CN107416072B

CN107416072B - Control method for omnidirectional motion and walking mechanism

Info

Publication number: CN107416072B
Application number: CN201710673998.5A
Authority: CN
Inventors: 张军; 赵艺; 郭永存; 王成军; 杨洪涛; 张继明; 黎俊楠
Original assignee: Anhui University of Science and Technology
Current assignee: Anhui University of Science and Technology
Priority date: 2017-08-09
Filing date: 2017-08-09
Publication date: 2023-03-17
Anticipated expiration: 2037-08-09
Also published as: CN107416072A

Abstract

The invention relates to a control method and a walking mechanism of omnidirectional motion, which are characterized in that: the omnidirectional walking mechanism adopted by the control method of the omnidirectional movement comprises the following steps: the device comprises a rack assembly, a first driving unit assembly, a first motor mounting frame assembly, a second driving unit assembly, a box body assembly, a third driving unit assembly, a third motor mounting frame assembly, a fourth motor mounting frame assembly and a fourth driving unit assembly; the invention realizes the front-back movement mode, the right oblique upward movement mode, the right oblique downward movement mode, the transverse movement mode, the left oblique upward movement mode and the left oblique downward movement mode of the omnidirectional walking mechanism by controlling the movement mode of the omnidirectional walking mechanism; the invention has simple structure and smart design.

Description

Control method for omnidirectional motion and walking mechanism

Technical Field

The invention relates to the technical field of ground vehicle processing and control, in particular to a control method and a walking mechanism for omnidirectional motion.

Background

With the continuous acceleration of the industrial modernization process, the strong technical strength and the efficient productivity become the core competitiveness of enterprises. The industrialization is continuously promoted towards the direction of innovative science and technology, industrial densification and product equipment heaviness. In order to meet the increasing production requirements in many industrial fields, such as the coal industry, the steel production industry, the ship manufacturing industry, the aerospace manufacturing field, the petrochemical industry and the like, the development process becomes the main position of large-scale heavy-duty product equipment. Under the situation of deep integration of industrialization and informatization, market demands of heavy equipment and large mechanical products are very vigorous, equipment with the mass of a single body being more than ten tons and even more than hundred tons is quite common, and how to quickly and efficiently transport the overweight large equipment is gradually paid attention to by the industry.

The traditional heavy-load transport vehicle often loses the mobility in a narrow working site and needs related personnel to command, regulate and control on the site when passing through a factory intersection or a small-angle corner, and the speed and the transport efficiency of the transport vehicle are affected. If the road and the plant field are widened for smooth operation of the transport vehicle, the construction period is prolonged and the cost is increased, resulting in a decrease in the production efficiency. In some special transportation fields, such as the towing of aircraft carriers and the towing of launching rockets, the towing mechanism capable of moving in all directions is required.

In the walking mechanism in the robot pouring system of the casting shop, as the pits on the road surface of the pouring shop are uneven, a common omnidirectional wheel trolley cannot work at the position, and the trolley which can move in all directions and adapt to different road conditions and can move in all directions is urgently needed.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a control method of omnidirectional motion and a walking mechanism.

The invention is realized by the following technical scheme:

a control method and a walking mechanism for omnidirectional movement are characterized in that: the omnidirectional walking mechanism adopted by the control method of the omnidirectional movement comprises the following steps: the motor driving device comprises a rack assembly (101), a first driving unit assembly (102), a first motor mounting frame assembly (103), a second motor mounting frame assembly (104), a second driving unit assembly (105), a box body assembly (106), a third driving unit assembly (107), a third motor mounting frame assembly (108), a fourth motor mounting frame assembly (109), a fourth driving unit assembly (110), a cover plate (1), a front end angle steel frame (2), a right side angle steel frame (3), a rear end angle steel frame (4) and a left side angle steel frame (5).

As a preferable technical scheme of the invention, the first driving unit assembly (102) consists of a first rotating platform assembly (111), a first fastener assembly (112), a first wheel driving unit assembly (113), a second fastener assembly (114), a first lifting platform (30), a gasket (31) and a first wheel (32); the first rotating platform assembly (111) consists of a third fastener assembly (115), a fourth fastener assembly (116), a fifth fastener assembly (117), a first motor (33), a first bearing end cover (34), a first bearing chamber (35), a first bearing (36), a first shaft elastic retainer ring (37), a first shaft (38), a first rotating platform connecting frame (39), a second bearing (40), a second shaft elastic retainer ring (41), a second rotating platform connecting frame (42) and a first hole elastic retainer ring (43); the first vehicle wheel driving unit assembly (113) is composed of a third fastener assembly (115), a sixth fastener assembly (118), a second motor (44), a second bearing end cover (45), a second bearing chamber (46), a third shaft elastic retainer ring (47), a third bearing (48), a fourth shaft elastic retainer ring (49), a second shaft (50), a fifth shaft elastic retainer ring (51) and a fourth bearing (52).

In the first driving unit assembly (102), the second bearing chamber (46) in the first wheel driving unit assembly (113), the first rotating table connecting frame (39) in the first rotating table assembly (111) and the mounting hole on the gasket (31) are matched, and the gasket (31) and the first wheel driving unit assembly (113) are sequentially fixed on the first rotating table assembly (111) through the first fastener assembly (112) in a screw connection mode; the first wheel (32) and the mounting hole on the second shaft (50) in the first wheel driving unit component (113) are matched, and the first wheel (32) is fixed on the first wheel driving unit component (113) through the second fastener component (114) in a screw connection mode; the first rotating platform assembly (111) and the first lifting platform (30) are matched through a second rotating platform connecting frame (42) in the first rotating platform assembly (111), the first lifting platform (30) and a mounting hole at one end of a front end cross beam (14) in the rack assembly (101) and are fixed on the rack in a screw connection mode;

as a preferable technical scheme of the invention, the structure composition, the connection mode and the function of the second driving unit assembly (105), the third driving unit assembly (107) and the fourth driving unit assembly (110) are completely the same as those of the first driving unit assembly (102).

Compared with the prior art, the invention has the beneficial effects that: the all-direction walking mechanism is simple in structure and ingenious in design, the front-back movement mode (60), the right oblique upward movement mode (61), the right oblique downward movement mode (62), the transverse movement mode (63), the left oblique upward movement mode (64) and the left oblique downward movement mode (65) of the all-direction walking mechanism are achieved by controlling the movement mode of the all-direction walking mechanism, and the all-direction walking mechanism can adapt to grassland-level pavements.

Drawings

FIG. 1 is a schematic view of the overall structure; FIG. 2 is a three-dimensional exploded view of the overall structure; fig. 3 is a three-dimensional exploded view of the rack assembly (101); fig. 4 is a three-dimensional exploded view of the first drive unit assembly (102); FIG. 5 is a three-dimensional exploded view of the rotary table assembly (111); fig. 6 is a three-dimensional exploded view of the wheel drive unit assembly (113); fig. 7 a three-dimensional exploded view of the first motor mount assembly (103); FIG. 8 is a three-dimensional exploded view of the box assembly (106); fig. 9 is a schematic diagram of the movement state of the omnidirectional walking mechanism.

1. A cover plate; 2. a front end angle steel frame; 3. a right side angle steel frame; 4. a rear end angle steel frame; 5. a left side angle steel frame; 6. a first channel steel bracket; 7. a second channel steel bracket; 8. a third channel steel bracket; 9. a fourth channel steel bracket; 10. a fifth channel steel bracket; 11. a sixth channel steel bracket; 12. a seventh channel steel bracket; 13. an eighth channel steel bracket; 14. a front end cross member; 15. a ninth channel steel bracket; 16. a tenth channel steel bracket; 17. a right side welding frame; 18. an eleventh channel steel bracket; 19. a twelfth channel steel bracket; 20. a thirteenth channel steel bracket 21 and a right channel steel underframe; 22. a left channel steel underframe; 23. a rear end cross member; 24. a fourteenth channel steel bracket; 25. a fifteenth channel steel bracket; 26. a sixteenth channel steel bracket 27, a seventeenth channel steel bracket 28 and an eighteenth channel steel bracket; 29. a left side welding frame; 30. a first elevating platform; 31. a gasket; 32. a first wheel; 33. a first motor; 34. a first bearing end cap; 35. a first bearing chamber; 36. a first bearing; 37. a circlip for the first shaft; 38. a first shaft; 39. a first rotating table connecting frame; 40. a second bearing; 41. a circlip for the second shaft; 42. a second rotating table connecting frame; 43. a circlip for the first hole; 44. a second motor; 45. a second bearing end cap; 46. a second bearing chamber; 47. a circlip for the third shaft; 48. a third bearing; 49. the fourth shaft is provided with an elastic retainer ring; 50. a second shaft; 51. the elastic retainer ring for the fifth shaft; 52. a fourth bearing; 53. welding a frame; 54. an upper housing; 55. a lower base plate; 56. a front end baffle; 57. a right baffle; 58. a rear end baffle; 59. a left baffle; 60. a forward-backward movement mode; 61. a right tilt up shift motion mode; 62. a right tilt down movement mode; 63. a lateral movement motion mode; 64. a left-tilt-up movement mode; 65. a left oblique downward movement motion mode; 101. a rack assembly; 102. a first drive unit assembly; 103. a first motor mount assembly; 104. a second motor mount assembly; 105. a second drive unit assembly; 106. a case assembly; 107. a third drive unit assembly; 108. a third motor mount assembly; 109. a fourth motor mount assembly; 110. a fourth drive unit assembly; 111. a first rotary table assembly; 112. a first fastener assembly; 113. a first wheel drive unit assembly; 114. a second fastener assembly; 115. a third fastener assembly; 116. a fourth fastener assembly; 117. a fifth fastener assembly; 118. a sixth fastener assembly; 119. a seventh fastener assembly (119).

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Please refer to fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6, fig. 7, fig. 8, and fig. 9.

The control method of the omnidirectional movement is characterized in that: the omnidirectional walking mechanism adopted by the control method of the omnidirectional motion comprises the following steps: the device comprises a rack assembly (101), a first driving unit assembly (102), a first motor mounting frame assembly (103), a second motor mounting frame assembly (104), a second driving unit assembly (105), a box body assembly (106), a third driving unit assembly (107), a third motor mounting frame assembly (108), a fourth motor mounting frame assembly (109), a fourth driving unit assembly (110), a cover plate (1), a front end angle steel frame (2), a right side angle steel frame (3), a rear end angle steel frame (4) and a left side angle steel frame (5);

the rack assembly (101) consists of a first channel steel bracket (6), a second channel steel bracket (7), a third channel steel bracket (8), a fourth channel steel bracket (9), a fifth channel steel bracket (10), a sixth channel steel bracket (11), a seventh channel steel bracket (12), an eighth channel steel bracket (13), a front end cross beam (14), a ninth channel steel bracket (15), a tenth channel steel bracket (16), a right side welding frame (17), an eleventh channel steel bracket (18), a twelfth channel steel bracket (19), a thirteenth channel steel bracket (20), a right side channel steel underframe (21), a left side channel steel underframe (22), a rear end cross beam (23), a fourteenth channel steel bracket (24), a fifteenth channel steel bracket (25), a sixteenth channel steel bracket (26), a seventeenth channel steel bracket (27), an eighteenth channel steel bracket (28) and a left side welding frame (29);

the first driving unit assembly (102) consists of a first rotating platform assembly (111), a first fastener assembly (112), a first wheel driving unit assembly (113), a second fastener assembly (114), a first lifting platform (30), a gasket (31) and a first wheel (32); the first rotating platform assembly (111) consists of a third fastener assembly (115), a fourth fastener assembly (116), a fifth fastener assembly (117), a first motor (33), a first bearing end cover (34), a first bearing chamber (35), a first bearing (36), a first shaft elastic retainer ring (37), a first shaft (38), a first rotating platform connecting frame (39), a second bearing (40), a second shaft elastic retainer ring (41), a second rotating platform connecting frame (42) and a first hole elastic retainer ring (43); the first vehicle wheel driving unit assembly (113) consists of a third fastener assembly (115), a sixth fastener assembly (118), a second motor (44), a second bearing end cover (45), a second bearing chamber (46), a third shaft elastic retainer ring (47), a third bearing (48), a fourth shaft elastic retainer ring (49), a second shaft (50), a fifth shaft elastic retainer ring (51) and a fourth bearing (52);

the structure composition, the connection mode and the function of the second drive unit assembly (105), the third drive unit assembly (107) and the fourth drive unit assembly (110) are completely the same as those of the first drive unit assembly (102);

the first motor mounting frame assembly (103) is composed of a seventh fastener assembly (119), a welding frame (53) and an upper shell (54); the welding frame (53) is matched with a mounting hole in the upper shell (54), and the first motor (33) is fixed on the frame assembly (101) through a seventh fastener assembly (119) in a screw connection mode;

the structure composition and the connection mode of the second motor mounting frame assembly (104), the third motor mounting frame assembly (108) and the fourth motor mounting frame assembly (109) are completely the same as those of the first motor mounting frame assembly (103);

the box body assembly (106) consists of a lower bottom plate (55), a front end baffle (56), a right side baffle (57), a rear end baffle (58) and a left side baffle (59);

the box body assembly (106) is welded on the rack assembly (101) in a welding mode according to a positioning hole reserved on the lower bottom plate (55);

the front-end angle steel frame (2) is welded on a sixth channel steel bracket (11) and an eighth channel steel bracket (13) in a frame assembly (101) in a welding mode, the right-side angle steel frame (3) is welded on a ninth channel steel bracket (15), a seventh channel steel bracket (12), a tenth channel steel bracket (16), an eleventh channel steel bracket (18), a twelfth channel steel bracket (19), a second channel steel bracket (7) and a thirteenth channel steel bracket (20) in the frame assembly (101) in a welding mode, the rear-end angle steel frame (4) is welded on a fourteenth channel steel bracket (24) and a fifteenth channel steel bracket (25) in the frame assembly (101) in a welding mode, and the left-side angle steel frame (5) is welded on a sixteenth channel steel bracket (26), a first channel steel bracket (6), a seventeenth channel steel bracket (27), an eighteenth channel steel bracket (28), a third channel steel bracket (8), a fourth channel steel bracket (9) and a fifth channel steel bracket (10) in the frame assembly (101) in a welding mode;

the cover plate (1) is matched and positioned with the mounting holes in the front end angle steel frame (2), the right side angle steel frame (3), the rear end angle steel frame (4) and the left side angle steel frame (5) through the mounting holes in the cover plate, and the cover plate (1) is fixed on the vehicle body in a screw connection mode;

all components in the rack assembly (101) form a whole rack structure by adopting a welding mode according to the layout relative position shown in figure 2;

the first driving unit assembly (102) is matched with a mounting hole in one end of a front end cross beam (14) in the rack assembly (101) through mounting holes in a first lifting table (30) and a second rotating table connecting frame (42), and the first driving unit assembly (102) is fixed at one end of the front end cross beam (14) in the rack assembly (101) in a screw connection mode; similarly, a screw connection mode is adopted, a second driving unit assembly (105) is fixed at the other end of the front end cross beam (14) in the rack assembly (101), a third driving unit assembly (107) is fixed at one end of the rear end cross beam (23) in the rack assembly (101), and a fourth driving unit assembly (110) is fixed at the other end of the rear end cross beam (23) in the rack assembly (101);

the first motor mounting frame assembly (103) is matched with a mounting hole at one end of a front end cross beam (14) in the rack assembly (101) through a mounting hole in a welding frame (53), and the first motor mounting frame assembly (103) is fixed at one end of the front end cross beam (14) in the rack assembly (101) in a screw connection mode; similarly, a screw connection mode is adopted, the second motor mounting frame assembly (104) is fixed to the other end of the front end cross beam (14) in the frame assembly (101), the third motor mounting frame assembly (108) is fixed to one end of the rear end cross beam (23) in the frame assembly (101), and the fourth motor mounting frame assembly (109) is fixed to the other end of the rear end cross beam (23) in the frame assembly (101);

the components in the box body assembly (106) are connected into a whole box body structure in a welding mode.

The control method of the omnidirectional movement is characterized in that: in the first rotating platform assembly (111), a first motor (33) is fixed on a frame assembly (101) through a first motor mounting frame assembly (103); the first motor (33) is matched with a mounting hole in one end of the first bearing end cover (34), and one end of the first bearing end cover (34) is fixed on the first motor (33) through a third fastener component (115) in a screw connection mode; meanwhile, the other end of the first bearing end cover (34) is matched with a mounting hole in the first bearing chamber (35), and the other end of the first bearing end cover (34) is connected with the first bearing chamber (35) through a fourth fastener component (116) in a screw connection mode; the first bearing (36) is arranged in the first bearing chamber (35) and is axially positioned by means of the first bearing end cover (34) and the inner hole of the first bearing chamber (35) respectively; the first shaft (38) is matched and positioned with the first bearing (36) by a shaft shoulder on the first shaft and a first shaft elastic retainer ring (37) respectively; the first shaft (38) is matched with a mounting hole in the first rotating table connecting frame (39), and the first shaft (38) is fixed in the first rotating table connecting frame (39) through a fifth fastener component (117) in a screw connection mode; the second bearing (40) is arranged in the second rotating table connecting frame (42) and is axially positioned by respectively relying on the elastic retainer ring (43) for the first hole and the inner hole of the second rotating table connecting frame (42); the protruding shaft outside the first rotating platform connecting frame (39) is matched with the inner hole of the second bearing (40) and is matched and positioned with the second bearing (40) by a shaft shoulder on the protruding shaft and a circlip (41) for the second shaft.

The control method of the omnidirectional movement is characterized in that: in the first wheel driving unit component (113), a second motor (44) is matched with a mounting hole at one end of a second bearing end cover (45), and one end of the second bearing end cover (45) is fixed on the second motor (44) through a third fastener component (115) in a screw connection mode; meanwhile, the other end of the second bearing end cover (45) is matched with a mounting hole in the second bearing chamber (46), and the other end of the second bearing end cover (45) is connected with the second bearing chamber (46) through a sixth fastener component (118) in a screw connection mode; an inner hole of the third bearing (48) is matched with the second shaft (50), and the third bearing is axially positioned by an elastic retainer ring (47) for the third shaft and an elastic retainer ring (49) for the fourth shaft; the fourth bearing (52) is arranged in the second bearing chamber (46), is matched with the second shaft (50), and is axially positioned by means of an inner hole of the second bearing chamber (46) and a fifth shaft elastic retainer ring (51); the third shaft elastic retainer ring (47), the fourth shaft elastic retainer ring (49) and the fifth shaft elastic retainer ring (51) are all arranged on the second shaft (50);

the first driving unit assembly (102), the second driving unit assembly (105), the third driving unit assembly (107) and the fourth driving unit assembly (110) respectively comprise a rotating platform assembly, a wheel driving unit assembly, a lifting platform and wheels, wherein the rotation of the first rotating platform assembly (111) is controlled by adjusting the rotating speed and the steering direction of the first motor (33), the lifting of the first driving unit assembly (102) is controlled by adjusting the lifting of the first lifting platform (30), and the first wheel driving unit assembly (113) can drive the first wheel (32) to rotate; similarly, the second driving unit assembly (105), the third driving unit assembly (107) and the fourth driving unit assembly (110) can realize three motions of rotation, lifting and rotation of the assemblies.

The control method of the omnidirectional movement is characterized in that: the motion modes of the omnidirectional walking mechanism comprise a front-back movement mode (60), a right oblique upward movement mode (61), a right oblique downward movement mode (62), a transverse movement mode (63), a left oblique upward movement mode (64) and a left oblique downward movement mode (65); the control method of the motion mode comprises the following steps:

1) Fore-and-aft movement pattern

A. Forward moving motion mode

When the omnidirectional walking mechanism moves forwards, the servo motor driver connected with the PLC drives the motor in the wheel driving unit assembly to synchronously drive the respective wheels to rotate forwards, and meanwhile, the PLC outputs an analog quantity voltage of 0 to plus or minus 10 volts to the servo driver, so that the rotating speed of the motor is in direct proportion to the voltage value of the analog quantity, and then the analog quantity voltage value output by the PLC is used for realizing the control of the revolution number of the motor, thereby controlling the omnidirectional walking mechanism to realize the forward movement at three different speeds of speed 1, speed 2 and speed 3, and the method comprises the following specific steps:

(1) when the analog quantity voltage value output by the PLC is adjusted to be 2V, the four servo motor drivers synchronously drive the motors in the wheel driving unit components respectively, so that the omnidirectional travelling mechanism moves forwards at the speed of 1;

(2) when the analog quantity voltage value output by the PLC is adjusted to be 4V, the four servo motor drivers synchronously drive the motors in the wheel driving unit components respectively, so that the omnidirectional travelling mechanism moves forwards at the speed of 2;

(3) when the analog quantity voltage value output by the PLC is adjusted to be 6V, the four servo motor drivers synchronously drive the motors in the wheel driving unit components respectively, so that the omnidirectional travelling mechanism moves forwards at the speed of 3;

B. backward moving motion mode

When the omnidirectional travelling mechanism moves backwards, a servo motor driver connected with the PLC drives a motor in a wheel driving unit assembly to synchronously drive respective wheels to rotate reversely, so that the omnidirectional travelling mechanism is controlled to realize the backwards movement at three different speeds of 4, 5 and 6, and the specific control method comprises the following steps:

(1) when the analog quantity voltage value output by the PLC is adjusted to be-2V, the four servo motor drivers synchronously drive the motors in the wheel driving unit components respectively, so that the omnidirectional walking mechanism moves backwards at the speed of 4;

(2) when the analog quantity voltage value output by the PLC is adjusted to be-4V, the four servo motor drivers synchronously drive the motors in the wheel driving unit components respectively, so that the omnidirectional walking mechanism moves backwards at the speed of 5;

(3) when the analog quantity voltage value output by the PLC is adjusted to be-6V, the four servo motor drivers synchronously drive the motors in the wheel driving unit components respectively, so that the omnidirectional walking mechanism moves backwards at the speed of 6;

2) Transverse movement

When the omnidirectional walking mechanism moves transversely, the omnidirectional walking mechanism can be divided into two movement modes of transverse leftward movement and transverse rightward movement according to different movement directions of the omnidirectional walking mechanism; when the vehicle wheel is regulated to move leftwards, the motor of the wheel driving unit component drives the vehicle wheel to rotate forwards; when the vehicle moves to the right in the transverse direction, the motor of the wheel driving unit component drives the wheels to rotate reversely;

A. lateral left shift motion pattern

Step (1): the control circuit triggers the hydraulic power driving unit to drive the lifting platforms in the four driving unit assemblies to synchronously and stably lift at a slow speed, simultaneously monitors and controls the synchronous lifting height of each lifting platform in real time through the pressure sensor, and controls each lifting platform to stop synchronous lifting after certain time delay when four wheels of the omnidirectional walking mechanism are separated from the ground (the pressure sensor reaches a set threshold value 1 at the moment);

step (2): the control circuit continuously controls the rotating speed and the steering of the motors in the four rotating platform assemblies to enable the motors to synchronously steer 90 degrees clockwise, so that the side surfaces of the four wheels are parallel to the transverse direction of the omnidirectional travelling mechanism body;

and (3): after the movement positions of the four wheels are adjusted, the control circuit triggers the hydraulic power driving units to drive the lifting platforms in the four driving unit assemblies to synchronously and stably descend at a low speed, simultaneously monitors and controls the synchronous descending height of each lifting platform in real time through the pressure sensors, and when the four wheels of the omnidirectional walking mechanism contact the ground (at the moment, the pressure sensors reach a set threshold value 2), the control circuit controls each lifting platform to stop synchronous descending after a certain time delay;

and (4): after a certain time delay, the control circuit triggers the hydraulic power driving unit to drive the lifting platforms in the four driving unit assemblies to continue to perform rapid synchronous stable contraction, and sets a certain time delay, and when the time delay is reached, the control circuit controls each lifting platform to stop synchronous contraction;

and (5): after certain time delay, the control circuit drives the motors in the wheel driving unit assemblies through servo motor drivers connected with the PLC, so that the wheels synchronously drive the motors to rotate forwards, and the omnidirectional travelling mechanism moves leftwards transversely at three different speeds, namely speed 1, speed 2 and speed 3;

and (6): the control circuit controls the motors in the four wheel driving unit assemblies to stop rotating, the omnidirectional travelling mechanism stops moving, and the omnidirectional travelling mechanism is adjusted to be in a reset state;

B. transverse rightward movement motion mode

The steps (1), (2), (3) and (4) are the same as the steps (1), (2), (3) and (4) when the transverse direction moves leftwards;

and (5): after certain time delay, the control circuit applies reverse voltage to the motors in the four wheel driving unit assemblies through the PLC to enable the wheels to rotate reversely, and the omnidirectional travelling mechanism is enabled to move transversely rightwards at three different speeds, namely speed 4, speed 5 and speed 6;

3) Oblique movement

The omnidirectional travelling mechanism can realize oblique movement in any direction in a plane, and the side surfaces of four wheels and the longitudinal horizontal line of the body of the omnidirectional travelling mechanism form a certain included angle theta, wherein theta is more than 90 and less than 90 degrees, and is not equal to 0 degree, so that when the angle theta is more than 0 and less than 90 degrees, the omnidirectional travelling mechanism can realize right oblique upward movement when the motors in the four wheel driving unit assemblies synchronously drive the respective wheels to rotate forwards, and conversely, the omnidirectional travelling mechanism can realize right oblique downward movement when the respective wheels are synchronously driven to rotate reversely; when theta is larger than 90 degrees and smaller than 0, the omnidirectional walking mechanism can realize the left oblique upward movement when the motors in the four wheel driving unit components synchronously drive the respective wheels to rotate forwards, and can realize the left oblique downward movement when the respective wheels are synchronously driven to rotate reversely;

A. right oblique upward movement mode

The step (1) is the same as the step (1) when the transverse direction moves leftwards;

step (2): the control circuit continuously controls the rotating speed and the rotating direction of the motors in the four rotating platform components, so that the clockwise synchronous rotating angle value of the motors is theta (theta is more than 0 and less than 90 degrees);

the steps (3), (4), (5) and (6) are the same as the steps (3), (4), (5) and (6) when the user moves leftwards transversely;

B. omnidirectional walking mechanism right-oblique downward movement mode

The steps (1), (2), (3) and (4) are the same as the steps (1), (2), (3) and (4) of the right oblique upward movement;

and (5): after certain time delay, the control circuit applies reverse voltage to the motors in the four wheel driving unit assemblies through the PLC to enable the wheels to rotate reversely, and the omnidirectional traveling mechanism is enabled to move downwards in a right inclined mode at three different speeds of 4, 5 and 6;

C. left oblique upward movement mode

step (2): the control circuit continuously controls the rotating speed and the rotating direction of the motors in the four rotating platform assemblies, so that the counterclockwise synchronous rotating angle value is theta (theta is more than 0 and less than 90 degrees);

the steps (3), (4), (5) and (6) are the same as the steps (3), (4), (5) and (6) in the case of the lateral leftward movement;

D. left-oblique downward movement mode

The steps (1), (2), (3) and (4) are the same as the steps (1), (2), (3) and (4) of the left oblique upward movement;

and (5): after certain time delay, the control circuit applies reverse voltage to the motors in the four wheel driving unit assemblies through the PLC to enable the wheels to rotate reversely, and therefore the omnidirectional traveling mechanism can move downwards in a left inclined mode at three different speeds of 4, 5 and 6;

4) Reset mode

After transverse movement and oblique movement of the omnidirectional travelling mechanism are completed, in order to ensure that the omnidirectional travelling mechanism always keeps the positions of the side surfaces of four wheels when the omnidirectional travelling mechanism is longitudinally parallel to the body of the omnidirectional travelling mechanism before the next movement mode is executed, namely the positions of the wheels during front and rear movement, the omnidirectional travelling mechanism needs to be reset, and the control steps are as follows:

(1) the control circuit triggers the hydraulic power driving unit to drive the lifting platforms in the four driving unit assemblies to synchronously and stably lift at a slow speed, simultaneously monitors and controls the synchronous lifting height of each lifting platform in real time through the pressure sensor, and controls each lifting platform to stop synchronous lifting after a certain time delay when the four wheels of the omnidirectional walking mechanism are disengaged from the ground (at the moment, the pressure sensor reaches a set threshold value 1);

(2) the control circuit controls the rotating speed and the steering of the motors in the four rotating platform assemblies to synchronously steer to a reset position (the reset position is set, namely the position when the side surfaces of the four wheels are parallel to the longitudinal direction of the omnidirectional travelling mechanism body);

(3) the control circuit triggers the hydraulic power driving unit to drive the lifting platforms in the four driving unit assemblies to synchronously and stably descend at a low speed, simultaneously monitors and controls the synchronous descending height of each lifting platform in real time through the pressure sensor, and controls each lifting platform to stop synchronous descending after certain time delay when four wheels of the omnidirectional walking mechanism contact the ground (at the moment, the pressure sensor reaches a set threshold value 2);

(4) the control circuit triggers the hydraulic power driving unit to continuously drive the lifting platforms in the four driving unit assemblies to realize rapid synchronous stable contraction, a certain delay time is set, and when the delay time is reached, the control circuit controls each lifting platform to stop synchronous contraction;

5) Movement of the lifting platform

The lifting platform in the four driving unit assemblies can realize three motion modes of slow synchronous stable rising, slow synchronous stable falling and fast synchronous stable contraction; according to the motion speed formula v = q/a of the actuator hydraulic cylinder, the method comprises the following steps: v is the movement speed of the actuating element, q is the input flow of the actuating element, a is the working area of the hydraulic cylinder, and the purpose of adjusting the movement speed of the actuating element can be achieved by changing the flow of the hydraulic cylinder of the actuating element in the lifting platform, so that the lifting platform in the four driving unit assemblies can move quickly and slowly

The lifting platform in the four driving unit assemblies realizes the functions of ascending, descending and contracting, and is realized by controlling the oil inlet and outlet directions of the hydraulic cylinder of the lifting platform, and the control steps are as follows:

A. lifting motion mode of lifting platform

When the lifting platform realizes lifting movement, oil is fed into the upper end of a hydraulic cylinder of the lifting platform, oil is discharged from the lower end of the hydraulic cylinder of the lifting platform, a pressure sensor monitors the internal pressure value of the upper end of the hydraulic cylinder in real time, and simultaneously the internal pressure value is compared with a preset threshold value 1, and when the pressure value reaches the threshold value 1, after a certain time delay, a control circuit controls each lifting platform to stop synchronous lifting;

B. lowering movement mode of lifting platform

When the lifting platform realizes descending movement, oil is discharged from the upper end of a hydraulic cylinder of the lifting platform, oil is discharged from the lower end of the hydraulic cylinder of the lifting platform, a pressure sensor monitors the internal pressure value of the lower end of the hydraulic cylinder in real time, and simultaneously the internal pressure value is compared with a preset threshold value 2, and when the pressure value reaches the threshold value 2, after a certain time delay, a control circuit controls each lifting platform to stop synchronous descending;

C. lowering movement mode of lifting platform

When the lifting platform realizes the contraction movement, the upper end of the hydraulic cylinder of the lifting platform is used for discharging oil, and the lower end of the hydraulic cylinder of the lifting platform is used for feeding oil.

The omnidirectional walking mechanism adopted by the control method of the omnidirectional movement is characterized in that: the omnidirectional walking mechanism comprises: the device comprises a rack assembly (101), a first driving unit assembly (102), a first motor mounting frame assembly (103), a second motor mounting frame assembly (104), a second driving unit assembly (105), a box body assembly (106), a third driving unit assembly (107), a third motor mounting frame assembly (108), a fourth motor mounting frame assembly (109), a fourth driving unit assembly (110), a cover plate (1), a front end angle steel frame (2), a right side angle steel frame (3), a rear end angle steel frame (4) and a left side angle steel frame (5);

the first driving unit assembly (102) consists of a first rotating platform assembly (111), a first fastener assembly (112), a first wheel driving unit assembly (113), a second fastener assembly (114), a first lifting platform (30), a gasket (31) and a first wheel (32); the first rotating platform assembly (111) consists of a third fastener assembly (115), a fourth fastener assembly (116), a fifth fastener assembly (117), a first motor (33), a first bearing end cover (34), a first bearing chamber (35), a first bearing (36), a first shaft circlip (37), a first shaft (38), a first rotating platform connecting frame (39), a second bearing (40), a second shaft circlip (41), a second rotating platform connecting frame (42) and a first hole circlip (43); the first vehicle wheel driving unit assembly (113) consists of a third fastener assembly (115), a sixth fastener assembly (118), a second motor (44), a second bearing end cover (45), a second bearing chamber (46), a third shaft elastic retainer ring (47), a third bearing (48), a fourth shaft elastic retainer ring (49), a second shaft (50), a fifth shaft elastic retainer ring (51) and a fourth bearing (52);

the structure composition, the connection mode and the functions of the second driving unit assembly (105), the third driving unit assembly (107) and the fourth driving unit assembly (110) are completely the same as those of the first driving unit assembly (102);

the first driving unit assembly (102) is matched with a mounting hole at one end of a front end cross beam (14) in the rack assembly (101) through mounting holes in a first lifting table (30) and a second rotating table connecting frame (42), and the first driving unit assembly (102) is fixed at one end of the front end cross beam (14) in the rack assembly (101) in a screw connection mode; similarly, a screw connection mode is adopted, a second driving unit assembly (105) is fixed at the other end of the front end cross beam (14) in the rack assembly (101), a third driving unit assembly (107) is fixed at one end of the rear end cross beam (23) in the rack assembly (101), and a fourth driving unit assembly (110) is fixed at the other end of the rear end cross beam (23) in the rack assembly (101);

in the first driving unit assembly (102), the second bearing chamber (46) in the first wheel driving unit assembly (113), the first rotating table connecting frame (39) in the first rotating table assembly (111) and the mounting hole on the gasket (31) are matched, and the gasket (31) and the first wheel driving unit assembly (113) are sequentially fixed on the first rotating table assembly (111) through the first fastener assembly (112) in a screw connection mode; the first wheel (32) and the mounting hole on the second shaft (50) in the first wheel driving unit component (113) are matched, and the first wheel (32) is fixed on the first wheel driving unit component (113) through the second fastener component (114) in a screw connection mode; the first rotating table assembly (111) and the first lifting table (30) are matched through a second rotating table connecting frame (42) in the first rotating table assembly (111), the first lifting table (30) and a mounting hole in one end of a front end cross beam (14) in the rack assembly (101) and are fixed on the rack in a screw connection mode;

the first motor mounting frame assembly (103) is matched with a mounting hole at one end of a front end cross beam (14) in the rack assembly (101) through a mounting hole in a welding frame (53), and the first motor mounting frame assembly (103) is fixed at one end of the front end cross beam (14) in the rack assembly (101) in a screw connection mode; similarly, a screw connection mode is adopted, the second motor mounting frame assembly (104) is fixed at the other end of the front end cross beam (14) in the frame assembly (101), the third motor mounting frame assembly (108) is fixed at one end of the rear end cross beam (23) in the frame assembly (101), and the fourth motor mounting frame assembly (109) is fixed at the other end of the rear end cross beam (23) in the frame assembly (101);

The omnidirectional movement and omnidirectional traveling mechanism is characterized in that: in the first rotating platform assembly (111), a first motor (33) is fixed on a frame assembly (101) through a first motor mounting frame assembly (103); the first motor (33) is matched with a mounting hole in one end of the first bearing end cover (34), and one end of the first bearing end cover (34) is fixed on the first motor (33) through a third fastener component (115) in a screw connection mode; meanwhile, the other end of the first bearing end cover (34) is matched with a mounting hole in the first bearing chamber (35), and the other end of the first bearing end cover (34) is connected with the first bearing chamber (35) through a fourth fastener component (116) in a screw connection mode; the first bearing (36) is arranged in the first bearing chamber (35) and is axially positioned by means of the first bearing end cover (34) and the inner hole of the first bearing chamber (35) respectively; the first shaft (38) is matched and positioned with the first bearing (36) by a shaft shoulder and a circlip (37) for the first shaft respectively; the first shaft (38) is matched with a mounting hole in the first rotating table connecting frame (39), and the first shaft (38) is fixed in the first rotating table connecting frame (39) through a fifth fastener component (117) in a screw connection mode; the second bearing (40) is arranged in the second rotating table connecting frame (42) and is axially positioned by respectively relying on the elastic retainer ring (43) for the first hole and the inner hole of the second rotating table connecting frame (42); the protruding shaft outside the first rotating platform connecting frame (39) is matched with the inner hole of the second bearing (40), and is matched and positioned with the second bearing (40) by a shaft shoulder on the protruding shaft and a second shaft elastic retainer ring (41).

The omnidirectional movement and omnidirectional traveling mechanism is characterized in that: in the first wheel driving unit component (113), a second motor (44) is matched with a mounting hole at one end of a second bearing end cover (45), and one end of the second bearing end cover (45) is fixed on the second motor (44) through a third fastener component (115) in a screw connection mode; meanwhile, the other end of the second bearing end cover (45) is matched with a mounting hole in the second bearing chamber (46), and the other end of the second bearing end cover (45) is connected with the second bearing chamber (46) through a sixth fastener component (118) in a screw connection mode; an inner hole of the third bearing (48) is matched with the second shaft (50), and the third bearing is axially positioned by an elastic retainer ring (47) for the third shaft and an elastic retainer ring (49) for the fourth shaft; the fourth bearing (52) is arranged in the second bearing chamber (46), is matched with the second shaft (50), and is axially positioned by means of an inner hole of the second bearing chamber (46) and a fifth shaft elastic retainer ring (51); a third shaft circlip (47), a fourth shaft circlip (49) and a fifth shaft circlip (51) are all arranged on a second shaft (50).

The omnidirectional movement and omnidirectional traveling mechanism is characterized in that: the first driving unit assembly (102), the second driving unit assembly (105), the third driving unit assembly (107) and the fourth driving unit assembly (110) respectively comprise a rotating platform assembly, a wheel driving unit assembly, a lifting platform and wheels, wherein the rotation of the first rotating platform assembly (111) is controlled by adjusting the rotating speed and the steering direction of the first motor (33), the lifting of the first driving unit assembly (102) is controlled by adjusting the lifting of the first lifting platform (30), and the first wheel driving unit assembly (113) can drive the first wheel (32) to rotate; similarly, the second driving unit assembly (105), the third driving unit assembly (107) and the fourth driving unit assembly (110) can realize three motions of rotation, lifting and rotation of the assemblies.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A control method of omnidirectional movement is characterized in that: the omnidirectional walking mechanism adopted by the control method of the omnidirectional motion comprises the following steps: the device comprises a rack assembly (101), a first driving unit assembly (102), a first motor mounting frame assembly (103), a second motor mounting frame assembly (104), a second driving unit assembly (105), a box body assembly (106), a third driving unit assembly (107), a third motor mounting frame assembly (108), a fourth motor mounting frame assembly (109), a fourth driving unit assembly (110), a cover plate (1), a front end angle steel frame (2), a right side angle steel frame (3), a rear end angle steel frame (4) and a left side angle steel frame (5);

the first driving unit assembly (102) consists of a first rotating platform assembly (111), a first fastener assembly (112), a first wheel driving unit assembly (113), a second fastener assembly (114), a first lifting platform (30), a spacer (31) and a first wheel (32); the first rotating platform assembly (111) consists of a third fastener assembly (115), a fourth fastener assembly (116), a fifth fastener assembly (117), a first motor (33), a first bearing end cover (34), a first bearing chamber (35), a first bearing (36), a first shaft elastic retainer ring (37), a first shaft (38), a first rotating platform connecting frame (39), a second bearing (40), a second shaft elastic retainer ring (41), a second rotating platform connecting frame (42) and a first hole elastic retainer ring (43); the first vehicle wheel driving unit assembly (113) consists of a third fastener assembly (115), a sixth fastener assembly (118), a second motor (44), a second bearing end cover (45), a second bearing chamber (46), a third circlip (47) for the shaft, a third bearing (48), a fourth circlip (49), a second shaft (50), a fifth circlip (51) and a fourth bearing (52);

in the first driving unit assembly (102), the second bearing chamber (46) in the first wheel driving unit assembly (113), the first rotating table connecting frame (39) in the first rotating table assembly (111) and the mounting hole on the gasket (31) are matched, and the gasket (31) and the first wheel driving unit assembly (113) are sequentially fixed on the first rotating table assembly (111) through the first fastener assembly (112) in a screw connection mode; the first wheel (32) is matched with a mounting hole on a second shaft (50) in the first wheel driving unit component (113), and the first wheel (32) is fixed on the first wheel driving unit component (113) through a second fastener component (114) in a screw connection mode; the first rotating platform assembly (111) and the first lifting platform (30) are matched through a second rotating platform connecting frame (42) in the first rotating platform assembly (111), the first lifting platform (30) and a mounting hole at one end of a front end cross beam (14) in the rack assembly (101) and are fixed on the rack in a screw connection mode;

the rack assembly (101) is formed by welding a vertically arranged left side channel steel underframe (22) and a vertically arranged right side channel steel underframe (21); 2 fourth channel steel brackets (9) and a fifth channel steel bracket (10) which are vertically arranged are welded in the vertical direction of the upper end of the left side channel steel underframe (22); 2 sixteenth channel steel brackets (26) and a first channel steel bracket (6) which are vertically arranged are welded in the vertical direction of the lower end of the left side of the left channel steel underframe (22); 2 seventh channel steel brackets (12) and ninth channel steel brackets (15) which are vertically arranged are welded in the vertical direction of the upper end of the right side of the right channel steel underframe (21); 2 thirteenth channel steel brackets (20) and a second channel steel bracket (7) which are vertically arranged are welded in the vertical direction of the lower end of the right side of the right channel steel underframe (21); a horizontally arranged front end cross beam (14) is welded at the upper ends of a left channel steel underframe (22) and a right channel steel underframe (21) which are vertically arranged; 2 sixth channel steel brackets (11) and eighth channel steel brackets (13) which are vertically arranged are welded on the front end beam (14); a horizontally arranged rear end cross beam (23) is welded at the lower ends of a left channel steel underframe (22) and a right channel steel underframe (21) which are vertically arranged; 2 fourteenth channel steel brackets (24) and fifteenth channel steel brackets (25) which are vertically arranged are welded on the rear end beam (23); a left welding frame (29) which is in U-shaped arrangement is welded on the left side of a left channel steel underframe (22) which is vertically arranged; 3 seventeenth channel steel brackets (27), eighteenth channel steel brackets (28) and third channel steel brackets (8) which are vertically arranged are respectively welded on the left welding frame (29); a U-shaped right welding frame (17) is welded on the right side of a vertically arranged right channel steel underframe (21); 3 tenth channel steel brackets (16), eleventh channel steel brackets (18) and twelfth channel steel brackets (19) which are vertically arranged are respectively welded on the right welding frame (17);

all components in the box body assembly (106) are connected into a whole box body structure in a welding mode;

the motion modes of the omnidirectional walking mechanism comprise a front-back movement mode (60), a right oblique upward movement mode (61), a right oblique downward movement mode (62), a transverse movement mode (63), a left oblique upward movement mode (64) and a left oblique downward movement mode (65); the control method of the motion mode comprises the following steps:

1) Fore-and-aft movement pattern

A. Forward moving motion mode

When the omnidirectional walking mechanism moves forwards, a servo motor driver connected with the PLC drives a motor in a wheel driving unit assembly to synchronously drive respective wheels to rotate forwards, and meanwhile, the PLC outputs an analog quantity voltage of 0 to plus or minus 10 volts to the servo driver, so that the rotating speed of the motor is in direct proportion to the voltage value of the analog quantity, and the analog quantity voltage value output by the PLC is used for controlling the rotating speed of the motor, thereby controlling the omnidirectional walking mechanism to realize the forward movement at three different speeds of speed 1, speed 2 and speed 3, and the method comprises the following specific steps:

B. backward moving motion pattern

2) Transverse movement

A. lateral left shift motion pattern

Step (1): the control circuit triggers the hydraulic power driving unit to drive the lifting platforms in the four driving unit assemblies to synchronously and stably lift at a slow speed, simultaneously monitors and controls the synchronous lifting height of each lifting platform in real time through the pressure sensor, when the four wheels of the omnidirectional walking mechanism are disengaged from the ground, the pressure sensor reaches a set threshold value 1, and the control circuit controls each lifting platform to stop synchronous lifting after a certain time delay;

and (3): after the motion positions of the four wheels are adjusted, the control circuit triggers the hydraulic power driving units to drive the lifting platforms in the four driving unit assemblies to synchronously and stably descend at a low speed, simultaneously, the synchronous descending height of each lifting platform is monitored and controlled in real time through the pressure sensors, when the four wheels of the omnidirectional walking mechanism contact the ground, the pressure sensors reach a set threshold value 2, and the control circuit controls each lifting platform to stop synchronous descending after a certain time delay;

B. transverse rightward movement motion mode

and (5): after certain time delay, the control circuit applies reverse voltage to the motors in the four wheel driving unit assemblies through the PLC to enable the wheels to rotate reversely, and the omnidirectional traveling mechanism is enabled to move transversely rightwards at three different speeds of 4, 5 and 6;

3) Oblique movement

A. right oblique upward movement mode

step (2): the control circuit continuously controls the rotating speed and the rotating direction of the motors in the four rotating platform components, so that the clockwise synchronous rotating angle value of the motors is theta, and the theta is more than 0 and less than 90 degrees;

B. omnidirectional walking mechanism right-oblique downward movement mode

C. left oblique upward movement mode

step (2): the control circuit continuously controls the rotating speed and the rotating direction of the motors in the four rotating platform components, so that the counterclockwise synchronous rotating angle value of the motors is theta, and the theta is more than 0 and less than 90 degrees;

D. left-oblique downward movement mode

and (5): after certain time delay, the control circuit applies reverse voltage to the motors in the four wheel driving unit assemblies through the PLC to enable the wheels to rotate reversely, and therefore the omnidirectional travelling mechanism can move downwards in a left inclined mode at three different speeds, namely 4, 5 and 6;

4) Reset mode

(1) the control circuit triggers the hydraulic power driving unit to drive the lifting platforms in the four driving unit assemblies to synchronously and stably lift at a slow speed, simultaneously monitors and controls the synchronous lifting height of each lifting platform in real time through the pressure sensor, when the four wheels of the omnidirectional walking mechanism are disengaged from the ground, the pressure sensor reaches a set threshold value 1, and the control circuit controls each lifting platform to stop synchronous lifting after a certain time delay;

(2) the control circuit controls the rotating speed and the steering of the motors in the four rotating platform assemblies to synchronously steer to a reset position, namely the position when the side surfaces of the four wheels are parallel to the longitudinal direction of the omnidirectional travelling mechanism vehicle body;

(3) the control circuit triggers the hydraulic power driving unit to drive the lifting platforms in the four driving unit assemblies to synchronously and stably descend at a low speed, simultaneously monitors and controls the synchronous descending height of each lifting platform in real time through the pressure sensor, when the four wheels of the omnidirectional walking mechanism contact the ground, the pressure sensor reaches a set threshold value 2, and the control circuit controls each lifting platform to stop synchronous descending after a certain time delay;

5) Movement of the lifting platform

A. lifting motion mode of lifting platform

B. lowering movement mode of lifting platform

C. lowering movement mode of lifting platform

2. A method for controlling an omnidirectional exercise according to claim 1, wherein: in the first rotating platform assembly (111), a first motor (33) is fixed on a frame assembly (101) through a first motor mounting frame assembly (103); the first motor (33) is matched with a mounting hole in one end of the first bearing end cover (34), and one end of the first bearing end cover (34) is fixed on the first motor (33) through a third fastener component (115) in a screw connection mode; meanwhile, the other end of the first bearing end cover (34) is matched with a mounting hole in the first bearing chamber (35), and the other end of the first bearing end cover (34) is connected with the first bearing chamber (35) through a fourth fastener component (116) in a screw connection mode; the first bearing (36) is arranged in the first bearing chamber (35) and is axially positioned by means of the first bearing end cover (34) and the inner hole of the first bearing chamber (35) respectively; the first shaft (38) is matched and positioned with the first bearing (36) by a shaft shoulder and a circlip (37) for the first shaft respectively; the first shaft (38) is matched with a mounting hole in the first rotating table connecting frame (39), and the first shaft (38) is fixed in the first rotating table connecting frame (39) through a fifth fastener component (117) in a screw connection mode; the second bearing (40) is arranged in the second rotating table connecting frame (42) and is axially positioned by the elastic retainer ring (43) for the first hole and the inner hole of the second rotating table connecting frame (42) respectively; the protruding shaft outside the first rotating platform connecting frame (39) is matched with the inner hole of the second bearing (40) and is matched and positioned with the second bearing (40) by a shaft shoulder on the protruding shaft and a circlip (41) for the second shaft.

3. A method for controlling an omni-directional movement according to claim 1, wherein: in the first wheel driving unit component (113), a second motor (44) is matched with a mounting hole at one end of a second bearing end cover (45), and one end of the second bearing end cover (45) is fixed on the second motor (44) through a third fastener component (115) in a screw connection mode; meanwhile, the other end of the second bearing end cover (45) is matched with a mounting hole in the second bearing chamber (46), and the other end of the second bearing end cover (45) is connected with the second bearing chamber (46) through a sixth fastener component (118) in a screw connection mode; an inner hole of the third bearing (48) is matched with the second shaft (50), and the third bearing is axially positioned by an elastic retainer ring (47) for the third shaft and an elastic retainer ring (49) for the fourth shaft; the fourth bearing (52) is arranged in the second bearing chamber (46), is matched with the second shaft (50), and is axially positioned by means of an inner hole of the second bearing chamber (46) and a fifth shaft elastic retainer ring (51); the third shaft elastic retainer ring (47), the fourth shaft elastic retainer ring (49) and the fifth shaft elastic retainer ring (51) are all arranged on the second shaft (50);