Double crank connecting rod cross slider type all-directional moving chassis structure and control method

Abstract

A double-crank connecting rod cross-slider omnidirectional mobile chassis structure and control method. In an underactuated configuration, commutation is achieved solely through the coupling of two sets of wheels, without the use of a steering servo. In a non-underactuated configuration, commutation can be expanded to include two steering servos. The diagonal wheels are connected by a double-crank connecting rod mechanism to ensure they are always parallel. The double connecting rods are connected by a cross-slider mechanism, forming a steering linkage for the four wheels. The double connecting rods are equipped with a limiter mechanism. In translation mode, the cross-slider mechanism cooperates with the limiter mechanism to constrain the relative position of the double connecting rods, allowing the cranks to break through dead points while maintaining the four wheels in parallel. In rotation mode, the wheels can rotate in place while in a self-rotating position, assisted by the cross-slider mechanism and the limiter mechanism. In the underactuated configuration, the eccentricity between the wheel geometric center and the steering center is small, resulting in high stability of the rotational center of gravity. By linking the two pairs of wheels, both stability and obstacle-crossing capability are further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of omnidirectional mobile robots, and in particular relates to a double crank connecting rod cross slider type omnidirectional mobile chassis structure and a control method thereof. Background Art

[0002] With the advancement of intelligent manufacturing and the expansion of the industrial logistics industry, omnidirectional mobile robot technology has been continuously developed. As an important component of multi-agent systems, it has broad application prospects and has become a cutting-edge topic in current scientific and technological research.

[0003] Omnidirectional mobile robots are widely used in aerospace, military, civil, service and other fields. The research on omnidirectional mobile robots involves a wide range of knowledge fields, including artificial intelligence, robotics, sensing technology, precision machinery, polymer materials and other disciplines. It has become a typical representative of mechatronics technology.

[0004] Omnidirectional mobile robots can achieve lateral and longitudinal translation and rotation around the center within the working plane, and can reach any target position while maintaining the robot's posture. They are very suitable for working in places with narrow spaces and high requirements for robot flexibility, such as crowded warehouses, narrow corridors and cabins, and workshops with dense equipment. Omnidirectional mobile robots can move freely and can make subtle adjustments to their own position.

[0005] Omnidirectional mobile robots can also replace humans in dangerous, toxic, or hazardous environments, performing tasks such as patrolling, mine clearance, and waste disposal. They can also serve as pioneers in space exploration, helping people uncover the mysteries of the universe. As research deepens and related technologies mature, omnidirectional mobile robots will inevitably be widely integrated into people's production and daily lives.

[0006] An omnidirectional mobile robot can move in any direction on a plane. Its greatest advantage is its ability to achieve a zero-radius rotation, high maneuverability, and the ability to move flexibly in narrow spaces. Research on its mechanical structure, kinematics, dynamics, motion path planning, motion control, and intelligent control methods has always attracted the attention of many researchers at home and abroad.

[0007] Currently, designs for omnidirectional mobile robots, both domestically and internationally, can be roughly divided into two categories. The first category achieves omnidirectional mobility through specialized structures, such as Mecanum wheels, omnidirectional wheels, and ball wheels, by modifying the wheel structure. However, these designs, due to the altered wheel structure, have higher environmental requirements than traditional wheels and are prone to damage in harsh environments. The second category achieves omnidirectional mobility through independent drive, where one wheel is controlled by two motors: one for walking and the other for steering. However, this design, due to the excessive number of motors used, makes the robot structure more complex and larger.

[0008] To this end, the Chinese patent application with application number 202210897858.7 discloses an all-round mobile chassis structure and control method driven by ordinary wheels without a steering servo. Each wheel only needs to be equipped with one motor, and no steering servo is required to achieve all-round movement of the robot. It also has the advantage of taking up little space, and the wheels only use ordinary wheels, which reduces the requirements of the wheels on environmental conditions, makes the structure simpler, and can effectively reduce the energy consumption of the robot system. However, after a period of application, it was found that the above scheme still has certain limitations. Since the scheme adopts gear transmission, it is difficult to apply it to large robots, and the eccentricity between the wheel and the center of rotation is too large, which makes it easy for the center of gravity to be unstable during rotation, and there is no linkage between the two pairs of wheels, resulting in the stability and obstacle crossing ability of the scheme being unsatisfactory. Summary of the Invention

[0009] To address the problems of the prior art, the present invention provides a double-crank connecting rod cross slider type omnidirectional mobile chassis structure and control method. The structure can be applied as an underactuated chassis, that is, without the use of a steering servo, only two sets of wheels are coupled to achieve commutation. Two steering servos can also be used to achieve commutation. The diagonal wheels are connected by a double-crank connecting rod mechanism to ensure that the diagonal wheels are always parallel. The double connecting rods are connected by a cross slider, so that the four wheels form a steering linkage. A limit mechanism is configured on the double connecting rods. In translation mode, the cross slider cooperates with the limit mechanism to constrain the relative position of the double connecting rods, which can break through the dead point position while maintaining the four wheels in parallel. In rotation mode, after the wheels move to the rotation position, they can rotate in place with the assistance of the cross slider and the limit mechanism, thereby achieving omnidirectional movement. The present invention can be applied to large robots. The eccentricity between the wheels and the rotation center is greatly reduced, which improves the center of gravity stability during rotation. The linkage between the two pairs of wheels further improves the stability and obstacle surmounting capability of the present invention.

[0010] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a double-crank connecting rod cross slider type omnidirectional mobile chassis structure, comprising a chassis frame assembly, a first wheel train assembly, a second wheel train assembly, a third wheel train assembly, a fourth wheel train assembly, a first rotation angle detection assembly and a second rotation angle detection assembly; the structure is characterized in that it also includes a first double-crank connecting rod mechanism, a second double-crank connecting rod mechanism and a cross slider mechanism; the first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly are evenly arranged on the chassis frame assembly, the first wheel train assembly and the second wheel train assembly are diagonally distributed, and the third wheel train assembly and the fourth wheel train assembly are diagonally distributed; the first rotation angle detection assembly is arranged between the second wheel train assembly and the chassis frame assembly; the second rotation angle detection assembly is arranged between the fourth wheel train assembly and the chassis frame assembly; the first double-crank connecting rod mechanism is arranged between the first wheel train assembly and the second wheel train assembly; the second double-crank connecting rod mechanism is arranged between the third wheel train assembly and the fourth wheel train assembly; and the cross slider mechanism is arranged between the first double-crank connecting rod mechanism and the second double-crank connecting rod mechanism.

[0011] The chassis frame assembly includes a lower cover plate, an intermediate support plate and an upper cover plate; the lower cover plate, the intermediate support plate and the upper cover plate are distributed sequentially and in parallel from bottom to top; a gap is left between the lower cover plate and the intermediate support plate, and the lower cover plate and the intermediate support plate are fixedly connected by a lower support frame; a gap is left between the intermediate support plate and the upper cover plate, and the intermediate support plate and the upper cover plate are fixedly connected by an upper support frame, and auxiliary support blocks are arranged between the four corners of the intermediate support plate and the upper cover plate; laser radars are arranged at two corner points on the diagonal line of the lower cover plate.

[0012] The first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly have the same structure and all include a hub motor wheel, a shock-absorbing suspension mechanism and a bearing hub; the bearing hub is vertically fixed on the chassis frame assembly through a shell, the top end of the bearing hub's rotating shaft is connected to the first wheel train assembly / the second wheel train assembly / the third wheel train assembly / the fourth wheel train assembly, the bottom end of the bearing hub's rotating shaft is connected to the shock-absorbing suspension mechanism, the motor shaft of the hub motor wheel is connected to the shock-absorbing suspension mechanism, and the control end of the hub motor wheel is electrically connected to the PID controller; a limit lever is provided on the chassis frame assembly, and the steering angle of the hub motor wheel is limited to within the range of ±180° by the limit lever.

[0013] The shock-absorbing suspension mechanism includes a motor shaft clamp body, a spring shock absorber and an adapter support plate; the motor shaft clamp body is fixedly installed on the motor shaft of the hub motor wheel, the lower end of the spring shock absorber is fixedly connected to the motor shaft clamp body, the upper end of the spring shock absorber is fixedly connected to the adapter support plate, and the adapter support plate is fixedly connected to the bottom end of the rotating shaft of the bearing hub; the spring shock absorber adopts a parallel double-row layout.

[0014] The first rotation angle detection component and the second rotation angle detection component have the same structure, and both include an angle sensor, an angle measurement limit frame, a driving pulley, a driven pulley and a synchronous belt; the angle sensor is vertically arranged, and the driven pulley is fixedly mounted on the outside of the angle sensor shell; one end of the angle measurement limit frame is fixedly connected to the chassis frame component, and the other end of the angle measurement limit frame is fixedly connected to the measuring shaft of the angle sensor; the driving pulley is located at the top of the rotating shaft of the bearing hub of the second wheel train component / the fourth wheel train component, and the driving pulley is coaxially distributed with the rotating shaft of the bearing hub of the second wheel train component / the fourth wheel train component, and the driving pulley and the driven pulley are connected by a synchronous belt; the driving pulley is installed on the first double crank connecting rod mechanism / the second double crank connecting rod mechanism.

[0015] The first double crank connecting rod mechanism and the second double crank connecting rod mechanism have the same structure, both including a first lower crank swing rod, a first upper crank swing rod, a connecting rod, a second lower crank swing rod and a second upper crank swing rod; the first lower crank swing rod is parallel to the first upper crank swing rod, and the second lower crank swing rod is parallel to the second upper crank swing rod; the connecting rods of the first double crank connecting rod mechanism and the second double crank connecting rod mechanism adopt a cross-cross layout; one end of the first lower crank swing rod of the first double crank connecting rod mechanism is connected to the top end of the bearing hub shaft of the first wheel train assembly The first lower crank swing arm of the first double crank connecting rod mechanism is fixedly connected, the other end of the first lower crank swing arm, one end of the connecting rod, and one end of the first upper crank swing arm are coaxially hinged together, the other end of the first upper crank swing arm of the first double crank connecting rod mechanism is coaxially fixedly connected to the driving pulley of the first rotation angle detection component, and is coaxially connected to the chassis frame component for rotation; one end of the second lower crank swing arm of the first double crank connecting rod mechanism is fixedly connected to the top end of the bearing hub shaft of the second wheel train component, the other end of the second lower crank swing arm of the first double crank connecting rod mechanism, the other end of the connecting rod, and the second One end of the upper crank rocker is coaxially hinged together, and the other end of the second upper crank rocker of the first double crank connecting rod mechanism is rotatably connected to the chassis frame assembly through a hinge shaft, and the hinge shaft is coaxially distributed with the bearing hub shaft below; one end of the first lower crank rocker of the second double crank connecting rod mechanism is fixedly connected to the top end of the bearing hub shaft of the third gear train assembly, and the other end of the first lower crank rocker of the second double crank connecting rod mechanism, one end of the connecting rod, and one end of the first upper crank rocker are coaxially hinged together, and the other end of the first upper crank rocker of the second double crank connecting rod mechanism is coaxially hinged to the The driving pulleys of the second rotation angle detection assembly are coaxially fixed together and coaxially connected to the chassis frame assembly; one end of the second lower crank rocker arm of the second double-crank connecting rod mechanism is fixedly connected to the top of the bearing hub shaft of the fourth wheel train assembly, the other end of the second lower crank rocker arm of the second double-crank connecting rod mechanism, the other end of the connecting rod, and one end of the second upper crank rocker arm are coaxially hinged together, and the other end of the second upper crank rocker arm of the second double-crank connecting rod mechanism is rotatably connected to the chassis frame assembly through a hinge shaft, and the hinge shaft is coaxially distributed with the bearing hub shaft below.

[0016] The cross slider mechanism includes an upper splint, a lower splint, a first guide block, a second guide block, a third guide block and a fourth guide block; the upper splint and the lower splint both adopt a cross-shaped structure, the upper splint and the lower splint are distributed parallel to and fixedly connected; the first guide block, the second guide block, the third guide block and the fourth guide block are respectively fixedly mounted on the four arm ends of the upper splint and the lower splint; the first guide block is adjacent to the first wheel train assembly, the second guide block is adjacent to the second wheel train assembly, the third guide block is adjacent to the third wheel train assembly, and the fourth guide block is adjacent to the fourth wheel train assembly; the connecting rod of the first double crank connecting rod mechanism passes through the first guide block and the second guide block in sequence; the connecting rod of the second double crank connecting rod mechanism passes through the third guide block and the fourth guide block in sequence; the upper splint and the lower splint are slidably connected to the connecting rods of the first double crank connecting rod mechanism and the second double crank connecting rod mechanism through flange bearings.

[0017] A first limiting mechanism is provided between the first guide block and the connecting rod of the first double-crank connecting rod mechanism; a second limiting mechanism is provided between the second guide block and the connecting rod of the first double-crank connecting rod mechanism; a third limiting mechanism is provided between the third guide block and the connecting rod of the second double-crank connecting rod mechanism; a fourth limiting mechanism is provided between the fourth guide block and the connecting rod of the second double-crank connecting rod mechanism; the first limiting mechanism, the second limiting mechanism, the third limiting mechanism and the fourth limiting mechanism have the same structure, and all include a limiting block, a magnet, an iron magnet and a buffer rubber pad; the limiting block is fixedly mounted on the connecting rod, and the magnet is fixedly mounted on the limiting block; the iron magnet is fixedly mounted on the first guide block / the second guide block / the third guide block / the fourth guide block, the iron magnet and the magnet are distributed opposite to each other and are adsorbed and matched, and the buffer rubber pad is provided on the outer surface of the iron magnet.

[0018] When the double crank connecting rod cross slider type omnidirectional mobile chassis structure adopts an under-driven structure, the first wheel train assembly and the third wheel train assembly are not equipped with steering servos, and the geometric center point of the wheel hub motor in the first wheel train assembly / the second wheel train assembly / the third wheel train assembly / the fourth wheel train assembly is eccentric to the central axis of the bearing hub; when the double crank connecting rod cross slider type omnidirectional mobile chassis structure adopts a non-under-driven structure, the first wheel train assembly and the third wheel train assembly are equipped with steering servos, which are fixedly mounted on the chassis frame assembly, and a driving gear is fixedly mounted on the motor shaft of the steering servo, and a driven gear is fixedly mounted on the top end of the bearing hub rotating shaft of the first wheel train assembly / the third wheel train assembly, and the driven gear is meshed with the driving gear, and the geometric center point of the wheel hub motor in the first wheel train assembly / the second wheel train assembly / the third wheel train assembly / the fourth wheel train assembly is located on the central axis of the bearing hub.

[0019] The control method of the double crank connecting rod cross slider type omnidirectional mobile chassis structure is as follows: when the chassis needs to translate in all directions, the desired wheel deflection angle and the desired translation speed are first input into the PID controller. After automatic calculation, the required rotational angular velocity of the four wheels will be obtained, and then the four hub motor wheels are controlled to rotate according to the rotational angular velocity obtained by the calculation, so as to realize the omnidirectional translation of the robot. During the omnidirectional translation of the robot, the desired wheel deflection angle is detected and fed back by the angle sensor; when the chassis needs to rotate in place, the hub motor wheels in the first wheel train assembly and the second wheel train assembly are first controlled to rotate clockwise to the extreme position, and the hub motor wheels in the third wheel train assembly and the fourth wheel train assembly are controlled to rotate counterclockwise. To the extreme position, the rotation angle of the wheel is detected and fed back through the angle sensor. If the chassis rotates clockwise in place, the hub motor wheels in the first and second wheel train components are the driving wheels, and the hub motor wheels in the third and fourth wheel train components are the driven wheels. If the chassis rotates counterclockwise in place, the hub motor wheels in the third and fourth wheel train components are the driving wheels, and the hub motor wheels in the first and second wheel train components are the driven wheels. Then, the desired rotation angular velocity is input into the PID controller. After automatic calculation, the required wheel rotation angular velocity will be obtained, and then the hub motor wheels as the driving wheels will be rotated according to the calculated rotation angular velocity, thereby realizing the robot's rotation in place.

[0020] Beneficial effects of the present invention:

[0021] The double-crank connecting rod cross slider type omnidirectional mobile chassis structure and control method of the present invention can be applied as an underactuated chassis, that is, without using a steering servo, only two sets of wheels are coupled to achieve reversing. Two steering servos can also be expanded to achieve reversing. The diagonal wheels are connected by a double-crank connecting rod mechanism to ensure that the diagonal wheels are always parallel. The double connecting rods are connected by a cross slider, so that the four wheels form a steering linkage. A limit mechanism is configured on the double connecting rods. In translation mode, the cross slider cooperates with the limit mechanism to constrain the relative position between the double connecting rods, which can break through the dead point position while maintaining the four wheels in parallel. In rotation mode, after the wheels move to the rotation position, they can achieve in-situ rotation with the assistance of the cross slider and the limit mechanism, thereby achieving omnidirectional movement. The present invention can be applied to large robots. The eccentricity between the wheels and the rotation center is greatly reduced, which improves the center of gravity stability during rotation. The linkage between the two pairs of wheels further improves the stability and obstacle surmounting ability of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1Schematic diagram of a double-crank connecting rod cross slider type omnidirectional mobile chassis structure (underactuated structure, upper cover plate not shown, translation posture) of the present invention (viewpoint one);

[0023] Figure 2 Schematic diagram of a double crank connecting rod cross slider type omnidirectional mobile chassis structure (underactuated structure, translation posture) of the present invention (viewpoint one);

[0024] Figure 3 Schematic diagram of a double-crank connecting rod cross slider type omnidirectional mobile chassis structure (underactuated structure, upper cover plate not shown, rotating posture) of the present invention (viewpoint one);

[0025] Figure 4 Schematic diagram of a double crank connecting rod cross slider type omnidirectional mobile chassis structure (underactuated structure, translation posture) of the present invention (viewpoint 2);

[0026] Figure 5 Schematic diagram of a double crank connecting rod cross slider type omnidirectional mobile chassis structure (underactuated structure, translation posture) of the present invention (viewpoint three);

[0027] Figure 6 Schematic diagram of a double crank connecting rod cross slider type omnidirectional mobile chassis structure (non-underactuated structure, translation posture) of the present invention (viewpoint one);

[0028] Figure 7 Schematic diagram of a double crank connecting rod cross slider type omnidirectional mobile chassis structure (non-underactuated structure, translation posture) of the present invention (viewpoint four);

[0029] In the figure, 1 is a lower cover plate, 2 is an intermediate support plate, 3 is an upper cover plate, 4 is a lower support frame, 5 is an upper support frame, 6 is an auxiliary support block, 7 is a laser radar, 8 is a wheel hub motor, 9 is a bearing hub, 10 is a motor shaft clamp, 11 is a spring shock absorber, 12 is a switching support plate, 13 is an angle sensor, 14 is an angle measurement limit frame, 15 is a driving pulley, 16 is a driven pulley, 17 is a first lower crank rocker, 18 is a first upper crank rocker, 19 is a connecting rod, 20 is a second lower crank rocker, 21 is a second upper crank rocker, 22 is an upper splint, 23 is a lower splint, 24 is a first guide block, 25 is a second guide block, 26 is a third guide block, 27 is a fourth guide block, 28 is a limit block, 29 is a magnet, 30 is an iron magnet, 31 is a steering servo, 32 is a driving gear, 33 is a driven gear, and 34 is a limit lever. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figures 1 to 7 As shown, a double crank connecting rod cross slider type omnidirectional mobile chassis structure includes a chassis frame assembly, a first wheel train assembly, a second wheel train assembly, a third wheel train assembly, a fourth wheel train assembly, a first rotation angle detection assembly and a second rotation angle detection assembly; its characteristic is that it also includes a first double crank connecting rod mechanism, a second double crank connecting rod mechanism and a cross slider mechanism; the first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly are evenly arranged on the chassis frame assembly, the first wheel train assembly and the second wheel train assembly are diagonally distributed, and the third wheel train assembly and the fourth wheel train assembly are diagonally distributed; the first rotation angle detection assembly is arranged between the second wheel train assembly and the chassis frame assembly; the second rotation angle detection assembly is arranged between the fourth wheel train assembly and the chassis frame assembly; the first double crank connecting rod mechanism is arranged between the first wheel train assembly and the second wheel train assembly; the second double crank connecting rod mechanism is arranged between the third wheel train assembly and the fourth wheel train assembly; the cross slider mechanism is arranged between the first double crank connecting rod mechanism and the second double crank connecting rod mechanism.

[0032] The chassis frame assembly includes a lower cover plate 1, an intermediate support plate 2 and an upper cover plate 3; the lower cover plate 1, the intermediate support plate 2 and the upper cover plate 3 are distributed sequentially and in parallel from bottom to top; a gap is left between the lower cover plate 1 and the intermediate support plate 2, and the lower cover plate 1 and the intermediate support plate 2 are fixedly connected by a lower support frame 4; a gap is left between the intermediate support plate 2 and the upper cover plate 3, and the intermediate support plate 2 and the upper cover plate 3 are fixedly connected by an upper support frame 5, and auxiliary support blocks 6 are arranged between the four corners of the intermediate support plate 2 and the upper cover plate 3; a laser radar 7 is arranged at two corner points on the diagonal line of the lower cover plate 1.

[0033] The first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly have the same structure, and all include a hub motor wheel 8, a shock-absorbing suspension mechanism and a bearing hub 9; the bearing hub 9 is vertically fixed on the chassis frame assembly through a shell, the top end of the rotating shaft of the bearing hub 9 is connected to the first wheel train assembly / the second wheel train assembly / the third wheel train assembly / the fourth wheel train assembly, the bottom end of the rotating shaft of the bearing hub 9 is connected to the shock-absorbing suspension mechanism, the motor shaft of the hub motor wheel 8 is connected to the shock-absorbing suspension mechanism, and the control end of the hub motor wheel 8 is electrically connected to the PID controller; a limit lever 34 is provided on the chassis frame assembly, and the steering angle of the hub motor wheel 8 is limited to within the range of ±180° by the limit lever 34.

[0034] The shock-absorbing suspension mechanism includes a motor shaft clamp body 10, a spring shock absorber 11 and an adapter support plate 12; the motor shaft clamp body 10 is fixedly installed on the motor shaft of the hub motor wheel 8, the lower end of the spring shock absorber 11 is fixedly connected to the motor shaft clamp body 10, the upper end of the spring shock absorber 11 is fixedly connected to the adapter support plate 12, and the adapter support plate 12 is fixedly connected to the bottom end of the rotating shaft of the bearing hub 9; the spring shock absorber 11 adopts a parallel double-row layout.

[0035] The first rotation angle detection component and the second rotation angle detection component have the same structure, both including an angle sensor 13, an angle measurement limit frame 14, a driving pulley 15, a driven pulley 16 and a synchronous belt; the angle sensor 13 is vertically arranged, and the driven pulley 16 is fixedly mounted on the outside of the shell of the angle sensor 13; one end of the angle measurement limit frame 14 is fixedly connected to the chassis frame component, and the other end of the angle measurement limit frame 14 is fixedly connected to the measuring shaft of the angle sensor 13; the driving pulley 15 is located at the top of the rotating shaft of the bearing hub 9 of the second wheel train component / the fourth wheel train component, and the driving pulley 15 is coaxially distributed with the rotating shaft of the bearing hub 9 of the second wheel train component / the fourth wheel train component, and the driving pulley 15 and the driven pulley 16 are connected by a synchronous belt; the driving pulley 15 is installed on the first double crank connecting rod mechanism / the second double crank connecting rod mechanism.

[0036] The first double crank connecting rod mechanism and the second double crank connecting rod mechanism have the same structure, both including a first lower crank swing rod 17, a first upper crank swing rod 18, a connecting rod 19, a second lower crank swing rod 20 and a second upper crank swing rod 21; the first lower crank swing rod 17 is parallel to the first upper crank swing rod 18, and the second lower crank swing rod 20 is parallel to the second upper crank swing rod 21; the connecting rods 19 of the first double crank connecting rod mechanism and the second double crank connecting rod mechanism adopt a cross-shaped layout; one end of the first lower crank swing rod 17 of the first double crank connecting rod mechanism is connected to the bearing hub of the first wheel train assembly 9 top end of the rotating shaft is fixedly connected, the other end of the first lower crank swing link 17 of the first double crank connecting rod mechanism, one end of the connecting rod 19, and one end of the first upper crank swing link 18 are coaxially hinged together, the other end of the first upper crank swing link 18 of the first double crank connecting rod mechanism is coaxially fixedly connected to the driving pulley 15 of the first rotation angle detection component, and the connection is coaxially connected to the chassis frame component for rotation; one end of the second lower crank swing link 20 of the first double crank connecting rod mechanism is fixedly connected to the top end of the rotating shaft of the bearing hub 9 of the second wheel train component, the other end of the second lower crank swing link 20 of the first double crank connecting rod mechanism, the connecting rod 19 The other end and one end of the second upper crank pendulum 21 are coaxially hinged together, the other end of the second upper crank pendulum 21 of the first double crank connecting rod mechanism is rotatably connected to the chassis frame assembly through a hinge shaft, and the hinge shaft is coaxially distributed with the rotating shaft of the bearing hub 9 below; one end of the first lower crank pendulum 17 of the second double crank connecting rod mechanism is fixedly connected to the top of the rotating shaft of the bearing hub 9 of the third gear train assembly, the other end of the first lower crank pendulum 17 of the second double crank connecting rod mechanism, one end of the connecting rod 19, and one end of the first upper crank pendulum 18 are coaxially hinged together, the first upper crank pendulum 18 of the second double crank connecting rod mechanism The other end is coaxially fixedly connected to the driving pulley 15 of the second rotation angle detection assembly, and is coaxially connected to the chassis frame assembly for rotation; one end of the second lower crank rocker arm 20 of the second double-crank connecting rod mechanism is fixedly connected to the top of the rotating shaft of the bearing hub 9 of the fourth wheel train assembly, the other end of the second lower crank rocker arm 20 of the second double-crank connecting rod mechanism, the other end of the connecting rod 19, and one end of the second upper crank rocker arm 21 are coaxially hinged together, and the other end of the second upper crank rocker arm 21 of the second double-crank connecting rod mechanism is rotatably connected to the chassis frame assembly through a hinge shaft, and the hinge shaft is coaxially distributed with the rotating shaft of the bearing hub 9 below.

[0037] The cross slider mechanism includes an upper clamping plate 22, a lower clamping plate 23, a first guide block 24, a second guide block 25, a third guide block 26 and a fourth guide block 27; the upper clamping plate 22 and the lower clamping plate 23 both adopt a cross-shaped structure, the upper clamping plate 22 and the lower clamping plate 23 are parallel and fixedly connected; the first guide block 24, the second guide block 25, the third guide block 26 and the fourth guide block 27 are respectively fixedly mounted on the ends of the four arms of the upper clamping plate 22 and the lower clamping plate 23; the first guide block 24 is adjacent to the first wheel train assembly The second guide block 25 is adjacent to the second wheel train assembly, the third guide block 26 is adjacent to the third wheel train assembly, and the fourth guide block 27 is adjacent to the fourth wheel train assembly; the connecting rod 19 of the first double crank connecting rod mechanism passes through the first guide block 24 and the second guide block 25 in sequence; the connecting rod 19 of the second double crank connecting rod mechanism passes through the third guide block 26 and the fourth guide block 27 in sequence; the upper splint 22 and the lower splint 23 are slidably connected to the connecting rod 19 of the first double crank connecting rod mechanism and the second double crank connecting rod mechanism through flange bearings.

[0038] A first limiting mechanism is provided between the first guide block 24 and the connecting rod 19 of the first double crank connecting rod mechanism; a second limiting mechanism is provided between the second guide block 25 and the connecting rod 19 of the first double crank connecting rod mechanism; a third limiting mechanism is provided between the third guide block 26 and the connecting rod 19 of the second double crank connecting rod mechanism; a fourth limiting mechanism is provided between the fourth guide block 27 and the connecting rod 19 of the second double crank connecting rod mechanism; the first limiting mechanism, the second limiting mechanism, the third limiting mechanism and the fourth limiting mechanism have the same structure, and all include a limiting block 28, a magnet 29, an iron magnet 30 and a buffer rubber pad; the limiting block 28 is fixedly mounted on the connecting rod 19, and the magnet 29 is fixedly mounted on the limiting block 28; the iron magnet 30 is fixedly mounted on the first guide block 24 / the second guide block 25 / the third guide block 26 / the fourth guide block 27, the iron magnet 30 is distributed opposite to the magnet 29 and is adsorbed and matched, and the buffer rubber pad is provided on the outer surface of the iron magnet 30.

[0039] When the double crank connecting rod cross slider type omnidirectional mobile chassis structure adopts an under-driven structure, the first wheel train assembly and the third wheel train assembly are not equipped with a steering servo 31, and the geometric center point of the hub motor wheel 8 in the first wheel train assembly / second wheel train assembly / third wheel train assembly / fourth wheel train assembly has an eccentricity with the central axis of the bearing hub 9; when the double crank connecting rod cross slider type omnidirectional mobile chassis structure adopts a non-under-driven structure, the first wheel train assembly and the third wheel train assembly are equipped with a steering servo 31, the steering servo 31 is fixedly mounted on the chassis frame assembly, a driving gear 32 is fixedly mounted on the motor shaft of the steering servo 31, a driven gear 33 is fixedly mounted on the top of the rotating shaft of the bearing hub 9 of the first wheel train assembly / third wheel train assembly, the driven gear 33 is meshed with the driving gear 32, and the geometric center point of the hub motor wheel 8 in the first wheel train assembly / second wheel train assembly / third wheel train assembly / fourth wheel train assembly is located on the central axis of the bearing hub 9.

[0040] The control method of the double crank connecting rod cross slider type omnidirectional mobile chassis structure is as follows: when the chassis needs to translate in all directions, the desired wheel deflection angle and the desired translation speed are first input into the PID controller. After automatic calculation, the required rotational angular velocity of the four wheels will be obtained, and then the four hub motor wheels 8 are controlled to rotate according to the rotational angular velocity obtained by the calculation, so as to realize the omnidirectional translation of the robot. During the omnidirectional translation of the robot, the desired wheel deflection angle is detected and fed back by the angle sensor 13; when the chassis needs to rotate in place, the hub motor wheels 8 in the first wheel train assembly and the second wheel train assembly are first controlled to rotate clockwise to the extreme position, and at the same time, the hub motor wheels 8 in the third wheel train assembly and the fourth wheel train assembly are controlled to rotate counterclockwise to At the extreme position, the rotation angle of the wheel is detected and fed back by the angle sensor 13. If the chassis rotates clockwise in situ, the hub motor wheel 8 in the first and second wheel train assemblies is the driving wheel, and the hub motor wheel 8 in the third and fourth wheel train assemblies is the driven wheel. If the chassis rotates counterclockwise in situ, the hub motor wheel 8 in the third and fourth wheel train assemblies is the driving wheel, and the hub motor wheel 8 in the first and second wheel train assemblies is the driven wheel. Then, the desired rotation angular velocity is input into the PID controller. After automatic calculation, the required wheel rotation angular velocity will be obtained, and then the hub motor wheel 8 as the driving wheel will rotate according to the calculated rotation angular velocity, thereby realizing the robot's rotation in situ.

[0041] Specifically, the magnet 29 is a collision-proof pot magnet, which is fixed to the limit block 28 by countersunk screws and anti-loosening nuts, and the buffer rubber pad is directly bonded to the surface of the magnet 29; the active pulley 15 and the first upper crank rocker arm 18 are fastened by screws, and the driven pulley 16 and the housing of the angle sensor 13 are fixed by interference fit, and the housing of the angle sensor 13 and the angle measurement limit frame 14 are connected by screws and anti-loosening nuts, while achieving the purpose of tensioning the synchronous belt; the limit lever 34 is connected to the chassis frame assembly through the bearing seat assembly, and the bearing seat assembly is installed on the middle support plate 2 of the chassis frame assembly by screws and anti-loosening nuts; the lower cover plate 1, the middle support plate 2, the upper cover plate 3, the lower support frame 4, the upper support frame 5 and the auxiliary support block 6 of the chassis frame assembly are all connected by screws and anti-loosening nuts; the motor shaft clamp body 10 is fastened by plugging screws and anti-loosening nuts.

[0042] When the under-driven structure is adopted, the two hub motor wheels 8 at the diagonal position are directly linked through the double crank connecting rod mechanism. By changing the length of the connecting rod, the size of the chassis can be completely changed. Since the hub motor wheel 8 adopts an eccentric installation method, that is, the geometric center of the hub motor wheel 8 is eccentric to the central axis of the bearing hub 9, when the wheel speeds of the two hub motor wheels 8 at the diagonal position are different, a torque along the direction of the crank rocker will be generated, causing the direction of the wheel to change, while the posture of the chassis does not change. The angle of rotation of the wheel in the vertical direction can be obtained by the angle sensor 13. By cooperating with the two pairs of wheels on the two diagonals, translational motion in all directions can be easily achieved. The cooperation between the cross slider mechanism and the limiting mechanism can maintain the relative position between the two connecting rods 19. The function of the magnet 29 is to prevent the cross slider mechanism from moving in the opposite direction. Under their combined action, the four wheels can always remain parallel during the translational movement, effectively enhancing the stability and obstacle-crossing ability of the chassis movement; when one set of crank rocker arms coincides with the connecting rod 19, that is, when it is in the dead point position, with the assistance of the cross slider mechanism and the limiting mechanism, the other set of crank rocker arms can break through the dead point position; when rotating in place, the cross slider mechanism is adsorbed and connected to another pair of limiting mechanisms through the magnet 29, which can maintain the stability of its rotation position. At this time, by changing the master-slave relationship between the two pairs of wheels, the rotation direction of the chassis can be changed.

[0043] 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. A double crank connecting rod cross slider type omnidirectional mobile chassis structure, comprising a chassis frame assembly, a first gear train assembly, a second gear train assembly, a third gear train assembly, a fourth gear train assembly, a first rotation angle detection assembly, and a second rotation angle detection assembly; characterized in that: It also includes a first double crank connecting rod mechanism, a second double crank connecting rod mechanism and a cross slider mechanism; the first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly are evenly arranged on the chassis frame assembly, the first wheel train assembly and the second wheel train assembly are diagonally distributed, and the third wheel train assembly and the fourth wheel train assembly are diagonally distributed; the first rotation angle detection assembly is arranged between the second wheel train assembly and the chassis frame assembly; the second rotation angle detection assembly is arranged between the fourth wheel train assembly and the chassis frame assembly; the first double crank connecting rod mechanism is arranged between the first wheel train assembly and the second wheel train assembly; the second double crank connecting rod mechanism is arranged between the third wheel train assembly and the fourth wheel train assembly; the cross slider mechanism is arranged at the first Between the double crank connecting rod mechanism and the second double crank connecting rod mechanism; the first double crank connecting rod mechanism / the second double crank connecting rod mechanism have the same structure, both including a first lower crank swing rod, a first upper crank swing rod, a connecting rod, a second lower crank swing rod and a second upper crank swing rod; the first lower crank swing rod is parallel to the first upper crank swing rod, and the second lower crank swing rod is parallel to the second upper crank swing rod; the connecting rods of the first double crank connecting rod mechanism and the second double crank connecting rod mechanism adopt a cross-cross layout; one end of the first lower crank swing rod of the first double crank connecting rod mechanism is fixedly connected to the top end of the bearing hub shaft of the first gear train assembly, and the other end of the first lower crank swing rod of the first double crank connecting rod mechanism, one end of the connecting rod, and one end of the first upper crank swing rod are coaxially hinged together The cam is connected to the chassis frame assembly via a hinged hinge, and the hinged hinge is coaxially distributed with the bearing hub shaft below; one end of the first lower crank swing arm of the second double crank connecting rod mechanism is fixedly connected to the top of the bearing hub shaft of the second wheel train assembly; the other end of the second lower crank swing arm of the first double crank connecting rod mechanism, the other end of the connecting rod, and one end of the second upper crank swing arm are coaxially hinged together; the other end of the second upper crank swing arm of the first double crank connecting rod mechanism is rotatably connected to the chassis frame assembly via a hinged shaft, and the hinged shaft is coaxially distributed with the bearing hub shaft below; one end of the first lower crank swing arm of the second double crank connecting rod mechanism is fixedly connected to the top of the bearing hub shaft of the third wheel train assembly The other end of the first lower crank rocker of the second double-crank connecting rod mechanism, one end of the connecting rod, and one end of the first upper crank rocker are coaxially hinged together, and the other end of the first upper crank rocker mechanism is coaxially fixed with the driving pulley of the second angle detection assembly, and is coaxially connected to the chassis frame assembly for rotation; one end of the second lower crank rocker of the second double-crank connecting rod mechanism is fixedly connected to the top end of the bearing hub shaft of the fourth wheel train assembly, and the other end of the second lower crank rocker of the second double-crank connecting rod mechanism, the other end of the connecting rod, and one end of the second upper crank rocker are coaxially hinged together, and the other end of the second upper crank rocker of the second double-crank connecting rod mechanism is rotatably connected to the chassis frame assembly through a hinge shaft, and the hinge shaft is coaxially distributed with the bearing hub shaft below.

2. The double crank connecting rod cross slider type omnidirectional movable chassis structure according to claim 1, characterized in that: The chassis frame assembly includes a lower cover plate, an intermediate support plate and an upper cover plate; the lower cover plate, the intermediate support plate and the upper cover plate are distributed sequentially and in parallel from bottom to top; a gap is left between the lower cover plate and the intermediate support plate, and the lower cover plate and the intermediate support plate are fixedly connected by a lower support frame; a gap is left between the intermediate support plate and the upper cover plate, and the intermediate support plate and the upper cover plate are fixedly connected by an upper support frame, and auxiliary support blocks are arranged between the four corners of the intermediate support plate and the upper cover plate; laser radars are arranged at two corner points on the diagonal line of the lower cover plate.

3. The double crank connecting rod cross slider type omnidirectional movable chassis structure according to claim 2, characterized in that: The first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly have the same structure and all include a hub motor wheel, a shock-absorbing suspension mechanism and a bearing hub; the bearing hub is vertically fixed on the chassis frame assembly through a shell, the top end of the bearing hub's rotating shaft is connected to the first wheel train assembly / the second wheel train assembly / the third wheel train assembly / the fourth wheel train assembly, the bottom end of the bearing hub's rotating shaft is connected to the shock-absorbing suspension mechanism, the motor shaft of the hub motor wheel is connected to the shock-absorbing suspension mechanism, and the control end of the hub motor wheel is electrically connected to the PID controller; a limit lever is provided on the chassis frame assembly, and the steering angle of the hub motor wheel is limited to within the range of ±180° by the limit lever.

4. The double crank connecting rod cross slider type omnidirectional movable chassis structure according to claim 3, characterized in that: The shock-absorbing suspension mechanism includes a motor shaft clamp body, a spring shock absorber and an adapter support plate; the motor shaft clamp body is fixedly installed on the motor shaft of the hub motor wheel, the lower end of the spring shock absorber is fixedly connected to the motor shaft clamp body, the upper end of the spring shock absorber is fixedly connected to the adapter support plate, and the adapter support plate is fixedly connected to the bottom end of the rotating shaft of the bearing hub; the spring shock absorber adopts a parallel double-row layout.

5. The double crank connecting rod cross slider type omnidirectional movable chassis structure according to claim 4, characterized in that: The first rotation angle detection component and the second rotation angle detection component have the same structure, and both include an angle sensor, an angle measurement limit frame, a driving pulley, a driven pulley and a synchronous belt; the angle sensor is vertically arranged, and the driven pulley is fixedly mounted on the outside of the angle sensor shell; one end of the angle measurement limit frame is fixedly connected to the chassis frame component, and the other end of the angle measurement limit frame is fixedly connected to the measuring shaft of the angle sensor; the driving pulley is located at the top of the rotating shaft of the bearing hub of the second wheel train component / the fourth wheel train component, and the driving pulley is coaxially distributed with the rotating shaft of the bearing hub of the second wheel train component / the fourth wheel train component, and the driving pulley and the driven pulley are connected by a synchronous belt; the driving pulley is installed on the first double crank connecting rod mechanism / the second double crank connecting rod mechanism.

6. The double crank connecting rod cross slider type omnidirectional movable chassis structure according to claim 5, characterized in that: The cross slider mechanism includes an upper splint, a lower splint, a first guide block, a second guide block, a third guide block and a fourth guide block; the upper splint and the lower splint both adopt a cross-shaped structure, the upper splint and the lower splint are distributed parallel to and fixedly connected; the first guide block, the second guide block, the third guide block and the fourth guide block are respectively fixedly mounted on the four arm ends of the upper splint and the lower splint; the first guide block is adjacent to the first wheel train assembly, the second guide block is adjacent to the second wheel train assembly, the third guide block is adjacent to the third wheel train assembly, and the fourth guide block is adjacent to the fourth wheel train assembly; the connecting rod of the first double crank connecting rod mechanism passes through the first guide block and the second guide block in sequence; the connecting rod of the second double crank connecting rod mechanism passes through the third guide block and the fourth guide block in sequence; the upper splint and the lower splint are slidably connected to the connecting rods of the first double crank connecting rod mechanism and the second double crank connecting rod mechanism through flange bearings.

7. The double crank connecting rod cross slider type omnidirectional movable chassis structure according to claim 6, characterized in that: A first limiting mechanism is provided between the first guide block and the connecting rod of the first double-crank connecting rod mechanism; a second limiting mechanism is provided between the second guide block and the connecting rod of the first double-crank connecting rod mechanism; a third limiting mechanism is provided between the third guide block and the connecting rod of the second double-crank connecting rod mechanism; a fourth limiting mechanism is provided between the fourth guide block and the connecting rod of the second double-crank connecting rod mechanism; the first limiting mechanism, the second limiting mechanism, the third limiting mechanism and the fourth limiting mechanism have the same structure, and all include a limiting block, a magnet, an iron magnet and a buffer rubber pad; the limiting block is fixedly mounted on the connecting rod, and the magnet is fixedly mounted on the limiting block; the iron magnet is fixedly mounted on the first guide block / the second guide block / the third guide block / the fourth guide block, the iron magnet and the magnet are distributed opposite to each other and are adsorbed and matched, and the buffer rubber pad is provided on the outer surface of the iron magnet.

8. The double crank connecting rod cross slider type omnidirectional movable chassis structure according to claim 7, characterized in that: When the double crank connecting rod cross slider type omnidirectional mobile chassis structure adopts an under-driven structure, the first wheel train assembly and the third wheel train assembly are not equipped with steering servos, and the geometric center point of the wheel hub motor in the first wheel train assembly / the second wheel train assembly / the third wheel train assembly / the fourth wheel train assembly is eccentric to the central axis of the bearing hub; when the double crank connecting rod cross slider type omnidirectional mobile chassis structure adopts a non-under-driven structure, the first wheel train assembly and the third wheel train assembly are equipped with steering servos, which are fixedly mounted on the chassis frame assembly, and a driving gear is fixedly mounted on the motor shaft of the steering servo, and a driven gear is fixedly mounted on the top end of the bearing hub rotating shaft of the first wheel train assembly / the third wheel train assembly, and the driven gear is meshed with the driving gear, and the geometric center point of the wheel hub motor in the first wheel train assembly / the second wheel train assembly / the third wheel train assembly / the fourth wheel train assembly is located on the central axis of the bearing hub.

9. The control method of the double crank connecting rod cross slider type omnidirectional movable chassis structure according to claim 8, characterized in that: When the chassis needs to translate in all directions, the desired wheel deflection angle and the desired translation speed are first input into the PID controller. After automatic calculation, the required rotational angular velocity of the four wheels will be obtained, and then the four hub motor wheels are controlled to rotate according to the calculated rotational angular velocity to realize the omnidirectional translation of the robot. During the omnidirectional translation of the robot, the desired wheel deflection angle is detected and fed back through the angle sensor; when the chassis needs to rotate in place, the hub motor wheels in the first and second wheel train components are first controlled to turn clockwise to the extreme position, and the hub motor wheels in the third and fourth wheel train components are controlled to turn counterclockwise to the extreme position. The rotation angle of the wheel is measured by the control unit. The angle sensor is used for detection and feedback. If the chassis rotates clockwise in place, the hub motor wheels in the first and second wheel train assemblies are driving wheels, and the hub motor wheels in the third and fourth wheel train assemblies are driven wheels. If the chassis rotates counterclockwise in place, the hub motor wheels in the third and fourth wheel train assemblies are driving wheels, and the hub motor wheels in the first and second wheel train assemblies are driven wheels. Then, the desired rotation angular velocity is input into the PID controller. After automatic calculation, the required wheel rotation angular velocity will be obtained, and then the hub motor wheels as the driving wheels will be rotated according to the calculated rotation angular velocity, thereby realizing the robot's rotation in place.

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