Pivot steering control method and device of vehicle

Abstract

The invention relates to the technical field of vehicle steering control, and provides a pivot steering control method and device of a vehicle. The method comprises the steps that a selected brake wheel in the vehicle is controlled to be in a braking state; according to the pedal opening degree of an accelerator pedal of the vehicle, the current rotating speed of each first driving wheel in the vehicle is controlled, and the first driving wheels and the brake wheel are located on the different axle center lines; and determining that the current rotating speed of each first driving wheel is greater than a preset rotating speed, and driving a second driving wheel which is located on the same axle center line as the brake wheel according to the pedal opening degree. According to the pivot steering control method of the vehicle, the stability of the vehicle during pivot steering can be improved, and the driving experience of a user is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle steering control technology, specifically to a pivot steering control method and device for a vehicle. Background Technology

[0002] Pivot steering in vehicles refers to braking a single wheel of the vehicle, using it as a pivot point, and then controlling the rotational speed of the remaining wheels based on the accelerator pedal opening to steer the vehicle at a corresponding yaw rate. In related technologies, pivot steering control methods involve braking one wheel while simultaneously controlling the rotational speed of the remaining wheels to achieve pivot steering at a specific yaw rate. However, this control method experiences rapid changes in vehicle acceleration when the remaining wheels overcome static friction to initiate pivot steering, leading to instability in the steering motion during the initial pivot steering initiation. This increases the driver's corrective effort and negatively impacts the driving experience. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the related art. To this end, this application proposes a pivot steering control method for vehicles, which can improve the stability of vehicles during pivot steering and enhance the user's driving experience.

[0004] A pivot steering control method for a vehicle according to a first aspect embodiment of this application includes: Control the selected brake wheel in the vehicle to be in a braking state; Based on the pedal opening of the accelerator pedal of the vehicle, control the current rotational speed of each first drive wheel in the vehicle that is located on a different axle centerline from the brake wheel; If the current rotational speed of each of the first drive wheels is determined to be greater than the preset rotational speed, the second drive wheel, which is located on the same axle centerline as the brake wheel, is driven according to the pedal opening. The preset rotational speed is determined based on the static friction critical rotational speed of the first drive wheel.

[0005] After the selected brake wheel in the vehicle is in a braking state, the current speed of each first drive wheel, which is on a different axle centerline from the brake wheel, is controlled according to the accelerator pedal opening. If the current speed of each first drive wheel is greater than a preset speed, then the second drive wheel, which is on the same axle centerline as the brake wheel, is driven according to the pedal opening. This phased control of the vehicle's pivot steering allows each first drive wheel to first form a pure rotational torque with the braking force of the brake wheel, establishing a stable instantaneous center of rotation. Once the vehicle has acquired initial angular momentum, the second drive wheel is driven. At this point, the rotational inertia has been partially overcome, and the second drive wheel only needs to provide incremental torque. This sequential separation avoids the instantaneous conflict of the three force vectors during synchronous driving, reduces the rate of lateral force buildup, and allows the vehicle's suspension system sufficient time to compensate for geometric deformation. This effectively reduces start-up instability during pivot steering, improves vehicle stability during pivot steering, and enhances the user's driving experience.

[0006] According to one embodiment of this application, driving a second drive wheel that is on the same axle centerline as the brake wheel, based on the pedal opening, includes: The target rotational speed of the second drive wheel is determined based on the pedal opening. Control the rotational speed of the second drive wheel to adjust it to the target speed.

[0007] According to one embodiment of this application, controlling the rotational speed of the second drive wheel to adjust to a target rotational speed includes: The rotational speed of the second drive wheel is controlled to transition from zero speed to the target rotational speed with a continuously differentiable angular acceleration.

[0008] According to one embodiment of this application, after controlling the rotational speed of the second drive wheel to adjust to the target rotational speed, the method further includes: Based on the pedal opening, determine the target yaw rate for the vehicle to perform pivot steering; Based on the angular velocity difference between the target yaw rate and the current yaw rate of the vehicle, the desired rotational speed corresponding to each of the first drive wheels is determined. Adjust the current speed of each of the first drive wheels according to the desired speed of each of the first drive wheels.

[0009] According to one embodiment of this application, determining the desired rotational speed of each of the first drive wheels based on the angular velocity difference between the target yaw rate and the current yaw rate of the vehicle includes: The difference between the target yaw rate and the current yaw rate of the vehicle is input into the fitting model corresponding to each of the first drive wheels to obtain the expected rotational speed of each of the first drive wheels. The fitting model is used to represent the relationship between the yaw rate of the vehicle when it performs pivot steering and the rotational speed of each of the first drive wheels.

[0010] According to one embodiment of this application, adjusting the current rotational speed of each of the first drive wheels based on the desired rotational speed corresponding to each of the first drive wheels includes: Based on the desired rotational speed corresponding to the first drive wheel, the first drive wheel is controlled to increase the desired rotational speed with a continuously differentiable angular acceleration until the current yaw rate of the vehicle reaches the target yaw rate.

[0011] A pivot steering control device for a vehicle according to a second aspect embodiment of this application includes: The braking control module is used to control the selected brake wheels in the vehicle to be in a braking state; The speed control module is used to control the current speed of each first drive wheel in the vehicle that is located on a different wheel axle centerline from the brake wheel, based on the pedal opening of the accelerator pedal of the vehicle. The steering control module is used to determine that the current speed of each of the first drive wheels is greater than the preset speed, and drive the second drive wheel that is on the same axle centerline as the brake wheel according to the pedal opening. The preset rotational speed is determined based on the static friction critical rotational speed of the first drive wheel.

[0012] An electronic device according to a third aspect of this application includes a processor and a memory storing a computer program, wherein the processor executes the computer program to implement the pivot steering control method for a vehicle as described in any of the above embodiments.

[0013] A computer-readable storage medium according to a fourth aspect of this application stores a computer program thereon, which, when executed by a processor, implements the pivot steering control method for a vehicle as described in any of the above embodiments.

[0014] The vehicle according to a fifth aspect embodiment of this application includes electronic equipment as described in the third aspect embodiment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1A schematic flowchart of a vehicle pivot steering control method provided in an embodiment of this application; Figure 2 This is a schematic diagram of the vehicle structure provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the pivot steering control device for a vehicle provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The pivot steering control method and device for vehicles provided in this application will be described in detail below through several specific embodiments.

[0019] Pivot steering in vehicles refers to braking a single wheel as a pivot point, then controlling the rotational speed of the remaining wheels based on the accelerator pedal opening to achieve a corresponding yaw rate and thus effectively reduce the vehicle's turning radius. In related technologies, pivot steering control methods involve braking one wheel while simultaneously controlling the rotational speed of the remaining wheels to achieve pivot steering at a specific yaw rate. However, this control method experiences rapid acceleration changes during the initial pivot steering maneuver, which can induce coupled oscillations between a sudden increase in drive wheel torque and vehicle inertial recoil. This can lead to instability in steering during pivot steering initiation, increasing the driver's corrective effort and negatively impacting the driving experience.

[0020] Therefore, in one embodiment, a pivot steering control method for a vehicle is provided. This method can be applied to a terminal device for pivot steering control of the vehicle. The terminal device may include a mobile terminal, a desktop terminal, or an in-vehicle terminal. The in-vehicle terminal may include the vehicle's VCU (Vehicle Control Unit), MCU (Microcontroller Unit), and / or PID controller, etc.

[0021] like Figure 1 As shown, this embodiment provides a vehicle pivot steering control method including: S101, control the selected brake wheel in the vehicle to be in a braking state; S102, based on the pedal opening of the accelerator pedal of the vehicle, control the current rotational speed of each first drive wheel in the vehicle that is located on a different wheel axle centerline from the brake wheel; S103, determine that the current speed of each of the first drive wheels is greater than the preset speed, and drive the second drive wheel that is on the same axle centerline as the brake wheel according to the pedal opening; The preset rotational speed is determined based on the static friction critical rotational speed of the first drive wheel.

[0022] In some embodiments, the vehicle may be a new energy vehicle or a non-new energy vehicle, which can achieve independent wheel drive, such as each wheel being driven by an independent motor or motor, and the rotational speed of each wheel can be controlled independently.

[0023] The brake wheel can be any selected wheel in the vehicle. For example, in pivot steering mode, a specific wheel can be designated as the brake wheel based on the driver's selected operation. After the brake wheel is designated, braking force is applied to that wheel to control it in a braking state. Figure 2 As shown, the vehicle includes a left front wheel A, a right front wheel B, a left rear wheel C, and a right rear wheel D. If the left front wheel A is selected as the braking wheel, then the left front wheel A is controlled to be in a braking state.

[0024] In some embodiments, wheels on a different axle centerline from the brake wheel can be designated as first drive wheels, and wheels on the same axle centerline as the brake wheel can be designated as second drive wheels. The axle centerline is a virtual straight line connecting the center points of two wheels on the same axle (e.g., front or rear axle) of the vehicle. For example, assuming the vehicle includes a left front wheel A, a right front wheel B, a left rear wheel C, and a right rear wheel D, then left front wheel A and right front wheel B are on the same axle centerline, and left rear wheel C and right rear wheel D are on the same axle centerline. If the brake wheel is left front wheel A, then left rear wheel C and right rear wheel D can be designated as first drive wheels, and right front wheel B as a second drive wheel. The same principle applies to other cases.

[0025] In some embodiments, after the brake wheel is in a braking state, the opening degree of the vehicle's accelerator pedal (i.e., the power accelerator pedal or accelerator pedal) is detected. The current speed of each first drive wheel is controlled based on the accelerator pedal opening degree, while simultaneously disabling the accelerator pedal's speed control over the second drive wheel. For example, if the brake wheel is the left front wheel A, the current speed of the left rear wheel C and right rear wheel D is controlled based on the accelerator pedal opening degree, while simultaneously disabling the accelerator pedal's speed control over the right front wheel B, keeping the right front wheel B stationary.

[0026] During the process of controlling the current speed of each first drive wheel based on the accelerator pedal opening, it is possible to detect in real time whether the current speed of each first drive wheel is greater than the corresponding preset speed. The preset speed can be the static friction critical speed of the first drive wheel. The static friction critical speed refers to the highest speed at which the tire is about to overcome static friction, i.e., about to slip. At this speed, the static friction between the tire and the ground reaches its maximum value; exceeding this speed causes the wheel to overcome static friction and begin to slip.

[0027] In some embodiments, during the process of controlling the current rotational speed of each first drive wheel according to the pedal opening of the accelerator pedal, it can be detected whether each first drive wheel is slipping. If so, it can be determined that the current rotational speed of each first drive wheel is greater than the preset rotational speed; otherwise, it can be determined that the current rotational speed of at least one first drive wheel is less than or equal to the preset rotational speed.

[0028] Alternatively, during the process of controlling the current speed of each first drive wheel according to the accelerator pedal opening, the current speed of each first drive wheel can be obtained separately, and the current speed of each first drive wheel can be compared with the preset speed to determine whether the current speed of each first drive wheel exceeds the preset speed.

[0029] Since the critical speed for static friction may differ for different wheels, preset speeds for different wheels can be pre-set through numerous experiments. During the process of controlling the current speed of each first drive wheel based on the accelerator pedal opening, the current speed of each first drive wheel can be acquired separately, and it can be checked whether the current speed of each first drive wheel exceeds its corresponding preset speed. For example, assuming the first drive wheels are the left rear wheel C and the right rear wheel D, the preset speed X corresponding to the left rear wheel C and the preset speed Y corresponding to the right rear wheel D can be acquired first. Then, during the process of controlling the current speeds of the left rear wheel C and the right rear wheel D based on the accelerator pedal opening, the current speeds of the left rear wheel C and the right rear wheel D can be acquired, and it can be checked whether the current speed of the left rear wheel C is greater than the preset speed X, and whether the current speed of the right rear wheel D is greater than the preset speed Y.

[0030] If the current rotational speed of each first drive wheel is determined to be greater than the preset rotational speed, it indicates that the first drive wheels have begun to slip, and the lateral resistance of the wheels has decreased. At this point, the accelerator pedal opening is used to control the rotational speed of the second drive wheels, or the accelerator pedal opening is used to control the rotational speed of the second drive wheels after a delay. If the current rotational speed of each first drive wheel is determined to be greater than the preset rotational speed for a preset duration, the accelerator pedal opening is used to control the rotational speed of the second drive wheels. This allows the second drive wheels to be driven according to the accelerator pedal opening, causing the first and second drive wheels to push the vehicle to rotate around the brake wheel, thus achieving pivot steering of the vehicle. The preset duration can be set according to actual conditions, such as 0.5 seconds.

[0031] For example, assuming the braking wheel is the left front wheel A, the first drive wheels are the left rear wheel C and the right rear wheel D, and the second drive wheel is the right front wheel B, the current speeds of the left rear wheel C and the right rear wheel D are controlled according to the accelerator pedal opening. Simultaneously, the accelerator pedal speed control for the right front wheel B is initially disabled, keeping the second drive wheel stationary, and the current speeds of the left rear wheel C and the right rear wheel D are detected. If the current speeds of the left rear wheel C and the right rear wheel D are greater than the corresponding preset speeds, indicating that the left rear wheel C and the right rear wheel D are starting to slip, the accelerator pedal speed control for the right front wheel B is delayed and activated. This allows the right front wheel B to be driven according to the accelerator pedal opening, causing the right front wheel B, left rear wheel C, and right rear wheel D to propel the vehicle around the left front wheel A, thus achieving pivot steering of the vehicle.

[0032] After the selected brake wheel in the vehicle is in a braking state, the current speed of each first drive wheel, which is on a different axle centerline from the brake wheel, is controlled according to the accelerator pedal opening. If the current speed of each first drive wheel is greater than a preset speed, then the second drive wheel, which is on the same axle centerline as the brake wheel, is driven according to the pedal opening. This phased control of the vehicle's pivot steering allows each first drive wheel to first form a pure rotational torque with the braking force of the brake wheel, establishing a stable instantaneous center of rotation. Once the vehicle has acquired initial angular momentum, the second drive wheel is driven. At this point, the rotational inertia has been partially overcome, and the second drive wheel only needs to provide incremental torque. This sequential separation avoids the instantaneous conflict of the three force vectors during synchronous driving, reduces the rate of lateral force buildup, and allows the vehicle's suspension system sufficient time to compensate for geometric deformation. This effectively reduces start-up instability during pivot steering, improves vehicle stability during pivot steering, and enhances the user's driving experience.

[0033] To more precisely control vehicle pivot steering, in some embodiments, a second drive wheel located on the same axle centerline as the brake wheel is driven according to the pedal opening, including: The target rotational speed of the second drive wheel is determined based on the pedal opening. Control the rotational speed of the second drive wheel to adjust it to the target speed.

[0034] In some embodiments, the terminal device may pre-store the correspondence between the opening degree of each accelerator pedal and the rotational speed of each wheel, such as the correspondence between the opening degree of each accelerator pedal and the rotational speed of the left front wheel A, the correspondence between the opening degree of each accelerator pedal and the rotational speed of the right front wheel B, the correspondence between the opening degree of each accelerator pedal and the rotational speed of the left rear wheel C, and the correspondence between the opening degree of each accelerator pedal and the rotational speed of the right rear wheel D.

[0035] If the current speed of each first drive wheel is determined to be greater than the preset speed, the target speed of the second drive wheel can be found by referring to the correspondence between the current accelerator pedal opening and the speeds of the second drive wheels. For example, if the second drive wheel is the right front wheel B, the target speed of the right front wheel B can be found by referring to the correspondence between the current accelerator pedal opening and the speeds of the right front wheel B.

[0036] Once the target speed of the second drive wheel is determined, the speed of the second drive wheel can be controlled according to the target speed to adjust the speed of the second drive wheel to the target speed.

[0037] To further improve the smoothness of the vehicle's pivot steering process, in some embodiments, controlling the rotational speed of the second drive wheel to adjust to a target speed includes: The rotational speed of the second drive wheel is controlled to transition from zero speed to the target rotational speed with a continuously differentiable angular acceleration.

[0038] Angular acceleration refers to the first derivative of angular velocity with respect to time. It represents the rate of change of angular velocity, i.e., the rate of change of wheel rotation speed. Continuously differentiable angular acceleration means that the change in angular acceleration is smooth and without abrupt changes. For example, S-curve speed planning can be used to control the rotational speed of the second drive wheel to smoothly transition from zero speed to the target speed.

[0039] Since the second drive wheel's speed transitions from zero to the target speed with a continuously differentiable angular acceleration, it can reduce sudden torque shocks during the second drive wheel's operation, ensuring that the second drive wheel's speed can smoothly transition from zero to the target speed. This further reduces the impact generated during pivot steering, thereby further improving the stability of the vehicle's pivot steering process.

[0040] To improve the accuracy of the vehicle's pivot steering, in some embodiments, after controlling the rotational speed of the second drive wheel to adjust to the target rotational speed, the method further includes: Based on the pedal opening, determine the target yaw rate for the vehicle to perform pivot steering; Based on the angular velocity difference between the target yaw rate and the current yaw rate of the vehicle, the desired rotational speed corresponding to each of the first drive wheels is determined. Adjust the current speed of each of the first drive wheels according to the desired speed of each of the first drive wheels.

[0041] In some embodiments, the terminal device may pre-store a mapping table showing the correspondence between the rotational speed of each first drive wheel and the yaw rate when the rotational speed of the second drive wheel is adjusted to the target rotational speed during the pivoting process of the vehicle. For example, there can be a mapping table 1 that records the correspondence between the rotational speeds of the left rear wheel C and right rear wheel D and the yaw rate of the vehicle when the rotational speed of the right front wheel B is adjusted to the target speed during pivot steering with the left front wheel A as the brake wheel; a mapping table 2 that records the correspondence between the rotational speeds of the left rear wheel C and right rear wheel D and the yaw rate of the vehicle when the rotational speed of the left front wheel A is adjusted to the target speed during pivot steering with the right front wheel B as the brake wheel; a mapping table 3 that records the correspondence between the rotational speeds of the left front wheel A and right front wheel B and the yaw rate of the vehicle when the rotational speed of the right rear wheel D is adjusted to the target speed during pivot steering with the left rear wheel C as the brake wheel; and a mapping table 4 that records the correspondence between the rotational speeds of the left front wheel A and right front wheel B and the yaw rate of the vehicle when the rotational speed of the left rear wheel C is adjusted to the target speed during pivot steering with the right rear wheel D as the brake wheel.

[0042] Considering that during vehicle pivoting, if the first drive wheels are directly controlled by the accelerator pedal opening, the actual yaw rate during pivoting will not reach the target yaw rate corresponding to that accelerator pedal opening due to friction. Therefore, after adjusting the speed of the second drive wheels to the target speed, the target yaw rate corresponding to that accelerator pedal opening can be determined first based on the accelerator pedal opening during pivoting.

[0043] After obtaining the target yaw rate corresponding to the pedal opening, if the current yaw rate is inconsistent with the target yaw rate (e.g., the current yaw rate is 0.3 and the target yaw rate is 0.5), the desired speed can be determined by looking up the corresponding rotational speed in the mapping table corresponding to each first drive wheel, based on the angular velocity difference between the target and current yaw rates (i.e., the difference between the target and current yaw rates). For example, if the left front wheel A is the brake wheel, the desired speed of the left rear wheel C, corresponding to the angular velocity difference between the target and current yaw rates, can be determined from mapping table 1, as the desired speed of the left rear wheel C, and the desired speed of the right rear wheel D, corresponding to the angular velocity difference between the target and current yaw rates, can also be determined from mapping table 1.

[0044] After determining the desired speed for each first drive wheel, the current speed of each first drive wheel can be adjusted according to the desired speed, such as increasing the current speed of the first drive wheel by the desired speed until the current yaw rate of the vehicle reaches the target yaw rate, so that the vehicle can pivot according to the target yaw rate.

[0045] By determining the target yaw rate for pivoting the vehicle based on the pedal opening, and then determining the desired speed of each first drive wheel based on the angular velocity difference between the target yaw rate and the current yaw rate, the current speed of each first drive wheel is adjusted according to the desired speed of each first drive wheel. This reduces the possibility of the vehicle failing to pivot at the target yaw rate corresponding to the accelerator pedal opening due to friction, thereby improving the accuracy of the vehicle's pivoting.

[0046] Considering the desired rotational speed of any first drive wheel, it can be obtained by matching the angular velocity difference between the target yaw rate and the current yaw rate from the corresponding mapping table. However, to avoid situations where the mapping table does not contain the desired rotational speed corresponding to the angular velocity difference between the target and current yaw rates, it is necessary to record as many yaw rates as possible for the first drive wheel at different speeds. However, this method leads to an excessive amount of recorded data, increasing storage pressure and reducing data retrieval efficiency. Furthermore, since it is impossible to exhaust all possible rotational speeds of the first drive wheel, searching the mapping table will still result in situations where the desired rotational speed of the first drive wheel cannot be determined based on the angular velocity difference between the target and current yaw rates, affecting the accuracy of the vehicle's pivot steering control.

[0047] Therefore, in some embodiments, the desired rotational speed corresponding to each of the first drive wheels is determined based on the angular velocity difference between the target yaw rate and the current yaw rate of the vehicle, including: The angular velocity difference between the target yaw rate and the current yaw rate is input into the fitting model corresponding to each of the first drive wheels to obtain the expected rotational speed of each of the first drive wheels. The fitting model is used to represent the relationship between the yaw rate of the vehicle when it performs pivot steering and the rotational speed of each of the first drive wheels.

[0048] In some embodiments, extensive experiments can be conducted beforehand to determine the correspondence between the rotational speed of each first drive wheel and the yaw rate when the rotational speed of the second drive wheel is adjusted to the target speed during pivoting of the vehicle. This correspondence is then fitted with a function to obtain a fitted model representing the correspondence between the yaw rate of the vehicle during pivoting and the rotational speed of each first drive wheel. Assuming the vehicle consists of a left front wheel A, a right front wheel B, a left rear wheel C, and a right rear wheel D, with left front wheel A and right front wheel B on the same axle centerline, and left rear wheel C and right rear wheel D on the same axle centerline, then through function fitting, we can obtain the following fitting models for the left rear wheel C and right rear wheel D when the vehicle is pivoting with left front wheel A as the brake wheel and the speed of right front wheel B is adjusted to the target speed: X1; X2; X3; X4; and X4.

[0049] After obtaining the angular velocity difference between the target yaw rate and the current yaw rate, a fitting model corresponding to each first drive wheel can be determined based on the brake wheel and each first drive wheel. The angular velocity difference between the target yaw rate and the current yaw rate can be input into this fitting model to obtain the desired rotational speed of each first drive wheel. For example, assuming the brake wheel is the left front wheel A, and the first drive wheels are the left rear wheel C and the right rear wheel D, the angular velocity difference between the target yaw rate and the current yaw rate can be input into the fitting model X1 to obtain the desired rotational speeds of the left rear wheel C and the right rear wheel D.

[0050] After obtaining the desired rotational speeds for each of the first drive wheels, the current rotational speeds of each first drive wheel can be adjusted accordingly. This eliminates the need to search for data when determining the desired rotational speeds of the first drive wheels, reducing storage and data query burdens, and minimizing instances where the desired rotational speeds cannot be obtained through data lookup. Furthermore, determining the desired rotational speeds of each first drive wheel using a constructed fitting model results in more accurate values, thereby improving the precision of pivot steering control of the vehicle.

[0051] To further improve the vehicle's stability during pivot steering, in some embodiments, the current speed of each first drive wheel is adjusted to the corresponding desired speed based on the desired speed of each first drive wheel, including: Based on the desired rotational speed corresponding to the first drive wheel, the first drive wheel is controlled to increase the desired rotational speed with a continuously differentiable angular acceleration until the current yaw rate of the vehicle reaches the target yaw rate.

[0052] In some embodiments, for any first drive wheel, after determining the desired rotational speed of the first drive wheel, the first drive wheel can be controlled to transition from its current rotational speed to its desired rotational speed with a continuously differentiable angular acceleration. For example, S-curve speed planning can be employed to control the rotational speed of the first drive wheel to smoothly increase from its current rotational speed to the desired rotational speed until the vehicle's current yaw rate reaches the target yaw rate.

[0053] Since the rotational speed of the first drive wheel increases with a continuously differentiable angular acceleration, sudden torque shocks can be avoided during the change of the rotational speed of the first drive wheel. This ensures that the current yaw rate of the vehicle can smoothly transition to the target yaw rate, thereby further reducing the impact generated during pivot steering and further improving the stability of the vehicle's pivot steering process.

[0054] The pivot steering control device for a vehicle provided in this application is described below. The pivot steering control device for a vehicle described below can be referred to in correspondence with the pivot steering control method for a vehicle described above.

[0055] In one embodiment, such as Figure 3 As shown, a pivot steering control device for a vehicle is provided, comprising: Braking control module 210 is used to control the selected brake wheel in the vehicle to be in a braking state; The speed control module 220 is used to control the current speed of each first drive wheel in the vehicle that is located on a different wheel axle centerline from the brake wheel, according to the pedal opening of the accelerator pedal of the vehicle. The steering control module 230 is used to determine that the current speed of each of the first drive wheels is greater than the preset speed, and drive the second drive wheel that is on the same axle centerline as the brake wheel according to the pedal opening. The preset rotational speed is determined based on the static friction critical rotational speed of the first drive wheel.

[0056] After the selected brake wheel in the vehicle is in a braking state, the current speed of each first drive wheel, which is on a different axle centerline from the brake wheel, is controlled according to the accelerator pedal opening. If the current speed of each first drive wheel is greater than a preset speed, then the second drive wheel, which is on the same axle centerline as the brake wheel, is driven according to the pedal opening. This phased control of the vehicle's pivot steering allows each first drive wheel to first form a pure rotational torque with the braking force of the brake wheel, establishing a stable instantaneous center of rotation. Once the vehicle has acquired initial angular momentum, the second drive wheel is driven. At this point, the rotational inertia has been partially overcome, and the second drive wheel only needs to provide incremental torque. This sequential separation avoids the instantaneous conflict of the three force vectors during synchronous driving, reduces the rate of lateral force buildup, and allows the vehicle's suspension system sufficient time to compensate for geometric deformation. This effectively reduces start-up instability during pivot steering, improves vehicle stability during pivot steering, and enhances the user's driving experience.

[0057] In one embodiment, the steering control module 230 is specifically used for: The target rotational speed of the second drive wheel is determined based on the pedal opening. Control the rotational speed of the second drive wheel to adjust it to the target speed.

[0058] In one embodiment, the steering control module 230 is specifically used for: The rotational speed of the second drive wheel is controlled to transition from zero speed to the target rotational speed with a continuously differentiable angular acceleration.

[0059] In one embodiment, the steering control module 230 is further configured to: After adjusting the rotational speed of the second drive wheel to the target speed, the target yaw rate for the vehicle to perform pivot steering is determined based on the pedal opening. Based on the angular velocity difference between the target yaw rate and the vehicle's current yaw rate, the desired rotational speed corresponding to each of the first drive wheels is determined. Based on the desired rotational speed corresponding to each of the first drive wheels, adjust the current rotational speed of each of the first drive wheels to the corresponding desired rotational speed.

[0060] In one embodiment, the steering control module 230 is specifically used for: The angular velocity difference between the target yaw rate and the current yaw rate is input into the fitting model corresponding to each of the first drive wheels to obtain the expected rotational speed of each of the first drive wheels. The fitting model is used to represent the relationship between the yaw rate of the vehicle when it performs pivot steering and the rotational speed of each of the first drive wheels.

[0061] In one embodiment, the steering control module 230 is specifically used for: Based on the desired rotational speed corresponding to the first drive wheel, the first drive wheel is controlled to increase the desired rotational speed with a continuously differentiable angular acceleration until the current yaw rate of the vehicle reaches the target yaw rate.

[0062] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other via the communication bus 840. The processor 810 can call a computer program in the memory 830 to execute a pivot steering control method for the vehicle, such as including: Control the selected brake wheel in the vehicle to be in a braking state; Based on the pedal opening of the accelerator pedal of the vehicle, control the current rotational speed of each first drive wheel in the vehicle that is located on a different axle centerline from the brake wheel; If the current rotational speed of each of the first drive wheels is determined to be greater than the preset rotational speed, the second drive wheel, which is located on the same axle centerline as the brake wheel, is driven according to the pedal opening. The preset rotational speed is determined based on the static friction critical rotational speed of the first drive wheel.

[0063] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0064] On the other hand, embodiments of this application also provide a storage medium, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the vehicle pivot steering control method provided in the above embodiments, for example including: Control the selected brake wheel in the vehicle to be in a braking state; Based on the pedal opening of the accelerator pedal of the vehicle, control the current rotational speed of each first drive wheel in the vehicle that is located on a different axle centerline from the brake wheel; If the current rotational speed of each of the first drive wheels is determined to be greater than the preset rotational speed, the second drive wheel, which is located on the same axle centerline as the brake wheel, is driven according to the pedal opening. The preset rotational speed is determined based on the static friction critical rotational speed of the first drive wheel.

[0065] In some embodiments, a vehicle is also provided, which is an electronic device as described in the above embodiments.

[0066] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0067] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for controlling the pivot steering of a vehicle, characterized in that, include: Control the selected brake wheel in the vehicle to be in a braking state; Based on the pedal opening of the accelerator pedal of the vehicle, control the current rotational speed of each first drive wheel in the vehicle that is located on a different axle centerline from the brake wheel; If the current rotational speed of each of the first drive wheels is determined to be greater than the preset rotational speed, the second drive wheel, which is located on the same axle centerline as the brake wheel, is driven according to the pedal opening. The preset rotational speed is determined based on the static friction critical rotational speed of the first drive wheel.

2. The vehicle pivot steering control method according to claim 1, characterized in that, Drive the second drive wheel, which is located on the same axle centerline as the brake wheel, according to the pedal opening, including: The target rotational speed of the second drive wheel is determined based on the pedal opening. Control the rotational speed of the second drive wheel to adjust it to the target speed.

3. The vehicle pivot steering control method according to claim 2, characterized in that, Controlling the rotational speed of the second drive wheel to adjust to the target rotational speed includes: The rotational speed of the second drive wheel is controlled to transition from zero speed to the target rotational speed with a continuously differentiable angular acceleration.

4. The vehicle pivot steering control method according to claim 2, characterized in that, After adjusting the speed of the second drive wheel to the target speed, the process also includes: Based on the pedal opening, determine the target yaw rate for the vehicle to perform pivot steering; Based on the angular velocity difference between the target yaw rate and the current yaw rate of the vehicle, the desired rotational speed corresponding to each of the first drive wheels is determined. Adjust the current speed of each of the first drive wheels according to the desired speed of each of the first drive wheels.

5. The vehicle pivot steering control method according to claim 4, characterized in that, Based on the angular velocity difference between the target yaw rate and the vehicle's current yaw rate, the desired rotational speed corresponding to each of the first drive wheels is determined, including: The difference between the target yaw rate and the current yaw rate of the vehicle is input into the fitting model corresponding to each of the first drive wheels to obtain the expected rotational speed of each of the first drive wheels. The fitting model is used to represent the relationship between the yaw rate of the vehicle when it performs pivot steering and the rotational speed of each of the first drive wheels.

6. The vehicle pivot steering control method according to claim 4, characterized in that, Adjusting the current speed of each of the first drive wheels according to the desired speed corresponding to each of the first drive wheels includes: Based on the desired rotational speed corresponding to the first drive wheel, the first drive wheel is controlled to increase the desired rotational speed with a continuously differentiable angular acceleration until the current yaw rate of the vehicle reaches the target yaw rate.

7. A pivot steering control device for a vehicle, characterized in that, include: The braking control module is used to control the selected brake wheels in the vehicle to be in a braking state; The speed control module is used to control the current speed of each first drive wheel in the vehicle that is located on a different wheel axle centerline from the brake wheel, based on the pedal opening of the accelerator pedal of the vehicle. The steering control module is used to determine that the current speed of each of the first drive wheels is greater than the preset speed, and drive the second drive wheel that is on the same axle centerline as the brake wheel according to the pedal opening. The preset rotational speed is determined based on the static friction critical rotational speed of the first drive wheel.

8. An electronic device comprising a processor and a memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the pivot steering control method for the vehicle according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1 to 6.

10. A vehicle, characterized in that, Including the electronic device as described in claim 8.

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