A Multimodal Vehicle Slope-Running Dynamic Control Method and System

Abstract

This invention provides a multimodal vehicle rollback dynamic control method and system. The method includes real-time acquisition of vehicle operating status parameters, including actual motor speed, actual motor torque, gear information, accelerator pedal opening, brake pedal opening, and vehicle fault information; determining the vehicle's rollback state based on the operating status parameters; dynamically selecting the vehicle's parking control mode according to the rollback state, and acquiring and storing the instantaneous actual motor torque at the corresponding moment when the parking control mode is switched; and generating motor control commands for adjusting the target motor torque or controlling the release of parking action based on the parking control mode, actual motor torque, vehicle load, and driver operation, to achieve anti-rollback control during vehicle start-up.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a multimodal dynamic control method and system for vehicle rollover. Background Technology

[0002] With the increasing popularity of electric vehicles, parking and anti-rollback control on slopes have become critical safety requirements. Current technologies primarily rely on zero-speed parking mode or electronic parking brake (EPB) systems for anti-rollback on slopes. Zero-speed parking mode relies solely on motor torque to keep the vehicle stationary; however, on steep slopes or for extended parking times, the motor may overheat due to continuous stall torque output. Furthermore, the fixed threshold for rollback detection cannot be dynamically adjusted based on the actual slope, vehicle load, and motor status, affecting control reliability. Electronic parking brake systems may experience rollback or power surges due to insufficient torque or high torque demands when the throttle is engaged or during downhill starts, posing safety risks. In addition, some solutions rely on slope sensors for slope detection, which not only increases hardware costs but also limits application in vehicles without sensors. Summary of the Invention

[0003] The purpose of this invention is to provide a multimodal vehicle slope dynamic control method and system to achieve dynamic adjustment of vehicle start-up anti-slip control and parking release under different slope and load conditions, so as to ensure the safety and reliability of the vehicle start-up process.

[0004] In a first aspect, the present invention provides a multimodal vehicle rollaway dynamic control method, comprising:

[0005] The vehicle's operating status parameters are acquired in real time, including the actual motor speed, actual motor torque, gear information, accelerator pedal opening, brake pedal opening, and vehicle fault information.

[0006] Based on the operating status parameters, the slope slippage status of the vehicle is determined;

[0007] Based on the slope slippage state, the vehicle's parking control mode is dynamically selected, and the instantaneous actual motor torque of the vehicle at the corresponding moment is acquired and stored when the parking control mode is switched.

[0008] Based on the parking control mode, the actual motor torque, the vehicle load, and the driver's operation, motor control commands are generated to adjust the target motor torque or to control the release of parking, so as to achieve anti-rollover control during vehicle start-up.

[0009] Optionally, the specific steps for determining the vehicle's slope slippage state based on the operating state parameters include:

[0010] When the vehicle is in forward gear and the actual speed of the motor is lower than the negative value of the first preset threshold for a period of time, or when the vehicle is in reverse gear and the actual speed of the motor is higher than the positive value of the first preset threshold for a period of time, the vehicle is determined to be in a slight rollback state.

[0011] When the vehicle is in forward gear and the actual speed of the motor is lower than the negative value of the second preset threshold for a period of time, or when the vehicle is in reverse gear and the actual speed of the motor is higher than the positive value of the second preset threshold for a period of time, the vehicle is determined to be in a large rollback state.

[0012] Optionally, the method for determining the first preset threshold and the second preset threshold includes:

[0013] Obtain the slope information of the current slope where the vehicle is located, and calculate the corresponding slope speed threshold based on the slope information and the preset allowable displacement of the slope using vehicle dynamics.

[0014] Convert the slope speed threshold into a motor speed threshold;

[0015] Based on the accelerator pedal opening, the motor speed threshold is corrected to obtain the first preset threshold and the second preset threshold used for determining the slope.

[0016] Optionally, the specific steps of dynamically selecting the vehicle's parking control mode based on the slope slippage state, and acquiring and storing the vehicle's instantaneous actual motor torque at the corresponding moment when the parking control mode is switched include:

[0017] When the vehicle is in the small slope state, put the vehicle into the first parking mode and record the duration of the vehicle in the first parking mode.

[0018] When the duration of the first parking mode reaches the third preset time, the vehicle exits the first parking mode and enters the second parking mode, and the instantaneous actual motor torque at the time of exiting the first parking mode is acquired and stored.

[0019] When the vehicle meets the first preset exit condition in the first parking mode, or when the vehicle has a serious malfunction, the vehicle exits the first parking mode and enters the third parking mode.

[0020] When the vehicle is on a steep incline, switch the vehicle to the fourth parking mode.

[0021] Optionally, the first preset exit condition includes:

[0022] The vehicle is in forward gear and the motor speed is less than a third preset threshold; or the vehicle is in reverse gear and the motor speed is greater than a third preset threshold; or the target torque of the motor is continuously higher than the actual torque of the motor for a duration that reaches a third preset time.

[0023] Optionally, the specific steps for generating motor control commands to adjust the target motor torque or to control the release of parking action based on the parking control mode, the actual motor torque, the vehicle load, and the driver's operation include:

[0024] When the vehicle is in the first parking mode and the second preset exit condition is met, it exits the first parking mode and acquires and stores the real-time actual motor torque when exiting the first parking mode.

[0025] The target torque of the motor is determined based on the actual real-time torque of the motor and the target corrected torque obtained by looking up the table according to the slope information;

[0026] The parking release torque is determined based on the vehicle weight and the slope information.

[0027] When the vehicle is in the second parking mode, the driver presses the accelerator pedal and the actual torque of the motor is greater than the fourth preset threshold, the parking valve is released. The fourth preset threshold is the larger value between the parking release torque and the instantaneous actual torque of the motor.

[0028] When the vehicle is in the third or fourth parking mode, and the driver presses the accelerator pedal, and the actual torque of the motor is greater than the parking release torque, the parking valve is released.

[0029] Optionally, the second preset exit condition includes:

[0030] The vehicle has a crawl function. The driver does not press the accelerator pedal, and the actual speed of the forward gear motor is greater than the negative value of the third preset threshold or the actual speed of the reverse gear motor is less than the positive value of the third preset threshold; or the driver presses the accelerator pedal, the target torque of the motor corresponding to the pedal is greater than the actual torque of the motor, and the actual speed of the forward gear motor is greater than the negative value of the third preset threshold or the actual speed of the reverse gear motor is less than the positive value of the third preset threshold.

[0031] Optionally, it also includes:

[0032] When the vehicle is parked on a slope, the driver shifts gears, causing the vehicle to shift from forward to reverse, or vice versa, putting the vehicle in a downhill position. The parking brake is released when the driver lightly presses the accelerator pedal.

[0033] Optionally, the specific steps for obtaining the slope information of the current slope where the vehicle is located include:

[0034] The slope is calculated by the ratio of the GPS elevation change rate to the horizontal velocity, and the GPS estimated slope is obtained.

[0035] The gradient is calculated by measuring the actual longitudinal acceleration of the vehicle, and the gradient is estimated by acceleration.

[0036] The weights of the GPS-estimated slope and the acceleration-estimated slope are determined based on the vehicle's speed, and the GPS-estimated slope and the acceleration-estimated slope are weighted and fused to obtain the slope information of the slope where the vehicle is currently located.

[0037] Secondly, the present invention provides a multimodal vehicle rollaway dynamic control system, the system comprising:

[0038] The data acquisition module is used to acquire the vehicle's operating status parameters in real time. These operating status parameters include the actual motor speed, actual motor torque, gear information, accelerator pedal opening, brake pedal opening, and vehicle fault information.

[0039] The slope condition determination module is used to determine the vehicle's slope slippage state based on the operating state parameters.

[0040] The parking control module is used to dynamically select the vehicle parking control mode according to the slope slippage state, and to acquire and store the instantaneous actual motor torque of the vehicle at the corresponding moment when the parking control mode is switched.

[0041] The motor control module is used to generate motor control commands based on the parking control mode, the actual motor torque, the vehicle load, and the driver's operation. The motor control commands are used to adjust the target motor torque or control the release of the parking action to achieve anti-rollover control during vehicle start-up.

[0042] According to the present invention, by acquiring the vehicle's operating status parameters in real time and combining them with the actual motor torque, gear information, driver operation, and vehicle fault information, the vehicle's rollback status on a slope can be dynamically determined, enabling intelligent selection of the parking control mode. During the starting process, based on control commands generated from real-time motor torque and vehicle load, the target motor torque can be precisely adjusted or the parking action can be released, thereby effectively preventing the vehicle from rolling backward when starting on a slope, improving the stability and safety of starting, while ensuring the continuity and comfort of driver operation.

[0043] Furthermore, by classifying and identifying minor and major slopes, and combining motor speed and time thresholds, dynamic selection of the parking mode is achieved, enabling dynamic control of vehicle start-up, anti-slippage, and parking release. This control logic can adapt to different slopes, vehicle loads, and driver operating conditions, ensuring safe starting on both minor and major slopes. It also allows for rapid parking release when the driver shifts to forward or reverse gear and lightly presses the accelerator, avoiding the risk of downhill impact caused by high torque, thus significantly improving vehicle driving safety and ease of operation.

[0044] Furthermore, by using multimodal fusion to accurately estimate vehicle slope information, including weighted processing of GPS elevation change rate and actual longitudinal acceleration of the vehicle, slope recognition has high accuracy and high reliability at different vehicle speeds, thus enabling dynamic slope judgment without the need for additional slope sensors.

[0045] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Attached Figure Description

[0046] Figure 1 A schematic flowchart of a multimodal vehicle rollaway dynamic control method according to an embodiment of the present invention is shown.

[0047] Figure 2 It shows Figure 1 A schematic flowchart of step S300, which dynamically selects the vehicle's parking control mode based on the slope slippage state and acquires and stores the instantaneous actual torque of the vehicle's motor at the corresponding moment when switching the parking control mode.

[0048] Figure 3 It shows Figure 1 A schematic flowchart of step S400 for generating motor control commands for adjusting the target torque of the motor or for controlling the release of parking action based on the parking control mode, the actual torque of the motor, the vehicle load, and the driver's operation.

[0049] Figure 4 A structural block diagram of a multimodal vehicle slope-rolling dynamic control system according to an embodiment of the present invention is shown. Detailed Implementation

[0050] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0051] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0052] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0053] Figure 1 A schematic flowchart of a multimodal vehicle rollaway dynamic control method according to an embodiment of the present invention is shown. Figure 1 As shown, the vehicle's dynamic slope control method includes:

[0054] Step S100: Real-time acquisition of vehicle operating status parameters, including actual motor speed, actual motor torque, gear information, accelerator pedal opening, brake pedal opening, and vehicle fault information.

[0055] In this step, by comprehensively acquiring the vehicle's operating status parameters, the vehicle's power status, driver's operating intentions, and overall vehicle safety status can be monitored in real time. This process not only provides an accurate data foundation for subsequent slope slippage judgment but also ensures that the system can respond promptly when vehicle anomalies or malfunctions occur, enhancing the safety and reliability of the entire control method. Furthermore, the multi-parameter fusion acquisition method reduces the risk of misjudgment caused by a single sensor malfunction, improving the overall robustness of the system.

[0056] Step S200: Determine the vehicle's slope slippage status based on the operating status parameters.

[0057] Step S200 dynamically identifies the rollback status, enabling the system to differentiate starting risks under different slopes and loads, providing a basis for selecting the appropriate parking control mode. This not only improves the accuracy of preventing rollback during vehicle start-up but also avoids the problems of response lag or excessive torque output that may occur with traditional fixed threshold methods under small or large slope conditions, thereby improving the safety and comfort of control.

[0058] Step S300: Based on the slope slippage state, dynamically select the vehicle's parking control mode, and acquire and store the vehicle's instantaneous motor actual torque at the corresponding moment when switching the parking control mode.

[0059] In this step, the system dynamically selects the vehicle's parking control mode based on the determined slope slippage condition, and acquires and stores the instantaneous actual motor torque at the corresponding moment when switching modes. This design allows the system to adopt different parking strategies for different slippage levels, thereby ensuring vehicle stability while reducing the continuous load on the motor. Storing the instantaneous actual motor torque provides a reference basis for subsequent torque adjustment, making motor control more precise. This ensures sufficient starting torque while reducing energy consumption and motor wear, and also provides data support for fault tolerance under abnormal operating conditions.

[0060] Step S400: Based on the parking control mode, the actual motor torque, the vehicle load, and the driver's operation, generate motor control commands for adjusting the target motor torque or for controlling the release of parking action, so as to achieve anti-rollover control during vehicle start-up.

[0061] According to the above embodiments, by acquiring the vehicle's operating status parameters in real time and combining them with the actual motor torque, gear information, driver operation, and vehicle fault information, the vehicle's rolling backward state on a slope can be dynamically determined, enabling intelligent selection of the parking control mode. During the starting process, based on control commands generated from real-time motor torque and vehicle load, the target motor torque can be precisely adjusted or the parking action can be released, thereby effectively preventing the vehicle from rolling backward when starting on a slope, improving the stability and safety of starting, while ensuring the continuity and comfort of driver operation.

[0062] In one embodiment, step S200 specifically includes:

[0063] Step S210: When the vehicle is in forward gear and the actual motor speed is lower than the negative value of the first preset threshold for a duration exceeding the first preset time, or when the vehicle is in reverse gear and the actual motor speed is higher than the positive value of the first preset threshold for a duration exceeding the first preset time, the vehicle is determined to be in a small rollback state.

[0064] Step S210 identifies whether the vehicle is in a slight roll-off state by determining the actual motor speed and duration when the vehicle is in forward or reverse gear. Step S210 can sensitively detect the roll-off trend under slight slope or low load conditions, thereby triggering the corresponding parking control strategy in advance, avoiding potential safety hazards caused by overlooking slope changes, while reducing excessive reliance on motor output and improving the vehicle's energy efficiency and response speed in slight slope environments.

[0065] Step S220: When the vehicle is in forward gear and the actual motor speed is lower than the negative value of the second preset threshold for a duration exceeding the second preset time, or when the vehicle is in reverse gear and the actual motor speed is higher than the positive value of the second preset threshold for a duration exceeding the second preset time, the vehicle is determined to be in a large rollback state.

[0066] Step S220 can identify working conditions with a large slope or obvious tendency to slide downhill, providing a basis for subsequent selection of a more reliable parking control mode or adjustment of motor torque, thereby ensuring the parking safety and starting stability of the vehicle on complex slopes, and reducing the risk of overheating caused by long-term high-load operation of the motor.

[0067] In steps S210 and S220, the positive and negative values ​​of the thresholds correspond to the direction of vehicle rollback in different gears: when in the current gear, a negative actual motor speed indicates that the vehicle is trending backward; while in reverse gear, a positive actual motor speed indicates that the vehicle is trending forward. By setting different speed thresholds and time conditions, not only can the severity of the rollback be accurately distinguished, but the method can also be applied to both forward and reverse driving conditions, improving the comprehensiveness and reliability of the judgment.

[0068] In one embodiment, the method for determining the first preset threshold and the second preset threshold includes:

[0069] The system acquires the slope information of the current slope the vehicle is on, and calculates the corresponding rollback speed threshold based on the slope information and the preset allowable rollback displacement using vehicle dynamics. This process quantifies the rollback trend based on the actual operating conditions of the vehicle, giving subsequent judgment criteria a physical basis and adjustability, and avoiding the inadequacy caused by using a single empirical threshold.

[0070] The vehicle speed threshold for slope slippage is converted into a motor speed threshold. By considering the characteristics of the transmission system and the dynamic coupling relationship, a precise mapping between the speed domain and the motor speed domain is achieved, thereby ensuring that the slope slippage determination directly affects the motor control level and improving the application efficiency and accuracy of the calculation results.

[0071] Based on the accelerator pedal opening, the motor speed threshold is corrected to obtain the first and second preset thresholds used for rollback determination. This correction dynamically reflects the driver's intention, making rollback determination more consistent with actual driving behavior, avoiding misjudgments or response delays caused by changes in driver operation, and further improving the sensitivity and adaptability of the system control.

[0072] The following section uses the first preset threshold as an example to illustrate the specific formula:

[0073] Speed ​​threshold for a slight incline The calculation formula is:

[0074]

[0075] Among them, S MicroHillHld The allowable displacement of the small slope is obtained from a table based on the slope, where g is the acceleration due to gravity, taken as 9.81 m / s². 2 , The slope angle is (°).

[0076] Convert the vehicle speed threshold on the small slope into the corresponding motor speed threshold. :

[0077]

[0078] Where i is the reduction ratio and r is the tire rolling radius (m).

[0079] A dynamic correction mechanism based on the driver's operating intention is introduced. That is, when the driver presses the accelerator pedal, the judgment threshold is increased to avoid misjudgment or unnecessary control intervention. The specific formula is as follows:

[0080] =1.0 + 0.5 × accelerator pedal opening percentage;

[0081] The final first preset threshold is:

[0082]

[0083] The calculation method for the second preset threshold under the steep slope is the same as the calculation method for the first preset threshold.

[0084] Figure 2 It shows Figure 1 A schematic flowchart illustrating step S300's dynamic selection of the vehicle's parking control mode based on the slope's slippage condition, and the acquisition and storage of the vehicle's instantaneous motor torque at the corresponding moment during parking control mode switching. (See attached flowchart.) Figure 2 As shown, step S300 includes:

[0085] Step S310: When the vehicle is in a small slope state, put the vehicle into the first parking mode and record the duration of the vehicle in the first parking mode.

[0086] Step S310 achieves efficient control of slight incline conditions by selecting the first parking mode when the vehicle is on a slight incline and recording its duration. In one embodiment, the first parking mode is the zero-speed parking mode, which mainly relies on motor torque to keep the vehicle stationary, avoiding frequent operation of the electronic parking mechanism, reducing wear on mechanical components and system energy consumption. Simultaneously, recording the duration provides a basis for determining whether to switch to other modes later, thereby improving the rationality and responsiveness of the overall control strategy.

[0087] Step S320: When the duration of the first parking mode reaches the third preset time, the vehicle exits the first parking mode and enters the second parking mode, and the instantaneous actual motor torque at the time of exiting the first parking mode is acquired and stored.

[0088] In step S320, after the first hill-start assist mode has been in effect for a third preset time, the vehicle is forcibly switched to the second hill-start assist mode, and the instantaneous actual motor torque at the time of exiting the first hill-start assist mode is stored. In one embodiment, the second hill-start assist mode uses a two-pin parking valve for parking, which provides mechanical locking to prevent the motor from overheating due to prolonged output of stall torque, while also improving parking stability. Storing the instantaneous motor torque provides a reference for dynamic compensation of subsequent starting torque, making the starting process more accurate and reliable.

[0089] Step S330: When the vehicle meets the first preset exit condition in the first parking mode, or when the vehicle has a serious malfunction, the vehicle exits the first parking mode and enters the third parking mode.

[0090] Step S330 switches control to the third parking mode when specific exit conditions are met or a serious vehicle malfunction occurs. In one embodiment, this third parking mode also uses a dual-pin parking valve for parking, which can quickly provide reliable braking lock-up in cases of insufficient motor performance or malfunction, ensuring that the vehicle does not roll back due to insufficient torque. By using a dual-pin parking valve, braking redundancy and reliability are significantly improved, helping to enhance the vehicle's safety protection capabilities in extreme scenarios.

[0091] In one embodiment, the first preset exit condition includes the vehicle being in forward gear and the motor speed being less than a third preset threshold, or the vehicle being in reverse gear and the motor speed being greater than the third preset threshold, or the target torque of the motor being continuously higher than the actual torque of the motor for a duration of a third preset time. When the vehicle is in forward gear and the motor speed is lower than the third preset threshold, or the vehicle is in reverse gear and the motor speed is higher than the third preset threshold, it indicates that the motor speed deviates from the normal parking range and may not be able to effectively keep the vehicle stationary. When the target torque of the motor is continuously higher than the actual torque for a duration of a third preset time, it indicates that the current motor output may be insufficient to cope with the tendency to roll backward. By setting this first preset exit condition, the system can dynamically determine whether to switch to the parking mode using a dual-pin parking valve based on the real-time motor status and vehicle gear position, thereby ensuring the safety and reliability of the vehicle during hill parking. The introduction of this first preset exit condition can identify potential rolling backward risks in advance, prevent the zero-speed parking mode from failing under extreme conditions, enhance the robustness of parking control, and provide a reliable basis for subsequent starting or torque adjustment.

[0092] Step S340: When the vehicle is on a steep slope, put the vehicle into the fourth parking mode.

[0093] Step S340 directly enters the fourth parking mode when the vehicle is on a steep incline. In one embodiment, this fourth parking mode also uses a dual-pin parking valve for parking, providing stronger parking force for high-slope or high-load conditions. This mode can achieve rigid locking on dangerous slopes, prevent slippage, and ensure the absolute safety and stability of the vehicle before starting.

[0094] In some embodiments, the mechanical parking actuator of the present invention employs a two-pin parking valve, achieving safe and reliable control under abnormal operating conditions through optimized electrical control logic and fail-safe design. The two-pin parking valve uses a high-level trigger for parking and a low-level trigger for release, clearly distinguishing the control state by level polarity and effectively avoiding malfunctions caused by signal interference. When the vehicle is in parking mode and a power outage occurs, the parking valve automatically enters a high-resistance state due to the loss of drive power, while still maintaining the parking action, thus avoiding the risk of parking release that may occur with conventional single-pin parking valves under power outage or signal interference conditions. Therefore, the present invention can significantly improve the safety and reliability of the parking control system under abnormal operating conditions.

[0095] Figure 3 It shows Figure 1 In step S400, a schematic flowchart is generated based on the parking control mode, actual motor torque, vehicle load, and driver operation to produce motor control commands for adjusting the target motor torque or for controlling the release of the parking brake. (See attached flowchart.) Figure 3 As shown, step S400 includes:

[0096] Step S410: When the vehicle is in the first parking mode and the second preset exit condition is met, exit the first parking mode and obtain and store the real-time actual motor torque when exiting the first parking mode.

[0097] In one embodiment, the second preset exit condition includes the vehicle having a crawl function, the driver not pressing the accelerator pedal, and the actual speed of the vehicle's forward gear motor being greater than a negative value of the third preset threshold or the actual speed of the reverse gear motor being less than a positive value of the third preset threshold; or the driver pressing the accelerator pedal, the target torque of the motor corresponding to the pedal being greater than the actual torque of the motor, and the actual speed of the vehicle's forward gear motor being greater than a negative value of the third preset threshold or the actual speed of the reverse gear motor being less than a positive value of the third preset threshold.

[0098] Step S410 is used to determine whether the vehicle needs to exit the first hill-hold mode, and exits when the conditions are met, while acquiring and storing the real-time actual motor torque. By introducing a second preset exit condition, the system can dynamically evaluate the continuous state of the zero-speed hill-hold mode based on driver operation and vehicle creep function. When the vehicle has creep function and the driver has not pressed the accelerator pedal, and the motor speed exceeds a set threshold, or when the driver actively presses the accelerator pedal, and the target motor torque corresponding to the pedal is greater than the actual motor torque and the motor speed exceeds the set threshold, the system determines that it needs to exit the first hill-hold mode. It should be noted that here, the motor speed exceeding the set threshold means that the actual motor speed in forward gear is greater than a negative value of the third preset threshold or the actual motor speed in reverse gear is less than a positive value of the third preset threshold. The advantage of step S410 is that it can promptly identify potential rolling back risks, avoid the zero-speed hill-hold mode from failing under specific operating conditions, and provide a reliable data basis for subsequent torque adjustment and parking release, improving starting safety and system robustness.

[0099] Step S420: Determine the target torque of the motor based on the real-time actual torque of the motor and the target corrected torque obtained by looking up the table according to the slope information.

[0100] Step S420 determines the target torque of the motor by combining the real-time actual motor torque with the target correction torque obtained from a slope lookup table. In this process, the real-time actual motor torque at the time of exiting the zero-speed parking mode is used as a reference value. The target motor torque is calculated by superimposing this reference torque with the additional target correction torque obtained from the slope lookup table. In this way, the system can dynamically adjust the motor output according to the actual vehicle condition and slope conditions, ensuring sufficient torque for the vehicle at start-up, guaranteeing a smooth start-up process, preventing rollback, and improving the reliability and safety of anti-rollback control.

[0101] Step S430: Determine the parking release torque based on vehicle weight and slope information.

[0102] Step S430 dynamically calculates the required parking release torque for different load and slope conditions, ensuring that the vehicle does not slide down when the parking is released, and also avoids unnecessary excessive torque output, thus balancing safety and power efficiency.

[0103] In one embodiment, the parking release torque is the torque used by the motor to overcome the resistance of the vehicle sliding down a slope. Its calculation takes into account both the vehicle weight and the slope influence coefficient K. The specific calculation formula is as follows:

[0104]

[0105] Where m is the total mass of the vehicle (kg), and g is the acceleration due to gravity, taken as 9.81 m / s². denoted as slope angle (°), r as tire rolling radius (m), i as reduction ratio, and K as a coefficient considering the influence of vehicle weight and slope.

[0106] Step S440: When the vehicle is in the second parking mode, the driver presses the accelerator pedal and the actual torque of the motor is greater than the fourth preset threshold, the parking valve is released. The fourth preset threshold is the larger value between the parking release torque and the instantaneous actual torque of the motor.

[0107] In this step, for the second parking slope mode, when the driver presses the accelerator pedal and the actual motor torque exceeds the fourth preset threshold, the parking release operation is executed. The fourth preset threshold is the larger of the calculated parking release torque and the instantaneous actual motor torque, ensuring sufficient parking release torque to prevent the vehicle from rolling backwards. This step S440 can dynamically respond based on real-time torque and driver operation, avoiding the risk of rolling backwards due to insufficient torque, while improving the convenience and safety of driver operation.

[0108] Step S450: When the vehicle is in the third or fourth parking mode, the driver presses the accelerator pedal and the actual torque of the motor is greater than the parking release torque, the parking valve is released.

[0109] Step S450 ensures that even in a more demanding hill-start assist mode, the release operation still matches the driver's intentions and the vehicle's power, thereby enabling a safe start, preventing the risk of slipping on downhill or steep slopes, and ensuring timely and reliable system response.

[0110] In one embodiment, the vehicle rollaway dynamic control method of the present invention further includes:

[0111] Step S500: After the vehicle is parked on the slope, when the driver shifts gears, causing the vehicle to shift from forward gear to reverse gear, or from reverse gear to forward gear, the vehicle is in a downhill state. The parking is released when the driver lightly presses the accelerator pedal.

[0112] Step S500 handles situations where the driver shifts gears while the vehicle is parked on a slope. When the vehicle shifts from drive to reverse, or vice versa, the system determines that the vehicle is on a downhill slope and automatically releases the parking brake when the driver lightly presses the accelerator pedal. Step S500 ensures safe control of the vehicle during gear shifting, avoiding the risk of the vehicle rolling backward or sliding due to sudden release of the parking brake or misoperation of the gear. Simultaneously, by responding to the driver's accelerator input, the system smoothly completes the parking brake release, allowing the vehicle to smoothly transition from a stationary state on the slope to a starting state, improving driving convenience and safety. This step is particularly suitable for multi-mode coordinated control under complex slope conditions, ensuring stable and reliable slope starts for the vehicle under different gradients and load conditions.

[0113] In one embodiment, for a vehicle without a slope sensor, the specific steps for obtaining the slope information of the current slope of the vehicle include:

[0114] The slope is estimated using GPS by calculating the ratio of the GPS elevation change rate to the horizontal speed. This step indirectly obtains the slope by utilizing the elevation change of the vehicle's location information. It allows for real-time updates of slope information during vehicle movement, providing a macroscopic reference for subsequent slope assessment. (GPS estimated slope) The specific calculation formula is as follows:

[0115] ;

[0116] in, The vehicle's current horizontal speed, This indicates the vehicle's current altitude.

[0117] The gradient is calculated by measuring the vehicle's actual longitudinal acceleration, resulting in an acceleration-estimated gradient. This step directly utilizes vehicle dynamics, capturing instantaneous gradient changes, and is particularly sensitive at low speeds or during start-up, facilitating accurate identification of the slope's inclination. Acceleration-Estimated Gradient The specific calculation formula is as follows:

[0118]

[0119]

[0120]

[0121] in, This represents the actual torque at the wheel end. denoted as , where is the actual resistance and m is the total vehicle mass.

[0122] The weights of GPS-estimated gradient and acceleration-estimated gradient are determined based on the vehicle's speed, and then weighted and fused to obtain the gradient information of the current slope the vehicle is on. GPS-estimated gradient is highly reliable at high speeds, but its accuracy is easily affected by noise at low speeds. Gradient estimation based on the vehicle's actual longitudinal acceleration is highly accurate in the short term, but may drift over long-term use due to accumulated errors in resistance calculations. This step, by fusing the two estimation results, balances the overall accuracy of GPS and the instantaneous response of acceleration, ensuring accurate reflection of the slope condition under different speeds and road conditions. The specific formula for the vehicle's current gradient is as follows:

[0123]

[0124] in, These are the weighting coefficients. This represents the vehicle's current horizontal speed.

[0125] According to the above embodiments, by classifying and identifying small and large slopes, and combining motor speed thresholds and time thresholds, dynamic selection of the parking mode is achieved, enabling dynamic control of vehicle start-up, anti-slippage, and parking release. This control logic can adapt to different slopes, vehicle loads, and driver operating conditions, ensuring safe starting on both small and large slopes. It also allows for rapid parking release when the driver shifts gears or lightly presses the accelerator, avoiding the risk of downhill impact caused by high torque, thereby significantly improving vehicle driving safety and operational convenience.

[0126] Furthermore, by using multimodal fusion to accurately estimate vehicle slope information, including weighted processing of GPS elevation change rate and actual longitudinal acceleration of the vehicle, slope recognition has high accuracy and high reliability at different vehicle speeds, thus enabling dynamic slope judgment without the need for additional slope sensors.

[0127] This invention also provides a multimodal vehicle rollaway dynamic control system, such as... Figure 4As shown, the vehicle rollback control system includes a data acquisition module 101, a slope condition determination module 102, a parking control module 103, and a motor control module 104. The data acquisition module 101 acquires real-time vehicle operating status parameters, including actual motor speed, actual motor torque, gear information, accelerator pedal opening, brake pedal opening, and vehicle fault information. The slope condition determination module 102 determines the vehicle's rollback state based on the operating status parameters. The parking control module 103 dynamically selects the vehicle parking control mode according to the rollback state and acquires and stores the instantaneous actual motor torque at the corresponding moment when switching parking control modes. The motor control module 104 generates motor control commands based on the parking control mode, actual motor torque, vehicle load, and driver operation. These commands adjust the target motor torque or control the release of the parking brake to achieve anti-rollback control during vehicle start-up.

[0128] The specific implementation of the vehicle slope dynamic control system based on the multimodal method described above refers to the relevant content of the embodiments in the above method, and will not be repeated here.

[0129] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A multi-modal based vehicle coasting dynamic control method, characterized in that, The method comprises: obtaining real-time running state parameters of the vehicle, the running state parameters comprising actual motor speed, actual motor torque, gear information, accelerator pedal opening, brake pedal opening, and vehicle fault information; determining the hill start state of the vehicle based on the running state parameters; dynamically selecting a vehicle parking control mode according to the hill start state, and obtaining and storing the instantaneous actual motor torque of the vehicle at the corresponding time when the parking control mode is switched; generating a motor control instruction for adjusting the motor target torque or for controlling the release of parking action based on the parking control mode, the actual motor torque, the vehicle load, and the driver's operation, to achieve anti-slip control during the vehicle starting process; the specific steps of determining the hill start state of the vehicle based on the running state parameters comprise: when the vehicle is in forward gear and the actual motor speed is lower than the negative value of a first preset threshold, and the duration exceeds a first preset time, or the vehicle is in reverse gear and the actual motor speed is higher than the positive value of the first preset threshold, and the duration exceeds the first preset time, it is determined that the vehicle is in a small hill start state; when the vehicle is in forward gear and the actual motor speed is lower than the negative value of a second preset threshold, and the duration exceeds a second preset time, or the vehicle is in reverse gear and the actual motor speed is higher than the positive value of the second preset threshold, and the duration exceeds the second preset time, it is determined that the vehicle is in a large hill start state; the determination method of the first preset threshold and the second preset threshold comprises: obtaining the slope information of the current slope of the vehicle, and calculating the corresponding hill start speed threshold based on the slope information and the preset hill start allowed displacement using vehicle dynamics; converting the hill start speed threshold into a motor speed threshold; correcting the motor speed threshold according to the accelerator pedal opening to obtain the first preset threshold and the second preset threshold used for hill start determination.

2. The vehicle coastdown dynamics control method according to claim 1, characterized by, The specific steps of dynamically selecting a vehicle parking control mode according to the hill start state, and obtaining and storing the instantaneous actual motor torque of the vehicle at the corresponding time when the parking control mode is switched, comprise: when the vehicle is in the small hill start state, the vehicle is in a first hill hold mode, and the duration of the vehicle in the first hill hold mode is recorded; when the duration of the first hill hold mode reaches a third preset time, the vehicle exits the first hill hold mode, enters a second hill hold mode, and obtains and stores the instantaneous actual motor torque when the first hill hold mode exits; when the vehicle in the first hill hold mode meets a first preset exit condition, or the vehicle has a serious fault, the vehicle exits the first hill hold mode and enters a third hill hold mode; when the vehicle is in the large hill start state, the vehicle is in a fourth hill hold mode.

3. The vehicle coastdown dynamics control method according to claim 2, characterized in that, The first preset exit condition comprises: the vehicle is in forward gear and the motor speed is less than a third preset threshold, or the vehicle is in reverse gear and the motor speed is greater than the third preset threshold, or the motor target torque continuously exceeds the actual motor torque for a duration reaching the third preset time.

4. The vehicle coastdown dynamics control method according to claim 3, characterized by, The specific steps of generating the motor control instruction for adjusting the motor target torque or for controlling the un-parking action based on the parking control mode, the motor actual torque, the vehicle load, and the driver's operation include: When the vehicle is in the first hill-hold mode and a second preset exit condition is met, the first hill-hold mode is exited, and a real-time motor actual torque when the first hill-hold mode is exited is obtained and stored; The motor target torque is determined based on the real-time motor actual torque and a target correction torque obtained by looking up a table according to the slope information; A parking un-parking torque is determined based on the vehicle weight and the slope information; When the vehicle is in the second hill-hold mode, the driver steps on the accelerator pedal, and the motor actual torque is greater than a fourth preset threshold value, the parking un-parking valve is un-parked, the fourth preset threshold value being a larger value between the parking un-parking torque and the instantaneous motor actual torque; When the vehicle is in the third hill-hold mode or the fourth hill-hold mode, the driver steps on the accelerator pedal, and the motor actual torque is greater than the parking un-parking torque, the parking un-parking valve is un-parked.

5. The vehicle coastdown dynamics control method according to claim 4, characterized in that, The second preset exit condition includes: The vehicle has a crawling function, the driver does not step on the accelerator pedal, and the motor actual speed in the forward gear is greater than a negative value of the third preset threshold value or the motor actual speed in the reverse gear is less than a positive value of the third preset threshold value; or the driver steps on the accelerator pedal, the motor target torque corresponding to the pedal is greater than the motor actual torque, and the motor actual speed in the forward gear is greater than a negative value of the third preset threshold value or the motor actual speed in the reverse gear is less than a positive value of the third preset threshold value.

6. The vehicle coastdown dynamic control method according to any one of claims 1 to 5, characterized by, Further comprising: When the vehicle is parked on a slope and the parking is effective, the driver switches the gear to cause the vehicle to switch from the forward gear to the reverse gear or from the reverse gear to the forward gear, the vehicle is in a downhill state, and the parking is un-parked when the driver lightly steps on the accelerator pedal.

7. The vehicle coastdown dynamics control method of claim 1, wherein The specific steps of obtaining the slope information of the slope on which the vehicle is currently located include: The slope is calculated by the ratio of the GPS elevation change rate to the horizontal speed to obtain a GPS estimated slope; The slope is calculated by the actual longitudinal acceleration of the vehicle to obtain an acceleration estimated slope; The weights of the GPS estimated slope and the acceleration estimated slope are determined according to the vehicle speed, and the GPS estimated slope and the acceleration estimated slope are weighted and fused to obtain the slope information of the slope on which the vehicle is currently located.

8. A vehicle coast-down dynamic control system employing the multi-modal based vehicle coast-down dynamic control method according to any one of claims 1-7, characterized in that, The system includes: A collection module configured to obtain running state parameters of the vehicle in real time, the running state parameters including a motor actual speed, a motor actual torque, gear information, an accelerator pedal opening degree, a brake pedal opening degree, and vehicle fault information; A slope state determination module configured to determine a slope rolling state of the vehicle based on the running state parameters; and A control module configured to control the vehicle based on the slope rolling state. The parking control module is used for dynamically selecting a vehicle parking control mode according to the hill start state, and acquiring and storing an instantaneous motor actual torque of the vehicle at a corresponding moment when the parking control mode is switched; and the motor control module is used for generating a motor control instruction based on the parking control mode, the motor actual torque, a vehicle load and a driver operation, the motor control instruction being used for adjusting a motor target torque or controlling a parking release action, so as to realize the anti-hill start control in the vehicle starting process.

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