As the connection between the arm and other components is splice, to avoid the increase of the local stiffness and stress by full constraints, using couple DOF of the two components that hinged together to simulate the rotation motion. 由于动臂与其它部件之间均为铰接,为避免对动臂进行全约束时所造成的局部刚度、应力增大,对铰接的两个构件进行了自由度的耦合来模拟实际的旋转运动。