Application Of Phased Array Radar Seeker To Anti-Aircraft Missile Guidance System

The main objective of this dissertation is study on intercepting high stealth performance,high speed and high maneuvering air targets,combined with the current developing trend of air-to-air/surface-to-air missile guidance control key technologies,aiming at the application of phased array seeker to anti-aircraft missile guidance system,the decoupling algorithm based on beam angel error compensation and beam stability control of phased array seeker,the effect on detection and guidance performance of phased array seeker due to phantom-bit technology,the effects of radome error and beam control error on missile guidance performance,high accuracy target maneuver estimation technique are deeply studied.Firstly,the causes of the incomplete decoupling of the phased array seeker are analyzed,based on the quaternion method,the attitude information of the missile can be obtained and the beam space pointing stability algorithm is studied.Three different line of sight(LOS)rate extraction methods were established,and the LOS rate extraction based on the beam scanning feedforward compensation control is taken as the research object,a mathematic model of discrete beam control is established,according to the beam motion of the phased array seeker in the inertial space,a mathematical model of LOS rate extraction of two-loop phased array seeker is established,the compensating strategy for the measurement of the offset angle of the beam transition is studied.Research indicates: the application of beam pointing angle error compensation can effectively eliminate the jump fluctuations of LOS rate extraction value,and achieve better decoupling effect.For the problem of beam granularity and discrete scanning of phased array seeker,the phase law of antenna element under real phase shifter and virtual phase shifter is analyzed,the amplitude pattern is established according to the principle of electromagnetic wave propagation,and the influence of the phantom-bit technique on the quantized sidelobe and first sidelobe of the antenna scanning pattern is analyzed,the expression of the subarray pattern and the synthesis factor pattern are established under the condition of subarray scanning,the positional relationship between the zeros and the grating lobes is compared,at the same time,the reason of beam pointing error is analyzed,according to the direction diagram derivation method,beam pointing error model using the phantom-bit technique is established.Research indicates: in the presence of the initial antenna beam scanning angle,the subarray is also scanned,the zero point position of the subarrays are substantially coincident with the position of the grating lobes,and can not result in excessive parasitic sidelobe level increments,phantom-bit technology will bring the beam pointing error,the larger the number of phantom bits,the greater the beam pointing error.The mechanism of beam pointing error from the radome and beam control is analyzed,and a parasitic loop model including the radome and beam control is established.Based on time-invariant theory,the effects of radome error and beam control error on the stability of the guidance system are studied.At the same time,under different error source input conditions,The influence of different guidance parameters and the beam pointing error slope on the missile’s non-dimensional miss distance are studied by using the dimensionless adjoint method.Research indicates: when the error slope of the radome is positive,the parasitic loop exhibits a negative feedback characteristic,but when the error slope of the beam control loop is positive,the parasitic loop exhibits a positive feedback characteristic,and the feedback characteristics of the parasitic loop in the radome error and wave control error of different superposition can not be accurately estimated,when both are positive feedback characteristics,which will make the most detrimental effect on the guidance loop.Beam pointing error slope parasitic loop will lead to the stability of the guidance loop decline or premature instability,it is easy to cause a larger miss distance in the case of an external disturbance source.According to the phased array seeker in the long-range detection tracking high-speed large maneuvering target exists slow response characteristics,the idea of integrated guidance and control based on phased array seeker is put forward,using estimated LOS rate by Kalman filter feed-forward compensate the angle tracking loop of phased array seeker.Respectively,take singer maneuver,the target constant maneuver,the target has a dynamic constant value command maneuver as typical target maneuver model,a Kalman filter equation of state for matching different maneuvering targets in Cartesian coordinate system is established,and according to different operational requirements and the use of different pulse repetition frequency conditions,established the nonlinear measurement equation under high repetition frequency and medium repetition frequency,respectively,the estimated value of the target acceleration is provided to the optimal guidance law,and then completed the integrated design.Research indicates: added the LOS rate feed-forward compensation value in the phased array seeker angle tracking loop can speed up the seeker’s response speed,reduce the offset angle quickly.A Kalman filter with a constant maneuver model,or a constant command maneuver model that takes into account the target’s dynamics,can be more robustly estimated for various types of target maneuvering accelerations,as medium repetition frequency mode can provide more distance measurement information than high repetition frequency mode,therefore,the estimation result in medium repetition frequency mode makes the missile have higher intercept precision.