Study Of Separation Dynamics And Inverse Problem For Submarine Launched Ballistic Missile

Separation system served as vital subsystem of missile involves launch, powered flight, orbit flight and other kinds of separation process, and its performance directly affects whether the task can be successfully completed. During the past several decades, researches related to separation design and verification still have some shortcomings. At present, the method of “empirical design-experiment-modification” is mainly adopted in the separation process development. Because of inadequate understanding of underlying principle of separation design, and lack of systematic researches about presence and transmission of separation failure, the method has its potential limitations. Moreover, in the current design process of separation system, parameters are set as certain values or approximately simulated by setting up safe coefficient without considering its uncertain nature. Thus the accuracy and credibility of the obtained results is lack of effective verification, and separation scheme cannot present the influence of original parameters on separation outcome. Accordingly, it is essential for researchers to design and test separation systems by the means of combining the forward simulation with reverse identification.For this reason, this article explore the separation of space vehicle and missile, including the forward problem study of separation in order to detect the uncertainty and safety of separation systems and the inverse problem study to deduce the reason of separation failure. This study establishes a generic separation model and force model, and reasonably analyzes various uncertainties in separation process and then scientifically and effectively quantifies those uncertainties of parameters, which are of important significance for designing efficient and reliable separation system. Meanwhile, for the known separation results, this article design the multiple types of solutions for inverse problem to reversely calculate the initial separation state and the model parameters. These results contribute to separation system evaluation and improvement.Considering varied separation system and inconsistent simulation model, the article builds unified separation dynamics model. This study firstly classifies separation systems and finds similarities and differences of modeling. And then the general constraint mode for separation by Constraint Force Equation(CFE) is built to deduce the corresponding constraint formula with modeling the elastic guiding model. The article also designs the general method of internal distance detection and external distance detection during separation, analyzes the interferences between separation bodies, and built the general detection model and method. By using the above methods, simulation analyses and interference detection for most separations at present, such as stage separation, cover separation and load separation, can be implemented, which lay the foundation for the subsequent researches on uncertainty.During separation process, the environments of separation bodies largely varied in the different separation schemes. The perfect and high-precision separation load and deviation libraries are built and are used to simulation, effectively avoiding simulation distortion resulting from multiple separation types, deviations and uncertainties. This study establishes a variety of targeted mathematical models, at separation energy including thrust, additional coriolis force, gas-thrust, release spring and thruster; at constraints friction from hinge mechanism, guide mechanism and separating-planting mechanism; and at environmental interference factors including shaking factor, aerodynamic force, wind interference, air negative pressure and etc. The separation processes that are close to actual situations and from different separation schemes are obtained by precise modeling for separation environments.Aiming at separation results uncertainties because of many deviation factors in separation process, probabilistic method and sensitivity analysis method are adopted in this article. Firstly, uncertainty factors of separation are classified, and then are researched by the means of Monte Carlo Method(MCM), Latin Hypercube Sampling(LHS) and improved sampling. In consideration of complex effects different factors have on separation results, global sensitivity based on experiments is used to analyze, and following the initial sensitivity analysis, more new methods of improved orthogonal test sensitivity analysis, sensitivity analysis based on LHS and Morris based on homogeneous design are proposed. Researches on whether the collision is happened during separation under the influence of uncertain factors and separation safety are also developed. The result from engineering example analysis shows that the influences of separation parameters can be effectively order, and separation distribute ranges also can be obtained to evaluate and verify the safety of separation schemes.In order to get the inputs from separation results, this paper proposes a variety of inverse problem solving methods. This paper established directly inverse dynamics equations for the simple separation inverse problem. For the case of input and output are known, part of the model parameters are unknown and output and models are known, part of the input parameters are unknown, the Identification scheme is used to solve the inverse problem. For the case of multiple uncertain factors are unknown, optimization method is used to solve the inverse problem. Using and separation results as optimization target and using improved fast elitist non-dominated sorting generic algorithm method to get the optimal results. For complex separation process, this paper used probability method to solve the inverse problem. For the case of separation system with multiple uncertain factors is complex and value range of the uncertain factors are unknown, complex method is used to solve the inverse problem. Firstly using probability method to reduce the value range of the uncertain factors, then using optimization method to get the optimal results. The inverse problem encountered in the separation process can be effectively solved through the above options.Finally, in this paper, the two representative bottom cover separation scheme has been analyzed, including program design, mathematical modeling, parameter design, uncertainty analysis, etc. By comparing the simulation results obtained the advantages and disadvantages of the two separation designs. The inverse problem of bottom cover separation has been studied too. The above studies provide a reference for researchers to design separation scheme.