Adaptive incremental particle filtering method for Mars atmosphere entry section

Abstract

The invention discloses an adaptive incremental particle filtering method for a Mars atmosphere entry section. The method comprises the following steps of: (1) initializing, namely sampling to obtain particles and endowing the same weight by employing a priori probability density function; (2) updating the particles and the weight by utilizing a likelihood probability density function of the particles under a motion equation and an incremental measurement equation; (3) comparing all weights calculated in the step (2), obtaining and storing the maximum weight, the minimum weight and corresponding serial numbers, and solving measurement information to calculate the Euclidean distance between the maximum and the minimum and the Euclidean distance from each particle to a particle which corresponds to the minimum weight according to the incremental measurement equation and an incremental measurement value corresponding to the current moment; (4) determining an adaptive coefficient value and recalculating the weight; (5) normalizing the weight calculated in the step (4), and obtaining a novel weight; (6) resampling; and (7) returning to the step (2) until the time is ended. According to the method, an unknown system error in the measurement system can be eliminated.

Description

technical field [0001] The invention relates to an adaptive incremental particle filter method for the Martian atmosphere entry section. It belongs to the technical field of aerospace navigation. Background technique [0002] The particle filter method is a very common method for determining the position and velocity of a spacecraft. Among them, the size of the unknown measurement system error in the measurement method has a great influence on the determination of the final state of the spacecraft's position and velocity. Excessively large unknown measurement system error data will lead to an increase in the position and velocity error, increase the navigation error of the spacecraft, and reduce the navigation accuracy. precision. [0003] In the prior art, there are many methods that can be used to determine the position and velocity of a spacecraft. [0004] The first prior art is an estimation method of extended Kalman filter based on Taylor expansion. The method give...

AI Technical Summary

Problems solved by technology

Even though the systematic error that has been calibrated in the ground test is no longer accurate in the new Martian environment (which is different from the earth), so the systematic error in the measurement data will affect the position and velocity of the spacecraft to adjust the correction, so it is not applicable Atmospheric entry of Mars

[0008] Prior art 12 has significant errors for unknown, biased and non-normal noise statistics in the Martian environment, so it is not suitable for the Martian atmosphere entry segment

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