A Simulation Method for Vibration of Manipulators Based on Joint Deformation Model

Abstract

A dynamic simulation method to estimate vibration and positioning error of industrial manipulators is proposed. This method has the merit that it needs only the same amount of calculation time as simulation methods ignoring elasticity, although it considers joint deformation. By some simulation experiments, the following facts are found :
(1) The proposed method can calculate vibration, positioning error and actuator torques at the stage of off-line teaching.
(2) The positioning error which cannot be measured by angular position sensors fixed at actuators can be large.
(3) By the effect of flexibility of joints, actuator torques of manipulators can be larger than the calculation results ignoring elasticity of joints.
(4) Selection of gears is important because backlashes at joints affect the characteristics of vibration and positioning error. The proposed method would be useful in the stages of the off-line teaching and the design of manipulators.