Two-step robust filtering method and two-step robust filtering system for GNSS/INS integrated navigation system

Abstract

The invention discloses a two-step robust filtering method and system of a GNSS/INS integrated navigation system. The method comprises the following steps: constructing a fading factor matrix according to information, constructing a gain coefficient matrix according to residual errors, constructing a state equation and a measurement equation of the GNSS/INS integrated navigation system, and fusingGNSS/INS data according to a Kalman filtering tight coupling mode; detecting whether the dynamic model is abnormal or not, and if the dynamic model exceeds a set threshold range, entering time updating through fading factor matrix adjustment; detecting whether the observed quantity is normal or not, if the observed quantity exceeds a set threshold range, adjusting an observation vector through multiple channels of a gain coefficient matrix, and entering measurement updating; and updating a Kalman filtering process, and outputting a GNSS/INS integrated navigation result. According to the method, the redundant information of the integrated navigation system can be fully utilized, meanwhile, scalar factors are expanded to a diagonal matrix, the algorithm complexity is reduced, and the positioning precision, tracking performance and stability of the integrated navigation system are enhanced.

Description

technical field [0001] The invention relates to the technical field of navigation, in particular to a two-step robustness filtering method and system of a GNSS / INS integrated navigation system. Background technique [0002] Global Navigation Satellite System (GNSS) plays an important role in military and life services. It can perform global positioning and time service all day and all day, but in forests, mountainous areas, tunnels, urban canyons and other scenarios , there is a problem that the signal is blocked and the navigation is not continuous. On the other hand, the inertial navigation system (Inertial Navigation System, INS) can theoretically position itself without relying on external information, but the positioning error accumulates over time, and external information is required for error correction to maintain continuous and high-precision navigation. GNSS can be provided to INS as external information to eliminate time accumulation errors; at the same time, IN...

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Problems solved by technology

[0003] In order to overcome the defects and deficiencies of the existing technology and solve the problem of gross errors in system noise and measurement noise, the present invention provides a two-step robustness filtering method and system for a GNSS / INS integrated navigation system, which can reduce system noise at the same time and measuring the influence of noise, this method adjusts the error covariance and gain matrix respectively through the fading factor matrix and the gain coefficient matrix to limit the interference of noise to the system step by step, and improve the positioning accuracy and anti-interference ability of the integrated navigation system

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