Research On Effect Of Geophysical Disturbance Factors And The Compensation Method For Hit Accuracy Of Long-range Ballistic Missile

The primary goal of the thesis is to improve hit accuracy of mobile long-range ballistic missile. Aiming at the requirements of high accuracy and short launching preparation time, geophysical disturbance factors impact was lucubrated and the compensatory approaches in ballistic data calculation and guidance equation were studied. Some meaningful results are achieved and shown as follows.At first ,the thesis put forward one group of fast trajectory calculation techniques considering geophysical disturbance factors:For power-flight reference trajectory, the thesis analyzed trajectory characteristics in different launching azimuths and launch latitudes. Then the atmospheric ballistic fitting method under constant flight program and the extra-atmospheric ballistic analytic method were advanced. The cutoff state evaluated error is less than 0.3m/s for velocity and 20m for position when the missile range is 12,000km, typically.For free-flight reference trajectory, the thesis first analyzed four analytic methods considering earth oblateness roundly, then deduced contour restricted analytic solution based on state space perturbance method, and advanced an modified mean element models in view of missile free-flight characteristics. If the terminal condition is geocentric range or geodetic height, state space perturbance method has no need for iterative computation process and can limit position error below 50m. So this method wins an advantage of other methods in calculating speed and precision.For warp trajectory considering gravity anomaly, the thesis applied extension approximate method and pole changing spherical harmonics method to gravity anomaly calculation, and gain faster calculating rate. Using the same memory space, extensive approximate method gets twice the precision as the finite element method can. Pole changing spherical harmonics method was modified to keep the fall point warp below 15m. Combining Pole changing spherical harmonics method and state space perturbance method, contour restricted range angle analytic solution considering J3,J4 perturbance was deduced.Then, the thesis analyzed geophysical disturbance factors impacting on hit accuracy such as gravity anomaly, positioning and orientation deviation, upper atmosphere, gravitation constant variety in power-flight phase, electromagnetic force systemically:Error propagation equations were given for every factor based on state space perturbance method. Experiment results indicate that gravity anomaly, positioning and orientation deviation are the most significant factors, and simplified methods have high calculating precision.Gravity anomaly influences power-flight trajectory, free-flight trajectory, explicit guidance and inertial system error calibration. All above were investigated in the thesis.Integrated analytic solution about positioning and orientation deviation impact was proposed in view of geometry item, initial state item and gravitation item, and different calculation equations were deduced depending on whether independent celestial observation is existed or guidance mode is considered. Experiment results show that the method has high calculating rate, and velocity deviation evaluation is less than 10%, and position deviation evaluation is less than 1%.At last, the thesis designed a data and guidance compensatory scheme, and developed a common dynamics simulation system:Initial azimuth determination method in view of ballistic deformation was deduced, that reduces estimated error from 5 to 0.5 .Geophysical disturbance factors compensatory arithmetic in data and guidance was built up, that can avoid complicated ballistic iterativeness and keep the fall point warp within 15m.Zero range orientation in the spinning earth was presented, and was applied to reference flight program design in terminal correction phase, multiple independently-targeted sequence plan and burnout guidance in solid rocket.A general simulation frame about ballistic missile dynamics was put forward based on object-oriented methodology and united modeling language, and common simulation software was developed to sustain study work. Design patterns can improve modeling level and efficiency, so four patterns were discussed, and two new patterns, namely common integral pattern and hiberarchy aggregation pattern, were put forward to satisfy vehicle dynamics specialty.In summing up, it may be stated that the research work has contributed to shorten launching preparation time, decrease guidance equation error and improve fighting efficiency for ballistic missile.