ANALYSIS OF RING JET LASER GYRO RESONANT DITHERING MECHANISM

This paper presents the design, manufacture, testing and improvement of newly developed piezoelectric torsion actuator which generates angular displacement using piezo ceramics and torsion bar. The proposed piezoelectric torsion actuator generates angular displacement during dithering, directly invoking the shear mode of the piezoelectric material and hence no complicated additional mechanism is needed. The piezo plates are formed from a rectangular PZT material duly poled along the axial direction. The dither mechanism is divided into four segments that are arranged in circular configuration. Each of the segments off our piezoplates is bonded in opposite poling directions with soldering adhesive. The key to design of such an actuator is to match the torsion resonant frequency of the actuator with the excitation frequency. FEA for the Torsion bar is carried out to find the different resonant mode sand mode shapes. Also, a set of torsion bars and resonator are analyzed to evaluate the maximum angular displacement and stresses on torsion bars. An experimental investigation in terms of electrical impedance and angular displacement measurement was conducted to verify the mode analysis. Based on the FEA analysis, a new material for the torsion actuator was selected having high Curie temperature and stable relative dielectric constant so that it has higher tentivity even after bonding the piezo plates on torsion bars and also wire soldering process. The design analysis was verified with the experimental results for incorporation of the selected mechanism for the production of dither in the system.