3 results about "Ballistic coefficient" patented technology

The application belongs to the technical field of aircraft overall design, and discloses a kind of aircraft high trajectory coefficient multi-objective optimization method considering complex coupling constraint, comprising: setting the design variable vector of aircraft and determining constraint condition, constructing multi-objective optimization mathematical model;Improved multi-objective particle swarm algorithm is used to solve, through particle coding and population initialization, fitness evaluation and constraint processing, non-dominated sorting and crowded distance calculation, individual optimal solution and global optimal solution selection, velocity vector and position update, external file maintenance and iterative convergence, output pareto optimal solution set;From it, the particle that satisfies all constraint conditions and realizes balanced improvement on all optimization objectives is selected as the final design scheme.The application can balance multiple optimization objectives under complex coupling constraint.

The planet atmosphere entry disturbance compensation state estimation method disclosed by the application belongs to the technical field of deep space exploration. The method of the application is as follows: a planet atmosphere entry dynamics model, an uncertain parameter disturbance model and a navigation measurement model are established, the uncertain parameters including atmosphere density, ballistic coefficient and lift-drag ratio; an accelerometer and a radio ranging and speed measurement combined navigation are adopted to improve the observability of the navigation system. For the dynamics model considering the influence of parameter uncertainty, a nonlinear disturbance observer is designed to estimate the disturbance caused by parameter uncertainty through the nonlinear disturbance observer. The disturbance estimation value is introduced to correct the filtering dynamics model and the navigation measurement model, and the disturbance estimation value is introduced into the filtering process to compensate the disturbance; a rank filtering method is adopted for state estimation. The application improves the navigation state estimation precision under the condition of uncertainty by observing the parameter disturbance and compensating the disturbance in the filtering process.

The invention provides an orbit forecasting method and device based on atmospheric density dynamic correction. The orbit forecasting method comprises the following steps: determining a plurality of target failure satellites and corresponding TLE orbit data from a failure satellite set; identifying an orbit control time period corresponding to the target failure satellite, so as to determine a real ballistic coefficient corresponding to the target failure satellite based on TLE orbit data of the target failure satellite in a non-orbit control time period; iteratively solving a correction coefficient time series data set according to a real ballistic coefficient corresponding to the target failure satellite and by combining the density-to-position partial derivative equation set; and through a correction coefficient prediction model obtained through pre-training, based on the correction coefficient time sequence data set and the spatial environment index, predicting an atmospheric density dynamic correction coefficient corresponding to the target moment, and carrying out orbit prediction to obtain satellite orbit ephemeris prediction data corresponding to the to-be-predicted satellite. According to the method, the orbit forecasting precision can be improved by using a more accurate atmospheric density dynamic correction coefficient.