A theory of degrees of freedom for mechanisms

In this paper, we put forward a stricter and more complete theory of degrees of freedom (DOF) for mechanisms, especially for the complex spatial mechanisms, which may not be solved correctly with traditional theories. We also point out that it is more appropriate to calculate the DOF of the mechanism with an output member rather than that of the whole mechanism. Furthermore, the new concept of configuration degrees of freedom (CDOF) in this theory can form a more complete and reasonable theoretical base for analyzing the mobility, singularity and stability of the mechanisms.