Spacecraft attitude estimation method based on norm-constrained cubature Kalman filter

Abstract

The invention discloses a spacecraft attitude estimation method based on norm-constrained cubature Kalman filter. The method comprises the following steps: a state equation of a spacecraft navigation system is established; a non-linear measurement equation of the spacecraft navigation system is established; a discretized state equation and a discretized measurement equation are obtained; a norm-constrained cubature Kalman filtering algorithm is used for the discretized state equation and the discretized measurement equation, and an attitude of the spacecraft is outputted. The norm-constrained cubature Kalman filter is used, norm constraint of quaternion for describing the spacecraft attitude is introduced into the attitude estimation, so that the problem of singular covariance existed in the process of attitude estimation without considering norm constraint is effectively solved, the influences of norm constraint conditions of quaternion on the spacecraft attitude estimation are effectively corrected by only adding small computational complexity, precision of attitude estimation is improved, navigation precision of the spacecraft is furthermore improved, and stability of the navigation process is enhanced.

Description

technical field [0001] The invention belongs to the technical field of nonlinear constraint state estimation and attitude estimation, and in particular relates to an aircraft attitude estimation method based on a norm-constrained volumetric Kalman filter, which can be used to improve the accuracy of aircraft attitude estimation. Background technique [0002] As we all know, the Kalman filter obtains the unconstrained optimal solution of the linear random estimation problem. However, when the state variables or part of the state variables meet certain constraints, the estimated results obtained by Kalman filtering are not necessarily optimal. The estimation problem of Kalman filter under the condition of research state constraints is a difficult problem that must be solved, and it has attracted more and more attention of scholars in recent years. [0003] Attitude estimation is a key technology for aircraft navigation and control, and it is also a typical nonlinear filtering...

AI Technical Summary

Problems solved by technology

[0004] In order to improve the problem that the existing aircraft attitude estimation is affected by the norm constraint and the accuracy is low, the present invention proposes an aircraft attitude estimation method based on the norm-constrained volumetric Kalman filter, which introduces the norm constraint into the volumetric Kalman filter , and apply it to the attitude estimation problem of the aircraft, which improves the accuracy of the attitude estimation of the aircraft

Images