Research On Transfer Alignment And Error Compensation Of Airborne Weapon On Moving Base

Transfer alignment(TA)is an efficient way for Strapdown inertial navigation systems(SINS)on moving base,which plays a key role in the operational effectiveness of airborne weapon systems whose actual operating conditions are harsh.In order to enhance the environmental adaptability of the transfer alignment method,the error model and appropriate filtering method are established for the interference factors such as flexible arm effect,misalignment errors,deflection deformation and delay of matching data from master SINS.to slave SINS in the transfer alignment process.The improved model and method can improve the accuracy of error estimation and compensation,and eventually improve the navigation performance.Focusing on the master-slave SINS transfer alignment technology of airborne weapon systems,this paper studied a series of problems,including flexible arm effect,matching data delay and application and improvement of filtering method.The main research contents are as follows:(1)The basic theory of transfer alignment of SINS is studied,and the device error model is constructed.The attitude error equation and velocity error equation of the platform error model(φangle model)and the measurement error model(ψ_m angle model)are derived.The relationship and the difference of the corresponding error compensation methods between the two kinds of TA error models are analyzed.(2)Aiming at the flexural problem of the flexible arm,the acceleration model of the flexible arm is built;The tracking differentiator is used to extract the angular acceleration information from the slave SINS angular velocity data,which is used to compensate the acceleration of the flexible lever arm;The acceleration model of the flexible lever arm is introduced into the system error model of measuring misalignment Angle(ψ_m angle model),then the system error model is established.The simulation results show that the acceleration model of the flexible arm is effective and improves the estimation accuracy of the attitude misalignment angle.(3)Aiming at the random delay problem of matched data,the systematic error model with benchmark information delay was constructed.The velocity error observation equation and attitude error observation equation of matched data delay were analyzed and improved,and the random delay was estimated and compensated by the simplified Sage-Husa adaptive filtering algorithm.The mathematical simulation shows that the algorithm can improve the navigation landing point accuracy by 16%.(4)Aiming at the problem of the inaccuracy of the linear model in the practical engineering application,the nonlinear system error model based on theψ_m angle model was derived,and the nonlinear transfer alignment method based on the UKF filtering algorithm was given.Through mathematical simulation and semi-physical simulation of measured data,it is verified that the navigation accuracy of the nonlinear filtering scheme is improved by at least 6.0%compared with that of the linear filtering method.