Vehicle drift control method, control device, control system, and storage medium

Abstract

The application discloses a vehicle drift control method, a vehicle drift control device, a vehicle drift control system and a computer readable storage medium. The vehicle drift control method comprises the following steps: receiving a start instruction, controlling the vehicle to enter a drift mode; receiving a drift level instruction, controlling the drift level of the vehicle; acquiring current information of the vehicle; determining a target drift parameter according to the current information; determining a vehicle drift strategy according to the drift level, the current information and the target drift parameter, so as to control the vehicle to drift, wherein in the vehicle drift strategy, the vehicle controls multiple front wheels and / or multiple rear wheels of the vehicle through independent steering and independent driving fusion; receiving a stop instruction, controlling the vehicle to exit the drift mode. In this way, the torque of the multiple front wheels and / or the multiple rear wheels of the vehicle can be flexibly distributed, the vehicle is easy to start drifting, and the drifting is smooth.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and in particular to a vehicle drift control method, a vehicle drift control device, a vehicle drift control system, and a computer-readable storage medium. Background Technology

[0002] Drifting is a driving skill that allows drivers to experience the joy of driving and perceive the handling characteristics of a vehicle. Many car manufacturers equip their vehicles with drifting features. During drifting, torque control is a key technology to ensure stable sideslip, maintain the drift state, and prevent loss of control. However, current drift control methods cannot flexibly control torque distribution. Summary of the Invention

[0003] This application provides a vehicle drift control method, a vehicle drift control device, a vehicle drift control system, and a computer-readable storage medium to solve at least one of the aforementioned technical problems.

[0004] The vehicle drift control method according to the embodiments of this application includes:

[0005] Receive the start command and control the vehicle to enter drift mode;

[0006] Receive drift level instructions and control the drift level of the vehicle;

[0007] Obtain the current information of the vehicle;

[0008] Determine the target drift parameters based on the current information;

[0009] A vehicle drift strategy is determined based on the drift level, the current information, and the target drift parameters to control the vehicle to drift. In the vehicle drift strategy, multiple front wheels and / or multiple rear wheels of the vehicle are controlled by a fusion of independent steering and independent drive.

[0010] Upon receiving a stop command, control the vehicle to exit the drift mode.

[0011] In some implementations, receiving the start command and controlling the vehicle to enter drift mode includes:

[0012] Receive the start command;

[0013] Determine whether the vehicle meets the drifting conditions;

[0014] When the vehicle meets the drift conditions, control the vehicle to enter the drift mode.

[0015] In some embodiments, after receiving the start command and controlling the vehicle to enter drift mode, the vehicle drift control method further includes:

[0016] Adjust the control strategy of the vehicle stability control system and reset the trigger threshold of vehicle stability control;

[0017] The trigger thresholds are different for different drift levels.

[0018] In some implementations, the current information includes the current steering wheel angle and the current vehicle speed, and determining the target drift parameters based on the current information includes:

[0019] The target drift parameters are determined based on the current steering wheel angle information and the current vehicle speed.

[0020] In some implementations, the target drift parameter includes a target yaw rate, and determining a vehicle drift strategy based on the drift level, the current information, and the target drift parameter to control the vehicle to drift includes:

[0021] The target yaw moment is determined based on the target yaw angular velocity.

[0022] The vehicle drift strategy is determined based on the target yaw moment.

[0023] In some implementations, determining the vehicle drift strategy based on the target yaw moment includes:

[0024] Determine the relationship between the target yaw moment and the preset drift threshold and the preset safety threshold;

[0025] When the target yaw moment is less than the preset drift threshold, the target yaw moment is increased to control the vehicle to drift.

[0026] When the target yaw moment is greater than or equal to the preset drift threshold and less than the preset safety threshold, the vehicle is controlled to drift.

[0027] When the target yaw moment is greater than or equal to the preset safety threshold, the vehicle is controlled to exit the drift mode;

[0028] The preset drift threshold and the preset safety threshold are different for different drift levels.

[0029] In some implementations, the current information includes the current slip ratio and the current vehicle speed, and increasing the yaw moment to control the vehicle's drift includes:

[0030] The front axle to rear axle torque ratio is determined based on the current slip ratio.

[0031] The compensation amount of the yaw moment is calculated based on the target yaw angular velocity and the preset drift threshold.

[0032] The drift control pattern of the vehicle is determined based on the current vehicle speed.

[0033] In some embodiments, determining the front axle to rear axle torque ratio based on the current slip ratio includes:

[0034] When the current slip ratio is less than the slip ratio threshold, the rear axle torque is increased;

[0035] When the current slip ratio is greater than or equal to the slip ratio threshold, the rear axle torque is reduced;

[0036] The slip ratio thresholds are different for different drift levels.

[0037] In some implementations, determining the vehicle's drift control pattern based on the current vehicle speed includes:

[0038] When the current vehicle speed is less than or equal to a preset vehicle speed threshold, the vehicle is controlled to drift in a first drift control style, in which multiple front wheels and multiple rear wheels of the vehicle rotate in opposite directions.

[0039] When the current vehicle speed is greater than the preset vehicle speed threshold, the vehicle is controlled to drift in a second drift control style, in which the left rear wheel and the right rear wheel of the vehicle form a figure-eight shape.

[0040] In some implementations, the control of multiple front wheels and / or multiple rear wheels of the vehicle via independent steering and independent drive fusion includes any one or more of the following:

[0041] Dynamically control the torque distribution ratio between the front and rear axles;

[0042] Dynamically control the left and right torque distribution ratio of the front axle;

[0043] Dynamically control the left and right torque distribution ratio of the rear axle;

[0044] Dynamically control the torque distribution ratio of the outer wheels on the front and rear axles.

[0045] The vehicle drift control device according to the embodiments of this application includes:

[0046] The control module is used to receive the start command and control the vehicle to enter drift mode;

[0047] The control module is also used to receive drift level commands and control the drift level of the vehicle;

[0048] The acquisition module is used to acquire the current information of the vehicle;

[0049] The determination module is used to determine the target drift parameters based on the current information;

[0050] The determining module is further configured to determine a vehicle drift strategy based on the drift level, the current information, and the target drift parameters, so as to control the vehicle to drift, wherein the vehicle drift strategy controls multiple front wheels and / or multiple rear wheels of the vehicle by integrating independent steering and independent drive.

[0051] The control module is also used to receive a stop command and control the vehicle to exit the drift mode.

[0052] The vehicle drift control system of this application includes one or more processors and a memory. The memory stores a computer program, which, when executed by the processor, implements the vehicle drift control method of any of the above embodiments.

[0053] The computer-readable storage medium of the present application embodiment stores a computer program thereon, which, when executed by a processor, implements the vehicle drift control method of any of the above embodiments.

[0054] In the vehicle drift control method, vehicle drift control device, vehicle drift control system, and computer-readable storage medium of this application, a vehicle drift strategy is determined based on the drift level, current information, and target drift parameters to control the vehicle to drift. In this vehicle drift strategy, multiple front wheels and / or multiple rear wheels of the vehicle are controlled by a fusion of independent steering and independent drive. This allows for flexible torque distribution to the multiple front wheels and / or multiple rear wheels, facilitating smooth and easy vehicle drift initiation.

[0055] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0056] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0057] Figure 1 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0058] Figure 2 This is a schematic diagram of a vehicle drift control system according to certain embodiments of this application;

[0059] Figure 3 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0060] Figure 4 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0061] Figure 5 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0062] Figure 6 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0063] Figure 7 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0064] Figure 8 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0065] Figure 9 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0066] Figure 10 This is a flowchart illustrating a vehicle drift control method according to certain embodiments of this application;

[0067] Figure 11 This is a schematic diagram of a first drift control pattern according to certain embodiments of this application;

[0068] Figure 12 This is a block diagram of a second drift control style according to certain embodiments of this application;

[0069] Figure 13 This is a schematic diagram of a vehicle drift control device according to certain embodiments of this application;

[0070] Figure 14 This is a schematic diagram illustrating the connection state between a computer-readable storage medium and a processor according to certain embodiments of this application. Detailed Implementation

[0071] The embodiments of this application will be further described below with reference to the accompanying drawings. The same or similar reference numerals in the drawings denote the same or similar elements or elements having the same or similar functions throughout. Furthermore, the embodiments of this application described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting this application.

[0072] Please see Figure 1 This application provides a vehicle drift control method, comprising:

[0073] 010: Receive the start command and control the vehicle to enter drift mode;

[0074] 020: Receives drift level commands and controls the vehicle's drift level;

[0075] 030: Obtain the vehicle's current information;

[0076] 040: Determine the target drift parameters based on the current information;

[0077] 050: Determine the vehicle drift strategy based on the drift level, current information and target drift parameters to control the vehicle to drift. In the vehicle drift strategy, multiple front wheels and / or multiple rear wheels of the vehicle are controlled by merging independent steering and independent drive.

[0078] 060: Receive stop command and control the vehicle to exit drift mode.

[0079] In the vehicle drift control method of this application, a vehicle drift strategy is determined based on the drift level, current information, and target drift parameters to control the vehicle to drift. In this vehicle drift strategy, multiple front wheels and / or multiple rear wheels of the vehicle are controlled by a fusion of independent steering and independent drive. This allows for flexible torque distribution to the multiple front wheels and / or multiple rear wheels, facilitating smooth and easy drift initiation.

[0080] Specifically, such as Figure 2 As shown, this application also provides a vehicle drift control system 200, which can be the executing entity of the vehicle drift control method. The start command is issued by the driver via a physical button on the vehicle or an electronic device with an interactive interface, such as an in-vehicle PAD. The driver presses the drift button on the PAD's interface, and the PAD sends the start command. The electronic device is communicatively connected to the vehicle drift control system 200, which receives the start command and controls the vehicle to enter drift mode. It should be noted that the vehicle should be in Park (P) gear when the driver issues the start command.

[0081] After the vehicle enters drift mode, the driver can select the drift level. Similarly, drift level commands can be issued by the driver via physical buttons on the vehicle or via an electronic device with an interactive interface. The vehicle drift control system 200 receives the drift level commands and controls the vehicle's drift level. Different drift levels correspond to different vehicle drift angles. For example, setting the drift level to 0-10 corresponds to drift angles of 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, and 55°, respectively. In this embodiment, three drift levels are provided: beginner mode, intermediate mode, and advanced mode. The beginner mode corresponds to a drift angle range of 10°-20°, the intermediate mode to 25°-40°, and the advanced mode to 45°-55°. It is understandable that different slip ratios, sideslip angles, and yaw rates can be set for different drift levels, as will be discussed later.

[0082] After setting the vehicle's drift level, the vehicle drift control system 200 acquires the vehicle's current information. This current information may include current vehicle speed, current slip ratio, current sideslip angle, current yaw rate, and current steering wheel angle. The vehicle is equipped with multiple sensors, such as a vehicle speed sensor, yaw rate sensor, and steering wheel angle sensor. The vehicle's current information can be obtained directly from these sensors or calculated. For example, the formula for calculating the sideslip angle β is as follows:

[0083]

[0084] Among them, V y For lateral vehicle speed, V x This refers to the longitudinal speed. Lateral and longitudinal speeds can be determined based on the current vehicle speed.

[0085] The target drift parameters can be determined based on the vehicle's current information. Based on the drift level, current information, and target drift parameters, a vehicle drift strategy can be determined, and then the vehicle can be controlled to drift according to this strategy.

[0086] In related technologies, drift control is relatively simple, mainly achieving drift by changing the distribution of longitudinal forces to control the vehicle's sideslip angle, with the control system primarily being the drive system. However, as user demands increase, some drifting techniques involve directional control to achieve different levels of drift.

[0087] In this embodiment, the vehicle may be equipped with dual rear-wheel motors, independent rear-wheel steering, and active suspension. The vehicle drift control process involves the drive system, front and / or rear-wheel steering system, active suspension system, and Electronic Stability Program (ESP). In the vehicle drift strategy, multiple front and / or rear wheels of the vehicle are controlled through a fusion of independent steering and independent drive. For example, multiple front wheels, multiple rear wheels, or both can be controlled through a fusion of independent steering and independent drive. "Multiple" refers to two or more. Independent steering refers to the steering motor applying different steering torques to control the multiple front and / or rear wheels to rotate at different angles. Independent drive refers to the drive motor applying different magnitudes of driving force to drive the multiple front and / or rear wheels. By fusion-controlling the multiple front and / or rear wheels of the vehicle through independent steering and independent drive, the torque distribution ratio of the multiple front and / or rear wheels can be dynamically controlled. In this way, the torque can be flexibly distributed to multiple front wheels and / or multiple rear wheels of the vehicle, making it easy for the vehicle to drift and drifting smoothly.

[0088] When it's time to exit drift mode, the driver can apply the brakes, and the vehicle will gradually come to a stop. At this time, the drift function is suppressed. Alternatively, the driver can send a stop command by shifting into Park (P), and the vehicle drift control system 200 will receive the stop command and control the vehicle to exit drift mode.

[0089] Please see Figure 3 In some implementations, receiving a start command and controlling the vehicle to enter drift mode (i.e., 010) includes:

[0090] 011: Receive start command;

[0091] 012: Determine if the vehicle meets the drifting conditions;

[0092] 013: When the vehicle meets the drift conditions, control the vehicle to enter drift mode.

[0093] Specifically, after receiving a start command, the vehicle drift control system 200 first determines whether the vehicle meets the drift conditions. Drift conditions can be set based on protecting the safety of the driver and other occupants. For example, drift conditions may include: whether the vehicle is on a closed road, whether the driver and passengers are wearing seatbelts, and whether the doors are closed. Of course, drift conditions can also be set based on other factors. The vehicle drift control system 200 can perform corresponding detection based on the preset drift conditions. When the vehicle meets the drift conditions, it controls the vehicle to enter drift mode. When the vehicle does not meet the drift conditions, it does not enter drift mode and prompts the driver. For example, the vehicle drift control system 200 can send a prompt command to the PAD, which displays that it cannot enter drift mode and prompts the driver to perform the appropriate operation to meet the drift conditions.

[0094] Please see Figure 4 In some implementations, after receiving the start command and controlling the vehicle to enter drift mode (i.e., 010), the vehicle drift control method further includes:

[0095] 070: Adjust the control strategy of the vehicle stability control system and reset the trigger threshold of vehicle stability control;

[0096] Different drift levels correspond to different trigger thresholds.

[0097] Under normal operating conditions, the trigger threshold of the vehicle stability control system (VSC) is relatively low. During drifting, the intervention of the VSC interrupts the drift, and the vehicle needs to exceed the normal vehicle stability boundaries to drift. Therefore, the VSC is usually disabled when designing a drift function. Less experienced drivers have poorer vehicle control and find it difficult to control the vehicle under extreme conditions. They may not be able to intervene in time when the vehicle is about to become unstable or out of control, increasing the risk of accidents.

[0098] Therefore, in this embodiment, after the vehicle enters drift mode, the vehicle drift control system 200 adjusts the control strategy of the vehicle stability control system, redesigns the trigger threshold of the vehicle stability control system, and classifies the drift control. Different drift levels correspond to different trigger thresholds, and the trigger threshold in drift mode differs from the threshold under normal operating conditions. The trigger threshold can be set according to the yaw rate. When the detected yaw rate exceeds the trigger threshold corresponding to the current drift level, the vehicle exits drift mode, and the vehicle stability control system intervenes to stabilize the vehicle. Of course, the trigger threshold can also be set according to other parameters such as the vehicle drift attitude angle, which is not limited here.

[0099] For example, the driver selects drift level 5, corresponding to a 30° drift angle. When the drift function is triggered, the vehicle stability control system calls the corresponding upper limit control program strategy. If the drift angle exceeds 30° due to driver operation or road surface changes, the drift control function is interrupted, and the vehicle stability control system intervenes to stabilize the vehicle. When the drift angle returns to within the range, the vehicle stability control system exits, and the drift control function is reactivated. This establishes a safety barrier for drift function safety, promoting safe and stable drift control and ensuring driver safety.

[0100] Please see Figure 5 In some implementations, the current information includes the current steering wheel angle and the current vehicle speed. Determining the target drift parameters (i.e., 040) based on the current information includes:

[0101] 041: Determine the target drift parameters based on the current steering wheel angle and current vehicle speed.

[0102] Specifically, based on the current steering wheel angle and vehicle speed, the target drift parameters can be calculated using the vehicle's two-degree-of-freedom formula. These parameters include the target yaw rate. The target yaw rate characterizes the yaw rate generated by the driver's steering wheel rotation.

[0103] Please see Figure 6 In some implementations, the target drift parameters include the target yaw rate. A vehicle drift strategy is determined based on the drift level, current information, and target drift parameters to control the vehicle to drift (i.e., 050), including:

[0104] 051: Determine the target yaw moment based on the target's yaw angular velocity;

[0105] 052: Determine the vehicle drift strategy based on the target yaw moment.

[0106] Specifically, based on the vehicle's target yaw rate, the target yaw moment can be calculated using a proportional-integral-derivative (PID) control algorithm. The target yaw moment characterizes the yaw torque generated by the driver's steering wheel rotation. The vehicle drift strategy can then be determined based on the target yaw moment.

[0107] Please see Figure 7 In some implementations, determining the vehicle drift strategy (i.e., 052) based on the target yaw moment includes:

[0108] 0521: Determine the relationship between the target yaw moment and the preset drift threshold and preset safety threshold;

[0109] 0522: When the target yaw moment is less than the preset drift threshold, increase the target yaw moment to control the vehicle to start drifting;

[0110] 0523: When the target yaw moment is greater than or equal to the preset drift threshold and less than the preset safety threshold, control the vehicle to drift.

[0111] 0524: When the target yaw moment is greater than or equal to the preset safety threshold, control the vehicle to exit drift mode;

[0112] Different drift levels correspond to different preset drift thresholds and preset safety thresholds.

[0113] It is understandable that yaw moment is determined based on yaw rate, and the trigger threshold of the vehicle stability control system can be set according to the yaw rate. Therefore, the need for vehicle stability control system intervention can also be determined based on the yaw moment. Different preset drift initiation thresholds and preset safety thresholds are set for different drift levels. The preset safety threshold is the trigger threshold of the vehicle stability system based on the yaw moment, representing the maximum yaw moment required for the vehicle to maintain stability at the corresponding drift level. The preset drift initiation threshold represents the minimum yaw moment required for the vehicle to initiate a drift at the corresponding drift level.

[0114] Specifically, when the target yaw moment is less than the preset drift threshold, it indicates that the yaw moment generated by the driver turning the steering wheel is insufficient to initiate a drift, and the target yaw moment needs to be increased to control the vehicle's drift. When the target yaw moment is greater than or equal to the preset drift threshold but less than the preset safety threshold, it indicates that the yaw moment generated by the driver turning the steering wheel is sufficient to initiate a drift, and the vehicle drift control system 200 can control the vehicle to drift without performing any additional operations. When the target yaw moment is greater than or equal to the preset safety threshold, it indicates that the vehicle is about to become unstable or is already in an unstable state, and the vehicle drift control system 200 controls the vehicle to exit drift mode, while the vehicle stability control system intervenes to stabilize the vehicle.

[0115] Please see Figure 8 In some implementations, the current information includes the current slip ratio and the current vehicle speed. The target drift parameters include the target yaw rate. Increasing the yaw moment to control vehicle drift initiation (i.e., 0522) includes:

[0116] 05221: Determine the front axle to rear axle torque ratio based on the current slip ratio;

[0117] 05222: Calculate the compensation amount of the yaw moment based on the target yaw moment and the preset drift threshold;

[0118] 05223: Determine the vehicle's drift control style based on the current vehicle speed.

[0119] Specifically, the slip ratio represents the proportion of slippage in wheel motion. The current slip ratio can be calculated based on the current yaw rate and the current vehicle speed, using the following formula:

[0120]

[0121] Where u is the current vehicle speed, ω is the current yaw rate, and r is the wheel rolling radius.

[0122] At the beginning of a vehicle drift, the torque ratio between the front and rear axles can be distributed in a 4:6 ratio, and then dynamically adjusted according to the vehicle's current slip ratio.

[0123] Next, the deviation between the target yaw moment and the preset drift threshold is calculated to obtain the yaw moment compensation. The vehicle's drift control style is determined based on the current vehicle speed. Different drift control styles are selected under different conditions, and the target yaw moment is increased according to the yaw moment compensation to control the vehicle's drift.

[0124] Please see Figure 9 In some implementations, determining the front-to-rear axle torque ratio (i.e., 0.5221) based on the current slip ratio includes:

[0125] 052211: When the current slip ratio is less than the slip ratio threshold, increase the rear axle torque;

[0126] 052212: When the current slip ratio is greater than or equal to the slip ratio threshold, reduce the rear axle torque;

[0127] Different drift levels correspond to different slip ratio thresholds.

[0128] It's understandable that a higher drift level means a higher vehicle speed during the drift, and a higher speed results in a higher slip ratio, thus requiring a larger slip ratio threshold. Therefore, different drift levels correspond to different slip ratio thresholds; the higher the drift level, the larger the slip ratio threshold. The slip ratio threshold can be a single value or a range.

[0129] When the current slip ratio is less than the slip ratio threshold, it indicates that the friction between the wheel and the ground is relatively high, and the wheel can grip the ground well. In this case, the rear axle torque can be increased to bring the current slip ratio closer to the slip ratio threshold, thereby increasing the vehicle's driving force. When the current slip ratio is greater than or equal to the slip ratio threshold, it indicates that the friction between the wheel and the ground is relatively low, and the wheel is beginning to slip excessively. In this case, the rear axle torque should be reduced to bring the current slip ratio closer to the slip ratio threshold to prevent the vehicle from becoming unstable or losing control.

[0130] Please see Figure 10 In some implementations, the vehicle drift control pattern (i.e., 05223) is determined based on the current vehicle speed, including:

[0131] 052231: When the current vehicle speed is less than or equal to a preset vehicle speed threshold, control the vehicle to drift in a first drift control style. In the first drift control style, the steering directions of multiple front wheels and multiple rear wheels of the vehicle are opposite.

[0132] 052232: When the current vehicle speed is greater than the preset vehicle speed threshold, control the vehicle to drift in the second drift control style. In the second drift control style, the left rear wheel and the right rear wheel of the vehicle form an "eight" shape.

[0133] Specifically, the preset speed threshold can be set according to the vehicle's actual configuration and other factors. When the current speed is less than or equal to the preset speed threshold, in order to quickly increase the vehicle's yaw rate, such as... Figure 11 As shown, the vehicle is controlled to drift using the first drift control style. The front wheels turn to the left at a certain angle, and the rear wheels turn to the right at a certain angle, meaning that the steering directions of the multiple front wheels and multiple rear wheels are opposite. The arrows in the diagram indicate the direction of wheel rotation; the front wheels all turn forward, the left rear wheel turns forward, and the right rear wheel turns backward. Due to the lateral load transfer generated during drifting, the adhesion of the inner wheels decreases. At this time, the torque of the inner wheels should be reduced, and differential torque control should be formed with the outer wheels, creating an additional yaw moment. It can be understood that the additional yaw moment is greater than or equal to the compensation amount of the yaw moment.

[0134] In related technologies, vehicles are all rear-wheel drive. To drift, the rear wheels need a large driving force to lose lateral friction and become unable to balance the lateral force of the front wheels, thereby generating a large yaw rate to achieve drifting. However, when drifting using the first drift control style of the present application, the rear wheels do not require a large driving force, and the vehicle can drift even at low speeds.

[0135] When the current vehicle speed exceeds a preset speed threshold, the driver's actions are more likely to affect the vehicle's stability. At this time, such as... Figure 12 As shown, the vehicle is controlled to drift in the second drift control style, where the left and right rear wheels form a figure-eight shape, and the yaw rate is gradually increased. The arrows in the diagram indicate the direction of wheel rotation: the front wheels all rotate forward, the left rear wheel rotates forward, and the right rear wheel rotates backward. According to the vector composition of forces, independent steering and independent drive of the rear wheels can generate an additional yaw moment M.

[0136] M = T r ×b

[0137] Among them, T rLet be the resultant torque, and b be the distance from the vehicle's center of gravity to the rear axle. The additional yaw moment is greater than or equal to the compensation amount of the yaw moment. Force analysis shows that the additional yaw moment helps the vehicle initiate a drift and improves smoothness. This reduces the likelihood of excessive yaw and fishtailing, decreasing the reliance of the drift function on driver experience.

[0138] In some implementations, controlling multiple front wheels and / or multiple rear wheels of the vehicle through the fusion of independent steering and independent drive includes any one or more of the following:

[0139] Dynamically control the torque distribution ratio between the front and rear axles;

[0140] Dynamically control the left and right torque distribution ratio of the front axle;

[0141] Dynamically control the left and right torque distribution ratio of the rear axle;

[0142] Dynamically control the torque distribution ratio of the outer wheels on the front and rear axles.

[0143] In related technologies, drift torque control strategies mostly employ a fixed torque distribution ratio between the front and rear axles, such as all-rear-wheel drive or a 3:7 fixed torque distribution. There is essentially no dynamic distribution control on the left and right rear wheels. The entire control process only involves controlling the torque values ​​of the front and rear axles, lacking flexible torque distribution control elements. For example, for rear-wheel drive vehicles with a fixed torque ratio, drift initiation will be very uneven, and in extreme cases, the vehicle may experience severe fishtailing.

[0144] In this embodiment, the vehicle drift control system 200 is a fusion control system based on independent steering and independent drive. During vehicle drifting, it offers multiple torque distribution methods, including: dynamically controlling the torque distribution ratio between the front and rear axles; dynamically controlling the left-right torque distribution ratio of the front axle; dynamically controlling the left-right torque distribution ratio of the rear axle; and dynamically controlling the torque distribution ratio of the outer wheels of the front and rear axles. During vehicle drift control, one or more of these torque distribution methods can be arbitrarily selected. This allows for flexible torque distribution to multiple front and / or rear wheels, considering the torque distribution on the left and right sides of a single axle, facilitating smooth and easy vehicle drift initiation.

[0145] In one example, the vehicle comprises two front wheels and two rear wheels, employing a three-motor integrated control scheme with independent rear-wheel steering and independent rear-wheel drive. This will be explained in detail using the second drift control style as an example. When the vehicle enters drift mode, the drift control function is activated when predetermined conditions are met. These predetermined conditions may include a steering wheel angle greater than a preset steering angle threshold, a throttle opening greater than a preset throttle opening threshold, and a vehicle speed greater than a preset vehicle speed threshold. For example, the preset steering angle threshold can be set to 30°, the preset throttle opening threshold to 90%, and the preset vehicle speed threshold to 40 km / h. The drift control function is activated when the predetermined conditions are met, such as a steering wheel angle greater than 30°, a throttle opening greater than 90%, and a vehicle speed greater than 40 km / h.

[0146] During drift initiation, the system monitors the yaw rate, sideslip angle, and front and rear wheel slip ratios corresponding to the selected drift level. To ensure smoothness and speed of drift initiation, the drive system gradually and linearly distributes the torque ratio between the front and rear axles from 5:5 to 3:7 to 2:8 to 0:10, while maintaining the driver's total torque demand. Additionally, the torque on the outer wheels of the front and rear axles is also gradually and linearly distributed from 5:5 to 3:7 to 2:8 to 0:10. The rear wheels respond synchronously with counter-rotation, meaning the left wheel turns forward and the right wheel turns backward. When the vehicle's sideslip angle reaches the corresponding drift level, the left and right torques of the front and rear axles are distributed in a 5:5 ratio. Simultaneously, the torque distribution between the front and rear axles is adjusted from 0:10 to 2:8 to appropriately reduce the rear axle torque, and the rear wheel steering returns to the neutral position (i.e., the rear wheel steering angle is 0) to stabilize the vehicle's posture. If, due to factors such as changes in the road surface adhesion coefficient, the vehicle's yaw rate continues to increase beyond the upper limit, the drive system reduces the rear axle torque and increases the front axle torque. In addition, the electric power steering (EPS) system provides auxiliary torque to remind the driver to turn the steering wheel, and the vehicle stability control system intervenes to adjust the vehicle's attitude.

[0147] According to the two-degree-of-freedom dynamics formula for vehicles:

[0148]

[0149] Where, k f For front wheel lateral stiffness; k r Rear wheel sideslip stiffness; β is the sideslip angle; a is the distance from the vehicle's center of gravity to the front axle; b is the distance from the vehicle's center of gravity to the rear axle; ω r δ is the yaw rate; δ is the steering wheel angle. I is the vehicle speed and acceleration; z Let be the moment of inertia of the vehicle about the z-axis; This is the yaw rate acceleration.

[0150] Eliminating β from the two equations yields the yaw rate ω1 generated by the steering wheel angle under steady-state response:

[0151]

[0152] Where L is the distance between the front and rear axles of the vehicle, and K is the steering characteristic stability factor.

[0153] The yaw rate ω2 corresponding to the yaw moment generated by the independent steering and independent drive of the rear wheels is:

[0154]

[0155] The actual yaw rate ω of the vehicle during drifting is:

[0156] ω=ω1+ω2

[0157] In this embodiment, the torque distribution ratio between the front and rear axles is dynamically controlled. For example, starting the drift from 5:5 to 3:7 to 2:8, while keeping the total required torque constant, the torque is gradually transferred to the rear axle, making the drift process smoother. Furthermore, by dynamically controlling the left and right torque of the rear axle, for example, distributing more torque to the outer rear wheels during drifting while reducing the drive torque of the inner rear wheels increases the yaw moment required for drifting. This makes steering transition easier and facilitates vehicle drifting.

[0158] Furthermore, if passengers select a higher drift level, this implies a greater expectation of yaw rate and sideslip angle. In this case, drift control in related technologies can no longer meet passengers' expectations for the vehicle's dynamic response, while the first drift control scheme of this application effectively solves the difficulty of initiating a large yaw drift. Thus, it can meet the diverse needs of drivers.

[0159] In the first drift control mode, the actual yaw rate ω of the vehicle during drift is:

[0160] ω=ω1+ω2

[0161] Where ω1 is the yaw rate generated by the independent steering of the rear wheels, which can be calculated according to the vehicle's two-degree-of-freedom formula, as follows:

[0162]

[0163] ω2 is the yaw rate generated by the independent rear-wheel drive, and the calculation formula is as follows:

[0164]

[0165] Among them, T 1,1 T 1,2 T2,1 T 2,2 These are the yaw moments of the four wheels.

[0166] In the first drift control style, when the rear wheels turn in the opposite direction to the front wheels, the resulting yaw rate is greater than that produced by the second drift control style and other drift control styles, which is beneficial for initiating a drift.

[0167] In some implementations, after the vehicle enters drift mode, to allow the driver to experience ultimate drift control, the vehicle drift control system 200 can control the lowering of the front and rear suspension heights, thus lowering the vehicle's center of gravity and making the vehicle more stable during drifting. Simultaneously, increasing the damping of the front and rear suspensions also facilitates drift control.

[0168] Please see Figure 13 This application also provides a vehicle drift control device 100. The vehicle drift control device 100 includes a control module 10, an acquisition module 20, and a determination module 30. The control module 10 receives a start command to control the vehicle to enter a drift mode. The control module 10 also receives a drift level command to control the vehicle's drift level. The acquisition module 20 acquires the vehicle's current information. The determination module 30 determines target drift parameters based on the current information. The determination module 30 also determines a vehicle drift strategy based on the drift level, current information, and target drift parameters to control the vehicle to drift. In this vehicle drift strategy, multiple front wheels and / or multiple rear wheels of the vehicle are controlled through a fusion of independent steering and independent drive. The control module 10 also receives a stop command to control the vehicle to exit the drift mode.

[0169] In some implementations, the control module 10 is specifically used to receive a start command; determine whether the vehicle meets the drifting conditions; and control the vehicle to enter drift mode when the vehicle meets the drifting conditions.

[0170] In some implementations, the control module 10 is also used to adjust the control strategy of the vehicle stability control system and reset the trigger threshold of the vehicle stability control; wherein, different drift levels correspond to different trigger thresholds.

[0171] In some implementations, the current information includes the current steering wheel angle and the current vehicle speed. Specifically, the determination module 30 is used to determine the target drift parameters based on the current steering wheel angle and the current vehicle speed.

[0172] In some implementations, the target drift parameters include the target yaw moment. Specifically, the control module 10 is used to determine the target yaw moment based on the target yaw angular velocity; and to determine the vehicle drift strategy based on the target yaw moment.

[0173] In some embodiments, the control module 10 is specifically used to determine the relationship between the target yaw moment and the preset drift threshold and the preset safety threshold; when the target yaw moment is less than the preset drift threshold, the target yaw moment is increased to control the vehicle to drift; when the target yaw moment is greater than or equal to the preset drift threshold and less than the preset safety threshold, the vehicle is controlled to drift; when the target yaw moment is greater than or equal to the preset safety threshold, the vehicle is controlled to exit the drift mode; wherein, the preset drift threshold and the preset safety threshold are different for different drift levels.

[0174] In some implementations, the current information includes the current slip ratio and the current vehicle speed. Specifically, the control module 10 is used to determine the front-to-rear axle torque ratio based on the current slip ratio; calculate the compensation amount of the yaw moment based on the target yaw rate and the preset drift threshold; and determine the vehicle's drift control pattern based on the current vehicle speed.

[0175] In some implementations, the control module 10 is specifically used to increase the rear axle torque when the current slip ratio is less than the slip ratio threshold, and to decrease the rear axle torque when the current slip ratio is greater than or equal to the slip ratio threshold; wherein, different slip ratio thresholds correspond to different drift levels.

[0176] In some embodiments, the control module 10 is specifically used to control the vehicle to drift in a first drift control style when the current vehicle speed is less than or equal to a preset vehicle speed threshold, in which multiple front wheels and multiple rear wheels of the vehicle rotate in opposite directions; and to control the vehicle to drift in a second drift control style when the current vehicle speed is greater than the preset vehicle speed threshold, in which the left rear wheel and right rear wheel of the vehicle form a figure-eight shape.

[0177] In some implementations, controlling multiple front wheels and / or multiple rear wheels of the vehicle through the fusion of independent steering and independent drive includes any one or more of the following:

[0178] Dynamically control the torque distribution ratio between the front and rear axles;

[0179] Dynamically control the left and right torque distribution ratio of the front axle;

[0180] Dynamically control the left and right torque distribution ratio of the rear axle;

[0181] Dynamically control the torque distribution ratio of the outer wheels on the front and rear axles.

[0182] It should be noted that the explanation of the vehicle drift control method in the foregoing embodiments also applies to the vehicle drift control device 100 of the embodiments of this application, and will not be elaborated here.

[0183] Please see Figure 2This application also provides a vehicle drift control system 200. The vehicle drift control system 200 includes one or more processors 210 and a memory 220. The memory 220 stores a computer program, which, when executed by the processor 210, implements the vehicle drift control method of any of the above embodiments.

[0184] For example, when the computer program is executed by the processor 210, the following vehicle drift control method is implemented:

[0185] 010: Receive the start command and control the vehicle to enter drift mode;

[0186] 020: Receives drift level commands and controls the vehicle's drift level;

[0187] 030: Obtain the vehicle's current information;

[0188] 040: Determine the target drift parameters based on the current information;

[0189] 050: Determine the vehicle drift strategy based on the drift level, current information and target drift parameters to control the vehicle to drift. In the vehicle drift strategy, the vehicle controls multiple front wheels and / or multiple rear wheels by integrating independent steering and independent drive.

[0190] 060: Receive stop command and control the vehicle to exit drift mode.

[0191] For example, when the computer program is executed by the processor 210, the following vehicle drift control method is implemented:

[0192] 011: Receive start command;

[0193] 012: Determine if the vehicle meets the drifting conditions;

[0194] 013: When the vehicle meets the drift conditions, control the vehicle to enter drift mode.

[0195] It should be noted that the explanations of the vehicle drift control method and vehicle drift control device 100 in the foregoing embodiments also apply to the vehicle drift control system 200 of the embodiments of this application, and will not be elaborated here.

[0196] Please see Figure 14 This application also provides a computer-readable storage medium 300 storing a computer program 310, which, when executed by a processor 320, implements the vehicle drift control method of any of the above embodiments.

[0197] For example, when the program is executed by processor 320, the following vehicle drift control method is implemented:

[0198] 010: Receive the start command and control the vehicle to enter drift mode;

[0199] 020: Receives drift level commands and controls the vehicle's drift level;

[0200] 030: Obtain the vehicle's current information;

[0201] 040: Determine the target drift parameters based on the current information;

[0202] 050: Determine the vehicle drift strategy based on the drift level, current information and target drift parameters to control the vehicle to drift. In the vehicle drift strategy, the vehicle controls multiple front wheels and / or multiple rear wheels by integrating independent steering and independent drive.

[0203] 060: Receive stop command and control the vehicle to exit drift mode.

[0204] For example, when the program is executed by processor 320, the following vehicle drift control method is implemented:

[0205] 011: Receive start command;

[0206] 012: Determine if the vehicle meets the drifting conditions;

[0207] 013: When the vehicle meets the drift conditions, control the vehicle to enter drift mode.

[0208] It should be noted that the explanations of the vehicle drift control method and vehicle drift control device 100 in the foregoing embodiments also apply to the computer-readable storage medium 300 of the embodiments of this application, and will not be elaborated here.

[0209] In summary, the vehicle drift control method, vehicle drift control device 100, vehicle drift control system 200, and computer-readable storage medium 300 of this application determine a vehicle drift strategy based on drift level, current information, and target drift parameters to control the vehicle to drift. In this vehicle drift strategy, multiple front wheels and / or multiple rear wheels of the vehicle are controlled by a fusion of independent steering and independent drive. This allows for flexible torque distribution to the multiple front wheels and / or multiple rear wheels, facilitating smooth and easy vehicle drift initiation.

[0210] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0211] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0212] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable storage medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, a computer-readable storage medium can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable storage medium could be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0213] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0214] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes one or a combination of the steps of the method embodiments. Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc.

[0215] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A vehicle drift control method, characterized in that, include: Receive the start command and control the vehicle to enter drift mode; Receive drift level instructions and control the drift level of the vehicle; Obtain the current information of the vehicle; Determine the target drift parameters based on the current information; A vehicle drift strategy is determined based on the drift level, the current information, and the target drift parameters to control the vehicle to drift. In this vehicle drift strategy, multiple front and / or rear wheels of the vehicle are controlled by a fusion of independent steering and independent drive. Furthermore, during the drift initiation process, the vehicle's drift control pattern is determined based on the current vehicle speed. When the current vehicle speed is less than or equal to a preset vehicle speed threshold, the vehicle is controlled to drift in a first drift control style, in which multiple front wheels and multiple rear wheels of the vehicle rotate in opposite directions. When the current vehicle speed is greater than the preset vehicle speed threshold, the vehicle is controlled to drift in a second drift control style, in which the left rear wheel and the right rear wheel of the vehicle form an "eight" shape; upon receiving a stop command, the vehicle is controlled to exit the drift mode.

2. The vehicle drift control method according to claim 1, characterized in that, The process of receiving the start command and controlling the vehicle to enter drift mode includes: Receive the start command; Determine whether the vehicle meets the drifting conditions; When the vehicle meets the drift conditions, control the vehicle to enter the drift mode.

3. The vehicle drift control method according to claim 1, characterized in that, After receiving the start command and controlling the vehicle to enter drift mode, the vehicle drift control method further includes: Adjust the control strategy of the vehicle stability control system and reset the trigger threshold of vehicle stability control; The trigger thresholds are different for different drift levels.

4. The vehicle drift control method according to claim 1, characterized in that, The current information includes the current steering wheel angle and the current vehicle speed. Determining the target drift parameters based on the current information includes: The target drift parameters are determined based on the current steering wheel angle information and the current vehicle speed.

5. The vehicle drift control method according to claim 1, characterized in that, The target drift parameters include the target yaw rate. The step of determining a vehicle drift strategy based on the drift level, the current information, and the target drift parameters to control the vehicle to drift includes: The target yaw moment is determined based on the target yaw angular velocity. The vehicle drift strategy is determined based on the target yaw moment.

6. The vehicle drift control method according to claim 5, characterized in that, The step of determining the vehicle drift strategy based on the target yaw moment includes: Determine the relationship between the target yaw moment and the preset drift threshold and the preset safety threshold; When the target yaw moment is less than the preset drift threshold, the target yaw moment is increased to control the vehicle to drift. When the target yaw moment is greater than or equal to the preset drift threshold and less than the preset safety threshold, the vehicle is controlled to drift. When the target yaw moment is greater than or equal to the preset safety threshold, the vehicle is controlled to exit the drift mode; The preset drift threshold and the preset safety threshold are different for different drift levels.

7. The vehicle drift control method according to claim 6, characterized in that, The current information includes the current slip ratio and the current vehicle speed. Increasing the target yaw moment to control the vehicle's drift includes: The front axle to rear axle torque ratio is determined based on the current slip ratio. The compensation amount of the target yaw moment is calculated based on the target yaw angular velocity and the preset drift threshold. The drift control pattern of the vehicle is determined based on the current vehicle speed.

8. The vehicle drift control method according to claim 7, characterized in that, Determining the front axle to rear axle torque ratio based on the current slip ratio includes: When the current slip ratio is less than the slip ratio threshold, the rear axle torque is increased; When the current slip ratio is greater than or equal to the slip ratio threshold, the rear axle torque is reduced; The slip ratio thresholds are different for different drift levels.

9. The vehicle drift control method according to claim 1, characterized in that, The control of multiple front wheels and / or multiple rear wheels of the vehicle through the fusion of independent steering and independent drive includes any one or more of the following: Dynamically control the torque distribution ratio between the front and rear axles; Dynamically control the left and right torque distribution ratio of the front axle; Dynamically control the left and right torque distribution ratio of the rear axle; Dynamically control the torque distribution ratio of the outer wheels on the front and rear axles.

10. A vehicle drift control device, implementing the vehicle drift control method according to any one of claims 1-9, characterized in that, include: The control module is used to receive the start command and control the vehicle to enter drift mode; The control module is also used to receive drift level commands and control the drift level of the vehicle; The acquisition module is used to acquire the current information of the vehicle; The determination module is used to determine the target drift parameters based on the current information; The determining module is further configured to determine a vehicle drift strategy based on the drift level, the current information, and the target drift parameters, so as to control the vehicle to drift, wherein the vehicle drift strategy controls multiple front wheels and / or multiple rear wheels of the vehicle by integrating independent steering and independent drive. The control module is also used to determine the drift control pattern of the vehicle based on the current vehicle speed during the drift initiation process: When the current vehicle speed is less than or equal to a preset vehicle speed threshold, the vehicle is controlled to drift in a first drift control style, in which multiple front wheels and multiple rear wheels of the vehicle rotate in opposite directions. When the current vehicle speed is greater than the preset vehicle speed threshold, the vehicle is controlled to drift in a second drift control style, in which the left rear wheel and the right rear wheel of the vehicle form an "eight" shape; upon receiving a stop command, the vehicle is controlled to exit the drift mode.

11. A vehicle drift control system, characterized in that, The vehicle drift control system includes one or more processors and a memory, the memory storing a computer program that, when executed by the processor, implements the vehicle drift control method according to any one of claims 1-9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the vehicle drift control method according to any one of claims 1-9.

Images