On-line parameter identification method for jumping type reentry of lunar spacecraft

Abstract

The invention discloses an on-line parameter identification method for jumping type reentry of a lunar spacecraft. The on-line parameter identification method comprises the steps of obtaining on-line estimation values of an atmospheric density scaling factor and a lift-drag ratio scaling factor through a low-pass filter at a primary reentry descending branch, executing track forecasting, correcting the deflection of a drop point, and constructing a fitting function relation between the atmospheric density scaling factor and the height; obtaining an atmospheric density scaling factor at a primary reentry ascending branch and in the initial stage of a secondary reentry branch via a constructed fitting function, estimating a lift-drag ratio scaling factor of the lunar spacecraft on line, executing track forecasting, and correcting the deflection of the drop point; estimating an atmospheric density scaling factor and a lift-drag ratio scaling factor in the later stage of the secondary reentry branch, executing track forecasting, and correcting the deflection of the drop point. According to the on-line parameter identification method, the robustness and the precision of a guidance algorithm are improved; the adaptability to a real atmosphere model is high.

Description

technical field [0001] The invention relates to the technical field of guidance and control, and can be applied to the guidance of a jumping reentry of a lunar exploration spacecraft, in particular to an online parameter identification method for a jumping reentry of a lunar exploration spacecraft. Background technique [0002] When the lunar exploration spacecraft returns and re-enters the earth, the initial state of reaching the boundary of the atmosphere is very different from that of the near-Earth spacecraft. The most obvious feature is that the re-entry speed of the lunar exploration spacecraft is higher, reaching 11km / s, while the near-Earth spaceflight The reentry speed of the vehicle is generally about 7.8km / s. This high-speed re-entry condition makes the re-entry trajectory more sensitive to atmospheric and aerodynamic parameter errors, the dynamic coupling during the re-entry process is more serious, and the dynamic pressure, heat flow, and overload of the spacecr...

AI Technical Summary

Problems solved by technology

Atmospheric density errors vary with parameters such as solar activity, season, latitude, and day and night. The empirical atmospheric density model obtained through different observation methods and theoretical analysis is not ideal when applied.

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