Design and Control of the Piezo Actuated Micro Manipulator

摘要

The goal of the research was to develop a micro hand module consisting of twomicro manipulators. Both micro manipulators are piezo actuated Stewart platform type parallel-link structures capable of operating with an accuracy of one tenth of a micrometre. The parallel structure is very compact and six degrees of freedom is easily realized by using only linear actuators. The main topic of the work was to increase the total workspace that was originally limited because of the small displacements of the piezo actuators and the parallel structure. Only translational motions of the end-effector of the manipulator are measured because of the limitations of the sensor information. Therefore, rotational motions were redundant and the workspace was slightly enlarged by minimizing the actuator displacements optimizing the extra three degrees of freedom. Another method was to couple the redundant rotations to translations directly introducing three virtual links to replace the six actual ones. Hence, the redundancy of rotational motions in the kinematic solution of the manipulator was omitted, and calibration became easier with better results. (Copyright (c) 1997 Helsinki instutite of Technology.)