Kinematic properties of wheeled mobile robots in round ducts/pipes

To solve the motion control problem of wheeled mobile robots in round ducts/pipes, kinematic properties of wheeled mobile robots in round ducts/pipes are analyzed. The description of posture and motion of a single wheel on a plane is applied to the wheel rolling on the wall of round ducts/pipes by dint of the tangent plane of the cylinder at the contacting point. The trajectory and velocity of the center of a single wheel pure rolling in round ducts/pipes are educed. Geometric constraints of two-wheel robots and three-wheel robots in round ducts/pipes are analyzed respectively. With the theory of instantaneous screw of a rigid-body motion, the kinematic properties of type (1,1) two-wheel robots, type (1,1) three-wheel robots, moving in round ducts/pipes is presented and discussed respectively. Simulation results are presented to show the trajectory of the center of a single wheel pure rolling on the wall of round ducts/pipes, the virtuality of the geometrical restriction equations and performance of the instant screw of the wheeled mobile robots in vertical round ducts.