Kinematics of a wrist based on spherical gear & ring-rack

A novel 2-DOF wrist based on spherical gear and ring-rack is presented in this paper. Firstly, geometrical structure and mobility analysis are addressed. Then, the direct and inverse kinematics are analyzed with direction cosine matrix method. The velocity and acceleration analysis are developed, and the one order, two order kinematic influence coefficient matrixes can be deduced. Finally, the displacement, velocity, acceleration distribution figures are obtained on the basis on of the conclusions above.