Four-gyro redundant strapdown inertial navigation system fault detection and isolation method in dynamic environment

Abstract

The invention discloses a four-gyro redundant strapdown inertial navigation system fault detection and isolation method in a dynamic environment, which belongs to the technical field of strapdown inertial navigation systems. A redundant inertial navigation system inertial device is used to output data to build an inertial device error model, a fault detection and isolation method based on the combination of a generalized likelihood ratio, Kalman filter and linear estimation ideas is designed, and an inertial navigation system with hard fault is detected; and a linear estimation method is usedfor processing data, the prediction value of the inertial device at the fault moment is obtained, the difference between the prediction value of each group of inertial device and the output value is compared, and a fault inertial device is positioned and isolated. When hard fault happens to a single inertial device of the four-gyro redundant strapdown inertial navigation system in the dynamic environment, the reliability of the strapdown inertial navigation system is ensured.

Description

technical field [0001] The invention relates to the technical field of strapdown inertial navigation systems, in particular to a method for detecting and isolating hard faults of a four-gyro redundant strapdown inertial navigation system in a dynamic environment. Background technique [0002] For a long time, the aerospace and aviation fields have attached great importance to the reliability of autonomous navigation systems, and improved the reliability of inertial navigation systems through system-level redundancy or device redundancy. Therefore, redundancy technology has become the most commonly used method to improve the reliability of inertial navigation systems in this field. System measures. Among them, device-level redundancy has greater advantages than system-level redundancy in improving reliability and controlling costs. For example, the four-gyro configuration can increase the reliability by 75% compared with the three-gyro configuration by adding only one gyrosco...

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Problems solved by technology

However, this method cannot be applied in a dynamic environment and cannot isolate faults in a four-gyro system

Yang Bojun and others proposed a fault detection method combining extended Kalman filter and generalized likelihood ratio in "Research on Fault Detection and Identification Technology of Parity Vector Method in Inertial Redundant System" (published in "Tactical Missile Technology", 2009, Issue 04) The method can detect faults in the system in a dynamic environment. The extended Kalman filter algorithm is more complex than the Kalman filter, and it is also unable to isolate the faults in the four-gyroscope system.

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