Design And Research Of Micro-gyroscope Based On Gratings Detection

With the continuous expansion of the autonomous navigation market,the demand for micro inertial devices is also increasing.As a key sensor of micro navigation components,micromachined gyroscope is an important research direction of the high precision micro-inertial device.The detection of weak Coriolis force is the core technology of high precision micromachined gyroscope,and the actual application has increased the requirement for the detection accuracy of micromachined gyroscope year by year,but the conventional detection methods have reached the limit of resolution,so the future research of micromechanical gyroscope should focus on the innovative research on the structural design and detection principle.Optical measurement has a very high detection accuracy.In this paper,grating interferometry is introduced into the effect detection of micro gyroscope.The design and research of opto-electromechanical micro-gyroscope are studied.This paper introduces the working principle of the micromachined gyroscope.The dynamic equation of micromachined gyroscope is deduced in detail.The expression of the structural sensitivity,quality factors and bandwidth of the gyroscope are obtained.The damping type and calculation model are analyzed.The principle of electromagnetic for closed-loop drive and the theory of grating interference are discussed.Based on the above theoretical guidance,this paper designed a new type of micro-gyroscope combined with grating detection and micro mechanical structure,It adopts in-plane drive outof-plane detection method.Through matching modal frequency,finite element analysis results display structure sensitivity up to 80 nm/°/s;Grating optical properties is analyzed,the sensitivity of optical effect and electrical sensitivity are 0.00625mW/nm,400 mV/mW.The total sensitivity of micro-gyroscope is 105.75 mV/°/s.Finally,the whole micro gyroscope is simulated at system level to verify the feasibility of the mechanical model,and the range,resolution and noise of the micro gyroscope are calculated.Combined with micro gyroscope structure characteristics and the current process capability,the process design of gyroscope is carried out.The machining process and mask have been designed.Micro-displacement measurement is the key technology of micro-gyroscope.The manufacture of grating samples has been completed,a platform of optics has been set up for micro-displacement measurement.The research paves the way for the optoelectronic measuring system of micro-gyroscope.