A 6-axes Motion Control Method for Parallel-Linkage-Type Fine Motion Stage

This paper describes a position control method and a control system configuration for newly developed fine motion stage using parallel linkage mechanism. A new static decoupling control method is proposed to compensate interference characteristics of 6-axes stage, including compensation of machine and actuator accuracy. Its decoupling parameters (Jacobian matrix) are calibrated by iterative process, and as a result total decoupling accuracy of 5% is obtained. The control algorithm, which requires complicated matrix calculation, could be executed within 250μs by parallel processing method using multi transputers. By experimental results of step response for each degree of freedom, it is confirmed that proposed decoupling method is more effective than conventional one. Consequently positioning resolution of 0.01μm (x, y), 0.123μrad (θz), response of 30-40 Hz, and dynamic rigidity of more than 12.3 N/μm (x-direction, frequency