An Adaptive Estimation Method of Martian Atmosphere Entry Based on Model Perturbation

Abstract

The invention discloses an adaptive estimation method of Mars atmosphere entry based on model perturbation and belongs to the technical field of deep-space exploration. A coupling relation between uncertain parameters and an aerodynamic model of a Mars entry section is analyzed and perturbation on a dynamic system, caused by the uncertain parameters, is converted into aerodynamic model deviation so as to reduce the number of the uncertain parameters; according to a change rule of the perturbation of the aerodynamic model, filtering models aiming at perturbation amount deviation in the dynamic system are established; the perturbation amount in each filtering model dynamic system corresponds to a deviation value; a measurement residual error is predicated through each filtering module and a weight value of each model is self-adaptively updated based on measurement residual error information; and iterative approximation is close to real model perturbation so that influences of the aerodynamic model deviation on state estimation precision are inhibited. By adopting the self-adaptive estimation method disclosed by the invention, influences of the aerodynamic model perturbation on the state estimation precision in a Mars entry section combined navigation method can be reduced, and the state estimation precision of a detector in an entering process and the stability of a navigation system are guaranteed.

Description

technical field [0001] The invention relates to an adaptive estimation method for Mars atmosphere entry based on model perturbation, and belongs to the technical field of deep space exploration. Background technique [0002] The future Mars sampling return and manned exploration missions require the probe to have the ability to land on the surface at a fixed point. Active guidance and control during the entry phase is an effective way to achieve a fixed-point landing on Mars. The probe guidance system needs the navigation system to provide accurate state information to ensure the accuracy of the instructions transmitted to the control system, which requires the probe to achieve high-precision autonomous navigation during the entry process. [0003] At present, the Mars atmosphere entry section adopts the dead position recursion navigation method based on the output of the inertial measurement unit (Inertial Measurement Unit, IMU). Influenced by it, it cannot meet the accura...

AI Technical Summary

Problems solved by technology

When there is a large deviation between the parameters of the dynamic system model and the real model parameters during the actual flight, the perturbation caused by the uncertain parameters will degrade the performance of the navigation system and even lead to the divergence of state estimation errors

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