Structure Design and Nonlinear Control of a Precision Rotating Stage

In this paper, the principle of imitating inchworm motion is applied to the rotating mechanism, and a precise rotating mechanism based on Piezoelectric Ceramic Transducer (PZT) actuator is proposed, which can be applied to the rotational positioning in the process of multi-station precision operation, so as to reduce the positioning complexity of the multi-station precision operation and improve operation efficiency. The rotating mechanism proposed in this paper consists of two parts that are stator and rotor, in which the stator is equipped with the driving unit to provide driving torque, and the rotor is equipped with the clamping unit to provide the clamping force. At the same time, in order to ensure high output precision, the modeling and control of hysteresis nonlinearity of the drive unit are studied in the paper. Finally, a prototype is manufactured by wire cutting, and the experimental system is established to verify the output performance of the precision rotating stage and the control effect of the controller. The results show that the resolution of the precision rotating stage is 10.76µrad and the repetitive motion accuracy is less than 2%. The linearity error of the system under the control of the composite controller is 2.12 %. The experimental data shows that the stage can achieve good motion accuracy, and the controller basically eliminates the hysteresis nonlinearity of the driving unit.