Dynamic control of a flexible robot arm by using experimental modal analysis.

Abstract

A new control method for a flexible robot arm has been developed. First, two methods for piecewise linearized representation of the input-output relation between a control command and the resulting end effector motion have been proposed such that they include the effect of arm flexibility through the use of measured transfer function data of the input-output relation. These methods are then used for predicting a vibratory motion of the end effector which is commanded by a trapezoidal velocity pattern to obtain a good correspondence with the actual motion. finally, based on the results obtained above, a method to compute the control command which realizes a desired smooth motion has been developed as the inverse method of the above motion prediction. Experimental results show considerable suppression of flexibility-induced vibration of the robot arm.