4 results about "Libration" patented technology

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.

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.

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.