Design And Study Of Differential-drive Adaptive In-pipe Robot

Nowadays,the pipeline transport as a material conveying mode having the character of efficiency,security and environmentally friendly is widely used by people.Pipeline in the process of using is inevitable to face the problem of aging,corrosion,cracking and other issues,In order to meet the needs of pipeline maintenance and detection,pipeline robot has been applied in many aspects,such as pipeline internal cleaning,foreign body detection,defect detection and so on.With the continuous development of the the pipeline,the design of high environment adaptability,high efficiency and running flexible pipe robot has become a focus of research.In order to achieve efficient operation of robot in the interior of pipeline,a pipeline robort with the characters of autonomous differential motion and adaptive variable diameter is designed by adopting the single motor to drive.The differential output mechanism is used in the pipeline robot.When the robot is progessing in the bend pipe,it can automatically adjust the rotation speed of the driving wheel through the differential mechanism,to eliminate the relative sliding between the driving wheels and pipe wall.The robot's external support wheels and spring mechanism is matched,combined into an adjustable mechanical structure,when the robot confronted with obstacles or the change of pipe diameters in progressing in the internal pipe,the robot can use the variable diameter mechanism to adapt to the change of the external environment to improve robot's operation reliability in the pipe.Six wheels are congfigurated on the robot,with three auxiliary support wheels and three drive rear wheels,which acting on the wall with radial radiation at the same time,so as to ensure the stability of the robot in different types of pipeline in the environment.Based on the robot Structure,the force equation of working state for the variable diameter mechanism of pipe robot is theoretically deduced,and the mechanical relation between the driving wheels and pipe wall in robot's moving is obtained,to ensure that under the action of spring force,there is enough friction between the wheel and pipe wall,provide sufficient driving force for the body to run.In the model,the movement of the robot in pipe is built,and the relationship between the angular velocity and the othervariables in the model is obtained by the study of the whole movement and the transmission characteristics of the robot.Analysis of four differential gear train's relations between the output shaft torque and rotational speed,then explain the differential-drive adaptive In-Pipe robot through the pipe bending can be achieved when the corresponding differential working independently,and there is no parasite power generated.Using 3D design software to complete the design of three-dimensional differential-drive adaptive In-Pipe robot,and to analyze the rationality of the structure,the use of mechanical dynamics analysis software to establish a virtual prototype model of the robot running in elbow pipe and variable diameter pipe.Through the simulation analysis of the robot,the autonomous differential characteristics and the adaptive characteristics is verified,Which illustrate the correctness of the theoretical analysis and structure design.