A motion control method of a mobile platform, a storage medium and an electronic device

Abstract

The present application relates to the field of motion control, in particular to a kind of motion control method of mobile platform, storage medium and electronic equipment.It includes the following steps: obtaining the target moving speed of mobile platform, target turning angle and the wheel spacing and wheel diameter of mobile platform;According to the wheel spacing of mobile platform, current average turning radius and wheel diameter, target moving speed and target turning angle are motion decomposition processing, generate each drive wheel corresponding target wheel speed and target wheel angle;According to each drive wheel corresponding target wheel speed, target wheel angle, current wheel speed and current wheel angle, control mobile platform to carry out motion.In the present application, through motion decomposition processing, the motion instruction (mainly for turning angle instruction) inputted by human through remote controller can be calculated into the turning angle value of four drive wheels on mobile platform respectively.And by controlling the value of K, mobile platform can keep as stable as possible in turning operation.

Description

A motion control method, storage medium, and electronic device for a mobile platform. Technical Field

[0001] This invention relates to the field of motion control, and in particular to a motion control method, storage medium, and electronic device for a mobile platform. Background Technology

[0002] Autonomous driving technology refers to the ability of a vehicle to drive autonomously under certain conditions by integrating advanced sensors (such as radar, lidar, cameras, etc.), GPS positioning systems, high-precision maps, and complex software algorithms.

[0003] Currently, many applications use autonomous driving technology to control mobile platforms, enabling them to move along preset paths and complete corresponding business tasks. For example, a mobile platform that provides mobile charging for vehicles will autonomously move to the location of the target vehicle and charge it according to a pre-planned path in a parking lot.

[0004] In practical use, operators may send corresponding operating commands to control the movement of the mobile platform by manipulating the joystick on a remote control. However, due to the uneven swing amplitude of the joystick when manually operated, the movement commands received by the vehicle may be uneven and unstable. For mobile charging platforms, the battery mounted on top raises the overall center of gravity of the platform to a relatively high level, making it more prone to instability or even tipping over in the narrow and winding sections of underground parking garages. Summary of the Invention

[0005] To address the aforementioned technical problems, the technical solution adopted by this invention is as follows:

[0006] According to one aspect of the present invention, a motion control method for a mobile platform is provided. The mobile platform includes four drive wheels, each drive wheel being equipped with an independent steering motor and a drive motor. The steering motor is used to control the steering angle of the drive wheel, and the drive motor is used to control the rotational speed of the drive wheel.

[0007] The method includes the following steps:

[0008] Obtain the target moving speed, target turning angle, wheel spacing, and wheel diameter of the mobile platform;

[0009] Based on the wheel spacing, current average turning radius and wheel diameter of the mobile platform, the target moving speed and target turning angle are processed by motion decomposition to generate the target wheel speed and target wheel turning angle corresponding to each drive wheel;

[0010] The moving platform is controlled to move based on the target wheel speed, target wheel rotation angle, current wheel speed, and current wheel rotation angle for each drive wheel.

[0011] Motion decomposition processing includes:

[0012] If the mobile platform turns to the left, the target steering angle is kinematically decomposed based on the wheel spacing of the mobile platform to generate the target wheel steering angle corresponding to each drive wheel; wherein, the target wheel steering angle corresponding to each drive wheel satisfies the following relationship:

[0013]

[0014]

[0015]

[0016]

[0017] FL Deg, FR Deg, RR Deg, and RR Deg represent the target wheel steering angles corresponding to the left front drive wheel, right front drive wheel, left rear drive wheel, and right rear drive wheel, respectively; L is the wheel spacing between the front and rear drive wheels; W is the wheel spacing between the left and right drive wheels; r is the turning radius corresponding to the target steering angle; K is the distribution coefficient, which is obtained as follows:

[0018] If the absolute value of the difference between the average speed of the mobile platform in the previous speed monitoring cycle and the average speed in the current monitoring cycle is less than or equal to the speed difference threshold, then K = 0.5;

[0019] If the absolute value of the difference between the average speed of the mobile platform in the previous speed monitoring cycle and the average speed in the current monitoring cycle is greater than the speed difference threshold, then K is obtained by the PID control algorithm; and

[0020] If the mobile platform accelerates during the turning process, then K < 0.5;

[0021] If the mobile platform decelerates during the turning process, then K > 0.5.

[0022] According to a second aspect of the present invention, a non-transitory computer-readable storage medium is provided, which stores a computer program that, when executed by a processor, implements the motion control method of a mobile platform described above.

[0023] According to a third aspect of the present invention, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the motion control method of a mobile platform described above.

[0024] The present invention has at least the following beneficial effects:

[0025] In this invention, motion decomposition processing converts motion commands (mainly turning commands) input by the user via remote control into turning angle values ​​on the four drive wheels of the mobile platform. Furthermore, by controlling the value of K, the mobile platform can maintain stability as much as possible during turning. Different K values ​​result in different turning angles distributed on the four drive wheels. Therefore, when the change in the mobile platform's speed is small, the speed change during turning is minimal, and the corresponding change in centrifugal force is also not significant, generally not affecting the vehicle's stability. Therefore, K = 0.5, meaning the turning angles of the inner and outer drive wheels remain constant during the turn. This process avoids frequent adjustments to the vehicle's turning angle, thus ensuring stable vehicle operation.

[0026] When the moving platform experiences significant speed variations, the speed changes during cornering are also substantial, resulting in corresponding large variations in centrifugal force, which typically affects vehicle stability. In this situation, adjusting the K value using a PID control algorithm allows for smoother cornering by allocating different steering angles to each drive wheel. Specifically, if the moving platform is accelerating during a turn, K < 0.5. In this case, the steering angle of the front wheels is smaller than that of the rear wheels, and the steering angle of the drive wheel closer to the apex is smaller than that of the drive wheel farther from the apex. This posture makes cornering smoother. Conversely, if the moving platform is decelerating during a turn, K > 0.5, the opposite of acceleration, which also allows for smoother cornering. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 is a flowchart of a motion control method for a mobile platform provided in an embodiment of the present invention;

[0029] Figure 2 is a schematic diagram of the geometric decomposition of the motion state when K = 0.5, provided in an embodiment of the present invention;

[0030] Figure 3 is an algorithm logic diagram of the PID control algorithm provided in the embodiment of the present invention for the vehicle stability control center of gravity allocation coefficient K;

[0031] Figure 4 is a flowchart of a method for controlling the autonomous driving state of a mobile platform according to another embodiment of the present invention;

[0032] Figure 5 is a structural block diagram of a motion control device provided in another embodiment of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] As an embodiment of the present invention, as shown in Figure 1, a motion control method for a mobile platform is provided. The mobile platform includes four drive wheels, each equipped with an independent steering motor and a drive motor. The steering motor controls the steering angle of the drive wheel, and the drive motor controls the rotational speed of the drive wheel. This is a four-wheel, eight-drive mobile platform, which could be a mobile charging platform for charging new energy vehicles in a parking lot.

[0035] The motion control method includes the following steps:

[0036] S100: Obtain the target moving speed, target turning angle, wheel spacing, and wheel diameter of the mobile platform.

[0037] The target movement speed and target turning angle can be generated by the operator through the joystick on the remote control. For example, if the target movement speed is 10 m / s and the target turning angle is 20° to the left, the target movement speed and target turning angle represent the state the moving platform will change from its current state to. Because the sensors of the autonomous driving system cannot accurately detect the position of obstacles due to obstructions from pillars on turning sections, remote control driving can generally be handed over to the operator on turning sections.

[0038] S200: Based on the wheel spacing, current average turning radius and wheel diameter of the mobile platform, perform motion decomposition processing on the target moving speed and target turning angle to generate the target wheel speed and target wheel turning angle corresponding to each drive wheel.

[0039] This motion decomposition process involves breaking down a general control command into control commands for each drive wheel. This process is typically only necessary during turns to ensure the mobile platform can navigate smoothly. This embodiment uses a left turn as an example; the decomposition process for a right turn is similar and can be directly derived by those skilled in the art without further explanation.

[0040] Motion decomposition processing includes:

[0041] S201: If the mobile platform turns to the left, the target steering angle is kinematically decomposed based on the wheel spacing of the mobile platform to generate the target wheel steering angle corresponding to each drive wheel. The target wheel steering angles corresponding to each drive wheel satisfy the following relationship:

[0042]

[0043]

[0044]

[0045]

[0046] FL Deg, FR Deg, RR Deg, and RR Deg represent the target wheel steering angles corresponding to the left front drive wheel, right front drive wheel, left rear drive wheel, and right rear drive wheel, respectively. L is the wheel spacing between the front and rear drive wheels. W is the wheel spacing between the left and right drive wheels. r is the turning radius corresponding to the target steering angle. K is the distribution coefficient.

[0047] S202: If the mobile platform turns to the left, the target speed is decomposed based on the wheel spacing, the current average turning radius, and the wheel diameter to generate the target wheel rotation speed for each drive wheel. The target wheel rotation speeds for each drive wheel satisfy the following relationship:

[0048]

[0049]

[0050]

[0051]

[0052] FL rpm, FR rpm, RR rpm, and RR rpm represent the target wheel speeds for the left front drive wheel, right front drive wheel, left rear drive wheel, and right rear drive wheel, respectively. V represents the target speed. R L R is the wheel diameter of the driving wheels of the mobile platform. R is the current average turning radius of the mobile platform. Specifically, R is the average turning radius of each of the four driving wheels of the mobile platform.

[0053] Figure 2 shows the geometric decomposition diagram of the motion state when K = 0.5. In the above formula, KL is the length represented by q in the figure, and (1-K)×L is the length represented by g in the figure.

[0054] Based on the above decomposition diagram, the rotation angle and speed values ​​can be decomposed horizontally and vertically. Then, according to geometric principles, the target wheel's speed and rotation angle can be calculated using the Pythagorean theorem and trigonometric relationships. Therefore, through motion decomposition processing, motion commands input manually via remote control can be calculated as the rotation angle and speed values ​​on the four drive wheels of the mobile platform.

[0055] K is obtained as follows:

[0056] S203: If the absolute value of the difference between the average speed of the mobile platform in the previous speed monitoring cycle and the average speed in the current monitoring cycle is less than or equal to the speed difference threshold, then K = 0.5. The average speed in the current monitoring cycle can also be the current actual wheel speed of the mobile platform.

[0057] S204: If the absolute value of the difference between the average speed of the mobile platform in the previous speed monitoring cycle and the average speed in the current monitoring cycle is greater than the speed difference threshold, then K is obtained by the PID control algorithm. PID is an abbreviation for Proportional, Integral, and Differential. The PID control algorithm is a control algorithm that combines proportional, integral, and derivative components into one. It is the most mature and widely used control algorithm in continuous systems.

[0058] S2035: If the mobile platform accelerates during the turning process, then K < 0.5.

[0059] S206: If the mobile platform decelerates during the turning process, then K>0.5.

[0060] By controlling the value of K, the moving platform can maintain stability as much as possible during turning. Different values ​​of K result in different steering angles distributed on the four drive wheels. Therefore, when the change in the moving platform's speed is small, the speed change during turning is not significant, and the corresponding change in centrifugal force is also not large, usually not affecting the vehicle's stability. Therefore, K = 0.5, which means keeping the steering angle of the inner and outer drive wheels constant during the turn. This avoids frequent adjustments to the vehicle's steering angle, thus ensuring smooth vehicle operation.

[0061] When the moving platform experiences significant speed variations, the speed changes during cornering are substantial, resulting in corresponding large changes in centrifugal force, which typically affects vehicle stability. In this case, adjusting the K value using a PID control algorithm allows for smoother cornering by allocating different steering angles to each drive wheel. In this embodiment, the difference in average speed between two speed monitoring cycles can be used as input, and the corresponding K value is obtained using the PID control algorithm. The PID control algorithm can determine the corresponding K value more promptly and effectively. Changes in the K value can appropriately adjust the center of gravity of the moving platform, making it more stable during cornering. Specifically, the logic diagram of the PID control algorithm in this embodiment can be referenced in Figure 3, showing the allocation logic of the K coefficient. The coefficients Kp (i.e., P_term in Figure 3) and Ki (i_term in Figure 3) in the PID control algorithm can be obtained by looking up a table. The corresponding mapping table can be calibrated by those skilled in the art for each moving platform based on the actual usage scenario.

[0062] The PID control algorithm allocates the K coefficient as follows: if the moving platform accelerates during a turn, then K < 0.5. In this case, the steering angle of the front wheels is smaller than that of the rear wheels, and the steering angle of the drive wheel closer to the apex of the turn is smaller than that of the drive wheel farther from the apex. This posture makes it easier to corner smoothly. Conversely, if the moving platform decelerates during a turn, then K > 0.5. The state is the opposite of acceleration, and it can also corner more smoothly.

[0063] S300: Controls the moving platform to move according to the target wheel speed, target wheel angle, current wheel speed and current wheel angle corresponding to each drive wheel.

[0064] Specifically, the S300 includes:

[0065] S301: Verify the rotational speed of the target wheel based on the rotational angle of the target wheel corresponding to each drive wheel, and generate a reliable rotational speed of the target wheel.

[0066] S301 includes:

[0067] S311: Obtain the corresponding speed limit coefficient b based on the target wheel's steering angle. The target wheel's steering angle is negatively correlated with the speed limit coefficient.

[0068] Specifically, the corresponding speed limit coefficient b can be obtained by looking up a table using the target wheel's steering angle. The mapping table is as follows:

[0069] Table 1:

[0070] Target wheel steering angle (°) b 0 115 0.8 30 0.6 45 0.4 60 0.3 49 975 0.3 90 0.2 surface

[0071] The target wheel angles shown in the table above are endpoint values ​​corresponding to different turning intervals. The value b corresponding to the target wheel angle in each turning interval changes linearly. For example, if the target wheel angle is 14°, then its corresponding b = 1 - [14*(1-0.8) / 15] = 0.8133. Therefore, the rate of change of b is not the same in different turning intervals, thus making it more adaptable.

[0072] S321: Generate the upper limit value V of the target wheel speed based on the target wheel speed and the speed limit coefficient. limt V limt The following conditions must be met:

[0073] V limt =Rmp m ×b.

[0074] If Rmp m >V limt Then V limt As a reliable target wheel rotational speed V kx .

[0075] If Rmp m ≤V limt Then Rmp m As a reliable target wheel rotational speed V kx .

[0076] In actual use, due to human unfamiliarity or minor errors, when generating control commands via the joystick, a mismatch may occur between the target wheel's rotation angle and its speed. For example, if the target wheel's speed exceeds the maximum speed corresponding to its rotation angle, the platform may easily tip over when turning.

[0077] S302: Generate acceleration values ​​based on the rotational speed of the reliable target wheel and the current rotational speed of the wheel.

[0078] S302 includes:

[0079] S312: Obtain the current rotational speed of the sub-wheel according to the preset monitoring cycle. Among them, The rotational speed of the current wheel is obtained during the i-th preset monitoring cycle.

[0080] S322: If Then according to Obtain the acceleration value a corresponding to the i-th preset monitoring period. i If V kx >Rmp act ,but With a i Negative correlation. If V kx <Rmp act ,but With a i Positive correlation. Rmp act This represents the current wheel speed.

[0081] The corresponding a i Alternatively, it can be obtained by looking up a table. The corresponding acceleration value is set as follows: when the running process is an acceleration process, then... With a i Negative correlation. When the running process is a deceleration process, then With a i Positive correlation. Therefore, the acceleration process is a process of first accelerating slowly and then accelerating rapidly, while the deceleration process is a process of first decelerating rapidly and then decelerating slowly.

[0082] S332: If Then a i =0.

[0083] S342: Using the acceleration value corresponding to each preset monitoring cycle, accelerate or decelerate the rotational speed of the current sub-wheel in each preset monitoring cycle.

[0084] S303: Generate steering adjustment amplitude based on the target wheel angle and the current wheel angle.

[0085] S303 includes:

[0086] S313: Generate the steering adjustment value R for each drive wheel based on the target wheel angle and the current wheel angle. pid R pid The following conditions must be met:

[0087]

[0088] Among them, Deg m The target wheel's steering angle is any one of FL Deg, FR Deg, RR Deg, and RRDeg. actThis represents the current wheel angle. T is the steering cycle. Deg max This is the preset maximum steering angle.

[0089] S323: Based on the R corresponding to each drive wheel pid It controls the drive wheel to change its rotation angle from the current wheel to the target wheel.

[0090] S304: Controls the movement of the mobile platform based on the acceleration value and steering adjustment amplitude.

[0091] As another embodiment of the present invention, as shown in FIG4, a method for controlling the autonomous driving state of a mobile platform is also provided. The mobile platform includes an autonomous driving module, which is used to generate a target moving speed of the mobile platform.

[0092] The control methods for this autonomous driving state include:

[0093] S400: Based on the multiple target movement speeds received within the verification period corresponding to the road segment to be detected, a preliminary confidence level A is generated. A is the number of times the difference between two adjacent target movement speeds is not zero within the verification period. The road segment to be detected is the segment between two adjacent turning points in the planned driving path of the mobile platform.

[0094] The method in this embodiment is more suitable for the straight-line driving scenario of the mobile platform. For mobile charging platforms, they usually operate in underground parking lots. Since the roads in this scenario are usually arranged in a horizontal and vertical intersection and there are few obstacles on the road surface, in order to maintain stable operation, the mobile platform usually maintains straight-line driving between two turning points. In addition, it generally needs to decelerate when turning at the turning points. Therefore, the corresponding straight-line driving section will have acceleration section, constant speed section and deceleration section.

[0095] The S400 includes:

[0096] S401: Based on the multiple target movement speeds obtained within the verification period, generate a second state determination sequence (C1, C2, ..., C...). f ..., C z-1 C f Based on the (f+1)th target's movement speed V within the verification period f+1 With the movement speed V of the f-th target f The difference between them is obtained. C f The following conditions must be met:

[0097]

[0098] Where Y2 is the second threshold.

[0099] The above Cf In the calculation formula, only |V f+1 -V f Only under the condition of |>Y2 will C be able to f It is not equal to 0. This setting is because, for safety reasons, mobile charging platforms typically operate at lower speeds in underground parking lots. Even if the autonomous driving module occasionally issues a slightly off-center speed value due to an error, it will not affect the stable operation of the vehicle. Furthermore, since the speed commands issued by the autonomous driving module are generated based on the current state of the mobile platform, in a constant-speed driving state, a certain deviation in the speed command may be used for compensation to maintain the constant speed. For example, if the constant speed target is 3 m / s, the possible compensation speed commands would be 3.1 m / s, 3.2 m / s, 2.9 m / s, and 3.05 m / s, etc.

[0100] Therefore, none of the above situations will cause instability in the operation of the mobile platform, and thus will not be included in the above calculation formula.

[0101] S402: If every element in the second state decision sequence is greater than or equal to 0 or less than or equal to 0, then generate a primary confidence level A based on the number of non-zero elements in the second state decision sequence.

[0102] Preferably, the number of non-zero and unequal elements in the sequence can also be determined based on the second state, and used as A. This is to exclude normal driving states with uniform acceleration and uniform deceleration.

[0103] S403: If there are multiple positive and negative adjacent elements in the second state determination sequence, then stop the automatic driving state of the mobile platform.

[0104] If there are multiple positive and negative adjacent elements in the second state determination sequence, it means that the mobile platform is constantly switching between acceleration and deceleration. This state is an abnormal state. This state usually occurs when the autonomous driving program malfunctions due to abnormal related sensors, resulting in abnormal situations where the issued speed commands have repeated changes in direction or fluctuate in size.

[0105] S500: If A > Y1, then perform secondary verification processing on the mobile platform to generate secondary credibility B. Y1 is the first threshold.

[0106] To ensure the smooth operation of the mobile platform, autonomous driving modules typically use their algorithms to calculate more uniform and linear speed commands, thus controlling the platform to operate more smoothly. Therefore, under normal circumstances, the speed values ​​in the speed command sequence generated by the autonomous driving module generally exhibit a relatively linear change; for example, the speed value remains constant in a constant speed state and changes linearly during acceleration and deceleration. Furthermore, to maintain the smooth operation of the mobile platform as much as possible, it generally maintains a constant speed for as long as possible and undergoes acceleration and deceleration for as short a time as possible. Based on this characteristic, this invention can generate a primary confidence level A based on the difference patterns between the movement speeds of multiple targets received within a verification period. This primary confidence level A serves as the trigger condition for secondary verification judgments.

[0107] Secondary verification processing includes:

[0108] S501: Obtain the movement speed of multiple targets within the secondary verification period. The secondary verification period is the next verification period adjacent to the current verification period.

[0109] S502: Generate a first state determination sequence (a1, a2, ..., a...) based on the movement speeds of multiple targets within the secondary verification cycle. e ... a z-1 a e The value is obtained from the difference between the (e+1)th target's movement speed and the eth target's movement speed within the secondary verification cycle. Specifically, C f With a e The method for obtaining z is the same. z is the total number of target movement speeds received within the secondary verification period.

[0110] If every element in the first state determination sequence is greater than 0, then the first check state value B1>0.

[0111] If every element in the first state determination sequence is equal to 0, then the first check state value B1 = 0.

[0112] If every element in the first state determination sequence is less than 0, then the first check state value B1 < 0.

[0113] S503: Generate the second verification status value B2 based on the historical motion information of the mobile platform in the historical period corresponding to the secondary verification cycle.

[0114] If the historical motion information indicates an acceleration state, then B2>0.

[0115] If the historical motion information indicates a constant speed travel state, then B2 = 0.

[0116] If the historical motion information indicates a decelerated driving state, then B2 < 0.

[0117] Specifically, B2 can be generated in the following two ways:

[0118] Firstly, S503 includes:

[0119] S513: Based on the endpoint positions of each acceleration sub-segment, constant speed sub-segment, and deceleration sub-segment included in the road segment to be detected, generate the corresponding acceleration segment interval, constant speed segment interval, and deceleration segment interval.

[0120] S523: Obtain the two check positions corresponding to the two endpoint times of the secondary check cycle.

[0121] S533: Generate B2 based on the road segment interval to which the two verification locations belong.

[0122] Secondly: S503 includes:

[0123] S543: Obtain the two historical driving speeds corresponding to the two endpoint times of the secondary verification cycle.

[0124] S553: ​​If Then B2>0.

[0125] S563: If Then B2 < 0.

[0126] S573: If Therefore, B2 = 0.

[0127] in, The historical driving speed corresponding to the start time of the secondary verification cycle. Y3 represents the historical driving speed corresponding to the end time of the secondary verification cycle. Y4 and Y3 represent the third and fourth thresholds, respectively, with Y3 > 0 and Y4 < 0.

[0128] S504: Generate B based on B1 and B2. B satisfies the following condition: B = B1 × B2.

[0129] S600: If B < 0, then stop the automatic driving state of the mobile platform.

[0130] The secondary verification process obtains B1 from the first state determination sequence in the next verification cycle and B2 from the actual planned operating state of the mobile platform in the next verification cycle. The mutual verification between the two states determines whether the autonomous driving module has malfunctioned, and the autonomous driving state of the mobile platform is cut off in time, thereby improving the operational stability and safety of the mobile platform.

[0131] As another embodiment of the present invention, as shown in FIG5, a motion control device is also provided, including: a motion command receiving module, a wheel motion decomposition module, a motion driving module, and multiple drive wheel control modules.

[0132] In this embodiment, the motion command receiving module, wheel motion decomposition module, motion drive module, and multiple drive wheel control modules are all integrated into the domain controller shown in Figure 4. Specifically, the motion command receiving module can be used to complete the content of S100. The wheel motion decomposition module can be used to complete the content of S200. The multiple drive wheel control modules can be used to complete the content of S300.

[0133] The wheel motion decomposition module is electrically connected to both the motion command receiving module and the motion drive module. The wheel motion decomposition module is used to generate the target rotational speed and target turning angle for each drive wheel.

[0134] Multiple drive wheel control modules are electrically connected to the motion drive module. The motion drive module is used to generate the speed change amplitude and angle change amplitude for each drive wheel.

[0135] Specifically, the motion drive module includes: a speed limiting module, a speed drive module, and a cornering drive module.

[0136] The speed limiting module can be used to complete the steps in S301. The speed driving module can be used to complete the steps in S302. The corner driving module can be used to complete the steps in S303.

[0137] The speed limiting module is electrically connected to the wheel motion decomposition module. The speed limiting module filters the target speed for each drive wheel to ensure the target speed is within a preset speed range. The speed drive module is electrically connected to the speed limiting module. The speed drive module determines the amplitude of speed changes. The angle drive module is electrically connected to the speed limiting module. The angle drive module determines the amplitude of angle changes.

[0138] Each drive wheel control module is electrically connected to the drive motor and steering motor of the corresponding drive wheel in the mobile platform, and is used to control the movement of the corresponding drive motor and steering motor.

[0139] In addition, the motion control device also includes: a remote control receiver, an intelligent driving controller, and steering controllers and drive controllers corresponding to each drive wheel.

[0140] The remote control receiver is wirelessly connected to the remote control, and the motion command receiving module is connected to the remote control receiver via a CAN bus. The remote control is used to generate motion control commands. Furthermore, the remote control includes a speed control joystick and a rotation control joystick.

[0141] The intelligent driving controller is electrically connected to the motion command receiving module, and the intelligent driving controller is used to generate motion control commands. The motion command receiving module and the intelligent driving controller are electrically connected via a CAN bus.

[0142] The drive wheel control module is electrically connected to the steering controller and drive controller corresponding to each drive wheel via a CAN bus.

[0143] As another embodiment of the present invention, a mobile platform is also provided, comprising: four drive wheels and a motion control device as described above. Each drive wheel of the mobile platform is equipped with an independent steering motor and a drive motor; the steering motor controls the steering angle of the drive wheel, and the drive motor controls the rotational speed of the drive wheel.

[0144] The drive wheel control module is used to control the motion of the corresponding drive motor and steering motor. Furthermore, the steering motor is a worm gear steering motor.

[0145] This invention utilizes a wheel motion decomposition module to first decompose the received overall target motion command into motion commands for each drive wheel. Then, the motion drive module calculates the corresponding speed and angle change amplitudes based on the target rotational speed and angle for each drive wheel. Finally, the drive wheel control module controls each drive wheel to adjust its motion state according to these corresponding change amplitudes. This allows each drive wheel to move in different ways depending on the actual situation when receiving the same motion command, thus ensuring greater stability of the mobile platform in special road conditions (such as curves).

[0146] Furthermore, although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0147] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, mobile terminal, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0148] In an exemplary embodiment of this disclosure, an electronic device capable of implementing the above-described method is also provided.

[0149] Those skilled in the art will understand that various aspects of the present invention can be implemented as systems, methods, or program products. Therefore, various aspects of the present invention can be specifically implemented in the following forms: entirely hardware implementations, entirely software implementations (including firmware, microcode, etc.), or implementations combining hardware and software aspects, collectively referred to herein as “circuits,” “modules,” or “systems.”

[0150] An electronic device according to this embodiment of the invention. The electronic device is merely an example and should not be construed as limiting the functionality or scope of the embodiments of the invention.

[0151] Electronic devices are manifested in the form of general-purpose computing devices. Components of an electronic device may include, but are not limited to: at least one processor, at least one memory, and buses connecting different system components (including memory and processor).

[0152] The memory stores program code that can be executed by a processor, causing the processor to perform the steps described in the "Exemplary Methods" section above, according to various exemplary embodiments of the present invention.

[0153] The storage may include readable media in the form of volatile storage, such as random access memory (RAM) and / or cache memory, and may further include read-only memory (ROM).

[0154] The storage may also include programs / utilities having a set (at least one) of program modules, including but not limited to: an operating system, one or more applications, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0155] A bus can represent one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus that uses any of the various bus architectures.

[0156] The electronic device can also communicate with one or more external devices (e.g., keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable a user to interact with the electronic device, and / or any device that enables the electronic device to communicate with one or more other computing devices (e.g., routers, modems, etc.). This communication can be performed via input / output (I / O) interfaces. Furthermore, the electronic device can communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter. The network adapter communicates with other modules of the electronic device via a bus. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0157] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0158] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible embodiments, various aspects of the present invention may also be implemented as a program product comprising program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the present invention described in the "Exemplary Methods" section above.

[0159] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0160] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0161] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0162] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0163] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0164] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0165] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A motion control method for a mobile platform, characterized in that, The mobile platform includes four drive wheels, each equipped with an independent steering motor and a drive motor. The steering motor controls the steering angle of the drive wheel, and the drive motor controls the rotational speed of the drive wheel. The method includes the following steps: obtaining the target moving speed, target steering angle, wheel spacing, and wheel diameter of the mobile platform; performing motion decomposition processing on the target moving speed and target steering angle based on the wheel spacing, current average turning radius, and wheel diameter of the mobile platform to generate the target wheel rotational speed and target wheel turning angle corresponding to each drive wheel. The mobile platform is controlled to move based on the target wheel speed, target wheel rotation angle, current wheel speed, and current wheel rotation angle corresponding to each drive wheel; The motion decomposition process includes: if the mobile platform turns to the left, then based on the wheel spacing of the mobile platform, the target steering angle is motion decomposed to generate the target wheel rotation angle corresponding to each drive wheel; wherein, the target wheel rotation angles corresponding to each drive wheel satisfy the following relationship: ； ； ； ； 、 、 and The target wheel turning angles are the left front drive wheel, right front drive wheel, left rear drive wheel, and right rear drive wheel, respectively; L is the wheel spacing between the front and rear drive wheels; W is the wheel spacing between the left and right drive wheels; r is the turning radius corresponding to the target turning angle; K is the allocation coefficient, which is obtained as follows: if the absolute value of the difference between the average speed of the mobile platform in the previous speed monitoring cycle and the average speed in the current monitoring cycle is less than or equal to the speed difference threshold, then K = 0.5; if the absolute value of the difference between the average speed of the mobile platform in the previous speed monitoring cycle and the average speed in the current monitoring cycle is greater than the speed difference threshold, then K is obtained by the PID control algorithm; and if the mobile platform is accelerating during the turning process, then K < 0.5; if the mobile platform is decelerating during the turning process, then K > 0.

5.

2. The method according to claim 1, characterized in that, The motion decomposition process further includes: if the mobile platform turns to the left, then based on the wheel spacing, the current average turning radius, and the wheel diameter of the mobile platform, the target moving speed is decomposed to generate the target wheel rotation speed corresponding to each of the drive wheels; wherein, the target wheel rotation speeds corresponding to each drive wheel satisfy the following relationship: ； ； ； ； 、 、 and These are the target wheel speeds for the left front drive wheel, right front drive wheel, left rear drive wheel, and right rear drive wheel, respectively. The target movement speed; The diameter of the drive wheel of the mobile platform; The current average turning radius of the mobile platform.

3. The method according to claim 2, characterized in that, Controlling the movement of the mobile platform based on the target wheel rotation speed, target wheel angle, current wheel rotation speed, and current wheel angle corresponding to each drive wheel includes: verifying the target wheel rotation speed based on the target wheel angle corresponding to each drive wheel to generate a reliable target wheel rotation speed; generating an acceleration value based on the reliable target wheel rotation speed and the current wheel rotation speed; generating a steering adjustment amplitude based on the target wheel angle and the current wheel angle; and controlling the movement of the mobile platform based on the acceleration value and the steering adjustment amplitude.

4. The method according to claim 3, characterized in that, Generating a steering adjustment amplitude based on the target wheel rotation angle and the current wheel rotation angle includes: generating a steering adjustment amplitude corresponding to each drive wheel based on the target wheel rotation angle and the current wheel rotation angle corresponding to each drive wheel. ； The following conditions must be met: ;in, For the target wheel's turning angle, 、 、 and any of them; The current wheel angle is T; T is the steering cycle. The preset maximum steering radius; based on the corresponding value of each drive wheel. The drive wheel is controlled to change its rotation angle from the current wheel to the target wheel.

5. The method according to claim 3, characterized in that, The rotational speed of the target wheel is verified based on the rotational angle of the target wheel corresponding to each drive wheel, and a reliable target wheel rotational speed is generated, including: obtaining the corresponding speed limiting coefficient based on the rotational angle of the target wheel. The target wheel's rotation angle is negatively correlated with the speed limiting coefficient; based on the target wheel's rotational speed and the speed limiting coefficient, an upper limit value for the rotational speed corresponding to the target wheel's rotational speed is generated. ； The following conditions must be met: ;like Then Rotation speed as a reliable target wheel ;like ,but Rotation speed as a reliable target wheel 。 6. The method according to claim 5, characterized in that, Based on the reliable target wheel rotation speed and the current wheel rotation speed, an acceleration value is generated, including: acquiring the current wheel rotation speed according to a preset monitoring cycle; wherein, The current wheel speed is obtained in the i-th preset monitoring cycle; if According to Obtain the acceleration value corresponding to the i-th preset monitoring period. ;like ,but and Negative correlation; if ,but and Positive correlation; The current wheel speed is used; the acceleration value corresponding to each preset monitoring cycle is used to accelerate or decelerate the current wheel speed in each preset monitoring cycle.

7. The method according to claim 6, characterized in that, After obtaining the current wheel speed according to the preset monitoring cycle, the method further includes: if ,but 。 8. A non-transitory computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a motion control method for a mobile platform as described in any one of claims 1 to 7.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements a motion control method for a mobile platform as described in any one of claims 1 to 7.

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