Research On Performance Assessment For Transfer Alignment On Ship Carried Weapon Inertial Navigation System

For transfer alignment of shipborne weapon inertial navigation system(SINS),the alignment time and accuracy directly impact the reaction capability of weapons and the effects of accurate attack.However,the accuracy of master inertial navigation system(MINS),maneuver mode of ship,matching method between MINS and SINS,lever arm,flexure effect and other factors appear to produce different degrees of impact on the performance of transfer alignment.By estimating the attitude error at the end of alignment,transfer alignment accuracy evaluation can effectively accomplish the performance analysis of transfer alignment for ship borne weapon INS,and has gradually become one of the key techniques in the ship navigation research.Because the traditional accuracy evaluation for airborne system is not appropriate for shipborne weapon,a research of accuracy evaluation for shipboard weapon INS has important theoretical and practical value.This thesis studies on the problem of transfer alignment accuracy evaluation,and focuses on two kinds of evaluation methods including the measured data evaluation and simulation method,and key technologies and issues involved are in-depth researched and analyzed.In this thesis,based on the error equation of SINS,a transfer alignment algorithm of velocity and angular velocity match has established.And through an quantitative analysis of the impact on the transfer alignment performance caused by correlative factors,the necessary of transfer alignment accuracy evaluation is proposed.Then,to solve the problem of high requirement on the maneuverability of carrier for effectively estimating the azimuth angle error when velocity and position of differential GPS are the only observations used to suit for the field for airborne,an approach of transfer alignment accuracy evaluation based on multi-observations is proposed by consulting the method of transfer alignment,line motion information plus angular motion information matching.In other words,by introducing the attitude of rotation INS as one of the observations,a method of transfer alignment accuracy evaluation using the reference information of velocity and position offered by differential GPS,attitude offered by rotation MINS is designed.By this method,only a swing motion can achieve accuracy evaluation,improving the speed and adaptability of accuracy evaluation.Meanwhile,for the different characteristics between the level and azimuth attitudes,to avoid the effect on the evaluation performance when MINS is on the peak value of oscillation error,an approach of accuracy evaluation is developed with the traditional Kalman filter being replaced by classified factors adaptive filter,and differential GPS is regarded as the criterion standard to adjust the factors appropriately.Simulation results show that this approach of transfer alignment accuracy evaluation based on multi-observations can reduce requirements of the carrier intentional motion and improve the accuracy of evaluation.As taking into account the different advantages of attitudes,high precision to celestial navigation system(CNS)and strong autonomy to MINS,an approach of transfer alignment accuracy evaluation based on fault-tolerant federal filter utilizing multi-observations has been proposed and researched in this thesis,containing two sub-filters constituted by CNS/SINS and MINS/SINS respectively,and then a data fusion for output.In order to deal with the step error,slope error and random noise error of observational information due to the poorly self-contained character of CNS,a fault detection method based on wavelet transform and modulus maxima has been put forward,realizing the detection of system fault and reconstruction of fault classes.Simulation results show that this method can greatly improve the performance of accuracy evaluation algorithm,and the adaptability to external environment.Because of the incomplete test boundary qualifications and the restriction that the results of evaluation can only be get by smoothing algorithm,an approach of transfer alignment accuracy evaluation based on the thought of simulation is explored.In order to improve the fidelity of the simulation,a transfer alignment performance verification algorithm considering the ship space motion and rotation SINS is proposed and designed.By introducing the model of ship space motion,considering the influence of the hull's dynamic flexure and level arm effect,a transform algorithm is researched and designed which realizing the output of ship space motion as the input of INS,to guarantee the correct transform among the inputs of the platform INS,strap-down INS and rotation INS,avoiding the problem originating from excessively ideal and simplex maneuver manner of carrier,to make the performance of transfer alignment in simulation approaching under the condition of real environment.Finally,a software of transfer alignment performance verification is designed based on the verification algorithm in simulation.Multiplicate situations for simulation are designed for guest setting,including of the ship's motion state,and the parameters of MINS and SINS,the initial states of system,the simulation time,et al.Based on the technique of dynamic link library,this software can accomplish the performance verification simulation of multiple transfer alignment algorithm.Simulation results of multiple sets show that the software is properly completed the transfer alignment performance verification simulation for ship under ship space motion environment.