Research Of Thermal Error Compensation For MEMS Gyroscope In Mini Attitude And Heading Reference System

Micromachined gyroscopes are the most key components of mini AHRS inertial navigation systems. The temperature error will bring great influence on various performance index on account of the sensitivity of silicon material. The resonant frequency will generate excursion and mechanical quality factor will change due to temperature variation which cause the variation of the scale factor and zero bias,so the output precision and performance reduce obviously. Consequently, it is critical to carry out researches on the temperature characteristics of gyroscopes and compensation algorithms, setting up appropriate temperature model to compensate temperature errors. The main content and work of this thesis are given as follows:1.At the beginning we introduce the basic principles and functions of Attitude and Heading Reference System, including the definition of inertia system,carrier's attitude denotation and coordinates conversion, basic equation and attitude equation in inertia system.Then elementarily expatiate the attitude algorithm. 2.Analyse the source of temperature error and ratiocinate the motion equations. It indicates that resent frequency and quality factor are the main factors which influence the motion displacement and structure sensitivity. The resonant frequency will generate excursion and quality factor will change with temperature variation, which will magnify the original error, and it will bring great influence on the output precision.3.Then we introduce several thermal error compensation algorithms. We elaborate three algorithms which are least square multinomial compensation, neural network and controlled Markov chain. These three methods provide a sound foundation for the following thermal experiment and compensation simulation.4.Set up the zero bias error compensation model of gyroscope at different temperature change condition respectively. The temperature error compensation model is set up at the range of whole temperature, nature temperature rise and small temperature variation experimentally, and take emulate compensation certification. Design the hardware circuit and develop data collection and waveform display software based on Visual C++ program language, and realize the temperature compensation. At last, take compensation certification at normal temperature startup condition and whole temperature range.5.At last, we do some comparisons between the results of compensations. We analyze the strength and weakness under different conditions of different algorithms. Besides, we also look forward to do some improvement of future mini AHRS. This essay has successfully achieved the goal to improve the precision of MEMS gyroscope.