To improve the phase-shifting accuracy, this paper presents a novel integrated framework\nfor design, control and experimental validation of the piezoelectric actuated phase shifter with a\ntrade-off between accuracy and cost. The piezoelectric actuators with built-in sensors are adopted\nto drive the double parallel four-bar linkage flexure hinge-based mechanisms. Three mechanisms\nform the tripod structure of the assembled phase shifter. Then, a semi-closed loop controller with\ninner feedback and outer feedforward loops via the external laser interferometer is developed for\naccurate positioning of the phase shifter. Finally, experiments related with travel range, step response,\nlinearity and repeatability are carried out. The linearity error is 0.21% and the repeatability error of\n10 �¼m displacement is 3 nm. The results clearly demonstrate the good performance of the developed\nphase shifter and the feasibility of the proposed integrated framework.
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