5 results about "Ballistic coefficient" patented technology

The invention provides a ballistic extrapolation method for estimating an optimal ballistic coefficient based on RANSAC (Random Sample Consensus). The method comprises the following steps: firstly, acquiring part of ballistic trajectory data of a flying projectile by using the emplacement reconnaissance and calibration radar, and carrying out secondary filtering on the part of ballistic trajectory data so as to reduce a measurement error generated in a radar measurement process and reduce a ballistic extrapolation distance; then, an RANSAC (Random Sample Consensus) algorithm is adopted to calculate different data parameter models for different ballistic coefficients and trace point data, and an optimal model is selected by utilizing a root-mean-square error, so that an optimal estimated ballistic coefficient is obtained; and finally, extrapolation is carried out by using the optimal estimation ballistic coefficient so as to improve the emplacement extrapolation precision. According to the method, the trajectory extrapolation precision can be greatly improved, and the shot point of emplacement extrapolation is more accurate.

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 discloses a planetary atmosphere entering disturbance compensation state estimation method, and belongs to the technical field of deep space exploration. The implementation method of the invention comprises the following steps: establishing a planet atmosphere entry kinetic model, an uncertain parameter disturbance model and a navigation measurement model, wherein uncertain parameters comprise atmospheric density, ballistic coefficient and lift-drag ratio; the accelerometer and radio distance measurement and speed measurement combined navigation is adopted, so that the observability of the navigation system is improved. Aiming at the kinetic model considering the influence of the parameter uncertainty, designing a non-linear disturbance observer, and estimating the disturbance caused by the parameter uncertainty through the non-linear disturbance observer. Introducing an interference estimation value to correct the filtering dynamic model and the navigation measurement model, and introducing the interference estimation value into a filtering process to compensate the disturbance; and performing state estimation by adopting a rank filtering method. According to the method, parameter disturbance is observed, disturbance compensation is carried out in the filtering process, and the navigation state estimation precision under the uncertain condition is improved.

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.