An optimization algorithm to expand the reduced workspace with fixed-joint method for redundant manipulator

In this paper, an optimization algorithm is proposed to settle the deficiency of fixed-joint method. The fixed-joint method leads to a reduced workspace which has some inaccessible points due to a special joint fixed. Since different fixed joint has different reduced workspace, we develop a method to make these workspaces mutual complementation. Manipulability is used to select the appropriate joint angle to be fixed in order to satisfy the given posture. By comparing 7-dof manipulator's real-time inverse kinematic solutions, we put forward detailed analysis of the workspace of the end-effector with different fixed joint angles. The kinematics simulation is implemented to verify the correctness of this method.