Modeling and Identification of a Single Link Flexible Arm with a Passive Gravity Compensation Mechanism

Abstract

In this paper, we present an experimental study concerning the gravity compensation of flexible link arms based on linear springs. In the field of flexible link robotics, the gravity compensation based on counterweights has been successfully applied in the past, but little effort has been made to examine the potential benefits and difficulties of using spring-based compensation mechanisms. This paper focuses on the modeling and identification of a single link flexible arm compensated with a spring based mechanism. As modeling approach, we followed the lumped-mass methodology to develop a model capable of reproducing the first vibrational frequency of the flexible link arm. Keeping in mind the forces that interact with the flexible link, a combination of sensors is suggested in order to measure and estimate the most important variables of the system. Subsequently, a very simple and reliable identification method based on the time and frequency response of the system is proposed. Finally, the results of the modeling and identification are validated on our experimental platform.