Dynamic Modeling and Coupling of

Underactuated Flexible Robot

CHEN Wei  YU Yueqing  ZHANG Xuping  SU Liying

(College of Mechanical Engineering & Applied Electronics Technology, Beijing University of Technology, Beijing 100022)

Abstract: A dynamic model for underactuated robots with link flexibility is presented using finite element method. Based on this model, the dynamic coupling effects are analyzed, including the acceleration coupling between active joints and passive ones, the dynamic coupling between passive joints and driving torques. A new index is proposed to describe the dynamic coupling between the elastic deformations of flexible links and the active as well as the passive joints, respectively. Comparing the simulation results of acceleration and torque coupling of underactuated flexible system with those of the rigid system, it has been shown that the former system can obtain greater coupling values at the certain actuator configuration. The flexible system can supply a better energy transmission at this configuration. Therefore, the results indicate that the elastic deformations of flexible links have important influence on the dynamic characteristics of the system. The dynamic coupling effects are of significance in structure design, configuration design, actuator placement and control of underactuated robots system. 

Key words: Underactuated robot  Flexibility  Dynamics  Modeling  Coupling

CLC No: TP24

国家自然科学基金(50575002)、北京市自然科学基金(3062004)、北京市科技新星B类(2003B04)和北京工业大学青年基金(7001014200501)资助项目. Received 20050824, received in revised form 20060106