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...

Images