Modelling and actuation optimization of a self-propelled robot subject to discontinuous friction

Abstract

Self-propelled robots have attracted significant attention due to their remarkable ability to navigate confined terrains. These robots usually have deformable structures while having discontinuous contact forces with the ground, resulting in a complex nonlinear system. To provide a solid foundation for the locomotion prediction and optimization for the self-propelled robots, it is necessary to conduct dynamic modelling and locomotion analysis of the robot. Motivated by these issues, this paper proposes a vibration-driven surrogate dynamic model for a deformable self-propelled robot and presents a detailed dynamic analysis. The surrogate dynamic model is employed to classify various types of stick-slip locomotion. Subsequently, the corresponding experiment demonstrates that the surrogate dynamic model effectively predicts the locomotion of the robot, particularly three types of stick-slip locomotion induced by discontinuous friction. Finally, a multi-objective coordinated optimization regarding the locomotion velocity, the cost of transport, and the energy conversion rate of the self-propelled robot is conducted, aiming to comprehensively enhance the robot’s locomotion performance. Additionally, suggestions for the selection of actuation parameters are presented.