Dynamic Modeling and Design Parameter Optimization of a 5-DoF Parallel Machining Robot

Low stiffness characteristic of robotic machining equipment makes it prone to vibration during machining. It is a practical and feasible way to improve robot’s machining performance through dynamic design. This paper built the dynamic model of a 5-DoF parallel robot based on the finite element method (FEM). The dimension and structure parameters involved in optimization are selected through sensitivity analysis, and their effects on main global vibration modes (GVMs) are analyzed. The appearance of local vibration modes (LVMs) is mentioned. Then the robot’s uniformity of stiffness, uniformity of first order main GVM frequency and mean value of first order main GVM frequency within workspace are optimized based on the multi-objective genetic algorithm. Finally, a 5-DoF parallel robot with small performance fluctuation and high first order main GVM frequency is designed.