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 put forward the model of the wheel legged pipe walking mechanism. In the IPRIVO80 era, Fukuda Toshio, shellfish, Okada Toku, Ma Yuki, Fukuda Ryoji and others made full use of the research results and modern technology of the law, the United States and other countries, and developed various kinds of inner tube robots. HyoukR.C. and others at Han Guocheng University have developed natural gas." 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." style="box-sizing: border-box">How much is the robot for pipeline inspection? 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, kinematics model is the foundation of 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. KarlIagnemma and others 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.