Trajectory planning with residual vibration suppression for space manipulator based on particle swarm optimization algorithm

Space manipulator suffers from vibration problems mainly due to the flexibility of joints and links in a microgravity environment. This article presents a new optimization method of trajectory planning with minimum residual vibration for space manipulator system which is modeled by absolute coordinate-based method. First, absolute nodal coordinate formulation, which can describe large rotation and large deformation of flexible bodies precisely, is used to describe the deformation of flexible links, and natural coordinate formulation with nonlinear torsion stiffness function is used to model flexible joints. Then, joint rotation trajectory resulting from the planned end-effector trajectory by inverse kinematics theory is discrete through the proposed cosine-based function that has been validated to suppress the residual vibration. The particle swarm optimization algorithm is employed to achieve minimum residual vibration by optimizing redundant coefficients of movement derived from inverse kinematics theory. The effectiveness of the proposed method is illustrated via simulation of a planar three-link manipulator taking large deformation and large rotation into account. Results show that the optimized method can exhibit better features for the residual vibration suppression as compared to those of the original cosine-based trajectory.