Design of in-pipe 3SPR/3RPS parallel manipulator and its kinestatics analysis

An in-pipe robot must be able to adapt to the various geometric changes of pipes and have large enough load carrying capacity in order to move freely in industry pipe and drag heavy load. A novel in-pipe 3SPR/3RPS type parallel manipulator is proposed and its kinematics is analyzed in this paper. First, an in-pipe parallel manipulator with multi-foot is designed, and its principle and characteristics are explained. Second, the kinematics formulae are derived for solving the displacement, velocity and acceleration of foot mechanism and parallel manipulator. Third, the statics formulae are derived for solving the active force of the foot mechanism and the active/constrained forces of the parallel manipulator. Finally, an analytic example is given for solving kinematics and statics of the in-pipe parallel manipulator and analytic solutions are verified by simulation solution.