Design and locomotion control strategy for a steerable in-pipe robot

A steerable in-pipe robot based on screw drive is proposed for curved pipes and T-pipes. The robot with only two motors is composed of the drive mechanism and steering mechanism. The design principles of the robot are analyzed based on the kinematic and statics models. The spring parameters of the elastic arms are selected in consideration of the stability of steering motion. Then the steering locomotion control strategy in curved and T-pipes is given based on a simplified planar connecting rod model. In order to select a proper posture to turn, a posture adjustment strategy making full use of the pipe constraint is also proposed. The simulation results show that the proposed robot can pass through the curved pipes and T-pipes, and adjust the posture by the proposed control strategies.