Daigoro Isobe, and Yoshiaki Moriya

Abstract:
Stress in robots operating at high speed may be considerable. Robots can also be subjected to unexpected, large reaction forces that may not be detected by sensors during high-speed impact. These present major problems since impact may damage the robotic mechanism. We propose the concept of impact force prediction using numerical models and a low-cost finite element scheme considering inertia and large motion of the whole system. We developed a scheme using gap elements to simulate the contact-impact phenomenon. To check the scheme's validity, we conducted tests and experiments whose results show that impact analysis considering the stiffness of contact objects is possible. Peak of impact forces in numerical analysis agrees well with those of experiments.

Keywords: robotic mechanism, contact-impact problem, impact force, finite element method, gap element