Distributed autonomous navigation method for Mars entry phase based on covariance cross fusion

Abstract

The present invention proposes a distributed autonomous navigation method for the Mars entry section based on covariance cross-fusion. The steps are: establishing a three-degree-of-freedom dynamic model of the Mars atmosphere entry section navigation system; establishing a measurement model for the Mars atmosphere entry section; Establish a distributed fault-tolerant autonomous navigation system; discrete and linearized three-degree-of-freedom dynamic model and measurement model of the distributed fault-tolerant autonomous navigation system; establish a sub-filter based on the EKF navigation filter algorithm; establish information based on the covariance cross-fusion algorithm Fusion. The present invention uses a distributed information fusion method with strong fault tolerance for autonomous navigation, which is beneficial to improving the utilization efficiency of radio communications, reducing the calculation amount of autonomous navigation filtering, improving the fault tolerance of the autonomous navigation system in the Mars atmosphere entry section, and enhancing This improves the stability of the navigation filter and effectively improves the autonomous navigation accuracy of the detector during the Martian atmosphere entry phase.

Description

technical field [0001] The invention relates to the technical field of multi-sensor information fusion of the Mars atmosphere entry section, in particular to a distributed autonomous navigation method for the Mars entry section based on covariance cross fusion, which can be used to improve the accuracy and fault tolerance of the Mars atmosphere entry section autonomous navigation. Background technique [0002] In the Martian atmosphere entry section, the Mars probe is faced with harsh environments such as peak overload, high temperature and high heat. The probe is installed in the protective cover, causing a large number of navigation sensors to fail to work, and only rely on the inertial measurement unit (abbreviated as IMU) With autonomous navigation, the accuracy of navigation is difficult to meet the requirements of future Mars exploration. Based on the research that the Mars atmospheric entry stage can rely on VHF radio for communication, scholars have proposed a combin...

AI Technical Summary

Problems solved by technology

[0004] The invention solves the technical problem that the existing non-linear autonomous navigation filter algorithm of Mars atmosphere entry segment combined navigation cannot eliminate the colored noise affecting navigation accuracy and poor fault tolerance. The invention proposes a Mars entry segment distribution based on covariance cross fusion In the autonomous navigation method, the extended Kalman filter algorithm is used in each sub-filter, and the covariance cross fusion algorithm is used to perform information fusion and feedback on each sub-filter, taking into account the colored noise problem and multi-sensor fault tolerance in the navigation system model The problem of information fusion has effectively improved the accuracy of the autonomous navigation of the probe in the Mars atmosphere entry section, and also improved the fault tolerance of the autonomous navigation.

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