Adaptive motion planning for CFETR multipurpose overload robot based on iterative tractrix

In this paper, an adaptive motion planning method is proposed for the control requirements of the China Fusion Engineering Test Reactor multipurpose overload robot (CMOR). Firstly, a kinematic model of CMOR is established by Denavit-Hartenberg method, and the working process of entering and leaving the vacuum chamber to complete the maintenance operation is analyzed. An iterative tractrix-based motion planning method is proposed by expanding the basic principle of tractrix. Assuming that the CMOR any link has two mutually perpendicular degrees of freedom to achieve spatial motion capability, a more natural and smooth movement of the CMOR is achieved by recursive operations on the tractrix traction. To accelerate the calculation process and avoid each joint rotation angle of CMOR exceeding the set value, a bidirectional iterative tractrix method and a joint limit rotation angle optimization method based on the bidirectional iterative tractrix method are proposed to improve the convergence speed and motion safety. Finally, a CMOR visualization simulation system is built, and the results show that the CMOR adaptive motion planning method can effectively track the target trajectory and avoid joint rotation angle overrun.