Dynamic modeling and computational efficiency analysis for a spatial 6-DOF parallel motion system

A common approach for simplification analysis of complex dynamic model is presented, and the simplified dynamic model of a spatial 6-DOF parallel motion system with high computational efficiency is proposed for high real time control. By using Kane method, the full dynamic model of a spatial 6-DOF parallel motion system viewed as 13 rigid bodies is built. With rigid body decomposition, the full dynamic model is separated into several parts firstly, and then some separated parts are further divided into many dynamic components in terms of motion separation and the relationship with acceleration or velocity. The contribution of each dynamic term is analyzed for a specified spatial 6-DOF parallel motion system, and the simplified model is derived. Comparing with full dynamic model, the simplified error is analyzed, and the computational efficiency of the simplified model is discussed in a real-time industrial computer. The simplified strategy is confirmed in simulation. The simplified error is less than 8%, the simplified model can improve the computational efficiency by more than 70%, and the execution time is less than 0.1 ms, which can achieve the requirements of high real time control. The numerical results illustrate that the proposed approach is feasible and effective for simplification analysis of dynamics and the derived simplified dynamic model can be used in real-time control system with small simplified error.