CN105667632A - Omnidirectional mobile platform for Mecanum wheels - Google Patents

Abstract

The invention discloses a Mecanum wheel omnidirectional mobile platform, which comprises a vehicle frame, a Mecanum wheel, an independent suspension module, a power transmission device, a main control box and a battery pack. Each Mecanum wheel is set under the frame through an independent suspension module; the main control box can coordinately control the speed and steering of all Mecanum wheels. The independent suspension module includes two cantilevers arranged parallel to each other, a connection plate and a shock absorber that connect the two cantilevers fixedly; one end of the shock absorber is connected with the connection plate, and the other end of the shock absorber is connected with the vehicle frame; two One end of the cantilever is connected to the transmission shaft with the Mecanum wheel through the bearing with seat. After adopting the above structure, it can flexibly realize omnidirectional movement in the plane, the structure is simple and reliable, the overall bearing capacity is strong, and it can ensure the full contact between the Mecanum wheel and the ground, which improves the running stability and control accuracy of the mobile platform. The structure is compact, the applicability is strong, and it is suitable for promotion.

Description

An Omnidirectional Mobile Platform with Mecanum Wheels

technical field

The invention relates to a mobile device, which belongs to the technical field of transportation and transportation devices, in particular to an omnidirectional mobile platform with Mecanum wheels.

Background technique

With the continuous expansion of the manufacturing industry and the continuous development of automatic control technology, the loadable mobile equipment based on the wheeled mobile platform has been widely used in the fields of manufacturing automation, storage material transportation, industrial robots and daily life. Traditional wheeled mobile equipment usually has many unfavorable factors such as large turning radius and inability to move laterally, so its space utilization rate is low and movement flexibility is poor during operation.

Compared with other omnidirectional wheels such as ball wheels and continuous switching wheels, Mecanum wheels have a stronger load-carrying capacity; at the same time, because of the special structure of Mecanum wheels, the omnidirectional mobile platform based on Mecanum wheels does not need to design a special steering mechanism for the wheels. At present, the omni-directional mobile equipment represented by Mecanum wheel technology can realize forward and backward, left and right, and in-situ rotation on a two-dimensional plane, and has the motion characteristics of moving in any direction without changing the posture of the car body itself. It can overcome the shortcomings of traditional wheeled mobile equipment that cannot achieve lateral movement and in-situ rotation, so it has greater flexibility in movement, and is especially suitable for working in occasions where the operating space is narrow and crowded, the movement route is tortuous, and the movement flexibility is high. .

When the Mecanum wheel omnidirectional mobile equipment is working, its sports field cannot be completely flat, which will inevitably cause the phenomenon of "hitting the ground" in the roller structure of the Mecanum wheel, which will be unfavorable to the stability of the body movement and its movement accuracy. influences.

The patent application with the application number 201410427677 (Beijing University of Aeronautics and Astronautics, an all-round mobile platform vehicle chassis with stepless wheelbase adjustment), discloses an omnidirectional mobile platform vehicle chassis with infinitely adjustable wheelbase, which uses Mecanum The wheels can move in all directions, and the whole vehicle is divided into four modules with the concept of modular design, and each module is connected by a ball screw to realize the function of wheelbase adjustment.

After the chassis in the above-mentioned patent application is adjusted, because the chassis actually belongs to a rigid body structure, a slight unevenness of the ground will cause the car body to vibrate and affect the control accuracy.

Contents of the invention

The technical problem to be solved in the present invention is to provide a kind of Mecanum wheel omnidirectional mobile platform for the above-mentioned deficiencies in the prior art. The Mecanum wheel omnidirectional mobile platform has a simple and reliable mechanical structure and stable operation. It has strong obstacle-surmounting ability and carrying capacity.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

An omnidirectional mobile platform with Mecanum wheels, including vehicle frame, Mecanum wheels, independent suspension module, power transmission device, main control box and battery pack;

Each Mecanum wheel is set under the frame through an independent suspension module, and each Mecanum wheel is connected to a power transmission;

The main control box and the battery pack are arranged under the frame, and the main control box can coordinately control the speed and steering of all Mecanum wheels.

The independent suspension module includes two cantilevers arranged in parallel to each other, a connecting plate and a shock absorber fixedly connecting the two cantilevers; one end of the shock absorber is connected to the connecting plate, and the other end of the shock absorber is connected to the vehicle frame; One end of the two cantilevers is connected to the transmission shaft with the Mecanum wheel through the bearing with seat.

The other ends of the two cantilevers are fixedly connected to the optical axis, and both ends of the optical axis are connected to the vehicle frame through bearings with seats.

A support is respectively arranged between the shock absorber, the connecting plate and the vehicle frame, and the shock absorber is rotatably connected with the support.

A shaft sleeve is arranged between the Mecanum wheel and the transmission shaft.

Each Mecanum wheel includes two hub discs, a roller and a roller mandrel. The rollers are coaxially fixed on the outer circumference of the roller mandrel. Both ends of the roller mandrel are connected by rotating pairs and distributed on the hub The circumference of the disc.

Each of the Mecanum wheels also includes a central connecting piece coaxially arranged with the hub disc, the central connecting piece is located in the cavity formed by the rollers, and the two ends of the central connecting piece are respectively fixedly connected to the two hub discs.

Each of the power transmission devices includes a speed reducer and a DC motor, one end of the speed reducer is connected with the DC motor, and the other end of the speed reducer is connected with a transmission shaft equipped with a Mecanum wheel.

The reducer is a worm gear reducer, and the axis of the DC motor is perpendicular to the axis of the drive shaft.

A fixed cavity is arranged at the center of the bottom of the vehicle frame, and the main control box and the battery pack are installed in the fixed cavity.

After the present invention adopts the above structure, it has the following beneficial effects:

1. The setting of the above-mentioned Mecanum wheel does not need to design a steering mechanism specifically for the wheel, but only needs to use the mutual cooperation between the rotation speed and steering of each wheel to realize the movement of the mobile platform in any direction in the plane, especially its ability to realize horizontal The unique advantages of side shifting and in-situ rotation (zero turning radius) make the movement flexibility of the whole device significantly improved.

2. The setting of the above-mentioned independent suspension module can not only buffer the car body when encountering uneven ground, but also ensure sufficient contact between the wheels and the ground. Compared with the rigid body suspension, it can significantly improve the stability of the platform movement. In addition, during the running process, the wheelbase and wheelbase of the whole vehicle change very little, which ensures the control accuracy of the platform movement.

3. The setting of the above-mentioned worm gear reducer can make the DC motor and the transmission shaft vertically placed. In addition, the main control box and the battery pack are installed in the fixed cavity of the vehicle frame, so that the overall structure of the omnidirectional mobile platform is more compact.

4. The installation of the shock absorber has universal interchangeability, which is convenient for replacement according to different load conditions, so that the stability and comfort of the omnidirectional mobile platform can be adjusted within a certain range.

5. The setting of the above-mentioned Mecanum wheels makes the mobile platform have a strong carrying capacity, and the maximum carrying capacity of the platform is 250 kg (excluding its own weight).

Description of drawings

Fig. 1 is the front view of the omnidirectional mobile platform of Mecanum wheel of the present invention;

Fig. 2 is the left view of the Mecanum wheel omnidirectional mobile platform of the present invention;

Fig. 3 is the bottom view of the Mecanum wheel omnidirectional mobile platform of the present invention;

Fig. 4 is the axonometric view of the Mecanum wheel omnidirectional mobile platform of the present invention;

Fig. 5 is an axonometric view of the independent suspension module of the Mecanum wheel omnidirectional mobile platform of the present invention.

Fig. 6 is an exploded view of the Mecanum wheel of the Mecanum wheel omnidirectional mobile platform of the present invention.

Fig. 7 is a partial sectional view of the independent suspension module of the Mecanum wheel omnidirectional mobile platform of the present invention.

In the picture:

1. Frame; 11. Fixed cavity;

2. Independent suspension module;

21. Cantilever; 22. Connecting plate; 23. Bearing with seat; 24. Optical axis; 25. Bracket; 26. Shock absorber;

3. Mecanum wheel;

31. Hub disc; 32. Center connector; 33. Roller; 34. Roller mandrel;

4. Power transmission device;

41. Reducer; 42. DC motor; 43. Transmission shaft; 431. Key; 432. Shaft sleeve; 433. Set screw;

5. Main control box;

6. Battery pack.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

As shown in Figure 1, Figure 2, Figure 3 and Figure 4, a Mecanum wheel omnidirectional mobile platform includes a vehicle frame 1, a Mecanum wheel 3, an independent suspension module 2, a power transmission device 4, a main control box 5 and a battery pack 6.

The number of Mecanum wheels 3 is preferably 4, and the 4 Mecanum wheels 3 are distributed at four corners below the vehicle frame 1 . The number of Mecanum wheels 3 can also be set to multiple according to needs, which are also within the protection scope of the present invention.

Each Mecanum wheel 3 is connected to the vehicle frame 1 through an independent suspension module 2 , and each Mecanum wheel 3 is connected to a power transmission device 4 .

The vehicle frame 1 is preferably an angle steel welded vehicle frame, which has high strength, light weight and strong load capacity of the platform.

The center of the bottom of the vehicle frame 1 is preferably provided with a fixed cavity 11 , and the main control box 5 and the battery pack 6 are installed in the fixed cavity 11 . On the one hand, it improves the space utilization rate, and on the other hand, it also plays a certain protective role.

The above-mentioned main control box 5 corresponds to the control system of the omnidirectional mobile platform, which can coordinately control the speed and steering of all Mecanum wheels 3; the battery pack 6 can provide power for the control system of the entire mobile platform.

As shown in FIG. 5 , each power transmission device 4 includes a reducer 41 , a motor and a transmission shaft 43 , and the motor is preferably a DC motor 42 .

One end of the reducer 41 is connected with the DC motor 42 , and the other end of the reducer 41 is connected with the drive shaft 43 on which the Mecanum wheel 3 is sleeved.

Further, the above-mentioned reducer 41 is preferably a worm gear reducer, and the axis of the DC motor 42 is perpendicular to the axis of the transmission shaft 43 . This setting method, compared with the common planetary gear reduction, can make the structure of the mobile platform more compact and easy to assemble.

The above-mentioned main control box 5 can coordinately control the rotation speed and steering of the four-way DC motors 42, so as to realize the movement of the omnidirectional mobile platform in any direction in the plane.

As shown in FIG. 6 , each Mecanum wheel 3 includes two hub discs 31 , a central link 32 , a roller 33 and a roller mandrel 34 .

The rollers 33 are coaxially and fixedly fitted on the outer circumference of the roller mandrels 34, and the two ends of the several roller mandrels 34 which are sheathed with the rollers 33 are all connected by rotating pairs and preferably evenly distributed on the 31 circumferences of the two hub discs.

The central connecting piece 32 and the hub disc 31 are preferably arranged coaxially. The central connecting piece 32 is located in the cavity formed by the rollers 33 . Both ends of the central connecting piece 32 are fixedly connected to the two hub discs 31 respectively.

Both the above-mentioned central connecting piece 32 and the two hub discs 31 have a central through hole capable of being fitted on the transmission shaft 43 .

The roller 33 of the above-mentioned Mecanum wheel 3 is supported at both ends, and the hub disk 31 is a high-hardness alloy processed part, so that the Mecanum wheel 3 used in the present invention has a higher load-bearing capacity.

The number of the aforementioned independent suspension modules 2 is also preferably four, and each independent suspension module 2 is preferably a longitudinal arm type independent suspension.

As shown in FIG. 5 , each independent suspension module 2 includes two cantilevers 21 , a connecting plate 22 , several bearings with seats 23 , an optical axis 24 , two brackets 25 and a shock absorber 26 .

The two cantilevers 21 are arranged parallel to each other, preferably with equal lengths.

The connecting plate 22 is preferably vertically arranged in the middle of the two cantilever arms 21 . The connecting plate 22 is preferably an L-shaped angle steel.

A bracket 25 is preferably fixedly welded at the center of the top of the connecting plate 22 , and the other end of the shock absorber 26 is also preferably connected to the bottom of the vehicle frame 1 through the bracket 25 . Both the bracket 25 and the shock absorber 26 are preferably rotationally connected.

One of the ends of the two cantilever arms 21, as shown in FIG. It is connected with the power transmission shaft 43 that is sleeved with the Mecanum wheel 3 through two belt seat bearings 23 .

As shown in FIG. 7 , a shaft sleeve 432 capable of axial positioning is preferably provided between the above-mentioned Mecanum wheel 3 and the bearing with seat 23 . The transmission shaft 43 transmits the torque through the key 431 and uses the set screw 433 to achieve radial positioning.

The other ends of the two cantilevers 21 are fixedly connected to the optical axis 24 , preferably welded to the optical axis 24 . Two ends of the optical axis 24 are respectively provided with a bearing with seat 23 , and the base of the bearing with seat 23 is preferably fixedly connected with the side wall of the fixed cavity 11 on the vehicle frame 1 .

During the actual operation of the omnidirectional mobile platform, since the ground cannot be absolutely flat, if there is no setting of the above-mentioned independent suspension module 2, that is, the wheels and the chassis are rigidly connected. In this way, there will be situations where the wheels do not touch the ground or are not in sufficient contact, causing the wheels to spin or slip. When the wheels are idling, the platform will not be four-wheel drive and cannot move in all directions; if the wheels slip, the friction between the wheels and the ground will become smaller, which will cause errors in the running track of the mobile platform.

The setting of the above-mentioned independent suspension module 2 can ensure the full contact between the four Mecanum wheels and the ground, and the vibration of the wheels will be absorbed by the shock absorber 26 and cannot be transmitted to the entire vehicle body, thereby effectively improving the stability; The moderate spring stiffness in the shock makes the wheelbase and wheelbase of the four wheels change in a very small range, thus ensuring the control accuracy. In addition, shock absorbers with different stiffness coefficients can be replaced according to different load conditions, and the mechanical structure has universal interchangeability.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be carried out to the technical solutions of the present invention. These equivalent transformations All belong to the protection scope of the present invention.

Claims (10)

1. a Mecanum takes turns Omni-mobile platform, it is characterised in that: include vehicle frame, Mecanum wheel, independent suspension module, actuating unit, primary control box and set of cells;

Each Mecanum wheel is arranged on below vehicle frame each through independent suspension module, and each Mecanum wheel is all connected with an actuating unit;

Primary control box and set of cells are arranged on the lower section of vehicle frame, and all Mecanum rotating speed taken turns can be carried out Collaborative Control with turning to by primary control box.

2. Mecanum according to claim 1 takes turns Omni-mobile platform, it is characterised in that: described independent suspension module includes two cantilevers arranged in parallel, two cantilevers is fixed connecting plate and the amortisseur of connection; One end of amortisseur is connected with connecting plate, and the other end of amortisseur is connected with vehicle frame; Wherein one end of two cantilevers is connected with the power transmission shaft being set with Mecanum wheel each through rolling bearing units.

3. Mecanum according to claim 2 takes turns Omni-mobile platform, it is characterised in that: the other end of two described cantilevers is fixedly connected with on optical axis, and the two ends of optical axis are connected with vehicle frame each through rolling bearing units.

4. Mecanum according to claim 2 takes turns Omni-mobile platform, it is characterised in that: being each provided with a support between described amortisseur and connecting plate and vehicle frame, amortisseur is connected with holder pivots.

5. Mecanum according to claim 2 takes turns Omni-mobile platform, it is characterised in that: it is provided with axle sleeve between described Mecanum wheel and power transmission shaft.

6. Mecanum according to claim 1 takes turns Omni-mobile platform, it is characterized in that: each described Mecanum wheel all includes two wheel hub disks, roller and roller mandrel, roller is coaxially fixedly set in the periphery of roller mandrel, and the roller mandrel two ends being set with roller all connect with revolute pair and are distributed in the circumference of wheel hub disk.

7. Mecanum according to claim 6 takes turns Omni-mobile platform, it is characterized in that: each described Mecanum wheel all also includes the central connector being coaxially disposed with wheel hub disk, central connector is positioned at roller and encloses the cavity of formation, and the two ends of central connector are fixing with two wheel hub disks respectively to be connected.

8. Mecanum according to claim 1 takes turns Omni-mobile platform, it is characterized in that: each described actuating unit all includes decelerator and direct current generator, one end of decelerator is connected with direct current generator, and the other end of decelerator is connected with the power transmission shaft being set with Mecanum wheel.

9. Mecanum according to claim 8 takes turns Omni-mobile platform, it is characterised in that: described decelerator is worm type of reduction gearing, the axis of direct current generator and the axis perpendicular of power transmission shaft.

10. Mecanum according to claim 1 takes turns Omni-mobile platform, it is characterised in that: described bottom of frame is provided centrally with lock chamber, primary control box and set of cells and is arranged in this lock chamber.