Simultaneous Optimization of Trajectory and Parameter for Biped Robot with Series Elastic Actuators

摘要

Nowadays, robots are being introduced to various fields. Since existing environmentsand tools are designed for humans, humanoid robots are particularly expected to be adaptableto human society and highly versatile.Recent researches proposed using Series Elastic Actuators(SEAs) as actuators of biped robots. In the SEA, a motor and a link joint are connected bya spring, therefore it enables to reduce the damages to the motor which are caused by high-frequency impact forces owing to elasticity.However, it is still a challenging problem to determinethe stiffness of SEAs and control imput. Furthermore, conventional walking robots have a moreserious problem that they are not energy efficient and camnot work contimuously for a long time.This paper presents a method for biped robots with SEAs to walk efficiently， by optimizingeach joint trajectory and spring stiffness simultaneously. We also propose a trajectory trackingcontrol method using input-output linearization, and the performance of the proposed controlleris verified with a numerical simulation.