Decoupling Dynamic Analysis of a Three-parallelogram Hybrid Spray-painting Robot

Hybrid robots have the time-varying dynamic load characteristics, which can affect the performance of electromechanical system, including the stability and motion accuracy, then determines the spraying quality. In this paper, the dynamic characteristics analysis is performed for a hybrid spray-painting robot with a three-parallelogram structure, taking into account the numerical properties of each component in the dynamic load. Firstly, the dynamic modeling of the mechanism is carried out by the principle of virtual work, and the inertia matrix and gravity matrix are calculated and analyzed. Then, by taking the dynamic load as the disturbance in the servo control system, the transfer function of the electromechanical system of the spray-painting robot is analyzed. The analysis results show that the stability will not change with the motion, and the coupling effect of multi-axis electromechanical systems is weakened under low acceleration conditions. Finally, the motion verification experiment is carried out to show that the gravity and friction are the main components of the driving force, and the motion accuracy will vary with the dynamic load.