부산대학교 도서관

This paper presents the theoretical derivation and the implementation of a footground contact dynamics system for legged robot physical simulation. The physical simulation imposes high requirements on the contact dynamics for fidelity and accuracy. Thus, we explored the contact mechanism and developed a contact model. We theoretically analyzed the ground reaction force (GRF) by the kinetic equation with constraints first. Considering the limitation of the numerical analysis method, we propose a new contact model based on Hertz theory and clarify the fundamental differences between the model and reality. Due to these differences, we optimized some key parameters by the genetic algorithm. Then, we expanded the contact model to nonhorizontal and nonstationary surface contact. At last, we simulated several cases to present the usefulness of this contact model and analyzed the dynamic contact behavior. The contact force based on this model highly accords with the results of theoretical analysis and includes all phenomena that may occur during a locomotion cycle.