Research On The Key Technology For Simply Correction Of Small Caliber Rocket Based On Telescopic Steering Gear

Simply guided munitions installed guidance device and correction implement mechanism on conventional ammunition,could effectively reduce projectile dispersion of the conventional munitions and improve damage efficiency.Because of low combat efficiency cost ratio,simply guided munitions were important guidance development directions of conventional munitions.Canard actuator was the key actuator for the guidance ammunition two-dimensional correction process,which could realize continuous revision of the flight trajectory and have wide range of application.Guided munitions correction system was trajectory correction technique.integrated using attitude detecting technology,real-time detecting technique and actuator control technology of ammunitions.Small caliber simply guided munitions were generally launched by tube,its simply guidance modification system must meet the requirements for low cost,small size and high impact resistance performance and so on.This paper took small caliber conventional rockets as the application background without changing the overall structure parameters,guided them by use of telescopic steering gear as the correction implement mechanism,studied on trajectory correction technology related to the two-dimensional simply guidance.The main works and researches include as follows:Compared of the advantages and disadvantages of the common guidance mode,program guidance was selected as the main guidance system for revision control system based on telescopic actuator and the working characteristic of revision control system were analyzed.The overall layout of simply guided correction bomb based on telescopic steering was designed,the key technologies such as telescopic steering overall optimization design,two-dimensional correction mathematical model&flight state estimation,aerodynamic characteristics calculation and simulation study on control strategy of two dimensional correction were analyzed.The working principle of telescopic steering gear was analyzed,the output torque characteristics was optimized,the best structure parameters and working range as 45°～135°were determined,in order to provide maximum revision control force of rudder,vane shapes of the wing as rectangular of trailing edge sharpening and plane shape as trapezoid were designed.After determining aerodynamic layout scheme of correction projectile,shape parameters of rudder were optimization designed based on genetic algorithm In order to verify the response time of telescopic steering could meet the demand of micro rotary guided rocket,the motion characteristics of telescopic steering gear was studied.Take small caliber rockets as the research object,according to coordinate systems and conversions relationship which were needed to establish the motion equations of projectile in exterior ballistics,force and torque both on the projectile uncontrolled fight and on full rudder were derived respectively.Because of micro rotating,the control force having average effect on body in roll process was needed to consider,pulse average control force of rudder was derived,effect of control force in different roll angle was graphical analysed.Combined with unguided rocket motion equations and control forces and moments of the rudder,6DOF rigid body motion equations of guided rocket based on telescopic actuator was derived and 6DOF model was simplified properly,in order to obtain subsequent scheme trajectory and parameter estimation of flight states for projectile.Flight state of projectile was estimated by using the kalman filter in order to reduce the effect of system noise on the accuracy of the spatial localization and improve the accuracy and adaptability of the real-time trajectory detection in the flying correction process,position error could be reduced by about 70%.Aerodynamic engineering algorithm of good generality,high accuracy and fast calculation speed was selected,the aerodynamic coefficient in subsonic transonic and supersonic range for single body,single rudder and correction projectile was calculated.The aerodynamic parameters for the prototype rocket,trajectory correction rocket and single rudder were numerical simulated respectively by Fluent software,whose results were used to analysis and verify engineering algorithm results.The rudder alone could provide about 15N lift force in the 1.9 Maher base on the telescopic steering rudder angle as +80.A control scheme for retractable canard rudder was studied to solve the coordination between system modules and steering gear,which was suitable for simply guided two-dimensional correction of small caliber rockets based on the control technology of double angle rotating electromagnet.Realizing two-dimensional modified for telescopic actuator required missile borne computer to sense roll attitude of projectile.The pitch angle&roll angle calculation model based on the three-dimensional magnetic attitude detection system were derived.Such as the choise of correction starting point,determination of control angle of telescopic steering and single direction correction ability of steering related to the correction&control strategy were preliminarily studied.The trajectory tracking guidance law and correction accuracy was researched through numerical simulation.Its CEP could be reduced 74%when lag angle was 120 degree,correction accuracy reduced with the increase of roll attitude angle error and position error for the real-time trajectory.According to the characteristics and requirements of correction control system,missile control circuit was designed,principle prototype of simply guided correction control system was developed.The static experiment for Correction capability verification of steering gear and wind tunnel simulation dynamic experiment were carried out.Experimental results showed that modified control scheme used was feasible,missile borne computer could control steering to drive vane out and back according to established deviation in the suitable roll angle,which realized two-dimensional correction of range&direction and verified the ability of two-dimensional correction in the 1Ma～2Ma.Correction control force provided by vane under the action of flow was indirect measured,whose results agreed with calculation results of numerical simulation well.The achievements such as the design method,the related theoretical model,numerical simulation technology and the experiment method and so on for simply guided correction control system of small caliber rocket based on telescopic steering gear in this dissertation provided design reference and theoretical basis for the guided reform of other small caliber conventional ammunition and established the theoretical and experimental basis for further study of two dimensional simply guided correction.