Dynamics and control of a 5-DOF manipulator based on an H-4 parallel mechanism

This paper presents a design of a unique hybrid five-degree-of-freedom manipulator based on an H-4 family parallel mechanism with three translational movements and one rotational movement (orientation angle) together with a single axis rotating table. Forward or direct kinematics, inverse kinematics, and Jacobian are derived in details as well as the dynamic model. The dynamic model is derived from the Lagrangian formulation and is shown to be suitable in the real-time feedback control. The numerical results of the analysis of kinematics, inverse kinematics, and the dynamic model are compared with the results from a popular commercial software using a virtual modeling data, the ADAMS solver. Friction models obtained from the experiment are used to compensate for the actual friction of the system in the resolve acceleration control strategy. The inverse dynamics is implemented for the first four axis of the chosen configuration to perform feedback linearization. From the experimental results, the tracking performance is satisfied and can be improved by increasing the rigidity of the railway structure and reducing the numerical truncation error.