A multi-blDCM cooperative control method based on intelligent fractional order controller

Abstract

The application discloses a multi-BLDCM coordinated control method based on an intelligent fractional order controller, and belongs to the field of vehicle intelligent control, and comprises the following steps: acquiring a theoretical track of a driving wheel set of a vehicle; acquiring a displacement vector of a center point of a connecting line of the driving wheel set based on the theoretical track of the driving wheel set of the vehicle; acquiring a theoretical vector of a driven wheel set of the vehicle; acquiring a theoretical track of the driven wheel set corresponding to each theoretical track of the driving wheel set; acquiring an actual track of the driving wheel set and an actual track of the driven wheel set of the vehicle; acquiring a motion vector of each driving wheel and driven wheel based on the actual track of the driving wheel set and the actual track of the driven wheel set of the vehicle; acquiring control parameters for each driving wheel and driven wheel based on the motion vector of each driving wheel and driven wheel, and coordinating control of multi-BLDCM based on an intelligent fractional order controller. The multi-BLDCM coordinated control method solves the problem that in the prior art, it is difficult to ensure that a vehicle can quickly, accurately and one-time complete automatic parking or driving-off-parking actions in a multi-BLDCM coordinated control scheme.

Description

Technical Field

[0001] This application belongs to the field of vehicle intelligent control, specifically, it relates to a multi-BLDCM collaborative control method based on an intelligent fractional-order controller. Background Technology

[0002] The rise of new energy vehicles has enhanced wheel-end power and created opportunities for decoupling between the wheel-end power systems. This decoupling of the control schemes between the wheels allows for a better driving experience in almost all scenarios. Especially with the advancement of intelligent control technology, some driving experiences have reached or even surpassed those of inexperienced drivers or those with poor driving habits. However, it's still evident that some current control modes fail to fully leverage the advantages of multi-wheel-drive (BLDCM) technology, particularly during parking and departure. This manifests in several situations where vehicles struggle to reach their designated positions on the first attempt, requiring multiple adjustments and occupying more lane space, leading to lower efficiency and a higher risk of accidents.

[0003] Therefore, how to develop a system that enables vehicles to quickly, accurately, and in one go automatically park or leave a parking space through multi-BLDCM collaborative control is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address the problem in existing technologies that vehicles cannot guarantee fast, accurate, and one-time completion of parking or leaving a parking space, this application discloses a multi-BLDCM cooperative control method based on an intelligent fractional-order controller, specifically:

[0005] A multi-BLDCM cooperative control method based on an intelligent fractional-order controller, the cooperative control method comprising:

[0006] Based on the vehicle's initial position and target location, the theoretical trajectory of the vehicle's active wheel set is obtained;

[0007] Based on the theoretical trajectory of the vehicle's active wheel set, the displacement vector of the center point of the corresponding active wheel set connection line is obtained to obtain the target vector of the active wheel set;

[0008] Based on the target vector of the active wheel set, the theoretical vector of the vehicle's driven wheel set is obtained;

[0009] Based on the theoretical vector of the driven wheelset of the vehicle, obtain the theoretical track of the driven wheelset corresponding to each theoretical track of the driving wheelset;

[0010] The theoretical trajectory of the driven wheel set is verified to obtain the actual trajectory of the vehicle's driving wheel set and the actual trajectory of the driven wheel set.

[0011] Based on the actual tracks of the vehicle's active wheel set and driven wheel set, the motion vectors of each active wheel and driven wheel are obtained respectively.

[0012] Based on the motion vectors of each driving wheel and driven wheel, control parameters for each driving wheel and driven wheel are obtained, and multiple BLDCMs are coordinated and controlled based on an intelligent fractional-order controller.

[0013] Optionally, obtaining the theoretical trajectory of the vehicle's active wheel set based on the vehicle's initial position and target location includes:

[0014] The vehicle's direction of motion is obtained, and the group of wheels preceding the vehicle in that direction is identified as the driving wheel set.

[0015] Based on vehicle performance data, the maximum steering angle and maximum permissible speed difference between the two drive wheels are obtained to determine the steering angle range of the drive wheel set;

[0016] The initial position and target location of the vehicle are obtained, and all theoretical tracks of the active wheelset are obtained based on the steering angle range and allowable speed difference range of the active wheelset.

[0017] Optionally, obtaining the displacement vector of the center point of the corresponding active wheel set connection line based on the theoretical trajectory of the vehicle's active wheel set to obtain the target vector of the active wheel set includes:

[0018] Obtain the midpoint of the line connecting the axles of the two drive wheels within the vehicle's drive wheel assembly, in order to obtain the center point of the line connecting the drive wheel assemblies;

[0019] The center point of the active wheel assembly connection line and the theoretical trajectory of the active wheel assembly of the vehicle are always coincident on the ground projection, so that the theoretical trajectory of the active wheel assembly is the trajectory of the center point of the active wheel assembly connection line.

[0020] Obtain the tangents of all theoretical points on the track of the center point of the active wheel set connection, and based on the vehicle's direction of motion, obtain the target direction of the displacement vector of the center point of the active wheel set connection;

[0021] Based on the vehicle's driving scenario, the vehicle's driving speed parameters are obtained, and the displacement vector velocity of the center point of the active wheel assembly connection is obtained.

[0022] The target direction of the displacement vector and the velocity of the displacement vector at the center point of the line connecting the drive wheelsets are combined to obtain the target vector of the drive wheelsets.

[0023] Optionally, obtaining the theoretical vector of the driven wheelset of the vehicle based on the target vector of the active wheelset includes:

[0024] Based on the target vector of the active wheel set, obtain the selectable vector of the active wheel set at the center point of the line connecting the active wheel sets;

[0025] Based on the difference between the selectable vector direction of the active wheel set and the target vector direction of the active wheel set, the static compensation amount of the vector direction of the vehicle's active wheel set is obtained;

[0026] The difference in static compensation amount of the vector direction of the active wheel assembly is obtained between the current point and the next adjacent detection point on the theoretical track of the active wheel assembly, so as to obtain the dynamic compensation amount of the vector direction of the active wheel assembly.

[0027] Based on the selectable vector velocity of the active wheel set and the dynamic compensation amount of the vector direction of the active wheel set, the vector velocity of the driven wheel set is obtained;

[0028] The vector velocity and vector direction of the center point of the driven wheel set are combined to obtain the theoretical vector of the driven wheel set.

[0029] Optionally, obtaining the vector velocity of the driven wheel set based on the selectable vector velocity of the driving wheel set and the vector compensation amount of the driving wheel set includes:

[0030] Based on the velocity value of the selectable vector of the active wheel set, the arrival time between adjacent detection points on the theoretical track of the active wheel set is obtained;

[0031] The dynamic compensation amount of the active wheel group vector direction and the ratio of the arrival time between adjacent detection points are obtained to obtain the active wheel group vector compensation speed;

[0032] Based on the vector compensation speed and wheelbase of the active wheel set, the vector compensation speed of the driven wheel set is obtained;

[0033] Based on the selectable vector and wheelbase of the active wheel set, the corresponding vector velocity of the driven wheel set is obtained;

[0034] The vector velocity of the driven wheel set is obtained by merging the vector velocity of the driven wheel set and the vector compensation velocity of the driven wheel set.

[0035] Optionally, obtaining the theoretical trajectory of the driven wheelset corresponding to each theoretical trajectory of the driving wheelset based on the vehicle's driven wheelset theoretical vector includes:

[0036] Obtain the theoretical vector of the driven wheel set corresponding to the optional vector of the driving wheel set, and construct the theoretical trajectory of the driven wheel set;

[0037] Establish the correlation between the theoretical tracks of the driven wheelset and the theoretical tracks of the driving wheelset, thereby obtaining the theoretical track of the driven wheelset corresponding to each theoretical track of the driving wheelset.

[0038] Optionally, verifying the theoretical trajectory of the driven wheelset to obtain the actual trajectory of the vehicle's driving wheelset and the actual trajectory of the driven wheelset includes:

[0039] Based on the theoretical trajectory of the driven wheel set, the spatiotemporal coupling between the vehicle and surrounding obstacles is obtained;

[0040] The theoretical tracks of the driven wheel sets that have spatiotemporal coupling relationships with surrounding obstacles are removed, and the remaining theoretical tracks of the driven wheel sets are the candidate tracks of the driven wheel sets;

[0041] Based on the candidate tracks of the driven wheelset, obtain the corresponding candidate tracks of the driving wheelset;

[0042] The track group with the lowest probability of spatiotemporal coupling with obstacles around the vehicle is obtained from the candidate tracks of the active wheel group and the corresponding candidate tracks of the driven wheel group, so as to obtain the actual tracks of the active wheel group and the actual tracks of the driven wheel group.

[0043] Optionally, the step of obtaining the track group with the lowest probability of spatiotemporal coupling with obstacles around the vehicle from the candidate tracks of the active wheel set and the corresponding candidate tracks of the driven wheel set, to obtain the actual tracks of the active wheel set and the driven wheel set, includes:

[0044] Real-time monitoring of the location of obstacles in the vehicle's surrounding environment and acquisition of predicted obstacle trajectories;

[0045] Obtain the correspondence between vehicle position, attitude, and time in the candidate tracks of the driven wheelset and the candidate tracks of the driving wheelset;

[0046] Find the minimum distance between the vehicle's tracks and the obstacle at the same time, and obtain the probability of spatiotemporal coupling based on the minimum distance.

[0047] Obtain the track group with the lowest probability of spatiotemporal coupling to obtain the actual tracks of the driving wheel group and the driven wheel group.

[0048] Optionally, the step of obtaining the motion vector of each driving wheel and driven wheel based on the actual trajectory of the driving wheel set and the actual trajectory of the driven wheel set of the vehicle includes:

[0049] On the actual tracks of the driving wheel set and the actual tracks of the driven wheel set, respectively, the actual motion vectors of the driving wheel set and the driven wheel set at the same moment are obtained;

[0050] Based on the relationship between the actual motion vector of the driving wheel set and the motion vectors of the two driving wheels, and the relationship between the actual motion vector of the driven wheel set and the motion vectors of the two driven wheels, selectable values ​​for the motion vectors of the two wheels in the driving wheel set and the driven wheel set are obtained respectively.

[0051] The selectable values ​​of the motion vectors of the two wheels in the driving wheel set and the selectable values ​​of the motion vectors of the two wheels in the driven wheel set are verified separately to configure and obtain the motion vector of each driving wheel and driven wheel.

[0052] Optionally, the step of obtaining control parameters for each driving wheel and driven wheel based on the motion vector of each driving wheel and driven wheel, and co-controlling multiple BLDCMs based on an intelligent fractional-order controller, includes:

[0053] Based on the motion vector of each driving wheel and driven wheel, obtain the steering angle and moving speed of each driving wheel and driven wheel;

[0054] The steering angle data of each driving wheel and driven wheel is sent to the steering control motor control system of the wheel, and then sent by the control system to the intelligent fractional-order controller for steering angle control.

[0055] The speed data of each driving wheel and driven wheel is sent to the wheel speed control system to obtain the speed signal of each wheel, and then sent to the intelligent fractional-order controller for wheel speed control.

[0056] The beneficial effects of this application include:

[0057] 1. This application achieves one-time execution of automatic parking or leaving a parking space actions. The technical solution of this application plans the vehicle's trajectory, and during this process, simultaneously plans the running paths of both the front and rear wheel sets. In subsequent operations, the front and rear wheels only need to move according to the trajectory's motion vectors. In other words, the trajectory planning itself ensures that once the vehicle reaches a specific position, it can directly park or leave the parking space, thus achieving one-time execution of the parking or leaving action.

[0058] 2. This application expands the technical adaptability for automatic parking and departure from parking spaces. In this technical solution, determining the trajectory of the front and rear wheel sets does not involve completely decoupling all wheel motion vectors. Instead, it determines the driving and driven wheel sets according to the vehicle's direction of travel, and analyzes the motion vectors of the driving and driven wheel sets separately based on their dynamic relationship. Then, based on the analysis results, the motion vector of each wheel is determined, thereby executing the wheel set's motion vector trajectory. This technology can be applied to vehicles with various motor distribution modes, thus improving the technical adaptability.

[0059] 3. This application achieves spatial adaptation for automatic parking or leaving a parking space. The technical solution of this application allows for trajectory planning within the obtained front and rear wheel sets. During trajectory planning, the specific construction mode of the trajectory can be determined based on the vehicle's location within the given scenario. In other words, for all types of parking or leaving parking spaces, adjustments can be made directly based on the trajectory of the vehicle's front and rear wheel sets, enabling the vehicle to adapt to all parking or leaving parking spaces during operation. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the embodiments of this application or the prior art will be briefly introduced below. Obviously, the following description is only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are used to provide a further understanding of this disclosure and constitute a part of the specification. They are used together with the following detailed description to explain this disclosure, but do not constitute a limitation of this disclosure. In the drawings:

[0061] Figure 1 A flowchart of a multi-BLDCM collaborative control method based on an intelligent fractional-order controller is provided for embodiments of this application;

[0062] Figure 2 A schematic diagram of the theoretical trajectory of an active wheel group based on a multi-BLDCM cooperative control method using an intelligent fractional-order controller, provided in an embodiment of this application;

[0063] Figure 3 A schematic diagram of the theoretical trajectory of a driven wheel assembly based on a multi-BLDCM cooperative control method using an intelligent fractional-order controller, provided in an embodiment of this application;

[0064] Figure 4 A schematic diagram of the actual tracks of the active wheel set and the driven wheel set provided in this application embodiment of a multi-BLDCM cooperative control method based on an intelligent fractional-order controller;

[0065] Figure 5 This is a schematic diagram illustrating the motion vector verification method for each active and driven wheel in a multi-BLDCM cooperative control method based on an intelligent fractional-order controller, as provided in an embodiment of this application. Detailed Implementation

[0066] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. 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. Furthermore, in the embodiments of this application, "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0067] In the current development of the automotive industry, especially in the new energy vehicle industry, multi-motor vehicles have been developed. One of the key advantages of these vehicles compared to traditional vehicles is the decoupling of the motion vectors of each wheel, thus providing greater flexibility for precise control. This provides the hardware foundation for more flexible trajectory control and adjustment. Simultaneously, in the current development of the new energy vehicle industry, the development of control chips has reached the 4nm level, providing a hardware foundation for comprehensive control capabilities and computing power. These technologies can fully utilize the advantages of multi-motor systems, especially in scenarios such as parking and leaving parking spaces. However, in current applications of this technology, the main method used is still similar to manual control. This method often occupies a significant amount of road space during vehicle movement. In some scenarios—such as narrow roads with a large number of vehicles—this method is not optimal, easily leading to traffic accidents or congestion. The fundamental problem is the difficulty in achieving comprehensive adaptation to various scenarios, and it does not guarantee that parking or leaving a parking space can be completed in one go, resulting in a poor driving experience for both drivers and passengers.

[0068] To fully utilize the hardware resources of the current automotive industry, especially the new energy vehicle industry, and to improve the driving experience for drivers and passengers during automatic parking and departure from parking spaces, this application discloses a multi-BLDCM cooperative control method based on an intelligent fractional-order controller, such as... Figure 1 The diagram shown is a flowchart of a multi-BLDCM collaborative control method based on an intelligent fractional-order controller provided in an embodiment of this application. Specifically:

[0069] S110. Based on the vehicle's initial position and target location, obtain the theoretical trajectory of the vehicle's active wheel set.

[0070] S120. Based on the theoretical trajectory of the vehicle's active wheel set, obtain the displacement vector of the center point of the corresponding active wheel set connection line to obtain the target vector of the active wheel set.

[0071] S130. Based on the target vector of the active wheel set, obtain the theoretical vector of the driven wheel set of the vehicle.

[0072] S140. Based on the theoretical vector of the driven wheelset of the vehicle, obtain the theoretical track of the driven wheelset corresponding to each theoretical track of the driving wheelset.

[0073] S150. Verify the theoretical trajectory of the driven wheel set to obtain the actual trajectory of the vehicle's driving wheel set and the actual trajectory of the driven wheel set.

[0074] S160. Based on the actual trajectory of the active wheel set and the actual trajectory of the driven wheel set of the vehicle, obtain the motion vector of each active wheel and driven wheel respectively.

[0075] S170. Based on the motion vector of each driving wheel and driven wheel, obtain the control parameters for each driving wheel and driven wheel, and perform collaborative control of multiple BLDCMs based on the intelligent fractional-order controller.

[0076] The purpose of all the above steps is to establish a fast, accurate technical solution that can ensure the vehicle can complete automatic parking or leaving the parking space in one go, while also ensuring that the vehicle can fully adapt to the space in which it is located when it automatically parks or leaves the parking space, thereby greatly improving the driving experience.

[0077] The following will provide a detailed explanation of all the above steps, specifically:

[0078] As described in step S110, the purpose of this step is to configure the vehicle's wheelset and determine the theoretical trajectory within the wheelset, thereby establishing the basis for path selection required throughout the implementation of the entire technical solution. Specifically:

[0079] S111. Obtain the direction of movement of the vehicle and determine the first set of wheels in the direction of movement as the driving wheel set.

[0080] The purpose of this step is to group the front and rear wheels of the vehicle during automatic parking or departure from a parking space based on the performance they need to perform, thereby facilitating subsequent technical descriptions and the specific implementation of technical solutions.

[0081] Specifically, based on the vehicle's direction of motion, the two wheels in front of the vehicle's direction of motion are designated as the drive wheel set.

[0082] Among them, the driving wheel set and the driven wheel set are configured based on two front wheels and two rear wheels, rather than being grouped into two front and rear wheels on the same side.

[0083] The reason for adopting this method is that current multi-motor vehicles can already achieve steering function for both rear wheels. Of course, even if they do not have steering function, it does not affect the vehicle grouping method, so they can be grouped according to this rule.

[0084] S112. Based on vehicle performance data, obtain the maximum steering angle and maximum permissible speed difference between the two drive wheels to obtain the steering angle range of the drive wheel set.

[0085] The purpose of this step is to obtain the maximum steering angle range of the vehicle's drive wheelset. On the one hand, this can prevent the subsequent travel path of the drive wheelset from exceeding physical limits. On the other hand, it can determine in what situations additional large-angle supplementation is needed in the subsequent trajectory determination.

[0086] Among them, the combination result of the steering angle controlled by the two active wheels in the active wheel set of the vehicle is obtained. The lower limit is obviously 0°, and the upper limit is determined according to the characteristics of the vehicle itself.

[0087] Among them, the speed difference between the two wheels in the vehicle's drive wheel assembly is obtained. In the design and production of vehicles, the speed difference is usually limited to ensure the vehicle's operational safety and stability. This value only needs to be determined based on the obtained limit value.

[0088] Based on step S111, the specific details of the vehicle's active wheel set can be determined. In some cases, the vehicle's non-powered wheels do not have steering motors. If they become the active wheel set, their steering angle is limited to 0°.

[0089] For three-motor and four-motor schemes, where the drive wheels connected to these motors can turn, the steering angle of the wheel set needs to be specifically determined.

[0090] Among them, the steering angle of the drive wheel assembly is the steering angle at the center point of the line connecting the centers of the two drive wheels.

[0091] S113. Obtain the initial position and target location of the vehicle, and based on the steering angle range and allowable speed difference range of the active wheel set, obtain all theoretical tracks of the active wheel set.

[0092] The purpose of this step is to obtain the theoretical trajectory of the vehicle's drive wheel assembly when the vehicle is automatically parking or automatically leaving the parking space, so that the subsequent vehicle running lines can be determined based on the trajectory.

[0093] Specifically, it obtains the vehicle's position before automatic parking or automatic departure from the parking space begins, and obtains the position of the vehicle's drive wheel assembly.

[0094] Among them, the distance between the vehicle and all surrounding obstacles is obtained based on various sensors carried on the vehicle.

[0095] This involves obtaining the reachable tracks of the drive wheelset from its current position to the target location. This process considers only the steering angle range of the vehicle's drive wheelset and the allowable speed difference range between the two drive wheels to obtain all theoretical routes to these two points.

[0096] This process requires pre-screening all tracks of the active wheel assembly. Specifically, it involves obtaining the upper and lower limits of the vehicle's overall turning range. The lower limit is when only the active wheel assembly moves according to the track and has a turning action, while the driven wheel assembly does not provide any turning action, and any point on the vehicle collides with surrounding obstacles. The upper limit is when the active wheel assembly can ensure that the driven wheel assembly can always maintain a perpendicular turning track to the active wheel assembly and collide with surrounding obstacles. Of course, this also includes situations where the driven wheel assembly cannot provide sufficient turning angle assistance when the active wheel assembly achieves a specific angle, i.e., exceeding the range of the driven wheel assembly's following steering angle. Tracks outside these ranges need to be removed, and all remaining tracks are the theoretical tracks of the active wheel assembly.

[0097] Regarding the specific methods for determining all the tracks, after the limiting conditions are determined, the specific methods for constructing the coordinate system and determining the curve of the track are existing technologies, and this application does not limit or explain them.

[0098] One thing to ensure is that during the operation of the drive wheelset from the starting point to the end point, the theoretical trajectory of the drive wheelset will not cause the drive wheelset to reach the rear of the vehicle and will not collide with obstacles in the surrounding environment.

[0099] The beneficial effect of step S110 is that it delineates the active and passive wheel sets of the vehicle and determines the theoretical trajectory of the active wheel set, thereby ensuring the running trajectory of the active wheel set and laying the foundation for the subsequent execution of the multi-BLDCM cooperative control method for the vehicle.

[0100] As described in step S120, the purpose of this step is to improve the accuracy of multi-BLDCM cooperative control. The multi-BLDCM cooperative control method, which determines the time points according to vectors, can achieve this goal. Therefore, in the specific processing, after determining the theoretical trajectory of the vehicle's active wheel set, the vectors of the vehicle at each time point are obtained, thereby obtaining the constraint vector conditions of the active wheel set. Specifically:

[0101] S121. Obtain the midpoint of the line connecting the axles of the two drive wheels within the drive wheel assembly of the vehicle, so as to obtain the center point of the line connecting the drive wheel assemblies.

[0102] The purpose of this step is to determine the starting point of the vector, which is necessary for vehicle control. This step involves determining the starting point of the vector.

[0103] Specifically, according to step S110, for the method of limiting the steering angle range of the driving wheel set, the center point of the line connecting the driving wheel sets needs to be the starting point of the vector.

[0104] In this process, a line is drawn connecting the axes of the two drive wheels, and the center point of this line is obtained. This position is the center point of the drive wheel assembly connection.

[0105] S122. Keep the center point of the active wheel assembly line and the theoretical track of the active wheel assembly of the vehicle always coincide on the ground projection, so that the theoretical track of the active wheel assembly is the track of the center point of the active wheel assembly line.

[0106] The purpose of this step is to correlate the center point of the active wheel assembly with the theoretical trajectory of the vehicle's active wheel assembly, thereby ensuring the acquisition of the control basis in multi-BLDCM collaborative control.

[0107] In this process, the center point of the drive wheel assembly line and the theoretical track are projected onto the ground to obtain the projections.

[0108] This requires setting the projections obtained separately to ensure that the two projections always overlap. In other words, this content of always maintaining the overlap of projections belongs to the target of the vehicle's active wheel set trajectory control.

[0109] If the projections obtained from each wheel remain aligned, it means that the trajectory of the center point of the line connecting the active wheelsets is essentially the theoretical trajectory of the active wheelsets.

[0110] S123. Obtain the tangents of all theoretical points on the track of the center point of the active wheel set connection, and based on the vehicle's motion direction, obtain the target direction of the displacement vector of the center point of the active wheel set connection.

[0111] The purpose of this step is to obtain the vector direction of the center point of the active wheel assembly connection.

[0112] Among them, the tangents of all points on the trace of the center point of the active wheel assembly connection are obtained.

[0113] The tangent at the obtained point actually coincides with the target direction of the displacement vector of the center point of the line connecting the drive wheels.

[0114] Specifically, based on the vehicle's direction of movement, the displacement vector target direction of the center point of the line connecting the active wheel sets is obtained.

[0115] S124. Based on the vehicle's driving scenario, obtain the vehicle's driving speed parameters and get the displacement vector velocity of the center point of the active wheel assembly connection.

[0116] The purpose of this step is to determine the velocity of the displacement vector during the automatic parking or departure of a vehicle from a parking space.

[0117] As for the so-called vehicle driving scenario, the driving speed corresponding to the relevant driving scenario can be determined according to the vehicle's own automatic control mode. In other words, the driving scenario and the corresponding driving speed parameters are the vehicle's own control program, and the speed can be determined directly using the result without any additional processing.

[0118] S125. Combine the target direction of the displacement vector and the velocity of the displacement vector at the center point of the line connecting the drive wheelsets to obtain the target vector of the drive wheelsets.

[0119] The purpose of this step is to specifically determine the control target vector of the active wheel assembly in the specific control of the vehicle.

[0120] In this process, the target direction and displacement vector velocity are determined from the displacement vector of the center line connecting the active wheel set, thus combining the three elements of the vector and finally obtaining the target vector of the active wheel set.

[0121] The beneficial effect of step S120 is that it realizes the specific determination of the vector parameters of the center point of the active wheel group connection in the actual control of the vehicle's active wheel group, thereby obtaining the active wheel group control reference for the multi-BLDCM cooperative control process.

[0122] As described in step S130, after obtaining the target vector of the driving wheel set, it is necessary to achieve the target vector parameter. However, there are two scenarios in this process. One is that even when the driving wheel set reaches its maximum steering angle, it is still difficult to achieve the control target by relying solely on the automatic control of the driving wheel set. In other words, the steering angle limit of the driving wheel set is exceeded, so the driven wheel set needs to compensate. In this case, it is obviously necessary to obtain the motion vector of the driven wheel set. The other scenario is that the driving wheel set has not reached the steering angle limit, but theoretically, it should follow the theoretical trajectory. In this case, there is a lot of target vector data for the driving wheel set. In this process, it is necessary to simultaneously obtain the theoretical vector of the driven wheel set to support the driving wheel set in moving along the target vector. In either case, it is necessary to obtain the corresponding theoretical vector of the driven wheel set. Specifically:

[0123] S131. Based on the target vector of the active wheel set, obtain the selectable vector of the active wheel set at the center point of the line connecting the active wheel sets.

[0124] The purpose of this step is that after determining the target vector of the drive wheelset, the actual control result of the drive wheelset needs to be considered. Therefore, in this case, there may be situations that exceed the steering angle and / or speed difference of the drive wheelset. In this case, it is necessary to obtain the optional vector of the drive wheelset at the center point of the drive wheelset connection.

[0125] Among them, after obtaining the target vector of the active wheel group, the optional vector of the active wheel group is located at the center point of the line connecting the active wheel groups.

[0126] Among them, for the selectable vector of the active wheel set, if the direction and speed of the target vector of the active wheel set are determined and do not exceed the maximum steering angle and speed difference of the active wheel set, then the selectable vector of the active wheel set needs to point in the direction within the convex arc of the theoretical track. The specific degree of pointing can be limited to a certain range, such as 5%, or it can reach the upper limit of the steering angle of the active wheel set, such as pointing in the direction within the convex arc and the steering angle is 40°.

[0127] Among them, the minimum value of the optional vector is obviously the direction of the target vector, that is, the tangent line corresponding to that point on the theoretical track of the active wheel assembly.

[0128] S132. Based on the difference between the selectable vector direction of the active wheel set and the target vector direction of the active wheel set, obtain the static vector direction compensation amount of the vehicle's active wheel set.

[0129] The purpose of this step is that, as a whole structure, the vehicle needs to be controlled by multiple BLDCMs, and this characteristic obviously needs to be taken into account. Therefore, after obtaining the selectable vectors of the active wheel set, it is also necessary to obtain the vectors that the driven wheel set needs to be adjusted in this process based on the overall characteristics of the vehicle.

[0130] When the selectable vector direction of the active wheel set coincides with the target vector direction of the active wheel set, the vector direction compensation of the active wheel set is obviously 0°.

[0131] If the selectable vector direction of the active wheel set and the target vector direction of the active wheel set do not coincide, the difference between the two needs to be calculated, and the result is the vector direction compensation amount of the active wheel set.

[0132] It's important to explain why this method is used. Firstly, it allows for adjustments based on the driver's desired driving mode, such as comfort, aggressiveness, or scenario limitations. These factors influence the selectable vector, such as higher vector speed, smaller or higher vector steering angles. For example, in cases of significant surrounding constraints, the driving wheels must have a larger steering angle, while the driven wheels must have a smaller one to avoid collisions with obstacles, as only a small angle can prevent excessive outward rotation. Secondly, in extreme cases, the selectable vector direction might exceed the steering angle limits of the driving wheel set, requiring compensation from the driven wheel set. Figure 2The diagram shown illustrates the theoretical trajectory of an active wheel assembly based on a multi-BLDCM cooperative control method using an intelligent fractional-order controller, according to an embodiment of this application. Only one theoretical trajectory of the active wheel assembly is shown. The dashed line between the two active wheels represents the axle. In reality, many vehicles do not have a physically rigid axle, especially when each wheel has a steering motor; therefore, it is represented by a dashed line. This diagram only shows one theoretical trajectory of the active wheel assembly from its initial position to its target location. The black dots between the two axles represent the vehicle's initial and target positions, respectively. It should be noted that there are multiple theoretical trajectories for the active wheel assembly to reach the target location from its initial position without colliding with other vehicles. This application only shows one of them. Furthermore, the tire-to-axle ratio is not set according to actual conditions.

[0133] S133. Obtain the difference in the static compensation amount of the vector direction of the active wheel group corresponding to the current point and the next adjacent detection point on the theoretical track of the active wheel group, so as to obtain the dynamic compensation amount of the vector direction of the active wheel group.

[0134] The purpose of this step is to determine the vector compensation amount of the active wheel set. Considering that the vehicle is in motion, it is obviously impossible for the center point of the active wheel set connection to remain unchanged, and the vehicle's driven wheel set to adjust the steering to perform vector direction compensation. Instead, both the front and rear wheel sets are in motion. Therefore, this process needs to obtain the vector compensation amounts at two different time points and the total amount of vector direction compensation processing required between two adjacent detection points.

[0135] Specifically, the static compensation amount of the vector direction of the active wheel group corresponding to two adjacent detection points is obtained, and the difference is calculated.

[0136] The difference obtained is the dynamic compensation amount of the active wheel group vector direction. Obviously, this dynamic compensation amount is the dynamic compensation amount between these two adjacent points.

[0137] The obtained dynamic compensation amount needs to be executed by the driven wheel group to realize the execution of the compensation amount, thereby compensating for the final result.

[0138] S134. Based on the selectable vector velocity of the active wheel set and the dynamic compensation amount of the vector direction of the active wheel set, obtain the vector velocity of the driven wheel set.

[0139] The purpose of this step is to determine the vector velocity of the driven wheel set after obtaining the dynamic compensation amount of the driving wheel set's vector direction and the selectable vector velocity of the driving wheel set. This ensures that the vector velocity is determined, allowing for the subsequent determination of the driven wheel set's vector velocity. Specifically:

[0140] S1341. Based on the velocity value of the selectable vector of the active wheel set, obtain the arrival time between adjacent detection points on the theoretical track of the active wheel set.

[0141] The purpose of this step is that, during the determination of the vector velocity of the driven wheel set, it is obviously necessary to obtain the time value. Considering that the distance between two adjacent detection points is very short, the speed of the selectable vector of the driving wheel set can be considered to be uniform, and the two points are in a straight line. Therefore, by directly determining the speed value of the selectable vector of the driving wheel set and the distance between adjacent points, the arrival time can be determined.

[0142] Among them, the distance between adjacent detection points and the velocity value of the selectable vector of the active wheel group in this stage are obtained, and the arrival time between adjacent points on the theoretical track of the active wheel group is directly obtained. The equation is as follows:

[0143] ,

[0144] Among them, t i This represents the arrival time of the center point of the active wheel assembly connecting two adjacent detection points; l i Indicates the distance between two adjacent detection points; v i This represents the velocity value of the optional vector between two adjacent detection points; i represents the segment number of the adjacent detection points.

[0145] S1342. Obtain the dynamic compensation amount of the active wheel group vector direction and the arrival time ratio between adjacent detection points to obtain the active wheel group vector compensation speed.

[0146] The purpose of this step is to determine the step speed of the dynamic compensation amount of the vector direction for the obtained adjacent detection points, so that other subsequent parameters can be determined based on the compensation speed.

[0147] Specifically, for the vector compensation speed of the active wheel set, it is necessary to determine the dynamic compensation amount of the vector direction of the active wheel set. Only then can the content to be compensated be determined in the subsequent technical solution processing, so as to determine the result.

[0148] The equation for calculating the vector compensation speed of the active wheel is as follows:

[0149] ,

[0150] in, d represents the active wheel group vector compensation velocity between adjacent detection points in the i-th group; i This represents the dynamic compensation amount of the active wheel group vector direction between adjacent detection points in the i-th group.

[0151] In this process, the vector compensation speed of the active wheel group needs to be determined in the active wheel group processing between each group of adjacent detection points.

[0152] S1343. Based on the vector compensation speed of the active wheel set and the wheelbase, obtain the vector compensation speed of the driven wheel set.

[0153] The purpose of this step is that, in the technical solution of this application, after the vector compensation speed of the active wheel group is determined, the specific compensation process needs to be performed by the driven wheel group. At the same time, in the vector compensation of the active wheel group of the driven wheel group, the compensation speed that needs to be included in the movement of the driven wheel group needs to be determined based on the vehicle's own parameters.

[0154] Among them, the wheelbase of the vehicle, which is the distance between the center of the front wheel axle and the center of the rear wheel axle, can be directly determined based on the obtained vector compensation speed.

[0155] Essentially, the vector compensation velocity of the active wheel group between each pair of adjacent detection points can be considered as an angular velocity, and the rotation angle is also specific. Therefore, in the specific processing, considering the working mode of the driven wheel group, the vector compensation velocity of the driven wheel group perpendicular to the wheelbase direction can be obtained, and its equation is:

[0156] ,

[0157] Among them, v di denoted as the vector compensation velocity of the driven wheel group between adjacent detection points in the i-th group in the direction perpendicular to the wheelbase; W represents the wheelbase.

[0158] Considering that it is virtually impossible for the vehicle's driven wheels to achieve a steering angle of 90° during movement using current technology, the result obtained from the above equation is only one component of the driven wheel set vector compensation velocity. Therefore, it is necessary to determine the total driven wheel set vector compensation velocity, and its equation is as follows:

[0159] ,

[0160] Among them, V i This indicates the vector compensation speed of the driven wheel assembly; Let V represent the total compensated steering angle of the driven wheel group between adjacent detection points in the i-th group. Clearly, this process can establish V... i — The correspondence is that: as long as in When the value is not zero and does not exceed the upper limit of the steering angle, a corresponding relationship can be established. It should be noted that at this time, the driven wheel set needs to have steering capability or the ability to adjust the speed difference between the two driven wheels, and the relationship between the speed difference and the steering angle needs to be determined. This technology is existing technology, and it is sufficient to utilize this type of existing technology.

[0161] S1344. Based on the selectable vector and wheelbase of the active wheel set, obtain the corresponding vector velocity of the driven wheel set.

[0162] The purpose of this step is to perform a comprehensive calculation of the vector velocity, which is another key vector parameter in the vector velocity of the driven wheel assembly.

[0163] For the selectable vector direction of the active wheel assembly, it is necessary to obtain the angle between the line connecting two adjacent detection points and the tangent of the current detection point. This angle is the vector that the active wheel assembly needs to adjust.

[0164] In the process of processing the result, the time of obtaining the direction change of the active wheel group's selectable vector is exactly the same as the arrival time of the center point of the active wheel group connection between the two adjacent detection points mentioned above.

[0165] Specifically, it is necessary to obtain the velocity of change of the direction of the selectable vector of the active wheel set, and its equation is:

[0166] ,

[0167] in, This represents the rate of change of the direction of the selectable vector of the active wheel group between two adjacent detection points in the i-th group; This represents the angle of change in the direction of the optional vector of the active wheel group between two adjacent detection points in the i-th group.

[0168] In this process, still based on the same method as step S1343, during the process of obtaining the change of the selectable vector of the active wheel set, the driven wheel set needs to synchronously make a follow-up speed, the equation of which is:

[0169] ,

[0170] in, This represents the vector velocity of the driven wheel assembly between two adjacent detection points at the i-th position, for this process... Considering the integrity of the vehicle itself and the uniformity of the wheel steering angle at the same time point, its value must be the same as the total compensated steering angle of the driven wheel group between the i-th group of adjacent detection points.

[0171] In some embodiments, for the selectable vector of the driving wheel set, the rotational speed of the driven wheel set can be directly determined based on existing research results. For example, if only the front wheel or the rear wheel is the driving wheel and the remaining wheels are non-driving wheels, the relationship between the speeds of the steering wheel (i.e., the front wheel) and the non-steering wheels can be directly analyzed, and the follow-up speed of the driven wheel set can be determined based on this relationship.

[0172] S1345. Combine the corresponding vector velocity of the driven wheel set and the vector compensation velocity of the driven wheel set to obtain the vector velocity of the driven wheel set.

[0173] The purpose of this step is to determine the vector velocity of the driven wheel assembly in order to obtain the corresponding processing results.

[0174] The vector velocity of the driven wheel set can be obtained by simply combining the vector velocities corresponding to the driven wheel set and the vector compensation velocities of the driven wheel set. Since the two vector directions of the driven wheel set are exactly the same in this process, the vector velocities of the driven wheel set can be directly added together. The combined equation is:

[0175] ,

[0176] in, It represents the total vector velocity of the active wheel group between two adjacent detection points in the i-th group.

[0177] S135. Combine the vector velocity and vector direction of the center point of the driven wheel set connection line to obtain the theoretical vector of the driven wheel set.

[0178] The purpose of this step is to finally determine the vector of the center point of the driven wheel assembly after obtaining the vector velocity and direction of that point.

[0179] Specifically, by combining the vector velocity and vector direction at the center point of each driven wheel assembly line, the theoretical vector of the driven wheel assembly can be determined.

[0180] In addition, the obtained theoretical vector of the driven wheel group needs to be associated with the corresponding two adjacent detection point groups to obtain the theoretical vector of the driven wheel group between all adjacent detection points.

[0181] The beneficial effect of step S130 is that, after obtaining the theoretical trajectory of the vehicle's active wheel set, it determines the theoretical vector of the driven wheel set corresponding to the detection point of the active wheel set during the actual operation of the active wheel set, so as to ensure that the vehicle's driven wheel set can also obtain the controlled reference.

[0182] As described in step S140, the purpose of this step is that, after obtaining the theoretical trajectory of the active wheel set, considering that there are multiple selectable vectors for the driven wheel sets, for each theoretical vector of the active wheel set, the detection point of each theoretical vector corresponds to a specific driven wheel set vector. Then, these obtained driven wheel set vectors can be connected to finally obtain the theoretical trajectory of the driven wheel set. Based on the theoretical trajectory of the driven wheel set, the feasibility of the current vehicle control scheme can be further analyzed. Specifically:

[0183] S141. Obtain the theoretical vector of the driven wheel set corresponding to the selectable vector of the active wheel set, and construct the theoretical trajectory of the driven wheel set.

[0184] The purpose of this step is to determine the theoretical trajectory of the driven wheel set based on the theoretical vector of the driven wheel set corresponding to the selectable vector of the driving wheel set.

[0185] In obtaining the theoretical vector of the driving wheel set, for each driving wheel set optional vector, there is actually one or more driven wheel set theoretical vectors. Therefore, it is necessary to establish the driving wheel set optional vector and the corresponding driven wheel set theoretical vector.

[0186] After obtaining the corresponding driven wheel set theoretical vector, it is necessary to move the line segment at the center point of the running time when the driven wheel set theoretical vector reaches the center point of the corresponding driven wheel set connection, and then connect the adjacent line segments end to end.

[0187] The obtained end-to-end connection result is the theoretical trajectory of the driven wheel assembly.

[0188] In some embodiments, when it is found that the included angle between two adjacent line segments is acute after they are connected, the theoretical trajectory of the driven wheel assembly is abandoned.

[0189] S142. Establish the correlation between the theoretical tracks of the driven wheelset and the theoretical tracks of the driving wheelset, thereby obtaining the theoretical tracks of the driven wheelset corresponding to each theoretical track of the driving wheelset.

[0190] The purpose of this step is to correlate the theoretical tracks of the driving wheel set with the corresponding theoretical tracks of the driven wheel set, thereby obtaining the corresponding relationship.

[0191] For each theoretical track of the driving wheel set, it is necessary to obtain the correspondence between the theoretical track composed of all optional vectors and the corresponding theoretical track of the driven wheel set.

[0192] Specifically, when associating each active theoretical track with the corresponding theoretical tracks of all driven wheel sets, the association between the active wheel set theoretical track and the corresponding driven wheel set theoretical track can be directly constructed based on the association relationship between the theoretical vector of each detection point on the active wheel set and the theoretical vector of the corresponding driven wheel set. For example... Figure 3 The diagram shown illustrates the theoretical trajectory of a driven wheel set according to a multi-BLDCM collaborative control method based on an intelligent fractional-order controller provided in this application embodiment. For the theoretical trajectory of the driving wheel set, the driving wheel set's motion vector at various points can be different as it travels along the theoretical trajectory. The corresponding driven wheel set theoretical vector is determined according to step S1345, and all driven wheel set theoretical vectors are connected to form the driven wheel set theoretical trajectory. Each driving wheel set theoretical trajectory corresponds to multiple driven wheel set theoretical trajectories, as shown in driven wheel set theoretical trajectories 1-3 in the attached diagram. Obviously, the attached diagram does not show all the driven wheel set theoretical trajectories corresponding to the driving wheel set theoretical trajectory.

[0193] The beneficial effect of step S140 is that, based on the theoretical trajectory of the active wheel set, the corresponding theoretical trajectory of the driven wheel set is established. Then, in the multi-BLDCM cooperative control of the vehicle, the active wheel set and the driven wheel set can obtain the control target of the active and passive wheel sets according to the obtained theoretical trajectory.

[0194] As described in step S150, the purpose of this step is to verify the theoretical trajectory of the driven wheelset. This verification is necessary because during the operation of the theoretical trajectory of the driven wheelset, there is a possibility that the vehicle's structure might collide with obstacles in the surrounding environment. The purpose of the verification is to eliminate this possibility. Specifically:

[0195] S151. Based on the theoretical trajectory of the driven wheel set, obtain the spatiotemporal coupling between the vehicle and surrounding obstacles.

[0196] The purpose of this step is to consider that when a vehicle collides with its surroundings, it is essentially a matter of spatiotemporal coupling between any point on the vehicle and the surrounding obstacles. Therefore, in order to avoid a collision, it is necessary to obtain the spatiotemporal coupling between the vehicle and the surrounding obstacles.

[0197] In this process, after obtaining the theoretical tracks of the active and driven wheel sets, the motion vectors of the active and driven wheel sets are also determined during the track determination process. Therefore, the positions of the active and driven wheel sets on their respective theoretical tracks at each time point can be determined from the start of the vehicle's automatic parking or automatic departure from the parking space.

[0198] Among them, based on the various surrounding environment monitoring sensors carried on the vehicle, the positions of various dynamic and static obstacles and their rate of change are obtained. In particular, for dynamic obstacles, continuous monitoring is required, and the trajectory prediction of dynamic obstacles is also needed.

[0199] This requires analyzing the ground projection of each position of the vehicle as a whole in the space where the vehicle is located during the vehicle's movement along the theoretical trajectory of the driving and driven wheel sets.

[0200] Among them, it is determined whether there is a common spatial point between the overall ground projection point of the vehicle and the ground projection of various static and / or dynamic obstacles in the surrounding area at the same time point. If so, it is considered that there is spatiotemporal coupling, and the theoretical track of the driven wheel set needs to be eliminated. Of course, the theoretical track corresponding to the theoretical track of the driven wheel set, which is constructed by the optional vector of the active wheel set, also needs to be eliminated synchronously.

[0201] S152. Remove the theoretical tracks of the driven wheel sets that have a spatiotemporal coupling relationship with the surrounding obstacles. The remaining theoretical tracks of the driven wheel sets are the candidate tracks of the driven wheel sets.

[0202] The purpose of this step is to initially screen all theoretical tracks of driven wheel sets, so that further screening can be carried out.

[0203] Specifically, when it is found that there is a spatiotemporal coupling relationship between the vehicle and the surrounding obstacles under the action of a certain driven wheel set theoretical track, the theoretical track of the driven wheel set is removed. Of course, the theoretical track corresponding to the theoretical track of the driven wheel set, which is constructed by the optional vector of the active wheel set, also needs to be removed synchronously.

[0204] Among them, the theoretical tracks of the remaining driven wheel sets after the removal process are the candidate tracks of the driven wheel sets. The remaining tracks are guaranteed not to have spatiotemporal coupling problems with the surrounding obstacles.

[0205] S153. Based on the candidate tracks of the driven wheelset, obtain the corresponding candidate tracks of the driving wheelset.

[0206] The purpose of this step is that, after obtaining the candidate tracks of the driven wheel set, it is actually possible to infer whether the theoretical track of the driving wheel set still exists. In other words, the theoretical track of the driving wheel set is screened.

[0207] The so-called candidate tracks of the active wheel set refers to all the active wheel set theoretical tracks remaining after removing all the tracks based on the selectable vectors of the active wheel set during the removal of some passive wheel set theoretical tracks, and after removing all the active wheel set theoretical tracks whose corresponding active wheel set selectable vectors are associated with theoretical tracks whose number of active wheel set selectable vectors is 0.

[0208] Based on the above definition, the candidate tracks of the driving wheel set can be directly determined. That is, obtain all the tracks associated with each driving wheel set's theoretical track, which are composed of all the corresponding driving wheel set's selectable vectors, to obtain the driving wheel set's selectable vector tracks. At the same time, obtain the relationship between the driving wheel set's selectable vector tracks and the driven wheel set's theoretical curve. When the latter is removed, the former is also removed. When it is found that the number of driving wheel set's selectable vector tracks associated with a certain driving wheel set's theoretical curve is 0, then that driving wheel set's theoretical track is removed, and the remaining driving wheel set's theoretical tracks are the driving wheel set's candidate tracks.

[0209] S154. Obtain the track group with the lowest probability of spatiotemporal coupling with obstacles around the vehicle from the candidate tracks of the active wheel group and the corresponding candidate tracks of the driven wheel group, so as to obtain the actual tracks of the active wheel group and the actual tracks of the driven wheel group.

[0210] The purpose of this step is to select the trajectory group corresponding to when the vehicle automatically parks or leaves the parking space, and ultimately obtain the motion trajectory that the active and driven wheel groups need to follow during the multi-BLDCM cooperative control process of the vehicle, and then obtain the corresponding running vector. Specifically:

[0211] S1541. Real-time monitoring of the location of obstacles in the environment surrounding the vehicle, and acquisition of the predicted trajectory of the obstacles.

[0212] The purpose of this step is to monitor and predict the trajectory of obstacles in the analysis of the probability of spatiotemporal coupling, and then analyze whether the trajectory will come into contact with the vehicle based on the predicted trajectory.

[0213] In the real-time monitoring of obstacles, the relative distance between the vehicle and the obstacle can be obtained based on various sensors carried on the vehicle, and the real-time position of the obstacle can be determined based on geodetic coordinates or other coordinate systems.

[0214] The real-time position of the obstacle needs to be updated. The movement position of the obstacle at each time point is obtained, and then the specific position coordinates of the obstacle are obtained. If the obstacle is found to be moving in a straight line, the line can be extended. If it is a curve, the simulation equation is directly analyzed for the curve, and then the predicted trajectory of the obstacle is obtained.

[0215] S1543. Obtain the correspondence between vehicle position, attitude and time in the candidate tracks of the driven wheel set and the candidate tracks of the driving wheel set.

[0216] The purpose of this step is to determine the vehicle's kinematic parameters, and then, based on these determinations, to establish the relationship between the vehicle's kinematic parameters and time, in order to facilitate subsequent track conflict analysis.

[0217] This requires obtaining the motion vectors of each driven wheel set and its corresponding driving wheel set at the same moment in the vehicle.

[0218] Specifically, based on the motion vector obtained at the same moment, the motion vector direction of the vehicle's driving and driven wheel sets between that moment and the next moment is obtained, thereby obtaining the vehicle's attitude.

[0219] This requires timing at the start of the vehicle's automatic parking or automatic departure from the parking space, so as to continuously update the vehicle's position at each moment.

[0220] This requires associating each moment during the automatic parking or automatic departure from the parking space with the corresponding vehicle position and attitude, thereby obtaining the correspondence between vehicle position, attitude, and time.

[0221] S1544. Obtain the minimum value of the distance between the vehicle's track and the obstacle at the same time, and obtain the probability of spatiotemporal coupling based on the minimum distance.

[0222] The purpose of this step is to determine the correspondence between vehicle position, attitude, and time after determining the relationship between them, and then to obtain the distance between the obstacle tracks and the distance between the vehicle tracks during execution, and then to determine the probability of spatiotemporal coupling based on these values.

[0223] This requires real-time acquisition of obstacle tracks and vehicle position and attitude information, the specific methods for determining these two aspects have been explained above.

[0224] Among them, the so-called track distance between any point on the vehicle and the obstacle needs to be integrated with the vehicle's position and attitude. Then, the point where the track distance between the vehicle and the obstacle is minimized under the influence of position and attitude is analyzed. This parameter can be determined by the on-board system.

[0225] This involves determining the minimum distance between the vehicle and the obstacle's tracks after obtaining the obstacle's tracks, and then obtaining the minimum distance between the vehicle and the obstacle's tracks from all the candidate tracks of the driven wheel group and the candidate tracks of the driving wheel group.

[0226] The probability of spatiotemporal coupling is calculated based on all the obtained minimum values, and the determining equation is as follows:

[0227] ,

[0228] Among them, P j This represents the probability of spatiotemporal coupling occurring in the candidate tracks of the driven wheel set and the candidate tracks of the driven wheel set for the j-th vehicle; l j This represents the minimum distance between the candidate tracks of the driven wheel set and the candidate tracks of the driving wheel set of the vehicle; j and m both represent the labels of the candidate tracks of the driven wheel set and the candidate tracks of the driving wheel set of the vehicle; n represents the maximum value of the labels of the candidate tracks of the driven wheel set and the candidate tracks of the driving wheel set of the vehicle.

[0229] In some embodiments, other methods may be used to determine the probability of spatiotemporal coupling, and this application does not limit such methods.

[0230] S1545. Obtain the track group with the lowest probability of spatiotemporal coupling to obtain the actual track of the driving wheel group and the actual track of the driven wheel group.

[0231] The purpose of this step is to finally determine the movement trajectory of the driving and driven wheel sets when the vehicle automatically parks or leaves the parking space.

[0232] Among them, the candidate tracks of the driven wheel set and the candidate tracks of the driving wheel set of the vehicle with the lowest probability of spatiotemporal coupling are obtained.

[0233] Among them, the actual tracks of the driving wheel set and the actual tracks of the driven wheel set are corresponding. That is to say, these two track curves are completely consistent with the theoretical track of the driven wheel set corresponding to the theoretical track of the driving wheel set mentioned in step S140, because these two time tracks are derived from the theoretical tracks mentioned above.

[0234] Among them, the candidate tracks of the driving and driven wheels within the track group with the lowest probability of occurrence are directly determined as the actual tracks of the driving and driven wheel groups. For example... Figure 4The figure shows the actual tracks of the active and driven wheel sets according to a multi-BLDCM collaborative control method based on an intelligent fractional-order controller provided in this application embodiment. Only three theoretical tracks of the active wheel sets are shown in the figure: theoretical tracks 1 to 3, each corresponding to multiple theoretical tracks of the driven wheel sets. Specifically, theoretical track 1 corresponds to theoretical tracks 11 to 13 of the driven wheel sets, theoretical track 2 corresponds to theoretical tracks 21 to 22 of the driven wheel sets, and theoretical track 3 corresponds to theoretical tracks 31 to 32 of the driven wheel sets. Then, following the method mentioned above, the actual tracks of the active and driven wheel sets are selected, represented by the two solid lines in the figure.

[0235] The beneficial effect of step S150 is that by screening all the theoretical tracks obtained, the best track that strictly avoids collision problems can be found, so as to obtain the actual tracks of the driving wheel set and the actual tracks of the driven wheel set, thereby improving the rationality of track selection based on this method.

[0236] As described in step S160, the purpose of this step is to finalize the multi-BLDCM motion parameters of the vehicle after obtaining the actual tracks of the driving and driven wheel sets. In other words, it is necessary to obtain the motion vector of each wheel before multi-BLDCM cooperative control can be performed based on the corresponding motion vector. Specifically:

[0237] S161. Obtain the actual motion vectors of the driving wheel set and the driven wheel set at the same moment, based on their actual tracks.

[0238] The purpose of this step is to determine the motion vectors on the driving wheelset and the actual wheelset.

[0239] Using time as the dividing unit, the actual motion vectors corresponding to the driving wheel set and the driven wheel set are obtained respectively on the actual tracks of the driving wheel set and the actual tracks of the driven wheel set at the same moment.

[0240] As for the method of determining the time, it can be directly determined according to the detection points set on the theoretical track.

[0241] S162. Based on the relationship between the actual motion vector of the driving wheel set and the motion vectors of the two driving wheels, and the relationship between the actual motion vector of the driven wheel set and the motion vectors of the two driven wheels, selectable values ​​of the motion vectors of the two wheels in the driving wheel set and the driven wheel set are obtained respectively.

[0242] The purpose of this step is to obtain the motion vectors of the driving wheel set and the driven wheel set at each moment. These vectors are the motion vectors of the center points of the lines connecting the two driving wheel axles and the two driven wheel axles. The motion vectors obtained at this time can be achieved by the combined action of the two driving wheels and the two driven wheels. Therefore, this process needs to obtain the selectable values ​​of the motion vectors of the two driving wheels and the two driven wheels to obtain a wide range of usable parameters.

[0243] For both the driving and driven wheel sets, the relationship between the actual motion vector of the wheel set and the motion vectors of the two wheels at each moment is as follows:

[0244] ,

[0245] in, This represents the motion vector of the driving or driven wheel assembly at a given moment. and Let represent the motion vectors of the two wheels corresponding to the driving or driven wheel set at the same moment. This equation indicates that at each moment, the velocity of the actual motion vector of the driving or driven wheel set is half the sum of the motion vectors of the two wheels, and the direction of the actual motion vector of the wheel set is the direction of the sum of the motion vectors of the two wheels.

[0246] Specifically, at each moment, the motion vectors of the two driving wheels and the two driven wheels satisfy the above equation, and the motion vector sets that satisfy the equation are recorded.

[0247] For both the driving and driven wheel sets, all motion vector sets that conform to the equations are determined as two optional values ​​for the motion vectors of the two wheels, and all of them are used for the subsequent selection of motion vectors for each wheel.

[0248] S163. Verify the selectable values ​​of the motion vectors of the two wheels in the driving wheel set and the selectable values ​​of the motion vectors of the two wheels in the driven wheel set separately, so as to configure and obtain the motion vector of each driving wheel and driven wheel.

[0249] The purpose of this step is to verify the motion vectors of the two wheels in all wheelsets, and then select the motion vectors of the wheels that can be used.

[0250] In each wheel group, the velocities of the motion vectors of the two wheels are obtained separately, and the speed difference between the two wheels is calculated. If the obtained speed difference exceeds the maximum allowable speed difference of the wheel group, the motion vector group of the two wheels in the obtained wheel group is discarded.

[0251] After elimination, the motion vectors of the two wheels in each of the remaining driving and driven wheel sets, that is, all wheel vectors, are used as candidate motion vectors.

[0252] Specifically, the motion vectors of the two wheels on the same side of the vehicle are obtained, and the motion vector of the center point of the line connecting the axles of the two wheels is also obtained.

[0253] The equation for determining the motion vector of the center point of the line connecting the axles of both wheels is:

[0254] ,

[0255] in, This represents the motion vector of the center point of the line connecting the axles of both wheels. This represents the motion vector of the front wheel on one side of the vehicle. This represents the motion vector of the rear wheel on the same side of the vehicle.

[0256] For a vehicle, the center point of the line connecting the axles of the left and right wheels must have the same motion vector component perpendicular to the side of the vehicle; otherwise, it would not conform to the vehicle's motion characteristics. However, in this case, it is not guaranteed that the motion vectors on both sides are the same. Therefore, verification based on this characteristic is still required during the verification process.

[0257] During the verification process, the equation for the motion component perpendicular to the side of the vehicle is determined as follows:

[0258] ,

[0259] in, This represents the motion vector component perpendicular to the side of the vehicle, representing the motion vector of the center point of the line connecting the axles of both wheels. This represents the magnitude of the motion vector component perpendicular to the side of the vehicle, representing the motion vector at the center point of the line connecting the axles of both wheels. This represents the magnitude of the motion vector at the center point of the line connecting the axles of both wheels. This represents the motion vector of the center point of the line connecting the axles of both wheels and the angle between the two sides of the vehicle.

[0260] Among them, when the two sides of the vehicle are found If they are the same, then the motion vectors of the left and right wheels of the vehicle determined at this time are considered to conform to the vehicle's motion state, and the motion vector values ​​of each driving wheel and driven wheel can be directly applied at this time. For example... Figure 5The diagram illustrates a method for verifying the motion vectors of each active and passive wheel in a multi-BLDCM collaborative control method based on an intelligent fractional-order controller, as provided in this application embodiment. The 2x active wheel set motion vector in the diagram is the sum of active wheel motion vectors 1 and 2. Similarly, the 2x passive wheel set motion vector is the sum of passive wheel motion vectors 1 and 2. Vector component 1 refers to the motion vectors of active wheel motion vector 1 and passive wheel motion vector 1 in the direction perpendicular to the side of the vehicle. Similarly, vector component 2 refers to the motion vectors of active wheel motion vector 2 and passive wheel motion vector 2 in the direction perpendicular to the side of the vehicle. When vector component 1 and vector component 2 are identical, the obtained motion vectors of the two wheels are considered to have passed verification, and the multi-BLDCM collaborative control task of the vehicle can be directly executed according to their corresponding motion vector data.

[0261] In some embodiments, for the verification process, the motion vector components of the obtained active wheel set motion vector and driven wheel set motion vector along the wheelbase direction can also be obtained, and the values ​​of the motion vector components can be obtained. If the two are equal, it is considered to conform to the actual situation. At this time, the motion vectors of the four wheels can be directly used as the motion parameter control target of each wheel control process in the multi-BLDCM cooperative control of the vehicle.

[0262] In some embodiments, the verification is also performed on whether the verified results match the vehicle's operating scenario or driving mode. When a match is determined, the motion vectors of each driving wheel and driven wheel analyzed are considered usable.

[0263] The beneficial effect of step S160 is that when the vehicle is automatically parking or leaving the parking space, the motion vector of each wheel can be specifically determined, thereby ensuring that an appropriate control target is obtained in the specific multi-BLDCM collaborative control process.

[0264] As described in step S170, the purpose of this step is to perform specific multi-BLDCM collaborative control of the vehicle. Specifically:

[0265] S171. Based on the motion vector of each driving wheel and driven wheel, obtain the steering angle and moving speed of each driving wheel and driven wheel.

[0266] The purpose of this step is that, since each motion vector contains angle and velocity parameters, these two parameters need to be determined in the specific collaborative control before specific control can be performed.

[0267] After obtaining the motion vector of each wheel, the direction data of the vector is determined, and then the steering angle of the wheel is obtained.

[0268] After obtaining the motion vector of each wheel, it is necessary to obtain the numerical value of the motion vector to get the wheel's speed. It should be noted that this speed is the translational speed of the wheel axle.

[0269] S172. The steering angle data of each driving wheel and driven wheel is sent to the steering control motor control system of the wheel, and then sent by the control system to the intelligent fractional-order controller for steering angle control.

[0270] The purpose of this step is to control the steering angle of each wheel of the vehicle.

[0271] After obtaining the steering angle, the motion time between two adjacent detection points is obtained to determine the execution speed of the steering angle.

[0272] After obtaining the execution speed, the parameter is sent to the intelligent fractional-order controller and executed to ensure that the steering angle can be controlled and adjusted within a specified time.

[0273] S173. Send the speed data of each driving wheel and driven wheel to the wheel speed control system to obtain the speed signal of each wheel, and send it to the intelligent fractional-order controller for wheel speed control.

[0274] The purpose of this step is to control the wheel speed.

[0275] Once the speed of each wheel is obtained, it is equivalent to obtaining the linear velocity of the point of contact between that wheel and the ground.

[0276] Specifically, the angular velocity of each wheel, i.e., the wheel's rotational speed, is obtained based on the linear velocity and the length from the wheel axle to the contact point.

[0277] The rotational speed signal of each wheel is sent to the intelligent fractional-order controller, and the signal is executed to control the rotational speed of that wheel.

[0278] The beneficial effect of step S170 is that, based on the intelligent fractional-order controller, the control accuracy and control response speed of the BLDCM are improved, thereby improving the effectiveness of multi-BLDCM collaborative control.

[0279] The beneficial effects of this application include:

[0280] 1. This application achieves one-time execution of automatic parking or leaving a parking space actions. The technical solution of this application plans the vehicle's trajectory, and during this process, simultaneously plans the running paths of both the front and rear wheel sets. In subsequent operations, the front and rear wheels only need to move according to the trajectory's motion vectors. In other words, the trajectory planning itself ensures that once the vehicle reaches a specific position, it can directly park or leave the parking space, thus achieving one-time execution of the parking or leaving action.

[0281] 2. This application expands the technical adaptability for automatic parking and departure from parking spaces. In this technical solution, determining the trajectory of the front and rear wheel sets does not involve completely decoupling all wheel motion vectors. Instead, it determines the driving and driven wheel sets according to the vehicle's direction of travel, and analyzes the motion vectors of the driving and driven wheel sets separately based on their dynamic relationship. Then, based on the analysis results, the motion vector of each wheel is determined, thereby executing the wheel set's motion vector trajectory. This technology can be applied to vehicles with various motor distribution modes, thus improving the technical adaptability.

[0282] 3. This application achieves spatial adaptation for automatic parking or leaving a parking space. The technical solution of this application allows for trajectory planning within the obtained front and rear wheel sets. During trajectory planning, the specific construction mode of the trajectory can be determined based on the vehicle's location within the given scenario. In other words, for all types of parking or leaving parking spaces, adjustments can be made directly based on the trajectory of the vehicle's front and rear wheel sets, enabling the vehicle to adapt to all parking or leaving parking spaces during operation.

[0283] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to computer program instructions. The aforementioned computer program can be stored in a non-volatile storage medium, and when executed, it performs the steps of the above method embodiments. Alternatively, if the integrated unit of the present invention is implemented as a software functional module and sold or used as an independent product, it can also be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the embodiments of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a non-volatile storage medium and includes several instructions to cause an electronic device (which may be a personal computer, server, network device, etc.) to execute all or part of the methods described in the various embodiments of the present invention.

[0284] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-BLDCM cooperative control method based on an intelligent fractional-order controller, characterized in that, The collaborative control method includes: Based on the vehicle's initial position and target location, the theoretical trajectory of the vehicle's active wheel set is obtained; Based on the theoretical trajectory of the vehicle's active wheel set, the displacement vector of the center point of the corresponding active wheel set connection line is obtained to obtain the target vector of the active wheel set; Based on the target vector of the active wheel set, the theoretical vector of the vehicle's driven wheel set is obtained; Based on the theoretical vector of the driven wheelset of the vehicle, obtain the theoretical track of the driven wheelset corresponding to each theoretical track of the driving wheelset; The theoretical trajectory of the driven wheel set is verified to obtain the actual trajectory of the vehicle's driving wheel set and the actual trajectory of the driven wheel set. Based on the actual tracks of the vehicle's active wheel set and driven wheel set, the motion vectors of each active wheel and driven wheel are obtained respectively. Based on the motion vectors of each driving wheel and driven wheel, control parameters for each driving wheel and driven wheel are obtained, and multiple BLDCMs are coordinated and controlled based on an intelligent fractional-order controller.

2. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 1, characterized in that, The process of obtaining the theoretical trajectory of the vehicle's active wheel assembly based on the vehicle's initial position and target location includes: The vehicle's direction of motion is obtained, and the group of wheels preceding the vehicle in that direction is identified as the driving wheel set. Based on vehicle performance data, the maximum steering angle and maximum permissible speed difference between the two drive wheels are obtained to determine the steering angle range of the drive wheel set; The initial position and target location of the vehicle are obtained, and all theoretical tracks of the active wheelset are obtained based on the steering angle range and allowable speed difference range of the active wheelset.

3. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 1, characterized in that, The method of obtaining the displacement vector of the center point of the corresponding active wheel set line based on the theoretical trajectory of the vehicle's active wheel set, in order to obtain the target vector of the active wheel set, includes: Obtain the midpoint of the line connecting the axles of the two drive wheels within the vehicle's drive wheel assembly, in order to obtain the center point of the line connecting the drive wheel assemblies; The center point of the active wheel assembly connection line and the theoretical trajectory of the active wheel assembly of the vehicle are always coincident on the ground projection, so that the theoretical trajectory of the active wheel assembly is the trajectory of the center point of the active wheel assembly connection line. Obtain the tangents of all theoretical points on the track of the center point of the active wheel set connection, and based on the vehicle's direction of motion, obtain the target direction of the displacement vector of the center point of the active wheel set connection; Based on the vehicle's driving scenario, the vehicle's driving speed parameters are obtained, and the displacement vector velocity of the center point of the active wheel assembly connection is obtained. The target direction of the displacement vector and the velocity of the displacement vector at the center point of the line connecting the drive wheelsets are combined to obtain the target vector of the drive wheelsets.

4. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 1, characterized in that, The step of obtaining the theoretical vector of the vehicle's driven wheelset based on the target vector of the active wheelset includes: Based on the target vector of the active wheel set, obtain the selectable vector of the active wheel set at the center point of the line connecting the active wheel sets; Based on the difference between the selectable vector direction of the active wheel set and the target vector direction of the active wheel set, the static compensation amount of the vector direction of the vehicle's active wheel set is obtained; The difference in static compensation amount of the vector direction of the active wheel assembly is obtained between the current point and the next adjacent detection point on the theoretical track of the active wheel assembly, so as to obtain the dynamic compensation amount of the vector direction of the active wheel assembly. Based on the selectable vector velocity of the active wheel set and the dynamic compensation amount of the vector direction of the active wheel set, the vector velocity of the driven wheel set is obtained; The vector velocity and vector direction of the center point of the driven wheel set are combined to obtain the theoretical vector of the driven wheel set.

5. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 4, characterized in that, The process of obtaining the vector velocity of the driven wheel set based on the selectable vector velocity of the driving wheel set and the vector compensation amount of the driving wheel set includes: Based on the velocity value of the selectable vector of the active wheel set, the arrival time between adjacent detection points on the theoretical track of the active wheel set is obtained; The dynamic compensation amount of the active wheel group vector direction and the ratio of the arrival time between adjacent detection points are obtained to obtain the active wheel group vector compensation speed; Based on the vector compensation speed and wheelbase of the active wheel set, the vector compensation speed of the driven wheel set is obtained; Based on the selectable vector and wheelbase of the active wheel set, the corresponding vector velocity of the driven wheel set is obtained; The vector velocity of the driven wheel set is obtained by merging the vector velocity of the driven wheel set and the vector compensation velocity of the driven wheel set.

6. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 1, characterized in that, The theoretical vector of the driven wheelset based on the vehicle is used to obtain the theoretical track of the driven wheelset corresponding to each theoretical track of the driving wheelset, including: Obtain the theoretical vector of the driven wheel set corresponding to the optional vector of the driving wheel set, and construct the theoretical trajectory of the driven wheel set; Establish the correlation between the theoretical tracks of the driven wheelset and the theoretical tracks of the driving wheelset, thereby obtaining the theoretical track of the driven wheelset corresponding to each theoretical track of the driving wheelset.

7. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 1, characterized in that, The verification of the theoretical trajectory of the driven wheelset to obtain the actual trajectory of the vehicle's driving wheelset and the actual trajectory of the driven wheelset includes: Based on the theoretical trajectory of the driven wheel set, the spatiotemporal coupling between the vehicle and surrounding obstacles is obtained; The theoretical tracks of the driven wheel sets that have spatiotemporal coupling relationships with surrounding obstacles are removed, and the remaining theoretical tracks of the driven wheel sets are the candidate tracks of the driven wheel sets; Based on the candidate tracks of the driven wheelset, obtain the corresponding candidate tracks of the driving wheelset; The track group with the lowest probability of spatiotemporal coupling with obstacles around the vehicle is obtained from the candidate tracks of the active wheel group and the corresponding candidate tracks of the driven wheel group, so as to obtain the actual tracks of the active wheel group and the actual tracks of the driven wheel group.

8. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 7, characterized in that, The process of obtaining the candidate tracks of the active wheel set and the corresponding candidate tracks of the driven wheel set, and selecting the track group with the lowest probability of spatiotemporal coupling with obstacles around the vehicle, to obtain the actual tracks of the active wheel set and the driven wheel set, includes: Real-time monitoring of the location of obstacles in the vehicle's surrounding environment and acquisition of predicted obstacle trajectories; Obtain the correspondence between vehicle position, attitude, and time in the candidate tracks of the driven wheelset and the candidate tracks of the driving wheelset; Find the minimum distance between the vehicle's tracks and the obstacle at the same time, and obtain the probability of spatiotemporal coupling based on the minimum distance. Obtain the track group with the lowest probability of spatiotemporal coupling to obtain the actual tracks of the driving wheel group and the driven wheel group.

9. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 1, characterized in that, The actual trajectories of the driving and driven wheel sets based on the vehicle are used to obtain the motion vectors of each driving and driven wheel, including: On the actual tracks of the driving wheel set and the actual tracks of the driven wheel set, respectively, the actual motion vectors of the driving wheel set and the driven wheel set at the same moment are obtained; Based on the relationship between the actual motion vector of the driving wheel set and the motion vectors of the two driving wheels, and the relationship between the actual motion vector of the driven wheel set and the motion vectors of the two driven wheels, selectable values ​​for the motion vectors of the two wheels in the driving wheel set and the driven wheel set are obtained respectively. The selectable values ​​of the motion vectors of the two wheels in the driving wheel set and the selectable values ​​of the motion vectors of the two wheels in the driven wheel set are verified separately to configure and obtain the motion vector of each driving wheel and driven wheel.

10. The multi-BLDCM cooperative control method based on an intelligent fractional-order controller according to claim 1, characterized in that, The process of obtaining control parameters for each driving and driven wheel based on the motion vectors of each driving and driven wheel, and co-controlling multiple BLDCMs based on an intelligent fractional-order controller, includes: Based on the motion vector of each driving wheel and driven wheel, obtain the steering angle and moving speed of each driving wheel and driven wheel; The steering angle data of each driving wheel and driven wheel is sent to the steering control motor control system of the wheel, and then sent by the control system to the intelligent fractional-order controller for steering angle control. The speed data of each driving wheel and driven wheel is sent to the wheel speed control system to obtain the speed signal of each wheel, and then sent to the intelligent fractional-order controller for wheel speed control.

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