Similitude Analysis Method of the Dynamics of a Hybrid Spray-Painting Robot Considering Electromechanical Coupling Effect

This article proposes the similitude analysis method to predict the dynamics of a hybrid spray-painting robot, and the electro-mechanical coupling effect is considered. As the preliminary preparation, a novel method for similitude analysis of coupling system by taking the subsystems as the object of study is introduced, which has higher efficiency and more flexibility due to the consideration of coupling relationships. Besides, since classic controller designed in complex frequency domain is the key component in an electro-mechanical system, the modified similitude analysis methods defined in complex frequency domain are proposed for deriving scaling laws of the controller. Based on these preparations, the similitude analysis of the electro-mechanical dynamics of the hybrid spray-painting robot in ideal condition is carried out, and the modifications of reduction ratios and control parameters of the scaled model are also proposed to solve the motor inertia and resistance distortion problems. Finally, the scaled model of the hybrid spray-painting robot is determined, and the experiment of the prototype is carried out. The effectiveness of the similitude analysis method is then validated by the fitness between the experimental tracking errors of the prototype and the ones predicted from the scaled model.