Omnidirectional mobile robot driven by both conventional wheels and omnidirectional wheels and control method thereof

Abstract

A omnidirectional mobile robot driven by both conventional and omnidirectional wheels and a control method are disclosed. The robot comprises two omnidirectional wheels and two conventional wheels, arranged diagonally across the wheels. Each wheel is equipped with a motor, and no steering servo is provided. A coupling reversing mechanism is provided between the four wheels. The wheels are connected to the vehicle frame by a vertical axis, and an angle sensor is provided between the vertical axis and the vehicle frame. The control method is as follows: When the robot is omnidirectionally translating, an omnidirectional translation solution formula is established. The robot's translation speed and the wheel deflection angle corresponding to the translation direction are input. Based on the solution, the four motors are controlled to rotate the wheels, achieving omnidirectional translation. When the robot is spinning, a spin solution formula is established. The torque output of the left front omnidirectional wheel is controlled to maintain the wheel deflection angle corresponding to the robot's spin. The robot's rotational angular velocity is then input. Based on the solution, the four motors are controlled to rotate the wheels, achieving spin.

Description

Technical Field

[0001] The present invention belongs to the technical field of omnidirectional mobile robots, and in particular relates to an omnidirectional mobile robot jointly driven by ordinary wheels and omnidirectional wheels, and a control method thereof. Background Art

[0002] In recent years, with the development and progress of intelligent manufacturing and industrial logistics, research on wheeled mobile robots has become increasingly in-depth. As a typical representative of these robots, omnidirectional wheeled mobile robots have the advantages of flexible steering and high maneuverability. They are very suitable for working in limited and narrow spaces, and are widely used in various fields such as transportation, patrolling, and medical care.

[0003] However, in existing omnidirectional mobile robots, each wheel usually needs to be equipped with a drive motor and a steering servo. Only through the cooperation of the drive motor and the steering servo can the robot achieve omnidirectional movement. This design will inevitably lead to an increase in power consumption and will also increase the difficulty of controlling the robot system. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides an omnidirectional mobile robot and a control method that are jointly driven by ordinary wheels and omnidirectional wheels. Each wheel only needs to be equipped with one motor, and no steering servo is required to achieve omnidirectional movement of the robot. At the same time, it has the advantage of taking up little space, which can effectively reduce power consumption and the control difficulty of the robot system.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an omnidirectional mobile robot driven by ordinary wheels and omnidirectional wheels, comprising a vehicle body, a left front omnidirectional wheel, a right front ordinary wheel, a right rear omnidirectional wheel, a left rear ordinary wheel, a left front drive motor, a right front drive motor, a right rear drive motor, a left rear drive motor, an angle sensor, a coupling reversing mechanism and a PID controller; a left front bearing seat is fixedly provided at the left front end of the vehicle body, a left front vertical rotating shaft is installed in the left front bearing seat, and a left front motor seat is fixedly installed at the bottom of the left front vertical rotating shaft ; The left front drive motor is fixedly mounted on the left front motor seat horizontally, and the left front omnidirectional wheel is coaxially fixed to the motor shaft of the left front drive motor; a right front bearing seat is fixedly provided on the right front end of the vehicle body, a right front vertical rotating shaft is passed through the right front bearing seat, and a right front motor seat is fixedly mounted on the bottom of the right front vertical rotating shaft; the right front drive motor is fixedly mounted on the right front motor seat horizontally, and the right front ordinary wheel is coaxially fixed to the motor shaft of the right front drive motor; a right rear bearing seat is fixedly provided on the right rear end of the vehicle body, and a right rear The vertical rotating shaft has a right rear motor seat fixedly installed at the bottom of the right rear vertical rotating shaft; the right rear drive motor is fixedly installed on the right rear motor seat horizontally, and the right rear omnidirectional wheel is coaxially fixed to the motor shaft of the right rear drive motor; a left rear bearing seat is fixedly provided on the left rear end of the vehicle body, a left rear vertical rotating shaft is passed through the left rear bearing seat, and the left rear motor seat is fixedly installed at the bottom of the left rear vertical rotating shaft; the left rear drive motor is fixedly installed on the left rear motor seat horizontally, and the left rear ordinary wheel is coaxially fixed to the motor shaft of the left rear drive motor; the left front vertical rotating shaft The shaft, right front vertical shaft, right rear vertical shaft and left rear vertical shaft are all connected to the coupling reversing mechanism; the angle sensor is fixedly installed on the vehicle body through a sensor bracket, and the measuring end of the angle sensor is coaxially fixed with the left front vertical shaft, right front vertical shaft, right rear vertical shaft or left rear vertical shaft; the wheel diameters of the left front omnidirectional wheel, right front ordinary wheel, right rear omnidirectional wheel and left rear ordinary wheel are equal; the left front drive motor, right front drive motor, right rear drive motor, left rear drive motor and the angle sensor are all electrically connected to the PID controller.

[0006] When the robot is in an initial state, the left front omnidirectional wheel and the right front ordinary wheel are both facing the outside of the vehicle body, and the right rear omnidirectional wheel and the left rear ordinary wheel are both facing the inside of the vehicle body.

[0007] The vehicle body adopts a split structure, including a front vehicle body and a rear vehicle body; a front lower bearing seat is fixedly provided at the bottom of the front vehicle body; a positioning seat is fixedly provided at the bottom of the rear vehicle body; a horizontal rotating shaft is provided between the front lower bearing seat and the positioning seat, the front end of the horizontal rotating shaft is inserted into the front lower bearing seat, and the rear end of the horizontal rotating shaft is fixedly connected to the positioning seat.

[0008] The coupling reversing mechanism includes a rectangular connecting rod frame, a left front crank, a right front crank, a right rear crank and a left rear crank; one end of the left front crank is fixedly connected to the left front vertical rotating shaft, and the other end of the left front crank is connected to the left front end of the rectangular connecting rod frame; one end of the right front crank is fixedly connected to the right front vertical rotating shaft, and the other end of the right front crank is connected to the right front end of the rectangular connecting rod frame; one end of the right rear crank is fixedly connected to the right rear vertical rotating shaft, and the other end of the right rear crank is connected to the right rear end of the rectangular connecting rod frame; one end of the left rear crank is fixedly connected to the left rear vertical rotating shaft, and the other end of the left rear crank is connected to the left rear end of the rectangular connecting rod frame; the left front crank, right front crank, right rear crank and left rear crank are equal in length and exactly the same in orientation.

[0009] A bearing is built into the other end of the left front crank, and a left front vertical bolt is installed in the bearing. The screw rod of the left front vertical bolt passes through the rectangular connecting rod frame and extends to the top of the rectangular connecting rod frame, and a left front limiting nut is installed on the top of the screw rod of the left front vertical bolt; a left front shock absorber spring is mounted on the screw rod of the left front vertical bolt between the rectangular connecting rod frame and the left front crank.

[0010] A bearing is built into the other end of the right front crank, and a right front vertical bolt is installed in the bearing. The screw of the right front vertical bolt passes through the rectangular connecting rod frame and extends to the top of the rectangular connecting rod frame, and a right front limiting nut is installed on the top of the screw of the right front vertical bolt; a right front shock-absorbing spring is mounted on the screw of the right front vertical bolt between the rectangular connecting rod frame and the right front crank.

[0011] A bearing is built into the other end of the right rear crank, and a right rear vertical bolt is installed in the bearing. The screw rod of the right rear vertical bolt passes through the rectangular connecting rod frame and extends to the top of the rectangular connecting rod frame, and a right rear limiting nut is installed on the top of the screw rod of the right rear vertical bolt; a right rear shock absorber spring is mounted on the screw rod of the right rear vertical bolt between the rectangular connecting rod frame and the right rear crank.

[0012] A bearing is built into the other end of the left rear crank, and a left rear vertical bolt is installed in the bearing. The screw rod of the left rear vertical bolt passes through the rectangular connecting rod frame and extends to the top of the rectangular connecting rod frame, and a left rear limiting nut is installed on the top of the screw rod of the left rear vertical bolt; a left rear shock absorber spring is mounted on the screw rod of the left rear vertical bolt between the rectangular connecting rod frame and the left rear crank.

[0013] A control method for an omnidirectional mobile robot driven by a combination of conventional wheels and omnidirectional wheels. When the robot needs to translate in all directions, the omnidirectional translation solution is first established, as follows:

[0014]

[0015] Where ω1 is the angular velocity of the left front omnidirectional wheel, ω2 is the angular velocity of the right front ordinary wheel, ω3 is the angular velocity of the right rear omnidirectional wheel, ω4 is the angular velocity of the left rear ordinary wheel, r is the wheel radius of the left front omnidirectional wheel, the right front ordinary wheel, the right rear omnidirectional wheel and the left rear ordinary wheel, b is the length of the left front crank, the right front crank, the right rear crank and the left rear crank, v is the translation speed of the robot, θ is the wheel deflection angle corresponding to the translation direction of the robot, and t is the time;

[0016] Then, according to the established omnidirectional translation solution formula, the robot translation speed v and the wheel deflection angle θ corresponding to the robot's translation direction are input into the PID controller. After automatically solving the omnidirectional translation solution formula, the required rotational angular velocity of the four wheels will be obtained. Then, the four drive motors respectively drive the corresponding four wheels to rotate according to the rotational angular velocity obtained by the solution, thereby realizing the omnidirectional translation of the robot. During the omnidirectional translation process of the robot, the wheel deflection angle θ corresponding to the robot's translation direction is detected and fed back through the angle sensor.

[0017] A control method for an omnidirectional mobile robot driven by a combination of conventional wheels and omnidirectional wheels. When the robot needs to spin, a spin motion solution formula is first established, as follows:

[0018]

[0019] Wherein, ω1 is the angular velocity of the left front omnidirectional wheel, ω2 is the angular velocity of the right front ordinary wheel, ω3 is the angular velocity of the right rear omnidirectional wheel, ω4 is the angular velocity of the left rear ordinary wheel, r is the wheel radius of the left front omnidirectional wheel, the right front ordinary wheel, the right rear omnidirectional wheel and the left rear ordinary wheel, σ1 is the angle between the combined wheel velocity of the left front omnidirectional wheel and the wheel disc surface, σ2 is the angle between the combined wheel velocity of the right front ordinary wheel and the wheel disc surface, σ3 is the angle between the combined wheel velocity of the right rear omnidirectional wheel and the wheel disc surface, σ4 is the angle between the combined wheel velocity of the left rear ordinary wheel and the wheel disc surface, l1 is the distance between the left front omnidirectional wheel and the robot's rotation center, l2 is the distance between the right front ordinary wheel and the robot's rotation center, l3 is the distance between the right rear omnidirectional wheel and the robot's rotation center, l4 is the distance between the left rear ordinary wheel and the robot's rotation center, and ω is the robot's rotation angular velocity;

[0020] Then the left front drive motor is controlled to make the left front omnidirectional wheel output torque to maintain the wheel deflection angle θ corresponding to the robot's spin process. rAt the same time, according to the established spin motion solution formula, the robot's rotation angular velocity ω is input into the PID controller. After automatically solving the spin motion solution formula, the required rotation angular velocity of the four wheels will be obtained. Then, the four drive motors respectively drive the corresponding four wheels to rotate according to the rotation angular velocity obtained by the solution to realize the robot's spin motion. During the robot's spin motion, the deflection angle θ of the wheel corresponding to the robot's spin process is maintained. r Detection and feedback are performed through angle sensors.

[0021] Beneficial effects of the present invention:

[0022] The omnidirectional mobile robot and control method jointly driven by ordinary wheels and omnidirectional wheels of the present invention only need to be equipped with one motor for each wheel, and no steering servo is required to achieve omnidirectional movement of the robot. At the same time, it has the advantage of taking up little space, which can effectively reduce power consumption and the control difficulty of the robot system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A perspective view of an omnidirectional mobile robot driven jointly by ordinary wheels and omnidirectional wheels (the wheels are in an initial state) according to the present invention;

[0024] Figure 2 A perspective view of an omnidirectional mobile robot driven jointly by ordinary wheels and omnidirectional wheels (with the wheels in a deflected state) according to the present invention;

[0025] Figure 3 This is a side view of the omnidirectional mobile robot (with the wheels in the initial state) driven by a combination of ordinary wheels and omnidirectional wheels according to the present invention;

[0026] Figure 4 This is a block diagram of the speed control principle of the omnidirectional mobile robot driven by both ordinary wheels and omnidirectional wheels under omnidirectional translation;

[0027] Figure 5 A schematic diagram of the speed / force control principle of the omnidirectional mobile robot driven jointly by ordinary wheels and omnidirectional wheels during spin motion according to the present invention;

[0028] Figure 6 This is a schematic diagram of the omnidirectional translation principle of the omnidirectional mobile robot driven jointly by ordinary wheels and omnidirectional wheels of the present invention;

[0029] Figure 7 This is a schematic diagram of the spinning motion principle of the omnidirectional mobile robot driven jointly by ordinary wheels and omnidirectional wheels of the present invention;

[0030] In the figure, 1—left front omnidirectional wheel, 2—right front ordinary wheel, 3—right rear omnidirectional wheel, 4—left rear ordinary wheel, 5—left front drive motor, 6—right front drive motor, 7—right rear drive motor, 8—left rear drive motor, 9—angle sensor, 10—left front bearing seat, 11—left front vertical shaft, 12—left front motor seat, 13—right front bearing seat, 14—right front vertical shaft, 15—right front motor seat, 16—right rear bearing seat, 17—right rear vertical shaft, 18—right rear motor seat, 19—left rear bearing seat, 20—left rear vertical shaft, 21—left rear motor seat, 22—front body, 2 3—rear body, 24—front lower bearing seat, 25—locating seat, 26—horizontal rotating shaft, 27—rectangular connecting rod frame, 28—left front crank, 29—right front crank, 30—right rear crank, 31—left rear crank, 32—left front vertical bolt, 33—left front limiting nut, 34—left front shock absorber spring, 35—right front vertical bolt, 36—right front limiting nut, 37—right front shock absorber spring, 38—right rear vertical bolt, 39—right rear limiting nut, 40—right rear shock absorber spring, 41—left rear vertical bolt, 42—left rear limiting nut, 43—left rear shock absorber spring, 44—sensor bracket. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figures 1 to 3As shown, an omnidirectional mobile robot driven by a combination of ordinary wheels and omnidirectional wheels includes a vehicle body, a left front omnidirectional wheel 1, a right front ordinary wheel 2, a right rear omnidirectional wheel 3, a left rear ordinary wheel 4, a left front drive motor 5, a right front drive motor 6, a right rear drive motor 7, a left rear drive motor 8, an angle sensor 9, a coupling reversing mechanism and a PID controller; a left front bearing seat 10 is fixedly provided at the left front end of the vehicle body, a left front vertical shaft 11 is passed through the left front bearing seat 10, and a left front motor seat 12 is fixedly installed at the bottom of the left front vertical shaft 11; the left front drive motor 5 is fixedly mounted on the left front motor seat 12; On the seat 12, the left front omnidirectional wheel 1 is coaxially fixed to the motor shaft of the left front drive motor 5; a right front bearing seat 13 is fixedly provided at the right front end of the vehicle body, a right front vertical rotating shaft 14 is passed through the right front bearing seat 13, and a right front motor seat 15 is fixedly installed at the bottom of the right front vertical rotating shaft 14; the right front drive motor 6 is horizontally fixed on the right front motor seat 15, and the right front ordinary wheel 2 is coaxially fixed to the motor shaft of the right front drive motor 6; a right rear bearing seat 16 is fixedly provided at the right rear end of the vehicle body, a right rear vertical rotating shaft 17 is passed through the right rear bearing seat 16, and a right rear vertical rotating shaft 17 is fixedly installed at the right rear vertical rotating shaft 1 7 is fixedly installed with a right rear motor seat 18 at the bottom; the right rear drive motor 7 is horizontally fixedly mounted on the right rear motor seat 18, and the right rear omnidirectional wheel 3 is coaxially fixedly connected to the motor shaft of the right rear drive motor 7; a left rear bearing seat 19 is fixedly provided at the left rear end of the vehicle body, a left rear vertical rotating shaft 20 is passed through the left rear bearing seat 19, and a left rear motor seat 21 is fixedly installed at the bottom of the left rear vertical rotating shaft 20; the left rear drive motor 8 is horizontally fixedly mounted on the left rear motor seat 21, and the left rear ordinary wheel 4 is coaxially fixedly connected to the motor shaft of the left rear drive motor 8; the left front vertical rotating shaft 11 and the right front vertical rotating shaft The shaft 14, the right rear vertical shaft 17 and the left rear vertical shaft 20 are all connected to the coupling reversing mechanism; the angle sensor 9 is fixedly mounted on the vehicle body through the sensor bracket 44, and the measuring end of the angle sensor 9 is coaxially fixedly connected to the left front vertical shaft 11, the right front vertical shaft 14, the right rear vertical shaft 17 or the left rear vertical shaft 20; the wheel diameters of the left front omnidirectional wheel 1, the right front ordinary wheel 2, the right rear omnidirectional wheel 3 and the left rear ordinary wheel 4 are equal; the left front drive motor 5, the right front drive motor 6, the right rear drive motor 7, the left rear drive motor 8 and the angle sensor 9 are all electrically connected to the PID controller.

[0033] When the robot is in an initial state, the left front omnidirectional wheel 1 and the right front ordinary wheel 2 are both facing the outside of the vehicle body, and the right rear omnidirectional wheel 3 and the left rear ordinary wheel 4 are both facing the inside of the vehicle body.

[0034] The robot body is a split structure, comprising a front body 22 and a rear body 23. A front lower bearing seat 24 is fixedly mounted on the bottom of the front body 22, while a positioning seat 25 is fixedly mounted on the bottom of the rear body 23. A horizontal shaft 26 is disposed between the front lower bearing seat 24 and the positioning seat 25. The front end of the shaft 26 is inserted into the front lower bearing seat 24, while the rear end is fixedly connected to the positioning seat 25. When the robot traverses uneven terrain, relative rotation between the front and rear bodies 22, 23 is generated, ensuring that all four wheels maintain contact with the ground, preventing any wheel from becoming suspended and spinning.

[0035] The coupling reversing mechanism includes a rectangular connecting rod frame 27, a left front crank 28, a right front crank 29, a right rear crank 30 and a left rear crank 31; one end of the left front crank 28 is fixedly connected to the left front vertical rotating shaft 11, and the other end of the left front crank 28 is connected to the left front end of the rectangular connecting rod frame 27; one end of the right front crank 29 is fixedly connected to the right front vertical rotating shaft 14, and the other end of the right front crank 29 is connected to the right front end of the rectangular connecting rod frame 27; one end of the right rear crank 30 is fixedly connected to the right rear vertical rotating shaft 17, and the other end of the right rear crank 30 is connected to the right rear end of the rectangular connecting rod frame 27; one end of the left rear crank 31 is fixedly connected to the left rear vertical rotating shaft 20, and the other end of the left rear crank 31 is connected to the left rear end of the rectangular connecting rod frame 27; the left front crank 28, the right front crank 29, the right rear crank 30 and the left rear crank 31 are equal in length and have exactly the same orientation.

[0036] A bearing is built into the other end of the left front crank 28, and a left front vertical bolt 32 is installed in the bearing. The screw of the left front vertical bolt 32 passes through the rectangular connecting rod frame 27 and extends to the top of the rectangular connecting rod frame 27, and a left front limiting nut 33 is installed on the top of the screw of the left front vertical bolt 32; a left front shock-absorbing spring 34 is mounted on the screw of the left front vertical bolt 32 between the rectangular connecting rod frame 27 and the left front crank 28.

[0037] A bearing is built into the other end of the right front crank 29, and a right front vertical bolt 35 is installed in the bearing. The screw of the right front vertical bolt 35 passes through the rectangular connecting rod frame 27 and extends to the top of the rectangular connecting rod frame 27, and a right front limiting nut 36 is installed on the top of the screw of the right front vertical bolt 35; a right front shock-absorbing spring 37 is mounted on the screw of the right front vertical bolt 35 between the rectangular connecting rod frame 27 and the right front crank 29.

[0038] A bearing is built into the other end of the right rear crank 30, and a right rear vertical bolt 38 is installed in the bearing. The screw of the right rear vertical bolt 38 passes through the rectangular connecting rod frame 27 and extends to the top of the rectangular connecting rod frame 27, and a right rear limit nut 39 is installed on the top of the screw of the right rear vertical bolt 38; a right rear shock absorber spring 40 is mounted on the screw of the right rear vertical bolt 38 between the rectangular connecting rod frame 27 and the right rear crank 30.

[0039] A bearing is built into the other end of the left rear crank 31, and a left rear vertical bolt 41 is installed in the bearing. The screw of the left rear vertical bolt 41 passes through the rectangular connecting rod frame 27 and extends to the top of the rectangular connecting rod frame 27, and a left rear limiting nut 42 is installed on the top of the screw of the left rear vertical bolt 41; a left rear shock-absorbing spring 43 is mounted on the screw of the left rear vertical bolt 41 between the rectangular connecting rod frame 27 and the left rear crank 31.

[0040] A control method for an omnidirectional mobile robot driven by a combination of conventional wheels and omnidirectional wheels. When the robot needs to translate in all directions, the omnidirectional translation solution is first established, as follows:

[0041]

[0042] Wherein, ω1 is the rotation angular velocity of the left front omnidirectional wheel 1, ω2 is the rotation angular velocity of the right front ordinary wheel 2, ω3 is the rotation angular velocity of the right rear omnidirectional wheel 3, ω4 is the rotation angular velocity of the left rear ordinary wheel 4, r is the wheel radius of the left front omnidirectional wheel 1, the right front ordinary wheel 2, the right rear omnidirectional wheel 3 and the left rear ordinary wheel 4, b is the length of the left front crank 28, the right front crank 29, the right rear crank 30 and the left rear crank 31, v is the translation velocity of the robot, θ is the wheel deflection angle corresponding to the translation direction of the robot, and t is time;

[0043] Then, according to the established omnidirectional translation solution formula, the robot translation speed v and the wheel deflection angle θ corresponding to the robot translation direction are input into the PID controller. After automatically solving the omnidirectional translation solution formula, the required rotational angular velocity of the four wheels will be obtained, and then the four drive motors will respectively drive the corresponding four wheels to rotate according to the rotational angular velocity obtained by the solution to realize the omnidirectional translation of the robot. During the omnidirectional translation process of the robot, the wheel deflection angle θ corresponding to the robot translation direction is detected and fed back through the angle sensor 9.

[0044] A control method for an omnidirectional mobile robot driven by a combination of conventional wheels and omnidirectional wheels. When the robot needs to spin, a spin motion solution formula is first established, as follows:

[0045]

[0046] Wherein, ω1 is the angular velocity of the left front omnidirectional wheel 1, ω2 is the angular velocity of the right front ordinary wheel 2, ω3 is the angular velocity of the right rear omnidirectional wheel 3, ω4 is the angular velocity of the left rear ordinary wheel 4, r is the wheel radius of the left front omnidirectional wheel 1, the right front ordinary wheel 2, the right rear omnidirectional wheel 3 and the left rear ordinary wheel 4, σ1 is the angle between the combined wheel velocity of the left front omnidirectional wheel 1 and the wheel disc surface, σ2 is the angle between the combined wheel velocity of the right front ordinary wheel 2 and the wheel disc surface, σ3 is the angle between the combined wheel velocity of the right rear omnidirectional wheel 3 and the wheel disc surface, σ4 is the angle between the combined wheel velocity of the left rear ordinary wheel 4 and the wheel disc surface, l1 is the distance between the left front omnidirectional wheel 1 and the robot's rotation center, l2 is the distance between the right front ordinary wheel 2 and the robot's rotation center, l3 is the distance between the right rear omnidirectional wheel 3 and the robot's rotation center, l4 is the distance between the left rear ordinary wheel 4 and the robot's rotation center, and ω is the robot's rotation angular velocity;

[0047] Then the left front drive motor 5 is controlled to make the left front omnidirectional wheel 1 output torque to maintain the wheel deflection angle θ corresponding to the robot's spin process. r At the same time, according to the established spin motion solution formula, the robot's rotation angular velocity ω is input into the PID controller. After automatically solving the spin motion solution formula, the required rotation angular velocity of the four wheels will be obtained. Then, the four drive motors respectively drive the corresponding four wheels to rotate according to the rotation angular velocity obtained by the solution to realize the robot's spin motion. During the robot's spin motion, the deflection angle θ of the wheel corresponding to the robot's spin process is maintained. r Detection and feedback are performed by the angle sensor 9 .

[0048] Specifically, the omnidirectional mobile robot has two motion modes: omnidirectional translation mode and rotation mode, and the two motion modes can be switched freely.

[0049] In the omnidirectional translation mode, the four wheels of the robot rely on the coupling reversing mechanism to achieve synchronous deflection in any direction. At the same time, by controlling the output speed of the four drive motors, the synchronous speed control of the four wheels is achieved. Then, the omnidirectional translation of the robot is achieved through the synchronous speed control of the four wheels. The speed control principle block diagram is shown in the figure below. Figure 4 shown.

[0050] like Figure 6 As shown in the figure, when the four wheels reach the desired speed, the friction force exerted by the ground on the four wheels will generate four torques M1, M2, M3, and M4 in the same direction, causing the wheels to rotate in the same direction and at the same angle θ. The angle can be controlled by feedback from the angle sensor 9, and the posture of the vehicle body remains unchanged during the wheel rotation. On this basis, by superimposing the same speed on all four wheels, the robot can achieve omnidirectional translation.

[0051] In the spinning motion mode, the four wheels of the robot also rely on the coupling reversing mechanism to achieve synchronous deflection in any direction, and at the same time control the output torque τ of the left front drive motor 5 r , which causes the left front omnidirectional wheel 1 to output torque τ1 to maintain the corresponding wheel deflection angle θ during the robot's spin process r The speed of the other three wheels of the robot is controlled by the drive motor to make the wheels output speed, and finally the robot's spinning motion is achieved under the speed / force control of the four wheels. The speed / force control principle block diagram is shown in the figure. Figure 5 shown.

[0052] like Figure 7 As shown, since the axes of the right front ordinary wheel 2 and the left rear ordinary wheel 4 are collinear, the corresponding wheel deflection angle is θ r , then intersect the normal of the left front omnidirectional wheel 1 with the coaxial line of the right front conventional wheel 2 and the left rear conventional wheel 4. This intersection is the robot's rotation center Q. Based on this, the output torque of the left front omnidirectional wheel 1 is controlled. Since the normal of the left front omnidirectional wheel 1 intersects the robot's rotation center Q, the hub of the left front omnidirectional wheel 1 does not rotate during the robot's spin. Only the roller of the left front omnidirectional wheel 1 undergoes passive rolling. Therefore, the output torque of the left front omnidirectional wheel 1 does not affect the overall spin of the robot. The robot's spin motion is achieved solely through differential rotation of the other three wheels.

[0053] The solutions in the embodiments are not intended to limit the patent protection scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention is included in the patent scope of this case.

Claims

1. An omnidirectional mobile robot driven by a combination of conventional wheels and omnidirectional wheels, characterized by: The foldable vehicle comprises a vehicle body, a left front omnidirectional wheel, a right front ordinary wheel, a right rear omnidirectional wheel, a left rear ordinary wheel, a left front drive motor, a right front drive motor, a right rear drive motor, a left rear drive motor, an angle sensor, a coupling reversing mechanism and a PID controller; a left front bearing seat is fixedly provided at the left front end of the vehicle body, a left front vertical rotating shaft is passed through the left front bearing seat, and a left front motor seat is fixedly installed at the bottom of the left front vertical rotating shaft; the left front drive motor is fixedly installed on the left front motor seat horizontally, and the left front omnidirectional wheel is coaxially fixedly connected to On the motor shaft of the left front drive motor; a right front bearing seat is fixedly provided at the right front end of the vehicle body, a right front vertical rotating shaft is passed through the right front bearing seat, and a right front motor seat is fixedly installed at the bottom of the right front vertical rotating shaft; the right front drive motor is fixedly mounted on the right front motor seat horizontally, and the right front ordinary wheel is coaxially fixedly connected to the motor shaft of the right front drive motor; a right rear bearing seat is fixedly provided at the right rear end of the vehicle body, a right rear vertical rotating shaft is passed through the right rear bearing seat, and a right rear motor is fixedly installed at the bottom of the right rear vertical rotating shaft. The right rear drive motor is fixedly mounted on the right rear motor seat horizontally, and the right rear omnidirectional wheel is coaxially fixed to the motor shaft of the right rear drive motor; a left rear bearing seat is fixedly provided on the left rear end of the vehicle body, a left rear vertical rotating shaft is passed through the left rear bearing seat, and a left rear motor seat is fixedly mounted on the bottom of the left rear vertical rotating shaft; the left rear drive motor is fixedly mounted on the left rear motor seat horizontally, and the left rear ordinary wheel is coaxially fixed to the motor shaft of the left rear drive motor; the left front vertical rotating shaft, the right front vertical rotating shaft, and the right rear The vertical rotating shaft and the left rear vertical rotating shaft are both connected to the coupling reversing mechanism; the angle sensor is fixedly mounted on the vehicle body via a sensor bracket, and the measuring end of the angle sensor is coaxially fixedly connected to the left front vertical rotating shaft, the right front vertical rotating shaft, the right rear vertical rotating shaft, or the left rear vertical rotating shaft; the wheel diameters of the left front omnidirectional wheel, the right front ordinary wheel, the right rear omnidirectional wheel, and the left rear ordinary wheel are equal; the left front drive motor, the right front drive motor, the right rear drive motor, the left rear drive motor, and the angle sensor are all electrically connected to a PID controller; When the robot is in the initial state, the left front omnidirectional wheel and the right front normal wheel are both facing the outside of the vehicle body, and the right rear omnidirectional wheel and the left rear normal wheel are both facing the inside of the vehicle body; The vehicle body adopts a split structure, including a front vehicle body and a rear vehicle body; a front lower bearing seat is fixedly provided at the bottom of the front vehicle body; a positioning seat is fixedly provided at the bottom of the rear vehicle body; a horizontal rotating shaft is provided between the front lower bearing seat and the positioning seat, the front end of the horizontal rotating shaft is inserted into the front lower bearing seat, and the rear end of the horizontal rotating shaft is fixedly connected to the positioning seat; The coupling reversing mechanism includes a rectangular connecting rod frame, a left front crank, a right front crank, a right rear crank and a left rear crank; one end of the left front crank is fixedly connected to the left front vertical rotating shaft, and the other end of the left front crank is connected to the left front end of the rectangular connecting rod frame; one end of the right front crank is fixedly connected to the right front vertical rotating shaft, and the other end of the right front crank is connected to the right front end of the rectangular connecting rod frame; one end of the right rear crank is fixedly connected to the right rear vertical rotating shaft, and the other end of the right rear crank is connected to the right rear end of the rectangular connecting rod frame; one end of the left rear crank is fixedly connected to the left rear vertical rotating shaft, and the other end of the left rear crank is connected to the left rear end of the rectangular connecting rod frame; the left front crank, right front crank, right rear crank and left rear crank are equal in length and face exactly the same direction; A bearing is built into the other end of the left front crank, and a left front vertical bolt is installed in the bearing. The screw rod of the left front vertical bolt passes through the rectangular connecting rod frame and extends to the top of the rectangular connecting rod frame, and a left front limiting nut is installed on the top of the screw rod of the left front vertical bolt; a left front shock absorber spring is mounted on the screw rod of the left front vertical bolt between the rectangular connecting rod frame and the left front crank.

2. The omnidirectional mobile robot driven by a combination of conventional wheels and omnidirectional wheels according to claim 1, characterized in that: A bearing is built into the other end of the right front crank, and a right front vertical bolt is installed in the bearing. The screw of the right front vertical bolt passes through the rectangular connecting rod frame and extends to the top of the rectangular connecting rod frame, and a right front limiting nut is installed on the top of the screw of the right front vertical bolt; a right front shock-absorbing spring is mounted on the screw of the right front vertical bolt between the rectangular connecting rod frame and the right front crank.

3. The omnidirectional mobile robot driven by a combination of conventional wheels and omnidirectional wheels according to claim 1, characterized in that: A bearing is built into the other end of the right rear crank, and a right rear vertical bolt is installed in the bearing. The screw rod of the right rear vertical bolt passes through the rectangular connecting rod frame and extends to the top of the rectangular connecting rod frame, and a right rear limiting nut is installed on the top of the screw rod of the right rear vertical bolt; a right rear shock absorber spring is mounted on the screw rod of the right rear vertical bolt between the rectangular connecting rod frame and the right rear crank.

4. The omnidirectional mobile robot driven by a combination of conventional wheels and omnidirectional wheels according to claim 1, characterized in that: A bearing is built into the other end of the left rear crank, and a left rear vertical bolt is installed in the bearing. The screw rod of the left rear vertical bolt passes through the rectangular connecting rod frame and extends to the top of the rectangular connecting rod frame, and a left rear limiting nut is installed on the top of the screw rod of the left rear vertical bolt; a left rear shock absorber spring is mounted on the screw rod of the left rear vertical bolt between the rectangular connecting rod frame and the left rear crank.

5. The control method of the omnidirectional mobile robot driven by both conventional wheels and omnidirectional wheels according to claim 1, characterized in that: When the robot needs to translate in all directions, the omnidirectional translation solution formula is first established, as follows: ； Where, ω 1 is the angular velocity of the left front omnidirectional wheel, ω 2 is the angular velocity of the right front ordinary wheel, ω 3 is the angular velocity of the right rear omnidirectional wheel, ω 4 is the rotational angular velocity of the left rear ordinary wheel, r is the wheel radius of the left front omni wheel, right front normal wheel, right rear omni wheel and left rear normal wheel, b is the length of the left front crank, right front crank, right rear crank and left rear crank, v is the robot translation speed, θ is the wheel deflection angle corresponding to the robot's translation direction, t For time; Then, according to the established omnidirectional translation solution formula, the robot translation speed is input into the PID controller v and the wheel deflection angle corresponding to the robot's translation direction θ After automatically solving the omnidirectional translation solution formula, the required rotational angular velocity of the four wheels will be obtained, and then the four drive motors will drive the corresponding four wheels to rotate according to the rotational angular velocity obtained by the solution to realize the omnidirectional translation of the robot. In the process of omnidirectional translation of the robot, the wheel deflection angle corresponding to the translation direction of the robot is θ Detection and feedback are performed through angle sensors.

6. The control method of the omnidirectional mobile robot driven by both conventional wheels and omnidirectional wheels according to claim 1, characterized in that: When the robot needs to spin, first establish the spin motion solution formula, as follows: ； Where, ω 1 is the angular velocity of the left front omnidirectional wheel, ω 2 is the angular velocity of the right front ordinary wheel, ω 3 is the angular velocity of the right rear omnidirectional wheel, ω 4 is the rotational angular velocity of the left rear ordinary wheel, r is the wheel radius of the left front omni wheel, right front normal wheel, right rear omni wheel and left rear normal wheel, σ 1 is the angle between the total wheel speed of the left front omnidirectional wheel and the wheel disc surface, σ 2 is the angle between the total wheel speed of the right front ordinary wheel and the wheel disc surface, σ 3 is the angle between the total wheel speed of the right rear omnidirectional wheel and the wheel disc surface, σ 4 is the angle between the total wheel speed of the left rear ordinary wheel and the wheel disc surface, l 1 is the distance between the left front omnidirectional wheel and the robot's rotation center, l 2 is the distance between the right front ordinary wheel and the robot's rotation center, l 3 is the distance between the right rear omnidirectional wheel and the robot's rotation center, l 4 is the distance between the left rear ordinary wheel and the robot's rotation center, ω is the robot's rotation angular velocity; Then the left front drive motor is controlled to make the left front omnidirectional wheel output torque to maintain the corresponding wheel deflection angle during the robot's spin process θ r At the same time, according to the established spin motion solution formula, the robot rotation angular velocity is input into the PID controller ω After automatically solving the spin motion calculation formula, the required rotational angular velocity of the four wheels will be obtained, and then the four drive motors will drive the corresponding four wheels to rotate according to the calculated rotational angular velocity to realize the robot's spin motion. During the robot's spin motion, the deflection angle of the wheel corresponding to the robot's spin process is maintained. θ r Detection and feedback are performed through angle sensors.

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