The Mechanical Design And Control Methodology Of A2-DOF Precision Positioning Platform

Precision positioning platform has an important significant in precisionmanufacturing and micro-operation. The paper is based on National Natural ScienceFoundation of China. The work includes the mechanical design and controller designof a2-DOF precision positioning platform. Using the combination of simulation andexperiment, the work is implemented.In the mechanical design, the paper presents a2-DOF precision positioningplatform with decoupling effect. The output cross-axis coupled motion exists in the2-DOF precision positioning platform, which has a serious influence on the accuracy.Based on the analysis about some different guiding mechanisms, the paper designs a2-DOF precision positioning platform with dual parallel leaf-spring mechanism,which overcomes the cross-axis coupling. The experiment includes the simulationusing Ansys, the modal testing, the couplings testing, stiffness and the influence onmodal characteristics caused by mass.In the controller design, the paper design fuzzy-sliding mode controller. Thesliding mode control can cause severe oscillation caused by the discontinuity ofswitch, which makes a serious impact on the platform’s accuracy. The paper combinesthe fuzzy control and sliding mode control for the reason that the fuzzy control cansoften the control signal, which can reduce the oscillation. The new controlmethodology guarantees good robustness and reduces the oscillation caused by slidingmode control, improving the accuracy. The controller’s design is implemented bySimulink.Based on the controller design, the experiment is completed by dSPACE1103real-time control card. The work includes the identification of the platform’s transferfunction， step response testing and tracking testing with PID controller andfuzzy-sliding mode controller. According to the results, it is obtained that thefuzzy-sliding mode controller is better than PID controller.