Using Delta Range on GPS Positioning, Fault Detection and Fault Exclusion
Authors: | Chang Fan-Ren, National Taiwan University, Taiwan Tsai Yi-Hsueh, National Taiwan University, Taiwan Yang Wen-Chieh, Intelligent Business Technology Inc., Taiwan |
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Topic: | 7.3 Aerospace |
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Session: | Aerospace Control |
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Keywords: | Global positioning systems, Kalman filter, Position estimation, Fault detection, Fault isolation, Threshold value |
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Abstract
Conventionally, the well known position-velocity-acceleration (PVA) model is adopted as the dynamic model of Kalman filter for positioning. Under the hypothesis that the vehicle is moving with a constant velocity, the normalized innovation squared of Kalman filter will be chi-square distributed and thus can be adopted as the test statistic for fault detection and exclusion (FDE). However, as a moving vehicle accelerates or slows down more rapidly, or as the vehicle corners at faster speeds, the conventional PVA model without the extra sensors (such as INS sensors) is no longer adequate for describing the motion of the vehicle. Therefore, the position of the vehicle will be less accurate, and NIS is not suitable as the test statistic for FDE anymore. Therefore, the delta range equation is proposed to accurately model the dynamic behavior of a maneuvering vehicle.