Abstract:

The flexible feature of planetary surface sampling manipulator is obvious, since it usually consists of several slender arms and rotary joints in series, to meet the requirements of large area sampling and system weight optimization. A control strategy based on flexible compensation is proposed for the 4-DOF planetary surface sampling manipulator, to improve its motion precision. Based on hybrid coordinate method and considering bending deformation of joints and arms, the kinematics model of manipulator is established for calculating flexible deformation in real time. The variable acceleration-uniform motion-deceleration trajectory of manipulator tip in Cartesian space, while the acceleration is consistent and smooth, is planned with flexible deformation compensation. Models of dynamics and joint controller are established, to verify the effectiveness of the control strategy with the simulation of typical tasks of manipulator. The results show that the control strategy can obviously improves the dynamic tracing and tip location precision of manipulator.

Key words: control, manipulator, planetary surface, flexibility