Abstract: A method for improving the frequency property of flexible redundant manipulator is studied. Firstly, the factors which influence the natural frequencies of a flexible manipulator are analyzed and a conclusion is drawn. The conclusion is that the natural frequencies of a flexible manipulator can be increased through adjusting some joint kinematic parameters （e.g., joint-angle and joint-velocity） properly while its structural parameters remain unchanged. Then, the relationship between a flexible redundant manipulator's self-motions and its joint kinematic parameters is studied. On this basis, a method to adjust a flexible redundant manipulator's joint kinematic parameters by planning its self-motions properly is proposed. The natural frequencies of a flexible redundant manipulator can be increased by this method while its end-effector's nominal motion remains unchanged. And this method can be used for avoiding dynamic singularity and enhancing dynamic performance of a flexible redundant manipulator. Furthermore, the corresponding algorithm is suggested. Finally, by carrying out some simulations, the method is verified to be feasible.

Key words: flexible redundant manipulator, natural frequency, joint kinematic parameter, dynamic singularity