Research On Initial Alignment Technique Of Strapdown Attitude Heading Reference System Based On MEMS

The silicon micro-inertial sensor is a cutting-edge new technology in the world. It combines several new techniques such as the micro precision machinery, the microelectronics and the semiconductor IC process. This thesis mainly researched into micro inertial AHRS system which is made up of semiconductor IC process.Because of the silicon micro-gyroscope has many advantages such as its batch production, its small-sized and so on, it has played an increasingly important role in the military and civil applications.But to be restricted by the technology, the random error of the gyroscope is large. So we should process the mathematical treatment and build mathematical model to the random noise in order to compensate the random error. The thesis analyse the random noise of the gyroscope by using the method of time series analysis, and take advantage of the testing data and the ARMA model to modeling and analysis.Initial alignment technique is very important to the Micro Inertial AHRS, and the system's accuracy and speed depends on the accuracy of the technique. The article analyzes some theories about Strapdown Inertial Navigation System, and on this basis study the Initial alignment technique of the silicon micro system under the stationary base conditions. As the silicon micro-gyroscope has disadvantages:it cannot sense rotational angular velocity of the earth sensitively. In this thesis, we use the electronic compass to get aziumth so as to help finishing initial alignment.As the practical application of micro-inertial AHRS working environment is often very hard and can not be required to meet the Kalman filter system for linear systems, noise or similar to obey Gaussian distribution, with large initial misalignment alignment, the traditional Kalman filter often ineffective. In view of this question, the thesis proposed to apply the particle filtering theory to the process of filter when the initial alignment of Micro Inertial AHRS is under the non-linear and non-Gaussian condition, and introduces the basic theory of Particle filtering. And the thesis also analyzes the degeneracy phenomenon which hinder the Particle filtering technique using effectively in the real engineering. And the thesis comes up with two ways of solving the regression results. It introduces the principle and steps of unscented particle filter and the comparative analysis of simulation between the particle filter and the unscented particle filter.At last, the thesis makes a simulation experiment about the application of particle filtering technique in Micro Inertial AHRS initial alignment.The result proves that under the condition of non-linear and non-Gaussian, the effect of particle filter technique is much better than the Kalman filter, its system function can satisfy the need of practice, and it has a wide application in the future.