Solving the Dynamic Equations of a 3-PRS Parallel Manipulator

This paper presents and compares three approaches for solving the inverse dynamic model of a general 3-PRS parallel manipulator. The first method obtains the inverse dynamic model by describing the manipulator as three open kinematic chains. Then, the vector-loop closure constraints introduce the relationship between the dynamics of the open kinematic chains and the original closed loop chains. The second method exploits the characteristic of parallel manipulators such that the platform and the links are considered as subsystems. The third method is similar to the second method but uses a different formulation of the Jacobian matrix. This work provides some insight on some advantages and/or disadvantages on how to formulate the dynamic model of a lower mobility parallel manipulator, which can be considered in topic such as the optimal design, parameter identification, and model-based control.