Design and Development of Cam-Operated in-Pipe Robot (CIPR)

Abstract

This paper presented a novel mechanism and dynamic model of cam operated in-pipe robot (CIPR) as a proof of concept. The CIPR would be useful for in-pipe inspection for detecting the defects like cracks, surface wear, damage, scaling etc. Based on the dynamic model, a gripping mechanism actuated by a three-lobed cam has been developed. A special three-lobed cam provides sufficient frictional force to maneuver and stop the robot inside the pipe of diameter 250 mm during inspection and cleaning task. A proposed dynamic model determines the frictional force and torque required to move the robot. A specially designed three-lobed cam makes the overall mechanism compact as compared to available inpipe robots. A single cam is adequate to exert uniform gripping force between the contact surface of the wheel and the inner surface of the pipe. In the present work, solid model of the CIPR is used to analyze and simulate the dynamics of the CIPR using ADAMS. The model is tested in simulated environment for vertical motion to determine the frictional force and wheel torque characteristics. The simulation results are in line with the analytical results. Further, the prototype is successfully maneuvering inside the pipefor different orientations.