based on the first vehicle condition data and the road condition data; Based on the feedforward torque parameters, the operation of the rear axle drive motor is controlled, and the second vehicle status data corresponding to the vehicle at the second moment is obtained; Based on the second vehicle condition data and the road condition data, the closed-loop control torque control parameters are determined.

4. The vehicle slope parking assist control method according to claim 3, characterized in that, Based on the first vehicle condition data and the road condition data, the feedforward torque parameters of the vehicle are determined, including: The vehicle weight, tire radius, front axle mechanical braking torque, and rear axle mechanical braking torque are obtained from the first vehicle condition data, and the road slope and adhesion coefficient are obtained from the road condition data, wherein the adhesion coefficient is used to represent the friction coefficient between the road and the tire. Based on the vehicle weight, the tire radius, the road slope, and the adhesion coefficient, the rear axle adhesion torque and the front axle adhesion torque of the vehicle are determined. The feedforward torque parameter is determined based on the rear axle adhesion torque, the front axle adhesion torque, the front axle mechanical braking torque, and the rear axle mechanical braking torque.

5. The vehicle slope parking assist control method according to claim 4, characterized in that, Based on the rear axle adhesion torque, the front axle adhesion torque, the front axle mechanical braking torque, and the rear axle mechanical braking torque, the feedforward torque parameters are determined, including: The effective mechanical braking torque of the vehicle is determined based on the rear axle adhesion torque, the front axle adhesion torque, the front axle mechanical braking torque, and the rear axle mechanical braking torque. The feedforward torque parameters are determined based on the effective mechanical braking torque, the vehicle weight, and the road gradient.

6. The vehicle slope parking assist control method according to claim 5, characterized in that, Based on the effective mechanical braking torque, the vehicle weight, and the road gradient, the feedforward torque parameters are determined, including: Based on the vehicle weight and the road slope, determine the downward sliding moment of the vehicle weight along the slope; The feedforward torque parameter is determined based on the vehicle weight's downward sliding torque along the slope and the effective mechanical braking torque.

7. The vehicle slope parking assist control method according to claim 3, characterized in that, Based on the second vehicle condition data and the road condition data, the closed-loop control torque control parameters are determined, including: Obtain the rear axle drive motor speed from the second vehicle condition data, and obtain the road gradient from the road condition data; Determine the target difference between the speed of the rear axle drive motor and the preset speed of the vehicle parking motor; Based on the target difference and the road slope, the closed-loop control torque control parameters are determined.

8. The vehicle slope parking assist control method according to any one of claims 4 to 7, characterized in that, Obtaining the road slope from the road condition data includes: Obtain the vehicle speed and acceleration parameters from the vehicle condition data, and obtain the initial road gradient from the road condition data; Based on the vehicle speed parameters and / or acceleration parameters, the slope update magnitude is determined, wherein the slope update magnitude is positively correlated with the vehicle speed parameters and negatively correlated with the acceleration parameters; Based on the slope update magnitude, the initial road slope is updated to obtain the road slope.

9. The vehicle hill-start assist control method according to any one of claims 1 to 7, characterized in that, The method further includes: Obtain the preset activation conditions and deactivation conditions for the rear axle slope-holding assist; If the vehicle condition data and the road condition data meet the preset rear axle parking assist activation conditions, it is determined that the vehicle enters the slope parking scenario. If the vehicle condition data and the road condition data meet the preset rear axle hill-start assist exit conditions, the vehicle is determined to exit the hill-start parking scenario.

10. A vehicle hill-start assist control device, characterized in that, include: The acquisition module is used to acquire vehicle status data and road condition data where the vehicle is located; The determination module is used to respond to the scenario of the vehicle entering a slope parking, and determine the rear axle parking assist control torque based on the vehicle condition data and the road condition data, wherein the rear axle parking assist control torque is used to control the operation of the rear axle drive motor of the vehicle to generate torque to assist the vehicle in parking on a slope. The control module is used to control the operation of the rear axle drive motor based on the rear axle parking assist control torque.

11. An electronic device, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program executes the vehicle hill-start assist control method according to any one of claims 1 to 9 when it runs.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device on which the storage medium is located to perform the vehicle hill-start assist control method according to any one of claims 1 to 9.

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