Research on fiber optical gyro attitude determination system of long life aerocraft
- Paper number
IAC-06-B3.P.6.05
- Author
Dr. Pu Zhongqi, Beijing Institute of Control Devices, China
- Coauthor
Dr. Liqing Wang, Beijing Institute of Control Devices, China
- Year
2006
- Abstract
In the field of the long life aerocraft, the development of the long life ADS(Attitude Determination System) is one of the most important technology. The gyro is a kernel part of the ADS and its life determines the life of the ADS. Because its solid state and other natural virtues, the FOG(fiber optical gyro) is suitable for the use of the long life aerocraft. This paper introduces a redundant ADS with five FOGs and the de-noising algorithm for FOG signal based on wavelet theory. The conventional orthogonal ADS with three FOGs may cause the enormous navigation error when one FOG fault occurs. In order to overcome this problem, the system is constructed by configuring two redundant FOGs. The redundant system has a merit that it can detect and isolate the faults. By the studies of the probability and the mechanism of the fault, the fault model of the FOG is set up, and then the fault coefficients can be obtained using the six-position and the rate testing. After above studies, the algorithm of the fault diagnosis of the FOG is then acquired. The algorithm is integrated in the hardware based digital signal processing units of the ADS, so the fault diagnosis of the FOG is real-time and can be used in the actual aerocraft. The research shows that the redundant design can greatly improve the life of the aerocraft. With the development of the space exploration, the accuracy of the ADS becomes more important. It is a key project to improve the accuracy of the system based on the existing hardware. The low precision FOG has high noise and the FOG signal is pulled by the noise, so the de-noising algorithm for FOG signal is necessary to study. FIR(Finite Impulse Response) filter and IIR(Infinite Impulse Response) are always used in the de-noising. However, it is obviously unfit for research on the transient and non-stationary signal such as FOG signal. Wavelet transform is just localized, which is popularly used in analysis of transient signal. Methods of de-noising based on wavelet theory are presented in this paper. At the same time, mother wavelet option methods and other conditions are presented. The research shows that the methods are effective.- Abstract document