CN212766551U

CN212766551U - Moving platform motion system

Info

Publication number: CN212766551U
Application number: CN202021176957.9U
Authority: CN
Inventors: 肖湘江; 税海涛; 肖楠; 郭刚; 张冠勇; 刘荣; 陈婷婷
Original assignee: Hunan Chaonengrobot Technology Co ltd; Beijing Institute of Technology BIT
Current assignee: Hunan Chaonengrobot Technology Co ltd; Beijing Institute of Technology BIT
Priority date: 2020-02-21
Filing date: 2020-06-23
Publication date: 2021-03-23
Anticipated expiration: 2030-06-23

Abstract

The utility model relates to a moving platform motion belongs to the robot navigation technology field. The system comprises a running mechanism, a main body structure and a shell which are movably connected, wherein the running mechanism comprises a front wheel part, a rear wheel part and a single hinge point cantilever, and two ends of the single hinge point cantilever are respectively connected with the front wheel part and the rear wheel part; the front wheel part comprises a steering motor and front wheels, and the steering motor controls the front wheels to freely steer; the rear wheel part comprises a drive axle, a rear wheel and a drive motor, the rear wheel is connected with the drive axle, and the drive axle drives the rear wheel to rotate under the control of the drive motor; the single hinge point cantilever is a cantilever beam with a unique hinge point, and the cantilever beam is connected with the rear wheel part through the hinge point. The invention adopts the design of rear wheel differential and front wheel control steering, accurately controls the platform steering and can effectively avoid non-rolling friction abrasion between the tire and the ground caused by the differential.

Description

Moving platform motion system

Technical Field

The invention relates to the field of artificial intelligence, in particular to a moving platform motion system, and belongs to the technical field of robot navigation.

Background

In the field of robots, a mobile robot is an important branch of the robot research field, and the mobile robot integrates the technologies of laser SLAM, positioning technology, multi-sensor data fusion, image processing technology, motion control, path planning, navigation and the like, is a hotspot of the current robot technology, and is also a difficulty. The mobile robot is divided into an indoor robot and an outdoor robot, the two robots are mainly distinguished in application scenes and road conditions, and the outdoor robot provides higher requirements for the motion capability and the positioning capability of the robot. In the design of present outdoor robot platform, there are some problems, specifically are: the chassis without the suspension type platform is hard, so that the vehicle body is easy to vibrate violently during running, and the requirement on the damping performance of the sensor is high; the all-wheel damping type suspension platform has a soft chassis, and the accuracy of the sensor is easily influenced by the change in running. In addition, the existing robot mobile platform generally adopts a differential structure chassis, particularly an outdoor chassis for differential running, and when multiple wheels are used on one side, the steering is easy to cause non-rolling friction between the tires and the ground, so that the tires are damaged.

Disclosure of Invention

Based on this, there is a need to improve the existing motion system of the mobile platform, and provide a motion system of the mobile platform with stronger motion capability and positioning capability.

A moving platform motion system comprises a running mechanism, a main body structure and a shell which are movably connected, wherein the running mechanism comprises a front wheel part, a rear wheel part and a single hinge point cantilever, two ends of the single hinge point cantilever are respectively connected with the front wheel part and the rear wheel part, wherein,

the front wheel part comprises a steering motor and front wheels, and the steering motor controls the front wheels to freely steer;

the rear wheel part comprises a drive axle, a rear wheel and a drive motor, the rear wheel is connected with the drive axle and is driven by the drive axle to rotate under the control of the drive motor;

the single hinge point cantilever is a cantilever beam with a unique hinge point, and the cantilever beam is connected with the rear wheel part through the hinge point.

In one embodiment, the main body structure comprises a monitoring camera, a navigation positioning device, a main support, a power supply, a control box and a hand control frame; the monitoring camera is arranged on the main support and used for acquiring images of the surrounding environment; the power supply is contained in the control box and is independently arranged for the supply of the power supply and the control of the operation; the hand control frame is hinged to the main bracket; the navigation positioning device comprises a main control computing unit, and a GNSS module, a laser radar, an IMU inertia measurement unit and a code disc which are respectively connected with the main control computing unit and cooperate with the main control computing unit; the master control computing unit, the GNSS module, the IMU inertia measuring unit and the code disc are all contained in the control box, and the laser radar is arranged on the main support.

In one embodiment, the running mechanism further comprises a gearbox and a bracket thereof, a tire steering bracket, a shock absorber, a cantilever support and a chassis girder; the steering motor is connected with the gearbox and the bracket thereof; the front wheel is connected with the tire steering bracket; the gearbox and the bracket thereof are movably connected with the tire steering bracket; one end of the drive axle is connected with the cantilever support, and the other end of the drive axle is connected with the rear wheel; the front end of the single-hinge-point cantilever is fixedly connected with the gearbox and the bracket thereof, and the rear end of the single-hinge-point cantilever is hinged with the cantilever support; one end of the shock absorber is connected with the single-hinge-point cantilever, and the other end of the shock absorber is connected with the chassis crossbeam.

In one embodiment, the rear wheel, the drive axle and the drive motor respectively comprise two wheels, and the two wheels are respectively arranged on two sides of the chassis girder to form a differential structure.

In one embodiment, the lidar is a two-dimensional laser sensor.

Compared with the prior art, the moving platform moving system has the following beneficial effects:

the single-hinge-point cantilever structure can solve the problem of obstacle crossing trafficability. The cantilever beam single hinge point suspension is adopted, the arrangement direction of the cantilever beam is consistent with the running direction, when the platform runs and encounters obstacle collision, the cantilever beam single hinge point suspension can move upwards along the hinge point, large-amplitude jumping during obstacle crossing is realized, and the running trafficability is enhanced.

The invention solves the problem of grinding the tire by the chassis steering of the differential structure. The rear wheel of the invention is of a differential structure, the front wheel is matched with the differential steering of the rear wheel under the control of the steering motor, and the steering direction is consistent with that of the rear wheel, so that the non-rolling friction abrasion between the tire and the ground caused by differential can be effectively avoided.

The problem of combination of autonomous navigation and manual driving of the mobile platform is solved. By arranging the hand control frame, the automatic navigation device can be folded during automatic navigation, and can be vertically and fixedly used during manual control.

Drawings

Fig. 1 and fig. 2 are schematic structural diagrams of two operation states of a mobile platform motion system according to a preferred embodiment of the present invention;

FIG. 3 is a schematic diagram of the motion system of the mobile platform of FIG. 1;

FIG. 4 is an exploded view of the travel configuration of the mobile platform motion system of FIG. 1;

FIG. 5 is an exploded view of the main structure of the motion system of the mobile platform of FIG. 1;

fig. 6 is a schematic diagram of the navigation device of the motion system of the mobile platform shown in fig. 1.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Please refer to fig. 1 and fig. 2, which are schematic structural diagrams of two states of the mobile platform motion system according to the preferred embodiment of the present invention. Fig. 1 shows an automatic driving state of the moving platform moving system, and fig. 2 shows a manual driving state of the moving platform moving system.

Please refer to fig. 3, which is a schematic structural diagram of the motion system of the mobile platform shown in fig. 1. The moving platform motion system 100 comprises a running structure 1, a main body structure 2 and a shell 3.

Fig. 4 is an exploded view of the driving structure of the motion system of the mobile platform shown in fig. 1. The running structure 1 comprises a steering motor 101, a gearbox and a bracket 102 thereof, a tire steering bracket 103, a front wheel 104, a single-hinge-point cantilever, a shock absorber 106, a rear wheel 107, a drive axle 108, a cantilever support 109, a drive motor 110 and a chassis girder 111. The steering motor 101, the gearbox and its support 102, the tire steering support 103, the front wheel 104, the single-hinge-point suspension arm, the shock absorber 106, the rear wheel 107, the drive axle 108, the suspension arm support 109, the driving motor 110, and the like all include two sets, that is, the driving structure 1 is a bilateral symmetry structure, and a symmetry line is a connecting line between a midpoint of a connecting line of the front wheels and a midpoint of a connecting line of the rear wheels. The rear wheel 107 is mounted on the driving axle 108, and the driving axle 108 drives the rear wheel 107 to rotate under the control of the driving motor 110. The rear wheels 107 on both sides are respectively and independently driven and are connected into a whole through the chassis girder 111 to form a differential structure for driving. In a specific embodiment, the steering device may be in a three-wheel form, that is, the steering motor 101, the gearbox and its support 102, the tire steering support 103, and the front wheel 104 may be included, and two single-hinge-point cantilevers, a shock absorber 106, a rear wheel 107, a drive axle 108, a cantilever support 109, and a drive motor 110 may be included.

The single hinge point cantilever is a cantilever beam 1051 with a single hinge point 1052, one end of the cantilever beam 1051 is fixedly connected with the gearbox and the bracket 102 thereof, and the other end is hinged with the cantilever support 109 through the hinge point 1052. The cantilever beam 1051 rotates in a vertical plane about the hinge point 1052.

The cantilever mount 109 is fixed to the transaxle 108. One end of the shock absorber 106 is connected with the cantilever beam 1051, and the other end is connected with the chassis girder 111; after the assembly is completed, when the front wheel 104 collides with an obstacle, the front wheel is lifted upwards under the driving of the single-hinge-point cantilever, and meanwhile, the shock absorption and obstacle crossing are completed under the cooperation of the shock absorber 106. When the mobile platform runs and turns, the rear wheels 107 turn in a differential speed mode, and the front wheels 104 achieve flexible turning of running due to matching control of the steering motor 101. Because the steering motor 101 accurately controls the front wheels 104 and the steering direction is consistent, the problem of tire steering and grinding is effectively avoided.

Referring to fig. 5 and fig. 6, the main body structure 2 mainly includes a monitoring camera 201, a navigation positioning device 202, a main support 203, a power supply (not shown), a control box 205, and a hand control frame 206.

The monitoring camera 201 is installed on the main support 203 for obtaining pictures of the surrounding large environment.

The navigation and positioning device 202 includes a master computing unit 11, and a GNSS module 12, a lidar 14, an IMU inertial measurement unit 15, and a code wheel 16 respectively connected to and cooperating with the master computing unit. In a specific implementation process, the main control computing unit 11 may be an improved RK3288 motherboard or an industrial personal computer or a PC with a CPU above i3, and is configured to receive signals transmitted by the GNSS module 12, the laser radar 14, the IMU inertial measurement unit 15, and the code wheel 16, perform corresponding computation and determination according to the signal conditions, and control automatic switching of the positioning mode and actions of the steering motor 101 and the drive axle 108. In the preferred embodiment, the main control computing unit 11 is internally provided with ekf algorithm modules and particle filter algorithm modules.

The GNSS module 12 may be a separate GPS signal receiving module or a beidou signal receiving module, so that the direction of the platform 100 can be accurately calculated.

The master computing unit 11, the GNSS module 12, the IMU inertial measurement unit 15, and the code wheel 16 are all contained in the control box 205, which is not shown in the figure.

Preferably, the lidar 14 is a two-dimensional laser sensor. Compared with a three-dimensional laser radar, the two-dimensional laser sensor has the advantages of low cost, small operand, small CPU occupancy rate and less consumed memory, and can save the CPU occupancy rate and the memory consumption by one order of magnitude. The utility model discloses in choose the LMS141 model of SICK for use, have small, light in weight, power consumption are little to and have multiple communication interface, can switch advantages such as scanning area dynamically.

The IMU inertial measurement unit 15 belongs to strapdown inertial navigation and is composed of two acceleration sensors and angular rate sensors (gyroscopes) in three directions. Generally, the center of gravity of the platform 100 is located as close as possible to improve reliability. The utility model adopts XSENS MTI-300 model, which has strong anti-electromagnetic interference ability after test; the frequency is 10 to 200hz, and the angle error is less than 1 degree.

The code wheel 16, also called encoder, is a sensor for measuring rotation angle and rotation speed, and converts the mechanical geometric displacement on the rotating shaft into pulse or digital signal through the conversion of an observing electric signal.

In an actual working process, if the master control computing unit 11 checks that the GNSS module 12 has a good signal during the operation of the platform 100, combining the position change condition of the platform 100 acquired by the monitoring camera 201 with the acquired RTK GNSS signal, IMU signal, and code wheel signal, and then outputting the position of the platform 100; if the GNSS module 12 has weak signals, which are mostly caused by high-rise shielding and other reasons, the particle filter algorithm module is adopted to fuse the position change condition of the platform 100 acquired by the monitoring camera 201 with the IMU signal and the code wheel signal, and then the position of the platform 100 is output; if the main control computing unit 11 determines that the platform 100 is indoors, the platform 100 position is output after a two-dimensional laser matching algorithm, an IMU signal and a code disc signal are fused through a pre-established map. After the computer is started, when the IMU signal is abnormal and the methods are not effective, the abnormal condition is reported. Specifically, the GNSS module 12 determines that the signal quality is good by receiving eight or more satellite signals and detecting a differential signal. The received Gnss signal format is: GPGGA,000001,3112.518576, N,12127.901251, E,4,8,1,0, M, -32, M,3,0 x 4B; by analyzing the signals, the information such as the current longitude and latitude, the positioning error, the satellite number, the positioning mode, the time stamp and the like can be obtained, the longitude and latitude signals are converted into (x, y) in a Cartesian coordinate system available for the robot and converted into corresponding grids, and the probability of the GNSS module appearing in any grid in the positioning range of the GNSS module is obtained.

Referring to fig. 5 again, the single-line laser 204 is installed at the lower portion of the main support 203 for sensing the environment close to the ground, the control box 205 is independently arranged, and after being correspondingly sealed, the control box can effectively prevent dust and water, and the hand control frame 206 is hinged to the main support 203 and can be used fixedly in a vertical direction or folded down. The hand control frame 206 refers to the hand control lever functions and settings of the existing manual electric balance car.

Casing 3 adopts the preparation of 196 type high strength unsaturated polyester resin materials, wraps up major structure 2 plays the guard action. The specific shape of the autonomous navigation platform can be made into various types, and meanwhile, a plurality of assembly interfaces which can be expanded to be used, such as mechanical arms, fire water cannons, searchlights, tweeters and the like, can be added, so that the function of the autonomous navigation platform 100 is expanded.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the claims.

Claims

1. A moving platform moving system comprises a running mechanism, a main body structure and a shell which are movably connected, and is characterized in that the running mechanism comprises a front wheel part, a rear wheel part and a single hinge point cantilever, wherein two ends of the single hinge point cantilever are respectively connected with the front wheel part and the rear wheel part,

the front wheel part comprises a steering motor and front wheels,

the steering motor controls the front wheels to freely steer;

2. The mobile platform motion system of claim 1, wherein the body structure comprises a surveillance camera, a navigational positioning device, a main support, a power source, a control box, and a hand control frame; the monitoring camera is arranged on the main support and used for acquiring images of the surrounding environment; the power supply is contained in the control box and is independently arranged for the supply of the power supply and the control of the operation; the hand control frame is hinged to the main bracket; the navigation positioning device comprises a main control computing unit, and a GNSS module, a laser radar, an IMU inertia measurement unit and a code disc which are respectively connected with the main control computing unit and cooperate with the main control computing unit; the master control computing unit, the GNSS module, the IMU inertia measuring unit and the code disc are all contained in the control box, and the laser radar is arranged on the main support.

3. The mobile platform motion system of claim 1, wherein the travel mechanism further comprises a gearbox and its support, a tire steer support, a shock absorber, a cantilever support, and a chassis frame; the steering motor is connected with the gearbox and the bracket thereof; the front wheel is connected with the tire steering bracket; the gearbox and the bracket thereof are movably connected with the tire steering bracket; one end of the drive axle is connected with the cantilever support, and the other end of the drive axle is connected with the rear wheel; the front end of the single-hinge-point cantilever is fixedly connected with the gearbox and the bracket thereof, and the rear end of the single-hinge-point cantilever is hinged with the cantilever support; one end of the shock absorber is connected with the single-hinge-point cantilever, and the other end of the shock absorber is connected with the chassis crossbeam.

4. The mobile platform motion system of claim 3, wherein the rear wheels, the drive axle, and the drive motors are respectively two and respectively disposed on two sides of the chassis frame to form a differential structure.

5. The mobile platform motion system of claim 2, wherein the lidar is a two-dimensional laser sensor.