Kinetic drag force analysis of micro in-pipe robot

Kinetic drag force is an important performance for micro in-pipe robot. It influences the velocity, traveling distance and load ability of the robot directly. First, a novel creeping micro in-pipe robot is presented in this paper, and the system structure and operating principle are introduced. Then cable drag force, rolling resistance, moment of resistance in elbow, and climbing resistance are analyzed respectively in detail. The analytic model is established and the calculating formulas of resistances mentioned above are obtained. Finally, some useful conclusions are drawn, which are important for optimal design and motion control of the robot.