Terminal Guidance Law Design Based On Side Jet And Aerodynamic Compound Control

For the air defense intercept missile with side jet and aerodynamic compound control, the terminal guidance design is investigated. The main researches are as follows:I. The nonlinear mathematical model is constructed in polar coordinates. Under the assumption of a maneuvering target with a constant magnitude, the target acceleration is predicted by estimating the acceleration of the line of sight using a second order fading memory filter.II. By considering the magnitude and establishing time of overload command, Terminal guidance law based on command decomposition is designed, which guarantees the line of sight rate approach to zero at the time when the guidance loop is cut off. Reasonable threshold values are designed to attenuate the vibration of guidance command.III. Based on miss distance compensation and using of the guidance information obtained from the seeker when the guidance loop is cut off, an open loop command of side jet control is issued to compensate the predicted miss distance. Both situations with adjustable and non-adjustable thrust durations are discussed.The validity and feasibility of all the analysis and designs are verified by numerical simulations. The results show that under general conditions, the second order fading memory filter can give a satisfactory estimation of the target maneuvering acceleration. The terminal guidance law based on the command decomposition can restrain the line of sight rate effectively and reduce the miss distance. The proposed guidance strategy based on predicted miss distance compensation can effectively utilize side jet thrust to compensate miss distance while the guidance loop is cut off, and thus improve the guidance precision.