Research On The Parameter Identification And Simulation Of Large Parachute System

This manuscript focuses on the large parachute system, starting with the study on parameter identification on the opening process of the large parachute using different methods, which were also applied to the aerodynamic parameter identification in the full inflation stage of the parachute. Other than that, the simulation of influencing factors’ sensitivity was conducted by orthogonal experiment. The main research results are as follows:According to the features of the large parachute, the plane model for the parachutes’ inflation stage and the six degrees of freedom dynamic model for full inflation stage were established. Moreover, the study discussed the principle, procedure and feature of the maximum likelihood method, generic algorithm and combinational algorithm.In addition, the manuscript studied some key parameters identification of the parachutes’ inflation stage based on different algorithms, summarized their respective characteristics and proposed the combinational algorithm. Through the airdrop experiment data, the combinational algorithm was designed to estimate the parameters of a spaceship parachute, and the simulation results show marked similarities with the experiment data.The problem of aerodynamic parameter identification of large parachute system was researched. 1) The motion characteristics of parachute system under the mean wind field, turbulent wind field, gust wind field and unwindy condition were analyzed on simulation.2) The combinational algorithm for Single-objective and multi-objective observation data was used to study parameter identification with the initial disturbance, wind effect and noise, and the corresponding solutions were proposed.3) The identification using the airdrop experimental data of two flights was studied, and the identification results were discussed.The extrema of the peak values of parachutes’ opening load and velocity pressure in extreme conditions, also the influencing factors’ sensitivity were discussed by utilizing the orthogonal experiment, some reasonable conclusions were obtained.