Guidance Information Extraction Method Based On Cubature Kalman Filter

Precision guidance is one of the important requirements of modern warfare for weapons,and the seeker is the core component of the guidance system.The strapdown seeker is widely used in tactical missiles because of its simple structure,low cost and reliable performance.The background of this paper is that the ship's electromagnetic projectile intercepts the local cruise missile.After the missile is launched by the ship,the unpowered controlled flight to the target with a large initial velocity is adopted.The shipborne radar detects the target in real time and transmits the measured information of the target to the missile through the data link.Due to the limited working distance of the seeker,it can only be applied in the final guidance section.In order to make up for the lack of source of the LOS angular rate of the middle guidance section and improve the accuracy of the estimation of the LOS angular rate of the terminal guidance section,the paper has carried out some research work.The details are as follows:Firstly,in order to establish the trajectory model of the missile and the target,and better describe the line of sight and the line of sight measured by the strapdown seeker,the paper defines the relevant coordinate system and gives mathematical model of the strapdown seeker and data link and the inertial navigation system.By introducing the trajectory model of the missile and the target,it provides a theoretical basis for the subsequent simulation of the missile and target motion information.Then,the paper studies the method of tracking information by data link and finding the LOS angular rate.Three typical target tracking motion models are introduced.Combined with the motion information obtained by missile inertial navigation,the method of taking the LOS angular rate is given.Based on this,the paper uses the extended Kalman filter algorithm to perform mathematical simulations in three typical target motion forms,and verifies the feasibility of tracking the target through the data link and obtaining the LOS angular rate.The Monte Carlo simulation method analyzes the relationship between the performance parameters of different measuring components and the accuracy of the LOS angular rate estimation.Finally,the paper analyzes the method of estimating the LOS angular rate by combining the strapdown seeker with the data link measurement information.Based on the missile and target motion relationship paper,the state equation of LOS angular rate estimation is established.Based on the measurement model of strapdown seeker and data link,the observation equation of LOS angular rate estimation is established,which is different from the traditional method of estimating the LOS angular rate information based on strapdown seeker measurement information.The two angle information and the ranging information measured by the data link are amplified into measured quantities.On this basis,the paper introduces the cubature Kalman filtering method with higher nonlinear approximation accuracy.Mathematical simulations were carried out in three typical target motion patterns,and the effectiveness of the method of estimating the LOS angular rate by strapping the seeker and data link measurement information was verified.The Monte Carlo simulation method was used to analyze the effect of different measuring the performance parameters of the component on the accuracy of the LOS angular rate estimation.