" style="box-sizing: border-box;background: transparent">Industrial pipeline robot Domestic development.

In 70s, the development of petroleum, chemical industry, natural gas and nuclear industry and the need for pipeline maintenance stimulated the research of robot in the pipeline. It is generally believed that the French J. VR`ERTUT first launched the research on the theory and prototype of the robot inside the pipe. In 1978, he proposed the IPRIVO model of the wheel legged inner pipe walking mechanism. In 80s, Fukuda Toshio, sun Bei Ying Shi, Okada Tokuji, Ma Yuki and Fukuda Ryoji of Japan made full use of the research results and modern technology of the United States and other countries, and developed various kinds of inner tube robots. Natural gas was developed by Hyouk R. C. of Han Guocheng University." style="box-sizing: border-box">Pipe inspection robot MRINSPECT series. The research of robot technology in China has been over 20 years ago. The research work of Harbin Institute of Technology, the Shenyang Institute of automation, Chinese Academy of Sciences, Shanghai Jiao Tong University, Tsinghua University, Zhejiang University, Tsinghua University, China, Daqing, Petroleum Administration, Shengli Oilfield, Zhongyuan oil field and other units carried out research work in this field. For the research of pipeline robot, there are many researches on multi wheel support structure before, so that the traditional wheeled mobile robot is directly used in the detection and maintenance of circular pipes. When the wheel of a multi wheeled robot is in contact with the wall, the connection between the contact point and the wheel core is in the radial direction of the cylinder, and the direction of the wheel is parallel to the bus bar of the cylinder. This is a special case of the single wheel's upper position in the pipe surface. When the wheeled mobile robot is running in the pipeline, the position and posture of each wheel of the wheeled mobile robot in the pipeline is unpredictable due to the size of the pipe, the curve and the "T" joint. The axis direction of the wheel may not be perpendicular to the radius of the circular tube, so it is necessary to analyze the single wheel on any surface of the pipe surface to satisfy pure rolling and no sideslip. Kinematic characteristics under conditions. For the wheeled pipe robot in the actual application process, such as in the elbow and irregular pipes, the motion interference occurs. Due to the lack of driving force caused by internal friction, because of the deformation of the wall and the error of the robot itself, the robot can deviate from the correct posture, even rollover and block in the pipeline. Researchers at home and abroad mainly solve problems in terms of structure, such as differential, flexible connection, etc., but this will make the structure more complex and increase the cost.

For wheeled pipe robot, accurate kinematic model is the basis for accurate motion control. The kinematics and control theory of a single wheeled and wheeled mobile robot on the pipe surface are very few. It is necessary to set up a set of theories about the kinematics of wheeled pipe robot.

Campion et al. On the basis of previous research results, the kinematics and dynamics models of wheeled mobile robots on horizontal road surface are analyzed. Four state space models are summarized: two pose kinematics model, configuration kinematics model, pose dynamics model, and configuration dynamics model. Karl Iagnemma et al analyzed the various contact situations between wheels and the ground when the wheels and the ground were not rigid, and when the ground was irregular. However, the above model assumes that the wheel and the ground are not deformable, and the ground is a regular horizontal road surface. When a wheeled mobile robot is running in a circular tube, because the environment inside the circular tube is a three-dimensional curved surface environment, the wheeled mobile robot actually operates on a curved surface, so the above model can not be applied to the wheeled mobile robot in a circular tube.

Because wheel cleaning robot operates in three dimensional space when it runs in a circular pipe, its kinematic model is totally different from that of a wheeled mobile robot on the plane. Under the premise of geometric constraint and speed constraint, the relationship between the control input of mobile wheeled mobile robot and the change of robot posture and coordinates is analyzed, and its kinematics model is established. Recently, the research focus of wheeled pipe robot at home and abroad is mainly to improve controllability and controllability of wheeled pipe robot, and the robot develops towards the direction of autonomous operation.Although many scholars have improved the performance of robots from the aspect of structure, there is no systematic analysis of the motion control theory of wheeled mobile robots in circular tubes. Therefore, we need to design the corresponding algorithm according to the kinematics model, so that the robot can achieve stable control in the circle to meet the needs of engineering application.

For wheeled drainpipe robot, besides the structural design and material selection, the main scientific problem is to establish the kinematics model of wheeled robot in the circular pipe, and design corresponding control algorithm, so that the robot can run autonomously, and also can control its horizontal driving operation according to the gesture information, without lateral rollover and card operation. Death and driving force are not enough, so it has good controllability.

In order to establish the kinematic model of wheeled robot in a circular pip♚e, the following 4 problems🌠 should be solved and the corresponding motion control algorithm should be designed theoretically.

(1) the inst🧸antaneous speed of the wheel center of a single wheel in any position and position on the pipe surface. The scientific problem of the kinematic characteristics of a single wheel in the pipeline is the description of its position and position and the speed of its wheel core satisfying the con🔯dition of pure rolling and no sideslip.

(2) analyze the geometric constraints of wheeled mobile robots on the♎ pipe surface, and deduce the relationship between 6 pose coordinates.

Wheeled robot runs in a three-dimensional cylindrical environment in the pipeline, and its pose coordinates change from the 3 dimension on the plane to the 6 dimension of the space. But because the robot has a specific geometric constraint when running in the pipeline, the 6 pose coordinates of tY are not independent of each other, so it is necessary to deduce the relationship between the 6 pose coordinates.

(3) establish the kinematic model of wheeled mobile robot on the circular pipe surface. The difficulty of deriving the kinematic model is how to establish the relationship between the control rate and the change rate of position and posture coordinates. The control input directly affects the speed of the wheel core, and the wheel center determines the speed of the robot's rigid body, so it is necessary to analyze the relationship between the rigid body of the robot and the speed of the wheel core. The essence of this problem is to deduce the relationship between instantaneous screw motion parameters and control input, and the relationship between the pose change rate of the robot and the control input.

(4) according to the kinematic model and operation requirements, the corresponding control rate is designed to keep the robot running in a horizontal direction. According to the established kinematic model, the attitude angle is taken as the state variable, and the corresponding control rate is designed through the feedback of the attitude sensor, so that the robot can run in accordance with the required attitude in the pipeline. The kinematic model is mainly used to design the control ratio and to analyze the stability of Lee Yap Andrianof's (Lyapunov) function.

Main research contents:

(1) the geometric modeling of pipe surface. The kinematic characteristics of a single wheel on arbitrary surface position of a single w♑heel on a pipe surface are studied. The relationship between wheel speed and driving control input under pure rolling and no sideslip conditions is analyzed, and the relationship between wheel center trajectory and wheel position is also analyzed.

(2) the geometric constraint analysis of wheeled mobile robot on the curved sur🌊face of the tube. According to the condition that the wheeled mobile robot is tangent to the wall of each wheel in the circular tube, the geometric constraints in the circular tube are analyzed, especially the relationship between the 6 coordinates of the gesture coordinates and the space position coordinates.

(3) kinematic analysis of a wheeled mobile robot oไn a cylindrical🃏 surface.

This project will analyze the relationship between robot control input and robot screw motion parameters, and then deduce the kinematics model of wheeled mobile robot in circular tube, and verify the kinematics modelꦍ through simulation experiments.

(4) design a wheeled mobile robot system🌊 and corresponding control algorithm, design a set of wheels to expand, and design the cꦯorresponding motion control algorithm, so that the robot can maintain horizontal driving in the pipeline.

The overall re🍌sea🍒rch plan of Schroder industrial measurement and control equipment Co., Ltd. on the crawling robot platform

(1) kinema🅠tic analysis of a single wheel on a circular pipe surface.

The position and motion description of a single wheel on a circular pipe surface is used to describe the pose and motion of a single wheel in a plane, and to extend the tangent plane of the contact point to the surface of a circular tube. Take the analysis of a single wheel in a horizontal tube as an example. The point of the contact point between the wheel and the tube is a spatial surface, and the outer circle of the wheel is a space curve. Then Q is also on the space curve and the space surface. Q is used as the tangent m of the space curve and the tangent plane of the spatial surface, while the cylindrical busbar I is also made, so m and I are on the tangent plane. The normal vector of tangent plane, that is, the radius of the cylinder of the contact point, and the angle between the tangent line m and the normal line of the tangent line are denier. The angle between tangent m and the cylindrical busbar is a. After defining the single wheel's description of the upper surface of the pipe surface, the trajectory equation of the pure wheel on the pipe surface is derived. When the wheel is at angular speed. When the cylinder is pure rolling, the locus of the contact point between the cylinder and the wheel is a cylindrical helix, and its trajectory parameter equation can be derived. In order to deduce the locus of the wheel center, the active coordinate system is established based on the tangent vector, the main normal line and the auxiliary normal line at the contact point Q, namely the Furlong Nate (Frenet) moving frame, and the coordinates of the C center of the wheel center are solved. Then, the differential equations of the wheel center are obtained, and the same method of calculating the instantaneous speed of the wheel core and the wheel center trajectory of the single wheel satisfying the pure rolling and non sideslip conditions can be calculated. On the curved surface of the pipe bend, the wheel 16T meets the instantaneous speed and trajectory of the wheel under pure rolling and no sideslip conditions. According to the theory of derivation, the new wheel of wheeled pipe robot is designed.

(2) the geometric constraint analysis of wheeled mobile robot on the curved surface of the pipe is introduced. The position and position of the wheeled mobile robot on the pipe surface are represented by the coordinates of the robot and the Euler angles of the robot. After the wheel is simplified into a disc, the outer rim of each wheel can be shown by the square F of the circle. In the four wheel or more than four rounds of multi wheeled robot, when the robot runs on the cylinder surface, it can find three simultaneous contact with the wall wheels. When a robot is running on the cylinder of a circular tube, the 3 wheels that are in contact with the wall are always tangent to the cylinder surface. "Then for each wheel, the tangent vector of the contact point between the wheel and the wall is perpendicular to the radius of the circular tube, and at the same time it is perpendicular to the radius of the wheel. According to this tangent condition, 3 constraint equations can be derived, and the relationship between the 6 coordinates of the robot's spatial coordinates and Euler angles is derived.

(3) the kinematic modeling of wheeled mobile robots on circular surface: when the wheeled mobile robot runs in a circular tube, the relative distance between the wheel centers is invariable, and the distance between the wheel core and all the particles of the robot body remains unchanged, so that the wheel body without wheel core can be regarded as a rigid body. The motion of a wheeled robot in a circular pipe is a rigid body spiral motion. Wheel center is not only a point on the rigid body but also a point on the wheel, so the relationship between the kinematics characteristics of each wheel and the kinematics characteristics of the robot body is established through the speed of the wheel core.

The control input of wheeled mobile robot is usually the speed of the driving wheel and the steering angle of the steering wheel.At a certain time, the position and posture coordinates of the robot are known as state variables, and the driving wheel can be widely used to calculate the instantaneous velocity of the wheel center, and the instantaneous velocity of the wheel center can be solved according to the kinematic characteristics of the single wheel in front of the wheel.

According to the speed of two wheel centers, the spiral motion parameters of the wheeled mobile robot can be solved. According to the angular velocity vector of this screw motio🀅n, the rate of Euler angle and the velocity vector of the origin of the robot coordinate system can be deduced. The relationship between the control input and the pose coordinate changes of the robot can be derived, that is, the kinematic model of the wheeled mobile robot in the tube.

(4) develop two ☂sets of experimental system of wheeled mobile robot in circular tube, carry out relevant verification experiments and design a new wheeled mobile robot system th🅷at can be opened, that is, the left and right two rows of wheels can be stretched from parallel to eight.

The crawling robot carrying platform, also known as the "sport carrying platform", is a platform that can selectively carry relevant inspection instruments based on the production tasks. It has been applied to military, power, petroleum, petrochemical, nondestructive testing, municipal, archaeological and other industries. Schroder industry has invested a lot of energy in the research and development of this project, and has sold products at home and abroad under the conquest of a batch of talents. The Shenzhen quality report (three) explains in detail the company's excellent pipeline inspection equipment for the beating pulse of the city.