The Dynamic Behavior of Different Hollow Flexible Robot’s Arms

Abstract

In this paper, four different shapes of robots' hollow arm are suggested so as to investigate the effect of shape on the dynamic behavior of the arm. The finite element method is used to determine the strength of the arms and their equations of motion. The static deflection, stress and moment of inertia are calculated and compared as well as the angular displacement and tip vibration of the four different shapes. A PD controller with fuzzy logic is used for tracing the desired trajectory and reducing the overshoot of the system. All simulations were presented using MATLAB and SIMULINK on the arms under the same desired step trajectory for a time of two seconds. The preferred robot arm is the one that has less vibration in trajectory and after reaching the target. As a result, the tapered arm (shape B) shows better characteristics in which less deflection, stress and tracking. Key Words : Robot arm, Finite element, Flexible link, Fuzzy controller.