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

Abstract

The invention provides a covariance intersection and fusion based Mars entry section distribution type autonomous navigation method which comprises the following steps of establishing a three-degree-of-freedom kinetic model of a Mars atmospheric entry section navigation system; establishing a measurement model of a Mars atmospheric entry section; establishing a distribution type fault-tolerant autonomous navigation system; dispersing and linearizing a three-degree-of-freedom kinetic model and a measurement model of the distribution type fault-tolerant autonomous navigation system; establishing a subfilter based on an EKF (Extended Kalman Filter) navigation filtering algorithm; and establishing an information fusion device based on a covariance intersection and fusion algorithm. According to the covariance intersection and fusion based Mars entry section distribution type autonomous navigation method, autonomous navigation is carried out by adopting a mode of distribution type information fusion with stronger fault tolerance, so that improvement of utilization efficiency of wireless communication is facilitated, the calculated amount of autonomous navigation filtering is reduced, and the fault tolerance of the Mars atmospheric entry section autonomous navigation system, the navigation filtering stability and the autonomous navigation accurate of the Mars atmospheric entry section to a prober are improved.

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...

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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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