Robust filtering method for near-space vehicle transfer alignment model uncertainty

Abstract

The invention discloses a robust filtering method of near space aerocraft transfer alignment model uncertainty. The method comprises the following four steps: step 1, based on working principle and characteristics of a near space aerocraft transfer alignment system, establishing a math platform misalignment angle error equation, a velocity error equation, a position error equation and an observation equation of the system; step 2, establishing a state equation and the observation equation of model uncertainty according to the error equation of the system; step 3, providing a state variable initial value (x0) and a forecast error variance matrix initial value (sigma 0|0), providing a sparse grid quadrature point set (zeta j, epsilon j; j=1, 2,... Np), and providing robust filtering parameters gamma and epsilon; and step 4, estimating system state by robust filtering, performing error correction for a secondary inertial navigation system, and finishing the transfer alignment process. The method provided by the invention is applicable for transfer alignment in the case that primary and secondary inertial navigation systems have model uncertainty when the near space aerocraft is in dynamic state.

Description

technical field [0001] The invention relates to the field of nonlinear robust filtering of navigation systems, in particular to a robust filtering method for the uncertainty of transfer alignment models of near-space vehicles. Background technique [0002] Transfer alignment is the main method to solve the initial alignment problem of a hypersonic vehicle under the condition of a moving base. Generally, a nonlinear Kalman filter is used to estimate the state of the system. The performance of filters based on nonlinear Gaussian approximation depends on the accuracy of the system model and assumptions about the disturbance characteristics. In actual work, the external weapons and sensor pods of hypersonic vehicles are generally suspended under the wings or belly, and the aircraft is affected by various factors such as air flow, load changes, and engine noise during high-speed maneuvering flight. The airframe will undergo time-varying structural deformation. The more use of co...

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Problems solved by technology

[0004] Purpose of the invention: In order to solve the problem of poor modeling of the dynamic lever arm and deflection deformation in the transfer alignment of near-space vehicles, the robust filtering method with model uncertainty is used to combine the robust algorithm with a series of sparse The combination of grid integral nonlinear filtering technology provides a filtering method with high precision and strong robustness

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