Wheel-legged separation type quadruped robot and control method thereof

Abstract

The application discloses a wheel-leg separated four-legged robot and a control method thereof, which comprises a body, four wheel-leg separated hybrid wheel-leg mechanisms symmetrically arranged on the left and right sides of the body, wherein each hybrid wheel-leg mechanism comprises a first motor, a second motor, a first clutch, a second clutch, a wheel, a transmission box and a parallel leg; the first motor is a double-output-shaft motor; the output shaft of the second motor is connected with the first motor through the parallel leg; one end of the output shaft of the first motor is connected with the parallel leg through the second clutch, and the other end is connected with the input end of the transmission box through the first clutch; and the output end of the transmission box is connected with the wheel. The wheel-leg separated four-legged robot has three control modes, can simultaneously have the characteristics of high speed and high efficiency of a wheeled robot and strong adaptability and good obstacle surmounting capability of a legged robot, can surmount obstacles through the coordination between the hybrid wheel-leg mechanisms, and greatly improves the terrain adaptability and working efficiency of the robot.

Description

Technical Field

[0001] This invention relates to the field of mobile robot technology, specifically to a wheel-leg-detached quadruped robot and its control method. Background Technology

[0002] With the development of technology, robots have been widely used in various industries and are playing an increasingly important role. Currently, robots working in complex road conditions include wheeled, tracked, and legged robots. Wheeled robots have advantages such as high efficiency and speed, but their adaptability to complex and rugged terrain is poor. Compared to legged robots, tracked robots have strong terrain adaptability and good obstacle-crossing ability, but their structure is complex and their speed is slow. Legged robots have gait movement patterns and true obstacle-crossing ability, adapting to complex terrain, but their speed and efficiency are low. Therefore, combining different types of robots can leverage their strengths and compensate for their weaknesses. Wheeled-legged robots are mainly divided into three structural types: wheel-leg connected, wheel-leg variable, and wheel-leg separate. Wheel-leg connected type: The wheels are fixed to the ends of the legs, acting as feet. This type of robot has excellent obstacle-crossing performance and a smooth wheel-leg switching process, but it involves a large number of drives, making control relatively difficult. The wheels constantly bear the load on the legs, reducing leg flexibility. Wheel-legged morph robots alter their movement patterns through structural deformation. These robots are highly adaptable to different environments and move at high speeds, but their overall mechanical structure is relatively complex. In contrast to the other two types of wheel-legged robots, wheel-leg decoupling robots separate the wheels from the legs, employing different operating modes under varying conditions, thus more effectively leveraging the advantages of both wheeled and legged robots. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a wheel-leg-separated quadruped robot and its control method. This wheel-leg-separated quadruped robot has the advantages of high speed and efficiency of wheeled robots and strong adaptability and good obstacle-crossing ability of legged robots. Furthermore, it can cross obstacles by using a combination of wheels and legs, which greatly improves the robot's terrain adaptability and work efficiency.

[0004] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution.

[0005] A wheel-leg detachable quadruped robot includes a body with four symmetrically arranged hybrid wheel-leg mechanisms on its left and right sides. Each hybrid wheel-leg mechanism includes a first motor, a second motor, a first clutch, a second clutch, wheels, a transmission box, and parallel legs. The first motor is a dual-output-shaft motor. The output shaft of the second motor is connected to the first motor via the parallel legs. One end of the first motor's output shaft is connected to the parallel legs via the second clutch, and the other end is connected to the input end of the transmission box via the first clutch. The output end of the transmission box is connected to the wheels.

[0006] Specifically, the parallel leg includes a first screw, a second screw, a first connecting rod, a second connecting rod, and a third connecting rod. The output shaft of the first motor is connected to the first screw via a second clutch, and the output shaft of the second motor is connected to the second screw. One end of the first connecting rod and the second connecting rod are respectively sleeved on the first screw and the second screw, and the other end is respectively connected to both ends of the third connecting rod. The third connecting rod is the foot end of the hybrid wheel leg.

[0007] Furthermore, the pitches of the first screw and the second screw are different.

[0008] Furthermore, the connection between the first connecting rod and the first screw, and between the second connecting rod and the second screw, are threaded transmission connections.

[0009] Furthermore, the first link, the second link, and the third link are connected by a rotating joint.

[0010] The present invention also provides a control method for the above-mentioned wheel-leg separated quadruped robot, the control method including three control modes: wheel-type, leg-type, and wheel-leg combined; The wheel control mode is used for the robot to move straight and turn when traversing flat surfaces; The leg-based control mode is used for the robot to walk and overcome obstacles when traversing rough terrain. The wheel-leg composite control mode is used for the robot to assist in overcoming obstacles by using parallel legs when passing through steps or pits.

[0011] Specifically, in the wheel-type control mode: Clutch No. 1 is engaged; Clutch No. 2 is disengaged; Only motor number one is working; When the wheels of the four hybrid wheel-leg mechanisms rotate at the same speed, the robot moves in a straight line; When the wheels of the four hybrid wheel-leg mechanisms rotate at different speeds, the robot uses the speed difference to steer.

[0012] Specifically, in the leg-based control mode: Clutch number one disengages, clutch number two engages; Motor 1 and Motor 2 work simultaneously, driving Screw 1 and Screw 2 respectively; By utilizing the different pitches of screws one and two, and controlling the rotational speeds of motors one and two within each hybrid wheel-leg mechanism, different motion patterns are generated at the foot end: When the first motor and the second motor rotate at the same speed, the robot moves forward and backward through the cooperation of the four hybrid wheel-leg mechanisms. When the speeds of motor 1 and motor 2 multiplied by their lead values ​​are equal, the robot can move left and right along the screw axis by controlling the speed difference between motor 1 and motor 2. By coordinating the forward and backward or left and right movement of the four hybrid wheel-leg mechanisms, the robot can move diagonally or laterally.

[0013] Specifically, in the wheel-leg composite control mode: Clutch number one disengages, clutch number two engages; Motor 1 and Motor 2 are working simultaneously; By driving the parallel legs at the front of the fuselage to work, the front of the fuselage is lifted so that the front wheels leave the ground, while the rear wheels continue to work close to the ground. After passing over the obstacle, the parallel legs at the front of the fuselage are retracted, and the vehicle enters the wheel control mode. By driving the parallel legs at the rear of the fuselage to work, the rear of the fuselage is lifted so that the rear wheels leave the ground, while the front wheels continue to work close to the ground. After overcoming an obstacle, the parallel legs at the rear of the fuselage are retracted, and the vehicle enters wheel control mode.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention relates to a wheel-leg separable quadruped robot. It adopts a design that separates the wheels from the parallel legs, allowing the wheels and parallel legs to share a portion of the motor. This results in a compact structure, easy manufacturing, convenient wheel-leg switching, and the ability to withstand large loads. It combines the high speed and efficiency of wheeled robots with the strong adaptability and obstacle-crossing ability of legged robots. Furthermore, it can use a combination of wheels and legs to overcome obstacles, greatly improving the robot's terrain adaptability and work efficiency. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] Figure 2 This is a schematic diagram of a single wheel-leg separation structure.

[0018] Figure 3 This is a schematic diagram of the parallel leg working mode of the present invention.

[0019] In the diagram: 0. Body; 1. Motor 1; 2. Motor 2; 3. Tire; 4. Clutch 1; 5. Transmission box; 6. Clutch 2; 7. Screw 1; 8. Screw 2; 9. Connecting rod 1; 10. Connecting rod 2; 11. Connecting rod 3; 12. Hybrid wheel-leg mechanism; 13. Parallel leg. Detailed Implementation

[0020] To facilitate understanding and implementation of the present invention by those skilled in the art, the various steps of the method proposed in this invention are described in detail below, and experimental procedures are given. It should be understood that the implementation examples described herein are for illustration and explanation only and are not intended to limit the present invention.

[0021] Example like Figure 1 As shown, the present invention provides a wheel-leg separation quadruped robot, including a body 0. The body 0 has four symmetrically arranged hybrid wheel-leg mechanisms 12 on its left and right sides. Each hybrid wheel-leg mechanism 12 includes a first motor 1, a second motor 2, a first clutch 4, a second clutch 6, wheels 3, a transmission box 5, and parallel legs 13. The first motor 1 is a dual-output shaft motor. The output shaft of the second motor 2 is connected to the first motor 1 through the parallel legs 13. One end of the output shaft of the first motor 1 is connected to the parallel legs 13 through the second clutch 6, and the other end is connected to the input end of the transmission box 5 through the first clutch 4. The output end of the transmission box 5 is connected to the wheels 3.

[0022] like Figure 2 As shown, the parallel leg 13 includes a first screw 7, a second screw 8, a first connecting rod 9, a second connecting rod 10, and a third connecting rod 11. The output shaft of the first motor 1 is connected to the first screw 7 through the second clutch 6, and the output shaft of the second motor 2 is connected to the second screw 8. One end of the first connecting rod 9 and the second connecting rod 10 are respectively sleeved on the first screw 7 and the second screw 8, and the other end is respectively connected to both ends of the third connecting rod 11. The third connecting rod 11 is the foot end of the hybrid wheel leg.

[0023] The screw pitches of screw 7 and screw 8 are different.

[0024] The first connecting rod 9 and the first screw 7, and the second connecting rod 10 and the second screw 8 are connected by threaded transmission.

[0025] The first connecting rod 9, the second connecting rod 10, and the third connecting rod 11 are connected by a rotating joint.

[0026] like Figure 3As shown, this embodiment also provides a control method for the above-mentioned wheel-leg separated quadruped robot. The control method mainly includes three control modes: wheeled, legged, and wheel-leg combined. The wheel control mode is used for the robot to move straight and turn when traversing flat surfaces; The leg-based control mode is used for the robot to walk and overcome obstacles when traversing rough terrain. The wheel-leg composite control mode is used for the parallel legs 13 to assist the robot in overcoming obstacles when passing through steps or pits.

[0027] Specifically, in the wheel-type control mode: Clutch 4 (number one) is engaged; Clutch 6 (number two) is disengaged. Only motor 1 is working; When the wheels 3 of the four hybrid wheel-leg mechanisms 12 rotate at the same speed, the robot moves in a straight line; When the wheels 3 of the four hybrid wheel-leg mechanisms 12 rotate at different speeds, the robot uses the speed difference to turn.

[0028] Working Principle: When the robot traverses a flat surface, a wheel-based control mode is adopted to improve its operating efficiency. When the wheels 3 are working, the four parallel legs 13 are retracted to the side of the body 0. At this time, only motor 1 of each hybrid wheel-leg mechanism 12 is working, clutch 4 is engaged, and clutch 6 is disengaged. The power of motor 1 is transmitted to the wheels 3 through the transmission box 5. When the wheels 3 have the same speed, the robot travels in a straight line. When turning is required, the speed of the wheels 3 in the four hybrid wheel-leg mechanisms 12 is changed by controlling the speed of motor 1 and motor 2, so that a speed difference is generated between the wheels 3, and the robot can then use the speed difference to turn.

[0029] Specifically, in the leg-based control mode: Clutch 4 disengages, clutch 6 engages; Motor 1 and Motor 2 work simultaneously, driving screw 7 and screw 8 respectively. By utilizing the different pitches of screw 7 and screw 8, and controlling the rotational speeds of motor 1 and motor 2 within each hybrid wheel-leg mechanism 12, different movement patterns are generated at the foot end: When motor 1 and motor 2 rotate at the same speed, the robot moves forward and backward through the cooperation of the four hybrid wheel-leg mechanisms 12. When the speeds of motor 1 and motor 2 multiplied by their leads are equal, the robot can move left and right along the screw axis by controlling the speed difference between motor 1 and motor 2. By coordinating the forward and backward or left and right movement of the four hybrid wheel-leg mechanisms 12, the robot can move diagonally or laterally.

[0030] Working Principle: When navigating rough terrain and requiring strong obstacle-crossing capabilities, a leg-based control mode is employed. Clutch 4 is disengaged, and clutch 6 is engaged. At this point, motors 1 and 2 of each hybrid wheel-leg mechanism 12 operate simultaneously, driving screws 7 and 8 respectively. Because the two screws have different pitches, the calculation formula for screw drive shows that controlling the speed of the two motors allows for different movement patterns at the foot. When the two motors rotate at the same speed, each hybrid wheel-leg mechanism 12 can move in a circular direction. The forward and reverse rotation of the motors controls the direction of this circular movement. Through the cooperation of each hybrid wheel-leg mechanism 12, forward and backward movement is achieved. When the speeds of the two motors multiplied by their leads are equal, controlling the difference in speed between the two motors allows the robot to move left and right along the screw axis. Through coordinated control of the four hybrid wheel-leg mechanisms 12, the robot can move diagonally.

[0031] Specifically, in the wheel-leg composite control mode: Clutch 4 disengages, clutch 6 engages; Motor 1 and Motor 2 operate simultaneously; By driving the parallel leg 13 at the front of the fuselage 0, the front of the fuselage 0 is lifted so that the front wheel leaves the ground, while the rear wheel continues to work close to the ground. After passing the obstacle, the parallel leg 13 at the front of the fuselage 0 is retracted, and the wheel control mode is entered. By driving the parallel leg 13 at the rear of the motor body 0, the rear of the motor body 0 is lifted so that the rear wheels leave the ground, while the front wheels continue to work close to the ground. After passing the obstacle, the parallel leg 13 at the rear of the motor body 0 is retracted, and the motor body 0 enters the wheel control mode.

[0032] Working principle: When the obstacle in front is a single obstacle such as a step or a pit, a wheel-leg hybrid control mode is adopted. The parallel leg 13 acts as an auxiliary robotic arm of the robot to achieve obstacle crossing. When there is an obstacle in front, the first clutch 4 under the two hybrid wheel-leg mechanisms 12 at the front of the robot body 0 disengages, the second clutch 6 engages, and the first motor 1 and the second motor 2 work simultaneously to drive the parallel leg 13 to work, lifting the robot body 0 so that the front wheels leave the ground. The rear wheels continue to work with the rear wheels 3. After crossing the obstacle, the parallel leg 13 of the two hybrid wheel-leg mechanisms 12 at the front is retracted, returning to the wheel control mode. The rear wheels also use this method to achieve obstacle crossing.

[0033] It should be understood that the above description of the preferred embodiments is quite detailed, but it should not be considered as a limitation on the scope of protection of this invention. Those skilled in the art, under the guidance of this invention, can make substitutions or modifications without departing from the scope of protection of the claims of this invention, and all such substitutions or modifications fall within the scope of protection of this invention. The scope of protection of this invention should be determined by the appended claims.

Claims

1. A wheel-leg-separated quadruped robot, comprising a body (0), characterized in that, The fuselage (0) has four symmetrically arranged hybrid wheel-leg mechanisms (12) with separate wheel legs on its left and right sides. Each hybrid wheel-leg mechanism (12) includes a first motor (1), a second motor (2), a first clutch (4), a second clutch (6), a wheel (3), a transmission box (5), and a parallel leg (13). The first motor (1) is a dual-output shaft motor. The output shaft of the second motor (2) is connected to the first motor (1) via the parallel leg (13). One end of the output shaft of the first motor (1) is connected to the parallel leg (13) via the second clutch (6), and the other end is connected to the input end of the transmission box (5) via the first clutch (4). The transmission box (5) outputs... The outlet end is connected to the wheel (3); the parallel leg (13) includes a first screw (7), a second screw (8), a first connecting rod (9), a second connecting rod (10) and a third connecting rod (11). The output shaft of the first motor (1) is connected to the first screw (7) through the second clutch (6), and the output shaft of the second motor (2) is connected to the second screw (8). One end of the first connecting rod (9) and the second connecting rod (10) are respectively sleeved on the first screw (7) and the second screw (8), and the other end is respectively connected to both ends of the third connecting rod (11). The third connecting rod (11) is the foot end of the hybrid wheel leg; the pitch of the first screw (7) and the second screw (8) is different.

2. The wheel-leg-separated quadruped robot according to claim 1, characterized in that, The first connecting rod (9) and the first screw (7), and the second connecting rod (10) and the second screw (8) are connected by threaded transmission.

3. A wheel-leg-separated quadruped robot according to claim 1, characterized in that, The first link (9), the second link (10), and the third link (11) are connected by a rotating joint.

4. The control method for the wheel-leg-separated quadruped robot as described in any one of claims 1 to 3, characterized in that, It includes three control modes: wheeled control mode, legged control mode, and wheel-leg combined control mode; The wheel control mode is used for the robot to move straight and turn when traversing flat surfaces; The leg-based control mode is used for the robot to walk and overcome obstacles when traversing rough terrain. The wheel-leg composite control mode is used to assist the robot in overcoming obstacles by using the parallel legs (13) when passing through steps or pits.

5. The control method for the wheel-leg-separated quadruped robot according to claim 4, characterized in that, In the wheel control mode: Clutch No. 1 (4) is engaged; Clutch No. 2 (6) is disengaged; Only motor number one (1) is working; When the wheels (3) of the four hybrid wheel-leg mechanisms (12) rotate at the same speed, the robot moves in a straight line; When the wheels (3) of the four hybrid wheel-leg mechanisms (12) rotate at different speeds, the robot uses the speed difference to turn.

6. The control method for the wheel-leg-separated quadruped robot according to claim 4, characterized in that, In the leg-controlled mode: Clutch No. 1 (4) disengages, and clutch No. 2 (6) engages; Motor 1 (1) and Motor 2 (2) work simultaneously, driving Screw 1 (7) and Screw 2 (8) to work respectively; By utilizing the different pitches of screw 1 (7) and screw 2 (8), different motion patterns are generated at the foot end by controlling the rotational speeds of motor 1 (1) and motor 2 (2) within each hybrid wheel-leg mechanism (12): When the speeds of motor 1 (1) and motor 2 (2) are the same, the robot moves forward and backward through the cooperation of the four hybrid wheel-leg mechanisms (12); When the speed of motor 1 (1) and motor 2 (2) multiplied by the lead are equal, the robot can move left and right along the screw axis by controlling the difference between motor 1 (1) and motor 2 (2). By coordinating the forward and backward or left and right movement of the four hybrid wheel-leg mechanisms (12), the robot can move diagonally to the side.

7. The control method for the wheel-leg-separated quadruped robot according to claim 4, characterized in that, The wheel-leg composite control mode: Clutch No. 1 (4) disengages, and clutch No. 2 (6) engages; Motor 1 (1) and Motor 2 (2) work simultaneously; By driving the parallel leg (13) at the front of the fuselage (0), the front of the fuselage (0) is lifted so that the front wheel leaves the ground, while the rear wheel continues to work close to the ground. After passing the obstacle, the parallel leg (13) at the front of the fuselage (0) is retracted, and the wheel control mode is entered. By driving the parallel leg (13) at the rear end of the fuselage (0), the rear end of the fuselage (0) is lifted so that the rear wheel leaves the ground, while the front wheel continues to work close to the ground. After passing the obstacle, the parallel leg (13) at the rear end of the fuselage (0) is retracted, and the wheel control mode is entered.

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