Research On Information Extranction Of Seeker For Missile Blended With Lateral Jets And Aerodynamic Fins

Dual control of lateral jets and aerodynamic fins is used in kinetic kill vehicles, bringing new problems to line of sight rate extraction from seeker. On the one hand, thrust reaction of lateral jets will cause not only the elastic vibration of the missile body, but also significant change of missile attitude, which increases decoupling error of the extracted line of sight rate or even cause the miss of the target. On the other hand, high precision end-game control of homing guidance requires the seeker measuring effectively before lateral jets ignite, which raises the level of bandwidth of seeker's tracking loop. Therefore, extraction of terminal guidance information is focused in this dissertation considering about the end-game measuring problem caused by dual control of lateral jets and aerodynamic fins. The main contributions are the following:Firstly, for the elastic vibration problem, dynamic responses and vibration acceleration of missile body are investigated with the superposition method of mode of vibration based on Euler- Bernoulli beam, and an additional angle rate caused by flexibility is also defined. According to the research, it is indicated that elastic effect increases influence of mass eccentricity disturbance torque in stabilized platform of seeker.Secondly, considering the significant change of missile attitude, jets control model of missile attitude is established, according to which, frequency characteristic is investigated from the perspective of system transfer function, aλ-energy frequency distribution range is defined creatively and a method of calculating it is given for missile body attitude changing rate.Thirdly, considering bandwidth requirement of seeker's tracking loop, linearization method is used to analyze bandwidth of terminal guidance system by which bandwidth index of tracking loop of seeker is proposed.Fourthly, tracking and decoupling ability is analyzed according to the model of seeker with stabilized platform to present the requirement of control design.At last, tracking system of seeker with stabilized platform is designed using multi-loop method combining missile attitude disturbance characteristic and tracking bandwidth index. Friction compensation is designed based on the coulomb friction plus viscous friction model to improve the precision of line of sight extraction.The special problems of terminal guidance information extraction caused by dual control of lateral jets and aerodynamic fins are focused in this dissertation comprehensively. Analysis and designs are done to improve precision of terminal guidance information measuring. Schemes and conclusions proposed have instructional significance to high precision end-game interception.