The Techology Of Attitude And Heading Algorithm And Data Acquisition In Strapdown Navigation System

The Strapdown Inertial System is smaller, lighter and cheaper than the Inertial System with platform, and it is more reliable and convenient for uses. It has become one of the most important research directions of inertial technology. The strapdown of attitudes and heading Reference system (AHRS) is a inertial measurement system providing heading, attitude, angular and linear velocities for the Marine Weapon Equipment system, Therefore the research on AHRS in thesis is very significant.Strapdown inertial technique must solve a series of problems about theory, application and the related technique. This paper researched on some questions among them, included the following several respect mainly:1. Among all kinds of stapdown of attitude and heading algorithm, the four variable forth order Ronge-Kutta method and three samples rotation vector optimization algorithm are analyzed and simulated, and the impact of the accuracy and the noise with respect to the computing is compared.2. In this paper, we have analyzed the impulse counting method in the digital-rebalance circuits and the three sampling methods including V/F, A/D, I/F in analog-rebalance circuit. The advantages and the disadvantages of these four sampling methods are compared and finally we have decided data sampling scheme.3. For the analog-rebalance circuit, 16-bits parallel A/D sampling using automatic programming controlled dividing methods for the dynamic range is expanded. We mainly designed and tested the hardware and software of the programming controlled A/D board and optimized the parameters repeatedly.4. We used the 24-bits high accuracy multi-modal counter in digital rebalancecircuits and 24-bits serial A/D sampling for the accelerometer signal. We have designed the hardware for the circuit and the software for the data sampling andtested in the practical situation.5. The experiments of IMU on three-axis table are necessary for the IMU calibration and compensation no matter for software or hardware revise and improvement of the test method. The experiments mainly include the acquisition and processing of the signal, the drift and calibration for gyroscope and accelerometer, calibration and compensation for error.The theoretical research of the strapdown algorithm in this article can be applied in all kinds of strapdown systems. The data acquisition method has general reference meaning to other real-time data acquisition systems.