The Decline Of High-precision Optical Lever Accelerometer

The rapid development of Navigation and Guidance is due to the explosion of automatic driving of the vehicles and precision guided systems in modern military. As the only one having the ability of independence, Inertial Navigation and Guidance Systems (INGS) are the most important part of Navigation and Guidance, with the advantage of jamming immunity and invisibility. INGS is also the critical device for the precision attack and defense in modern war. The development of next generation precision guided weapon is in urgent situation. Its research mainly aims at inertial units with small size, high sensitivity and excellent reliability. Accelerometer and Gyroscope are the key components of inertial system. Successful steps towards miniaturized Gyroscope have been made in China. It is emergent to develop a kind of suitable miniature, integrated, high-performance, low-cost accelerometer to corporate with gyroscope. The target of this assignment is to present a novel accelerometer based on micro-optics with a resolution of less than 10^-5g, which is one or two orders of magnitude more sensitive than the current accelerometers based on MEMS. This accelerometer is also expected to have a wide dynamic range, which is about±50g. The dynamic range of excising micro- accelerometer in our country is±30g. Compared with traditional ones, this solution combines integrated-optics-on-chip systems with inertial systems.The principle, design and error analysis of accelerometer and micro -accelerometer are presented in this dissertation. A new micro-displacement measuring principle based on optical lever, and a miniaturized micro- accelerometer model based on this new principle are proposed. The stability, reproducibility and high measurement precision are proved by repetitive static acceleration and NC Turning Worktable testing systems. By theoretical derivations and experimental data analysis, it is demonstrated that this new type micro-accelerometer system of I model has a actual resolution of 3.1×10^-5g. The system' s sensitivity is 19mV/10^-5g. Theoretically, the resolution of this accelerometer can achieve 8.8×10^-7g. In experiments, the dynamic range of acceleration is more than±2.037mg. Another model of this micro-accelerometer system is II model which actual resolution is 3. 1×10^-5g and the theoretically resolution can achieve 7. 08×10^-7g. This model' s sensitivity is 1. 2mV/10^-5g. The dynamic range of this model is more than±1.48mg. Through the method of close-loop control, the result will be better.This paper proposed the fundamental research of this novel opticalinertial technology——the next generation micro-optical inertial unit.The main innovations include:1. Propose an improved optical-lever measuring principle.2. Design and realize a miniaturized micro-displacement measurement system, and present the performance analysis of the whole system.3. A theoretical miniaturized model of micro-optical accelerometer based on optical-lever was developed. Experimental data were used to validate the model.4. A scheme of optical-lever-micro-accelerometer, which is based on free space integrated optics and planar integrated MEMS technology, was proposed. In experiments, the optical path was tested, the results proved its feasibility.The successful research of this sensor will be very meaningful for the development of the accelerometer with high precision, suitable simple structure, which can meet the needs of modern national defense.