A Laboratory Experiment with a Flexible Surface: Hardware, Software, and Control

This paper describes the design, the construction and the control of a flexible surface that is able to shape arbitrary forms. From a hardware point of view, the surface is realized by fifty linear motors that are mounted beneath a latex foil and are capable of extending or retracting a piston. Through the correct position of each piston, the overall latex surface forms the desired shape. From the software side, three type of controllers are used: Synchronizing controllers that reduce the stress on the material, feedforward controllers that enable each motor to track a reference trajectory, and proportional-integral controllers to compensate for model uncertainties and mismatched initial conditions. The paper shows experiments in which the surface should form a travelling wave. The results demonstrate the effectiveness of the chosen controllers as the overall surface forms the desired shape with practically no tracking error.