Design of spring parameters for a screw drive in-pipe robot based on energy consumption model

The wall pressing arms of a screw drive in-pipe robot are usually designed by using springs to be elastic. This is because pipe-diameter adaptability and climbing obstacle capability can be enhanced by the elastic arms. However, the axis of the robot deviates from that of the pipe exactly because of elasticity and gravity. Some extra energy is consumed wastefully due to wheel slipping and spring deformation. In order to improve energy utilization, this paper focuses on the design of spring parameters including stiffness and preload force. Firstly, kinematics model and static model are proposed in consideration of wheel slipping and spring deformation. Secondly, the energy consumption relation with spring parameters is presented and analyzed numerically based on the robot models. Finally, a parameter design strategy is proposed by which the robot can be energy saving and climb up in the vertical pipe.