Design And Control Of 3-DOF Nanopositioning Stage

This paper designs a 3-DOF nanopositioning stage which can rotate about?_x and?_y and move along axis z.A control system of the nanopositioning stage is designed and an experiment system is established.Some experiments are conducted to verify the performance of the nanopositioning stage.An overall plan of the 3-DOF nanopositioning stage is proposed.Four-drive scheme is chosen and appropriate actuators are selected.And a compliant mechanism amplifier of the nanopositioning stage is designed with the combination of a bridge amplification mechanism and a parallelogram mechanism.A decouple flexure mechanism is designed with two circular flexure hinges.Based on the Castiglione's second theorem and the Lagrange's equation,static and dynamic model of the compliant mechanism amplifier is derived.A finite element analysis is also applied to verify the theoretical model.The results of the theoretical model and the FEM model is quite close.Sensitivity analysis is also conducted to find critical parameters of the complaint mechanism amplifier.An optimization model of the 3-DOF nanopositioning is established.Based on the critical parameter conducted in the sensitivity analysis,a co-simulation is applied in ANSYS Workbench and SolidWorks to simulate the nanopositioning stage and the optimized parameters are obtained.Hardware system of the nanopositioning stage is designed with the selection of an embedded real-time controller CompactRIO.And software architecture of the nanopositioning stage is also presented.The controller CompactRIO is programmed in the FPGA mode.A real-time program is coded for trajectory generation,data acquisition,data logging and UI update.A FPGA program is coded for the closed-loop control algorithm and hardware I/O manipulation.DMA is applied to transfer high throughput data with thereal-time processor and the FPGA.Experiment system of the 3-DOF nanopositioning is established.Performance of the nanopositioning stage is verified with the open-loop and closed-loop experiments.