Abstract

In this paper, we propose a 3D mass/spring model to use for real-time control of a robot with two flexible links moving in three dimensions. Based on this model, we derive the equation of motion and the state equation of a 3D flexible robot using Lagrange's method. We then show that accelerometers attached to the tips of elastic links are adequate for observing the state variables that represent flexibility in the model. Finally, we describe a controller designed by applying optimal regulator theory, and demonstrate with experimental results that the proposed controller can suppress vibrations of the arm.