A mecanum wheel mobile platform capable of self-adaptive balance of center of mass

Abstract

The application relates to a Mecanum wheel mobile platform capable of self-adaptive center of mass balance, which comprises a bearing platform, a Mecanum wheel system, a counterweight adjusting system and a controller, the Mecanum wheel system comprises a plurality of Mecanum wheel mechanisms, the plurality of Mecanum wheel mechanisms are symmetrically installed below the bearing platform, the counterweight adjusting system comprises a plurality of counterweight adjusting mechanisms corresponding to the number of the Mecanum wheel mechanisms, the plurality of counterweight adjusting mechanisms are uniformly installed above the bearing platform, the controller is arranged on the bearing platform and is electrically connected with each Mecanum wheel mechanism and counterweight adjusting mechanism, so as to dynamically adjust the rotating speed of each Mecanum wheel by controlling the current output, meanwhile, the position of the counterweight block on the bearing platform is adjusted by each counterweight adjusting mechanism according to the current signal, so as to self-adaptively balance the center of mass of the whole Mecanum wheel mobile platform. The application can effectively realize self-adaptive center of mass balance of the Mecanum wheel mobile platform during movement, has wide application range and low realization cost.

Description

Technical Field

[0001] This invention relates to the field of Mecanum wheel moving platform technology, and more specifically to a Mecanum wheel moving platform with an adaptively balancing center of mass. Background Technology

[0002] The working principle of a Mecanum wheel lies in the fact that the roller axis and the hub axis are arranged at a spatial angle of 45°. A Mecanum wheel system typically consists of two sets of Mecanum wheels that are mirror images of each other. Its omnidirectional movement mechanism relies on the roller acting as a ground contact component; its driving force can be decomposed into forward and lateral forces, which cancel each other out or reinforce each other to achieve omnidirectional movement. Therefore, Mecanum wheels are driven individually. However, when the load on a Mecanum wheel system is uneven, the Mecanum wheel in the direction of the center of gravity shift will bear a greater load, leading to an increase in driving force and consequently an increase in component force. This prevents the forward or lateral forces from completely canceling each other out, causing a deviation in motion. This problem severely limits the widespread adoption of Mecanum wheels, confining their application to small cargo transportation or designing them into large Mecanum wheel systems with 8 or 12 wheels, significantly increasing costs. Summary of the Invention

[0003] The purpose of this invention is to provide a Mecanum wheel moving platform with an adaptively balanced center of mass, which can effectively achieve adaptive center of mass balance during the movement of the Mecanum wheel moving platform, has a wide range of applications, and is low in cost.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a Mecanum wheel moving platform with adaptive center of gravity balance, comprising a load-bearing platform, a Mecanum wheel system, a counterweight adjustment system, and a controller. The Mecanum wheel system includes multiple Mecanum wheel mechanisms symmetrically installed below the load-bearing platform. The counterweight adjustment system includes multiple counterweight adjustment mechanisms of equal number to the Mecanum wheel mechanisms, uniformly installed above the load-bearing platform. The controller is located on the load-bearing platform and electrically connected to each Mecanum wheel mechanism and the counterweight adjustment mechanism, so as to dynamically adjust the rotational speed of each Mecanum wheel by controlling the current output, and simultaneously control each counterweight adjustment mechanism to adjust the position of its counterweight on the load-bearing platform according to the current signal, so as to adaptively balance the center of gravity of the entire Mecanum wheel moving platform.

[0005] Furthermore, the Mecanum wheel mechanism includes a servo driver, a drive motor, a first coupling, a reducer, and a Mecanum wheel. The servo driver and drive motor are mounted below the support platform via a suspension mechanism. The output shaft of the drive motor is connected to the reducer via the first coupling. The reducer is connected to the Mecanum wheel to drive the Mecanum wheel to rotate. The controller is electrically connected to the drive motor via the servo driver to adjust the current value in real time according to the rotational speed control requirements of the Mecanum wheel, outputting a corresponding current signal to the drive motor to control its rotation, and simultaneously sampling the output current signal.

[0006] Furthermore, the counterweight adjustment mechanism includes a base, a slide rail, a counterweight motor, a second coupling, a lead screw, and a counterweight block. The base is fixedly installed above the support platform. The counterweight motor is fixedly installed on the support platform, and its output shaft is fixedly connected to the horizontally arranged lead screw via the second coupling to drive the lead screw to rotate. The slide rail is arranged parallel to the lead screw and fixedly connected to the support platform. The counterweight block is helically engaged with the lead screw and simultaneously slidably engaged with the slide rail, thereby converting the rotational motion of the lead screw into the horizontal linear motion of the counterweight block. The controller is electrically connected to the counterweight motor to control the rotation of the counterweight motor, thereby changing the position of the counterweight block on the support platform.

[0007] Furthermore, the counterweight adjustment mechanism includes two slide rails, which are arranged parallel to each other on the left and right sides of the lead screw and fixedly connected to the bearing platform. The counterweight block slides with both slide rails. The counterweight adjustment mechanism also includes two bearing seats, which are fixedly installed on the front and rear sides of the base, respectively. The front and rear ends of the lead screw are rotatably connected to the base via the bearing seats, and the front and rear ends of the two slide rails are fixedly connected to the bearing seats.

[0008] Furthermore, the Mecanum wheel system includes four Mecanum wheel mechanisms, which are symmetrically arranged in pairs and distributed at the left front, right front, left rear, and right rear positions below the load-bearing platform; the counterweight adjustment system includes four counterweight adjustment mechanisms, which are correspondingly arranged on the load-bearing platform above the corresponding Mecanum wheel mechanisms. The center of each counterweight adjustment mechanism coincides vertically with the center of the corresponding Mecanum wheel, and one end of each counterweight adjustment mechanism faces the geometric center of the moving platform, thereby positioning each counterweight adjustment mechanism.

[0009] Furthermore, the counterweight motor on the Mecanum wheel mechanism is mounted at one end near the geometric center of the moving platform.

[0010] Furthermore, the control logic during the operation of the Mecanum wheel moving platform is as follows:

[0011] S1. When the Mecanum wheel moving platform starts working, the system is first initialized; then, according to the speed control requirements, the controller outputs the corresponding current signal to the drive motor through the servo driver to drive each Mecanum wheel to rotate at the set speed.

[0012] S2. When the Mecanum wheel moving platform is unevenly loaded, the controller detects that the rotation speed of each Mecanum wheel does not meet the set rotation speed control requirements. That is, it controls each servo driver to generate a current signal of different magnitude to the corresponding drive motor to generate different driving forces, so as to ensure that each Mecanum wheel can still rotate at the set speed. At the same time, the controller samples the output current signal.

[0013] S3. The controller calculates the current center of gravity position of the Mecanum wheel moving platform based on all sampled current signals and the relationship between the current of the drive motor and the load.

[0014] S4. The controller calculates the displacement of the counterweights on each counterweight adjustment mechanism based on the current center of gravity position, with the goal of balancing the center of gravity position of the entire Mecanum wheel moving platform, and ensures that the counterweights on each counterweight adjustment mechanism do not exceed the maximum displacement range.

[0015] S5. The controller converts the calculated displacement of the counterweight blocks on each counterweight adjustment mechanism into the control steps of the counterweight motor on each counterweight adjustment mechanism, and controls the corresponding configuration motor to work, driving each counterweight block to move to the set position.

[0016] S6. The controller updates the centroid position and calculates and adjusts the output current value in real time based on the updated centroid position. Then, it outputs the corresponding current signal to the drive motor through the servo driver to drive each Mecanum wheel to rotate.

[0017] S7. The controller detects whether the rotational speed of each Mecanum wheel meets the set rotational speed control requirements. If yes, an adaptive center of gravity balance is completed. Otherwise, it returns to step S2 and controls each servo driver to generate current signals of different magnitudes to the corresponding drive motors to generate different driving forces. At the same time, it samples the current signals and continues to execute steps S3-S6 until the center of gravity balance of the Mecanum wheel moving platform is achieved.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a Mecanum wheel mobile platform with an adaptively balancing center of mass, which solves the balance problem in the process of platform movement. Compared with the prior art, it has higher stability, stronger adaptability and better energy efficiency, and provides a new implementation scheme for the development of omnidirectional mobile platforms. It has strong practicality and broad application prospects. Attached Figure Description

[0019] Figure 1 This is a perspective view of the Mecanum wheel moving platform according to an embodiment of the present invention;

[0020] Figure 2 This is a top view of the Mecanum wheel moving platform according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the Mecanum wheel mechanism in an embodiment of the present invention (servo driver not shown);

[0022] Figure 4 This is a side view of the counterweight adjustment mechanism in an embodiment of the present invention;

[0023] Figure 5 This is a top view of the counterweight adjustment mechanism in an embodiment of the present invention (base not shown);

[0024] Figure 6 This is a schematic diagram of the working state of each counterweight adjustment mechanism before the center of mass position is adjusted in an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the working state of each counterweight adjustment mechanism after the center of mass position is adjusted in an embodiment of the present invention.

[0026] In the diagram: 1-Drive motor; 2-First coupling; 3-Reducer; 4-Mecanum wheel; 100-Mecanum wheel mechanism; 200-Bearing platform; 300-Counterweight adjustment mechanism; 301-Counterweight motor; 302-Second coupling; 303-Screw; 304-Counterweight block; 400-Controller. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] like Figure 1-2As shown, this embodiment provides a Mecanum wheel moving platform with an adaptively balanced center of mass, including a support platform 200, a Mecanum wheel system, a counterweight adjustment system, and a controller 400. The Mecanum wheel system includes multiple Mecanum wheel mechanisms 100, which are symmetrically installed below the support platform 200. The counterweight adjustment system includes multiple counterweight adjustment mechanisms 300, which are equal in number to the number of Mecanum wheel mechanisms and are evenly installed above the support platform 200. The controller 400 is disposed on the support platform 200 and electrically connected to each Mecanum wheel mechanism 100 and each counterweight adjustment mechanism 300, so as to dynamically adjust the rotational speed of each Mecanum wheel by controlling the current output, and simultaneously control each counterweight adjustment mechanism to adjust the position of its counterweight on the support platform according to the current signal, so as to adaptively balance the center of mass of the entire Mecanum wheel moving platform.

[0031] like Figure 3 As shown, the Mecanum wheel mechanism includes a servo driver, a drive motor 1, a first coupling 2, a reducer 3, and a Mecanum wheel 4. The servo driver and drive motor 1 are mounted below the support platform 200 via a suspension mechanism. The output shaft of the drive motor is connected to the reducer 3 via the first coupling 2. The reducer 3 is connected to the Mecanum wheel 4 to drive the Mecanum wheel to rotate. The controller is electrically connected to the drive motor through the servo driver to adjust the current value in real time according to the rotational speed control requirements of the Mecanum wheel, outputting a corresponding current signal to the drive motor to control its rotation, and simultaneously sampling the output current signal.

[0032] In this embodiment, as Figure 4-5 As shown, the counterweight adjustment mechanism includes a base, a slide rail, a counterweight motor 301, a second coupling 302, a lead screw 303, and a counterweight block 304. The base is fixedly installed above the support platform 200. The counterweight motor 301 is fixedly installed on the support platform 200, and its output shaft is fixedly connected to the horizontally arranged lead screw 303 via the second coupling 302 to drive the lead screw 303 to rotate. The slide rail is arranged parallel to the lead screw 303 and fixedly connected to the support platform 200. The counterweight block 304 is helically engaged with the lead screw 303 and simultaneously slidably engaged with the slide rail, thereby converting the rotational motion of the lead screw into the horizontal linear motion of the counterweight block. The controller 400 is electrically connected to the counterweight motor 301 to control the rotation of the counterweight motor, thereby changing the position of the counterweight block on the support platform.

[0033] In this embodiment, the counterweight adjustment mechanism includes two slide rails, which are arranged parallel to each other on the left and right sides of the lead screw and fixedly connected to the bearing platform. The counterweight block slides with both slide rails. The counterweight adjustment mechanism also includes two bearing seats, which are fixedly installed on the front and rear sides of the base, respectively. The front and rear ends of the lead screw are rotatably connected to the base via the bearing seats, and the front and rear ends of the two slide rails are fixedly connected to the bearing seats.

[0034] Depending on different load requirements and accuracy specifications, this invention allows for the free selection of different types of counterweight adjustment mechanisms. For applications requiring high precision and high thrust, a screw drive module can be used, offering higher accuracy and greater load capacity. For applications requiring higher speeds but less precise positioning and thrust, a synchronous belt drive module can be selected, which is more suitable for high-speed transmissions with lower precision requirements. Depending on the operating environment, the system can be adapted to different types of linear slide modules. In dusty environments, a closed linear slide module should be selected to prevent dust from affecting the transmission system; in low-dust environments, an open linear slide module can be chosen to reduce costs and improve transmission efficiency. For maintainability and high load requirements, when selecting a linear slide module, it is recommended to use a linear guide type under high load conditions to enhance its load-bearing capacity and stability; while under lighter loads, a linear shaft type linear slide module can be selected, which has a simple structure and is easy to maintain. Through these reasonable selections and combinations, the efficient operation and reliability of the entire counterweight adjustment system under different working conditions can be ensured.

[0035] In this embodiment, the Mecanum wheel system includes four Mecanum wheel mechanisms, which are symmetrically arranged in pairs and distributed at the left front, right front, left rear, and right rear positions below the support platform. The counterweight adjustment system includes four counterweight adjustment mechanisms, which are correspondingly arranged on the support platform above the respective Mecanum wheel mechanisms. The center of each counterweight adjustment mechanism coincides vertically with the center of the corresponding Mecanum wheel, and one end of each counterweight adjustment mechanism faces the geometric center of the moving platform, thereby positioning each counterweight adjustment mechanism. The counterweight motor on each Mecanum wheel mechanism is installed at the end closest to the geometric center of the moving platform.

[0036] The control logic during the operation of the Mecanum wheel moving platform is as follows:

[0037] S1. When the Mecanum wheel moving platform starts working, the system is first initialized; then, according to the speed control requirements, the controller outputs the corresponding current signal to the drive motor through the servo driver to drive each Mecanum wheel to rotate at the set speed.

[0038] S2. When the Mecanum wheel moving platform is unevenly loaded, the controller detects that the rotation speed of each Mecanum wheel does not meet the set rotation speed control requirements. That is, it controls each servo driver to generate a current signal of different magnitude to the corresponding drive motor to generate different driving forces, so as to ensure that each Mecanum wheel can still rotate at the set speed. At the same time, the controller samples the output current signal.

[0039] S3. The controller calculates the current center of gravity position of the Mecanum wheel moving platform based on all sampled current signals and the relationship between the current of the drive motor and the load.

[0040] S4. The controller calculates the displacement of the counterweights on each counterweight adjustment mechanism based on the current center of gravity position, with the goal of balancing the center of gravity position of the entire Mecanum wheel moving platform, and ensures that the counterweights on each counterweight adjustment mechanism do not exceed the maximum displacement range.

[0041] S5. The controller converts the calculated displacement of the counterweight blocks on each counterweight adjustment mechanism into the control steps of the counterweight motor on each counterweight adjustment mechanism, and controls the corresponding configuration motor to work, driving each counterweight block to move to the set position.

[0042] S6. The controller updates the centroid position and calculates and adjusts the output current value in real time based on the updated centroid position. Then, it outputs the corresponding current signal to the drive motor through the servo driver to drive each Mecanum wheel to rotate.

[0043] S7. The controller detects whether the rotational speed of each Mecanum wheel meets the set rotational speed control requirements. If yes, an adaptive center of gravity balance is completed. Otherwise, it returns to step S2 and controls each servo driver to generate current signals of different magnitudes to the corresponding drive motors to generate different driving forces. At the same time, it samples the current signals and continues to execute steps S3-S6 until the center of gravity balance of the Mecanum wheel moving platform is achieved.

[0044] Due to varying loads, the drive motors experience different forces of friction against the ground, resulting in different rotational currents for the four Mecanum wheels. The relationship between the drive motor current and the load is explained below.

[0045] In this embodiment, the drive motor is a DC motor, and the basic equations of the DC motor include:

[0046] Voltage equation: U = IR arm +K e ω

[0047] Torque equation: M motor =K t I

[0048] Where U is the motor voltage, I is the motor current, and R is the motor current. arm K is the armature resistance. e M is the back electromotive force constant, ω is the motor speed, and M is the motor speed. motor K is the output torque of the motor. t The torque constant is the motor output power obtained through the motor efficiency η. motor Converted into output mechanical power P mesh =η motor ·U·I, the motor output torque is amplified to M after being reduced by the reducer. output =M motor ·n·η gear Where n is the reduction ratio, η gear For reducer efficiency.

[0049] The frictional torque of a Mecanum wheel is determined by the coefficient of friction μ and the load F. n The frictional torque M is determined by the radius R of the wheel. friction =μF n R; Output torque M after speed reduction by the reducer output The frictional torque is equal to that of the Mecanum wheel, therefore M exists. motor ·n·η gear =μF n R; Solving the simultaneous motor torque equations, the relationship between current and load is obtained as follows:

[0050]

[0051] Further considering the motor efficiency η motor The relationship between current and load is obtained as follows:

[0052]

[0053] This formula applies to conditions not exceeding the critical load.

[0054] When the load is less than the critical load, the current and load satisfy the above equation, and the speed decreases linearly as the load increases; when the load equals the critical load, the speed is... When the load exceeds the critical load, stalling may occur, and the motor is prone to accidents.

[0055] Based on the relationship between current and load, the current value of the four Mecanum wheels can be used to calculate the current center of gravity of the Mecanum wheel moving platform. Specific details are as follows.

[0056] Four Mecanum wheels are symmetrically distributed in a rectangle, with a wheel spacing of 2a and a wheelbase of 2b. A coordinate system is established with the geometric center of the moving platform as the origin. The position coordinates of the four Mecanum wheels are represented as: wheel 1 (a1, b1), wheel 2 (a2, b2), wheel 3 (a3, b3), and wheel 4 (a4, b4), where (a1, b1) = (a, b), (a2, b2) = (-a, b), (a3, b3) = (-a, -b), and (a4, b4) = (a, -b). The equilibrium equations for the vertical force, the moment about the x-axis, and the moment about the y-axis in the static equilibrium equations are established as follows:

[0057]

[0058] By combining the equations for the current and the load, the coordinates (x, y) of the centroid can be obtained as follows:

[0059]

[0060] Among them, F n1 F n2 F n3 F n4 The load-bearing capacity of each of the four Mecanum wheels, F n1 +F n2 +F n3 +F n4 =F n I1, I2, I3, and I4 represent the drive motor currents of the four Mecanum wheels, respectively.

[0061] Based on the calculated current center of gravity position, the displacement of the counterweight blocks on each counterweight adjustment mechanism is calculated, and different priorities are assigned to different counterweight adjustment mechanisms. Different control signals are output to the corresponding counterweight motors to make them work and drive the counterweight blocks to move on the bearing platform, thereby changing the center of gravity position.

[0062] Let the mass of the counterweight be m, and the distance the counterweight moves be s. i , where s i This represents the displacement (unit vector) of the counterweight block about the center of the counterweight adjustment mechanism, along the horizontal line connecting the center of the counterweight adjustment mechanism and the geometric center of the moving platform. in Moving towards the geometric center of the moving platform is negative, and moving in the opposite direction is positive, i = 1, 2, 3, 4, and the movements of the four counterweights do not interfere with each other. The maximum displacement distance of the counterweights is s. max That is, the displacement range of the counterweight is [-s max ,s max ].

[0063] The goal of the center of mass balancing is to adjust s1, s2, s3, and s4 so that the center of mass of the Mecanum wheel moving platform returns from its current position (x,y) to the geometric center (0,0) of the moving platform.

[0064] The key to the above principle of moving counterweight lies in utilizing the center of mass equilibrium equation. Let the current center of mass position be (x, y), and the mass of the Mecanum wheel moving platform excluding the counterweight be M, satisfying the center of mass equation:

[0065]

[0066] Based on the positions of the four counterweights and the equation of their center of mass, we obtain the following set of equations for the displacement of the counterweights:

[0067]

[0068] The displacement of the counterweight is obtained by solving the minimum norm solution:

[0069]

[0070] Based on the equations for the counterweight displacement, the dynamic regression equation for the platform's center of mass can be obtained:

[0071]

[0072] When x = 0 and y = 0, s i =0, the counterweight does not move; when x>0, the right counterweight (s1,s4>0) moves inward and the left counterweight (s2,s3>0) moves outward; the calibration coefficient can be adjusted according to the actual operating conditions to adapt to the system.

[0073] The counterweight displacement can be achieved by using an optimal algorithm (designed separately and not within the scope of this invention) to adjust the movement of the four moving counterweights appropriately, thereby improving the movement efficiency and reducing the impact caused by the movement of the counterweights.

[0074] Based on the calculated movement distance of the counterweight, the counterweight motor rotates, driving the lead screw to rotate and thus moving the counterweight. Let the lead screw lead be P, the step angle of the drive motor be α, and the microstepping factor of the servo driver be N. The rotation angle of the drive motor is then calculated as follows: The number of control steps for the servo driver is

[0075] Figure 6 , 7 This is a schematic diagram showing the working status of each counterweight adjustment mechanism before and after the center of mass position adjustment in this embodiment.

[0076] The Mecanum wheel mobile platform proposed in this invention is not limited to a four-wheeled Mecanum wheel system, but can also be any Mecanum wheel system capable of omnidirectional movement, including 6 or 8 Mecanum wheel mechanisms. The counterweight adjustment system is configured with multiple counterweight adjustment mechanisms, which are equivalent to the number of Mecanum wheel mechanisms. The multiple counterweight adjustment mechanisms are correspondingly set on the bearing platform above the corresponding Mecanum wheel mechanism. The center of each counterweight adjustment mechanism coincides vertically with the center of the corresponding Mecanum wheel, and one end of each counterweight adjustment mechanism faces the geometric center of the mobile platform, thereby positioning each counterweight adjustment mechanism.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A Mecanum wheel mobile platform capable of self-adapting to balance the center of mass, characterized in that, The application relates to a mobile platform, which comprises a bearing platform, a Mecanum wheel system, a counterweight adjusting system and a controller, the Mecanum wheel system comprises a plurality of Mecanum wheel mechanisms which are symmetrically arranged below the bearing platform, the counterweight adjusting system comprises a plurality of counterweight adjusting mechanisms which are evenly arranged above the bearing platform, and the controller is arranged on the bearing platform and electrically connected with each Mecanum wheel mechanism and counterweight adjusting mechanism, so that the rotating speed of each Mecanum wheel is dynamically adjusted by controlling the current output, and the position of the counterweight on the bearing platform is adjusted by controlling the current signal of each counterweight adjusting mechanism, so that the center of mass of the whole Mecanum wheel mobile platform is adaptively balanced. The Mecanum wheel system comprises four Mecanum wheel mechanisms which are symmetrically arranged and distributed at left front, right front, left rear and right rear positions below the bearing platform, and the counterweight adjusting system comprises four counterweight adjusting mechanisms which are correspondingly arranged on the bearing platform above the corresponding Mecanum wheel mechanisms, the center of each counterweight adjusting mechanism is vertically coincident with the center of the corresponding Mecanum wheel, and one end of each counterweight adjusting mechanism is directed to the geometric center of the mobile platform, so that each counterweight adjusting mechanism is positioned.

2. The Mecanum wheel mobile platform capable of self-adaptive balance of center of mass according to claim 1, characterized in that, The Mecanum wheel mechanism comprises a servo driver, a driving motor, a first coupling, a speed reducer and a Mecanum wheel, the servo driver and the driving motor are arranged below the bearing platform through a suspension mechanism, the output shaft of the driving motor is connected with the speed reducer through the first coupling, and the speed reducer is connected with the Mecanum wheel to drive the Mecanum wheel to rotate. The controller is electrically connected with the servo driver and the driving motor, so that the current value is adjusted in real time according to the rotating speed of the Mecanum wheel, and the corresponding current signal is output to the driving motor to control the rotation of the driving motor, and the output current signal is sampled.

3. The Mecanum wheel mobile platform capable of self-adaptive balance of center of mass according to claim 1, characterized in that, The counterweight adjusting mechanism comprises a base, a slide rail, a counterweight motor, a second coupling, a screw rod and a counterweight block, the base is fixedly arranged above the bearing platform, the counterweight motor is fixedly arranged on the bearing platform, the output shaft of the counterweight motor is fixedly connected with the horizontally arranged screw rod through the second coupling to drive the screw rod to rotate, the slide rail is arranged in parallel with the screw rod and fixedly connected with the bearing platform, and the counterweight block is screw-connected with the screw rod and slidingly connected with the slide rail, so that the rotating motion of the screw rod is converted into the horizontal linear motion of the counterweight block; and the controller is electrically connected with the counterweight motor to control the rotation of the counterweight motor and change the position of the counterweight block on the bearing platform.

4. The Mecanum wheel mobile platform capable of self-adaptive balance of center of mass according to claim 3, characterized in that, The counterweight adjusting mechanism comprises two slide rails which are arranged in parallel on the left and right sides of the screw rod and fixedly connected with the bearing platform, and the counterweight block is slidingly connected with the two slide rails; the counterweight adjusting mechanism further comprises two bearing seats which are fixedly arranged on the front and rear sides of the base, and the front and rear ends of the screw rod are rotatably connected with the base through the bearing seats, and the front and rear ends of the two slide rails are fixedly connected with the bearing seats.

5. The omni-directional mobile platform of claim 1, wherein, The counterweight motor on the Mecanum wheel mechanism is arranged at one end close to the geometric center of the mobile platform.

6. The omni-directional mobile platform of claim 1, wherein, The control logic in the working process of the Mecanum wheel mobile platform is as follows: S1, when the Mecanum wheel mobile platform starts to work, first, system initialization is performed; then, the controller outputs corresponding current signals to the driving motors through the servo drivers according to the speed control requirements, so that each Mecanum wheel rotates at a set speed; S2, when the Mecanum wheel mobile platform is unevenly loaded, the controller detects that the speed of each Mecanum wheel does not meet the set speed control requirements, that is, the controller controls each servo driver to generate current signals of different sizes to the corresponding driving motors, so as to generate different driving forces, so that each Mecanum wheel can still rotate at a set speed; at the same time, the controller samples the output current signals; S3, the controller calculates the current center of mass position of the Mecanum wheel mobile platform based on the relationship between the current of the driving motor and the load according to all the sampled current signals; S4, the controller calculates the displacement of the counterweight block on each counterweight adjusting mechanism according to the current center of mass position, and ensures that the counterweight block on each counterweight adjusting mechanism does not exceed the maximum displacement range, with the goal of balancing the center of mass position of the entire Mecanum wheel mobile platform; S5, the controller converts the calculated displacement of the counterweight block on each counterweight adjusting mechanism into the control steps of the counterweight motor on each counterweight adjusting mechanism, and controls the corresponding counterweight motor to work, driving each counterweight block to move to the set position; S6, the controller updates the center of mass position and adjusts the output current value in real time according to the updated center of mass position, and then outputs corresponding current signals to the driving motor through the servo driver to drive each Mecanum wheel to rotate; S7, the controller detects whether the speed of each Mecanum wheel meets the set speed control requirements, if yes, the adaptive center of mass balancing is completed, otherwise, returns to step S2, controls each servo driver to generate current signals of different sizes to the corresponding driving motor, to generate different driving forces, and samples the current signals at the same time, and continues to execute steps S3-S6, until the center of mass balancing of the Mecanum wheel mobile platform is realized.

7. The Mecanum wheel mobile platform capable of self-adapting balance of center of mass according to claim 6, characterized in that, The relationship between the current of the driving motor and the load is as follows: The driving motor is a DC motor, and the basic equation of the DC motor includes: Voltage equation: Torque equation: wherein U is the motor voltage, I is the motor current, R is the armature resistance, K is the back EMF constant, n is the motor speed, T is the motor output torque, Kt is the torque constant; the motor output power is converted to output mechanical power via the motor efficiency ηm, the motor output torque is reduced by the reducer and amplified to wherein i is the reduction ratio, ηr is the reducer efficiency; The friction torque of the Mecanum wheel is determined by the friction coefficient , the load , and the wheel radius , and the friction torque ; the output torque of the reducer after deceleration is equal to the friction torque of the Mecanum wheel movement, so there is ; by combining the motor torque equation, the current and load relationship is obtained: Further considering motor efficiency The relationship between current and load is obtained as: When the load is less than the critical load, the current and the load satisfy the above formula, and the rotating speed linearly decreases with the increase of the load; when the load is equal to the critical load, the rotating speed is ; when the load is greater than the critical load, the motor will stall and an accident will occur. According to the relationship between the current and the load, the current values of the four Mecanum wheels are used to calculate the current center of mass position of the Mecanum wheel mobile platform; specifically: The four Mecanum wheels are symmetrically distributed in a rectangle, and the wheel track is , and the wheelbase is . A coordinate system is established with the geometric center of the moving platform as the coordinate origin. The position coordinates of the four Mecanum wheels are respectively represented as (a1, b1), (a2, b2), (a3, b3) and (a4, b4), wherein (a1, b1) = (a, b), (a2, b2) = (-a, b), (a3, b3) = (-a, -b) and (a4, b4) = (a, -b). The vertical force balance equation, the torque balance equation around the x-axis and the torque balance equation around the y-axis in the statics balance equation are as follows: The coordinates (x, y) of the center of mass position can be obtained by simultaneously solving the relationship between the current and the load: Wherein, F n1 , F n2 , F n3 , F n4 Respectively, the single wheel bearing capacity of the four Mecanum wheels, F n1 +F n2 +F n3 +F n4 =F n , I1, I2, I3, I4 respectively indicate the drive motor current of the four Mecanum wheels.

8. The omni-directional mobile platform of claim 7, wherein, Based on the calculated current center of mass position, the displacement of the counterweight block on each counterweight adjusting mechanism is calculated, and different priorities are given to different counterweight adjusting mechanisms, different control signals are output to the corresponding counterweight motor, so that the counterweight motor works and drives the counterweight block to move on the loading platform, thereby changing the center of mass position; Let the mass of the counterweight be , and the moving distance of the counterweight be , where represents the displacement of the counterweight along the horizontal line connecting the center of the counterweight adjustment mechanism and the geometric center of the moving platform, with the negative direction being towards the geometric center of the moving platform and the positive direction being in the opposite direction, i=1,2,3,4, and the movements of the four counterweights do not interfere with each other, and the maximum displacement distance of the counterweight is , that is, the displacement range of the counterweight is , ; the target of the center of mass balance is to return the center of mass of the Mecanum wheel moving platform from the current center of mass position , , , to the geometric center (0,0) of the moving platform by adjusting . Let the current centroid position be , the Mecanum wheel mobile platform except the mass of the counterweight is , satisfy the centroid equation: According to the positions of the four counterweight blocks and the center of mass equation, the counterweight displacement equation set is obtained: The counterweight displacement is obtained by the minimum norm solution: According to the counterweight displacement equation set, the dynamic regression equation of the platform center of mass is obtained: According to the calculated moving distance of the counterweight, the lead screw is rotated by the counterweight motor to move the counterweight; the lead of the lead screw is , the step angle of the driving motor is , the micro-step subdivision multiple of the servo driver is , the rotation angle of the driving motor is , and the control step number of the servo driver is .

9. The omni-directional mobile platform of claim 1, wherein, The Mecanum wheel system is all Mecanum wheel systems capable of achieving omnidirectional movement, including 6 Mecanum wheel mechanisms or 8 Mecanum wheel mechanisms, the counterweight adjusting system is configured with a plurality of counterweight adjusting mechanisms corresponding to the number of Mecanum wheel mechanisms, the plurality of counterweight adjusting mechanisms are arranged on the load-carrying platform above the corresponding Mecanum wheel mechanisms, the center of each counterweight adjusting mechanism is vertically coincident with the center of the corresponding Mecanum wheel, and one end of each counterweight adjusting mechanism is directed towards the geometric center of the mobile platform, thereby positioning each counterweight adjusting mechanism.

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