8 results about "Libration" patented technology

The invention discloses a lunar balance dynamic parameter high-precision resolving method and system combining LRR and LLR technologies, and belongs to the field of deep space exploration and celestial body dynamics, and the method comprises the steps: constructing an LRR and LLR combined observation data set, and carrying out the preprocessing; constructing an LRR and LLR combined moon measurement model, and deducing a partial derivative of the model for a moon rotation parameter and a tidal LOVE number to obtain a combined partial derivative matrix; iterative solution is carried out through nonlinear least square to obtain dynamic parameters of the moon balance; and evaluating a resolving result and optimizing a resolving strategy, and optimizing a resolving scheme by dynamically adjusting the weight, improving a tide model and eliminating abnormal values. According to the method, the parameter calculation error is reduced, the technical advantages of two types of data are effectively integrated, the problem of insufficient observation continuity or precision of a single data source is solved, and reliable parameter support is provided for moon rotation and internal structure research.

The invention discloses a construction method and system for a low-thrust transfer orbit family between earth-moon translation point orbits, and belongs to the technical field of aerospace. The method comprises the following steps: firstly, solving a time optimal transfer orbit based on a continuous low-thrust spacecraft motion equation; then taking the orbit as a seed, performing forward and reverse phase continuation along a departure orbit and an arrival orbit by adopting a self-adaptive step length numerical continuation method, and generating a time optimal transfer orbit family covering different phases; secondly, mapping the time optimal orbit family into an energy optimal orbit family based on control law consistency, and expanding the transfer time range of the energy optimal orbit family through time continuation; and finally, gradually reducing homotopy parameters by using a homotopy method, detecting and processing thrust switching discontinuity in combination with a switching function, and converting the energy optimal orbit family into a fuel optimal transfer orbit family. According to the method, a continuous and complete orbit family is efficiently generated from a single solution, and systematicness and engineering applicability of orbit design are improved.

The invention discloses an earth-moon L1 point track crossing behavior prediction method and system based on machine learning. According to the method, firstly, an initial state set is generated based on an earth-moon plane circular restrictive three-body model, and an orbit sample data set is constructed through numerical integration; secondly, a multi-class behavior classification system is established, and sample data is automatically labeled; on the basis, an XGBoost algorithm is adopted for model training, a category self-adaptive threshold optimization strategy based on a verification set is introduced for the problem of data extreme imbalance, and the overall prediction precision and category fairness of the model are remarkably improved by independently optimizing an optimal decision threshold for each category and applying the optimal decision threshold to normalized probabilistic decision. According to the method, the technical blank of spacecraft behavior prediction in the earth-moon translation point area is filled, and an effective means is provided for space situation awareness.

The application discloses a lunar orbit and libration parameter solving and forecasting method and system, and the method comprises the following steps: considering the interaction among the mass point gravity model based on the post-Newtonian framework, the moon figure, other planet mass points in the solar system and the influence of the earth figure, a high-precision lunar orbit dynamics model is established under the general relativity framework; considering the lunar moment of inertia and the lunar torque, a double-layer lunar libration attitude dynamics model is established; when the initial conditions of integration meet the preset accuracy, an adaptive step integrator and an adaptive step integrator with time delay effect are used to respectively forecast the orbit parameters and the libration parameters, and initial products of the orbit and the libration parameters with time sequence labels are obtained; when the initial conditions of integration do not meet the preset accuracy, an automatic differentiation-based nonlinear solver is used to process historical observation data, and the optimal solution of the to-be-estimated parameters in the initial conditions is obtained, and re-forecasting is performed.

Embodiments of the present application disclose a transfer orbit design method from GTO to the Sun-Earth collinear libration point, a device and a medium; the method comprises: calculating and obtaining an invariant manifold connected with the Halo orbit around the libration point according to the spacecraft dynamics equation and the potential function in the Sun-Earth barycenter coordinate system; taking the geosynchronous transfer orbit as the earth parking orbit to construct the constraint variable, taking the Halo orbit as the target orbit to construct the control variable, and correcting the control variable by using the least square differential correction method; based on the set constraint condition and performance index, the optimal HOI point corresponding to the optimal performance transfer orbit is selected from the transfer orbit meeting the constraint condition; according to the optimal HOI point, the relationship between the control variable and the parking orbit constraint variable is analyzed, and the differential correction initial value expression for determining the control variable initial value of the multi-constraint orbit design is constructed; the transfer orbit meeting multiple constraints is obtained by using the multi-stage differential correction method according to the differential correction initial value expression.

The application discloses a bifurcation construction method, system, equipment, medium and program of a clover orbit family in a geolunar three-body system, and belongs to the technical field of aerospace. The method comprises the following steps: constructing a geolunar circular restricted three-body dynamics model according to a geolunar three-body system; obtaining a halo orbit family based on the geolunar circular restricted three-body dynamics model; positioning a halo orbit family bifurcation point, and constructing a transition orbit; obtaining a first clover orbit based on the transition orbit, and extending to obtain a clover orbit family. The application can obtain complex periodic orbit families derived near the libration points L1 and L2 in a restricted three-body system, and quickly constructs the periodic orbit family.

The application discloses a kind of coordinate determination methods of lunar observation remote sensing image, steps are as follows: the three-dimensional coordinates of each pixel point in lunar image are established;Determine the satellite view angle libration based on the lunar observation position of satellite;The azimuth between any two points on the moon is determined according to the geographical coordinates of the two points, the projection coordinates of two latitude and longitude coordinate points on the image plane and the azimuth thereof are determined;The angle relationship between the scanning direction when satellite sampling and the lunar fixed coordinate system is determined;The geographical coordinates of the observed lunar image under the lunar fixed coordinate system are determined.The method of the application can avoid the complex imaging model based on rigorous geometric relationship, and can solve the deficiency that the image matching method has strong dependence on image gray or texture information;Only a small amount of image processing and simple coordinate conversion can establish the accurate mapping relationship between image coordinate and moon surface coordinate.

This invention discloses an improved method for designing orbits near the Earth-Moon triangular translation point. Based on the quasi-periodicity of orbits near the Earth-Moon triangular translation point applicable to space missions, this method obtains terms with different periodic frequencies through spectral analysis and multi-target tracking. Then, based on the analytical solution of the orbit near the Earth-Moon triangular translation point under an ephemeris model, the corresponding coordinate and frequency coefficients are fitted. Using the semi-analytical solution of the orbit enables rapid orbit design, thus avoiding the performance overhead of numerical iteration, and allows for the design of orbits with specified amplitudes and phases.