METHOD AND SYSTEM OF EVALUATING A CONSTELLATION SPARE STRATEGY BASED ON A STOCHASTIC TIME PETRI NET

    公开(公告)号:US20210389129A1

    公开(公告)日:2021-12-16

    申请号:US17346190

    申请日:2021-06-11

    Abstract: Provided is a method and system of evaluating a constellation spare strategy based on a stochastic time Petri net, which is applied in the technical field of constellation operation management. The method comprises: constructing a single satellite STPN model and an orbital plane STPN model, and establishing a navigation constellation STPN model that includes multiple spare strategies according to the single satellite STPN model and the orbital plane STPN model; establishing an availability model according to the number of malfunctioning satellites and the constellation value (CV) in the navigation constellation STPN model, and establishing a cost model according to operating costs of the navigation constellation STPN model; and evaluating the navigation constellation STPN model using the availability model and the cost model, and determining a target spare strategy from the multiple spare strategies according to an evaluation result.

    Non-approximate Voigt line profile fitting method for absorption spectrum spectroscopy

    公开(公告)号:US10274424B2

    公开(公告)日:2019-04-30

    申请号:US15959179

    申请日:2018-04-21

    Abstract: The present invention provides a Voigt line shape fitting method, including step 1: Calculate a Gauss line shape function and a Lorentz line shape function, and calculate a Voigt line shape function. Step 2: For determined line shape parameters to be fitted, calculate partial derivatives of the Voigt line shape function with respect to the parameters, convert a partial derivative of the Voigt line shape function with respect to a parameter into a partial derivative of the Gauss line shape function or the Lorentz line shape function with respect to the parameter. Step 3: Substitute the Voigt line shape function and the partial derivative of the Voigt line shape function with respect to the parameter to be fitted, into a least squares algorithm step, perform least squares fitting calculation, and determine whether to terminate the least squares fitting calculation or return to step 1 to perform next iterative calculation.

    Low-orbit satellite deorbit control method and system based on particle swarm algorithm

    公开(公告)号:US11787567B2

    公开(公告)日:2023-10-17

    申请号:US17363363

    申请日:2021-06-30

    CPC classification number: B64G1/242 B64G1/247 G06N3/08

    Abstract: The disclosure describes a low-orbit satellite deorbit control method and system based on a particle swarm algorithm. The method includes: constructing an objective function according to a position parameter and a perturbation acceleration of each of particles in a particle swarm as well as a preset Lagrangian multiplier and a penalty factor; determining an objective fitness of each particle and a population fitness of the particle swarm based on the objective function, updating the position parameter and the velocity of each particle, and obtaining a population optimal fitness at a maximum number of iterations; updating the Lagrangian multiplier and the penalty factor according to the population optimal fitness, comparing the objective deviation value with a preset convergence condition, and determining an objective population fitness and an objective position parameter according to a comparison result to obtain an objective deorbit mode.

    METHOD FOR MAINTAINING WALKER CONSTELLATION FORMATION AND TERMINAL DEVICE

    公开(公告)号:US20220063843A1

    公开(公告)日:2022-03-03

    申请号:US17458537

    申请日:2021-08-26

    Abstract: Provided are a method for maintaining Walker constellation formation and a terminal device. The method comprises: determining a first offset amount of each satellite within a simulation time period according to parameters of a Walker constellation; performing first offset on each satellite according to the first offset amount to obtain a Walker constellation after the first offset; determining a second offset amount of each satellite within the simulation time period according to parameters of the Walker constellation after the first offset; and superimposing the first offset amount and the second offset amount, and performing second offset on each satellite so as to maintain the formation of the Walker constellation.

    NON-APPROXIMATE VOIGT LINE PROFILE FITTING METHOD FOR ABSORPTION SPECTRUM SPECTROSCOPY

    公开(公告)号:US20180238798A1

    公开(公告)日:2018-08-23

    申请号:US15959179

    申请日:2018-04-21

    Abstract: The present invention provides a Voigt line shape fitting method, including step 1: Calculate a Gauss line shape function and a Lorentz line shape function, and calculate a Voigt line shape function. Step 2: For determined line shape parameters to be fitted, calculate partial derivatives of the Voigt line shape function with respect to the parameters, convert a partial derivative of the Voigt line shape function with respect to a parameter into a partial derivative of the Gauss line shape function or the Lorentz line shape function with respect to the parameter. Step 3: Substitute the Voigt line shape function and the partial derivative of the Voigt line shape function with respect to the parameter to be fitted, into a least squares algorithm step, perform least squares fitting calculation, and determine whether to terminate the least squares fitting calculation or return to step 1 to perform next iterative calculation.

    Measurement apparatus applicable to two-dimensional reconstruction of gas in combustion flow field

    公开(公告)号:US10260959B2

    公开(公告)日:2019-04-16

    申请号:US15959225

    申请日:2018-04-21

    Abstract: The present invention discloses a multi-lightpath and multi-angle measurement apparatus, including an electrically controlled rotary table, electronically controlled translation tables, a laser transmitting/receiving end face, laser couplers, a multipath data acquisition card, a laser controller, a translation controller, an etalon, a laser, detectors, and a computer. The measurement apparatus uses an all-fiber coupling structure, and two ends of the laser transmitting/receiving end face are respectively fixed on two electronically controlled translation tables. Therefore, a maximum area measured by the apparatus is 350 mm×350 mm, and an adjustable minimum translation distance is 1 mm. Bottoms of the translation tables are fixed on the electrically controlled rotary table. Featuring an ingenious design and a compact structure, the whole apparatus is easy to disassemble and easy to operate. The apparatus has high universality, and can implement two-dimensional measurement in a high-temperature combustion flow field.

    THRUST-QUANTITATIVELY-CONTROLLABLE AND SELF-NEUTRALIZABLE KAUFMAN ION THRUSTER AND USE METHOD THEREOF

    公开(公告)号:US20240418157A1

    公开(公告)日:2024-12-19

    申请号:US18460611

    申请日:2023-09-04

    Abstract: The present disclosure relates to the technical field of space electric propulsion of spacecrafts, and discloses a thrust-quantitatively-controllable and self-neutralizable Kaufman ion thruster and a use method thereof. The Kaufman ion thruster includes a discharge chamber, a central cathode, a gas supply assembly, a steel magnetic assembly, an insulating barrier and a grid system, wherein the central cathode is coaxially inserted in the center of a front panel; the gas supply assembly includes an electronegative working substance gas source, a conventional working substance gas source, N electronegative working medium gas supply pipes and N working medium gas supply pipes; the insulating barrier includes a central connecting rod and 2N fins. Self-neutralization can be achieved without the need of neutralizers. In addition, the center-oriented thrust modes can be used for spacecraft orbit control; and the eccentric thrust mode can be used for spacecraft attitude adjustment.

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