144 results about "Single star" patented technology

Provided is a measuring device and a calibration method for optical lens distortion. The measuring device comprises a single star light simulator, an adjusting rack, a to-be-tested lens, a CCD (charge coupled device) camera, a one-dimensional air flotation turntable, an angle encoder, a computer and an optical platform. The calibration method includes the steps of using a centroid localization algorithm to determine centroid position coordinates of a star point image when the to-be-tested lens is under different fields of view, establishing a calibration model for the to-be-tested lens distortion based on the distribution of the centroid position coordinates of the star point image under the entire field of view, and realizing the calibration of the distorted to-be-tested lens. The measuring device and the calibration method for the optical lens distortion has the advantages that the device is simple; the method is convenient; measurement accuracy is high; and the optical lens distortion can be easily measured and calibrated.

The invention discloses a star sensor calibrator and a method for calibrating a high-precision star sensor. The star sensor calibrator has the structure that a two-dimensional adjustable plane mirror is arranged on the optical path between a single-star simulator and a star sensor to be calibrated; the position forming an included angle of 90+ / -15 degrees with the two-dimensional adjustable plane mirror is provided with a laser device of a laser angle measuring device; the position 50-200 cm away from the center of the two-dimensional adjustable plane mirror is provided with a high-precision two-dimensional guide rail which can vertically and horizontally move on an optical hover platform; a laser detector of the laser angle measuring device is installed on the high-precision two-dimensional guide rail; after being reflected by the two-dimensional adjustable plane mirror, the laser emitted by the laser device is incident into the laser detector; and a data processing computer is respectively communicated with the star sensor to be calibrated and the laser detector. The invention does not need to rotate the star sensor, increases the tangential distortion and the deflection angle of the installation error, and can meet the requirements for very-high-precision (sub-arcsec) star sensors. The invention has the advantages of simple method and small amount of calculation.

The invention provides a nine-gear planetary automatic transmission of a vehicle drive system, which comprises planetary lines, input components, output components, transmission components, brakes and clutches. The input components and the output components are arranged on the two ends and are respectively connected with an input shaft and an output shaft, and four planetary lines, five transmission components, four brakes and two clutches are used. Compared with the prior art, due to adopting the four planetary lines, four brakes and two clutches with an additional forward gear, the invention realizes the purpose of nine forward gears with one brake reduced, thereby reducing the weight and cost of the transmission. Particularly, the four planetary lines are all single-star simple planetary lines, and the gear parameters of the planetary lines have two pairs of identical K values, further reducing the types of gears, and simultaneously obtaining the transmission ratio property with the optimal overall performance.

The present invention belongs to the technical field of optoelectronic equipment calibration, and particularly relates to a star sensor reference cube-prism installation error calibration apparatus. According to the present invention, a photoelectric autocollimator and a single star simulator are respectively placed on two orthogonal axes of a reference plane, a detected star senor is placed at the intersection point position of the two axes so as to make the normal lines of the two orthogonal light reflection surfaces of the detected star senor reference prism be respectively parallel to the two orthogonal axes, the optical axes of the photoelectric autocollimator and the single star simulator are respectively adjusted to parallel to the reference plane through a theodolite, the star sensor is installed on a star sensor three-dimensional adjustment reference base, the input optical axis of the star sensor and the output optical axis of the single star simulator are adjusted to achieve a parallel state through the star sensor three-dimensional adjustment reference base, a detected reference cube-prism is arranged on the upper surface of the housing of the detected star senor, the installation angle error of the reference cube-prism round the X-axis and the Y-axis is measured by using photoelectric autocollimation, the star sensor three-dimensional adjustment reference base rotates 90 DEG, and the installation angle error of the reference cube-prism round the Z-axis is measured.

The invention discloses a star light refraction satellite autonomous navigation method based on a single star sensor. The star light refraction satellite autonomous navigation method comprises the following steps: 1, installing the star sensor on a satellite according to an optimal installation angle; 2, after the star sensor shoots a star map, identifying normal stars in the star map by using a triangle algorithm; 3, calculating an optical axis direction and a satellite gesture of the star sensor by using the identified star sensors; 4, selecting a star from the star map according to the optical axis direction of the star sensor to generate a stimulation refraction star map; 5, identifying a refraction star by using the stimulation refraction star map, and calculating a star light refraction angle according to an identification result; and 6, substituting the star light refraction angle into a system model, and obtaining navigation information of the satellite by using an optimum estimation method by a spaceborne computer. According to the star light refraction satellite autonomous navigation method, the precision of autonomous navigation of a star light refraction satellite is improved, and the design cost is lowered.

The invention discloses a large visual field camera nonlinear distortion correction device and method. The device comprises a single-star starlight simulator, a two-dimensional turntable, a two-dimensional turntable control system, an optical table and a computer. The method comprises the steps of utilizing a mass center positioning algorithm to confirm mass center position coordinates of star point images at different positions in a camera visual field range, establishing a projection imaging model to calculate ideal imaging position coordinates corresponding to the star point images, fitting a nonlinear distortion model through a BP neural network optimized by a genetic algorithm and achieving distortion correction of a camera to be detected. The large visual field camera nonlinear distortion correction device has the advantages of having simple structure, automatic operation, convenient measurement and high correction algorithm accuracy and easily achieves large visual field camera nonlinear distortion correction.

The invention is a space measurement technology, involving the improvement to the star sensor calibration method. The invention uses the calibration system which comprising the air cushion platform, single star starlight simulator, star sensor, two-dimensional axial turntable and data processing computer, and its steps are: 1. establish the star sensor imaging model; 2. parameters calibrating. The invention uses no deviation strip to calibration focus and radial distortion coefficient, eliminating the internal parameter estimation effect by the external installation error; the method has simple model and small computing volume, particularly applied to the star sensor calibration based on radial distortion.

The GNSS multi star failure identification starts with feasibility analysis of self automatic completeness to make single or multi star failure judgment, comparing the inspection statistical gauge with single star or multi star inspection door limit, entering into corresponding failure identification if it exceeds the limit. It uses feature deviation line for single star failure identification, presumption for multi satellite failure identification, eliminating failure satellite in the chosen satellite group with repeated above procedures. With vigor failure elimination method, it can be determine all kinds of circumstances like single star or multi star failures, or incomplete inspection based on current data.

The invention relates to star sensor calibration method improvement. It is based on the calibration system includes hover-platform, single star starlight simulator, star sensor, two dimension axial turning table, data processing machine. It includes the following steps: calibrating system modeling, collecting data, and processing data. The invention adopts whole modeling method to avoid affecting parameter calibration accuracy caused by inducting external parameter deviation to inner in estimating process. The method can reduce complex star sensor installing aligning in calibrating process to satisfy the whole calibration process.

The invention discloses an operator construction method of a single-star scheduling. The operator construction method comprises the following steps that a question classifier which is constructed based on a distribution form of a task set conducts classification on single-star scheduling sub-questions; (2) an ant colony algorithm is constructed; (3) a question operator knowledge base is constructed through question classification, an operator design ruler and a score triple and records the historical performance when each operator design is used for solving each type of questions, and therefore operator design decision support is provided for solution of new concrete questions in the feature. The operator construction method of the single-star scheduling has the advantage that under the condition that solution quality is guaranteed, the solving efficiency is high.

The invention discloses a satellite formation realizing method for earth ultra-width imaging, relates to a formation technique of satellite stable imaging, and belongs to the technical field of control and regulation. The method is applied to the problem of distributed ultra-width imaging, which breaks the single-star lower-point imaging mode of traditional satellite imaging and enables the satellite to achieve high-precision ultra-width imaging in the manner of formation imaging by carrying high-precision imaging load and combined with distributed satellite control technology, thereby greatlyenhancing the efficiency of satellite search imaging. The method proposes a distributed satellite formation ultra-width imaging mode based on J2 stability, which solves the problem that the satelliteis unable to achieve continuous imaging on the adjacent areas of the ground caused by small satellite gaze range, narrow imaging width, and the earth rotation.

A transmission mechanism of an automatic transmission for vehicles, which realizes at least ten forward speeds and one reverse speed by combining four sets of single planetary gear sets with four clutches and two brakes, three friction elements Being operated at each gear speed, the transmission mechanism has advantages of simplifying the structure of the automatic transmission, improving power transmission performance and fuel economy.

The invention relates to the space technology, and to the improvement of the star sensor calibration method. The invention uses the calibration system which including air cushion platform, single-star starlight simulator, star tracker, two-dimensional axial turntable platform and data-processing computer, its steps being: establishing point spread function model, establishing a centroid algorithm formula, establishing a centroid algorithm pixel frequency error model, and data acquisition. The invention provides a more practical point spread model; improving satellite sensor calibration precision; the calibration model is simple and easy to calculate.

The invention provides a mathematical model construction method and solving method for a single-star task planning problem. According to the single-star multi-turn imaging satellite task planning problem, the problem is reasonably simplified and assumed, a mathematical model is constructed, and a software solving frame and nine branch function modules are introduced, wherein a heuristic sorting strategy is adopted in the sorting module, a time window subtractive algorithm is innovatively adopted in the activity arrangement module, the collision problem of time windows is better solved, and the utilization rate of the time windows is improved, so that feasible solutions approach the optimum.

The invention discloses a navigation satellite constellation availability assessment method based on the dynamic reliability estimation. The navigation satellite constellation availability assessment method comprises the steps of introducing a random failure factor, a degradation failure factor and a consumption failure factor of a satellite according to current operation data of an in-orbit constellation to establish a dynamic reliability estimation model and obtaining a time-varying curve of the single-star fault rate according to reliability estimation; then calculating out the constellation fault probability Pk,n (t) and the constellation inherent availability CVn,k value of an n kind of fault combination in the situation where k satellites in M satellites in the constellation are in fault; finally calculating out a time-varying relation of the constellation service availability of the navigation satellite system according to the Pk,n(t) and the CVn,k. The navigation satellite constellation availability assessment method can predict in-orbit reliability of the satellites in real time, can obtain high-accuracy and high-reliability satellite constellation availability and can solve the problems that a method only relying on a constellation configuration design to calculate out constellation availability is inaccurate and incomplete and cannot assess the constellation availability in real time.

The invention belongs to aerospace measurement technology, and relates to a star sensor dynamic calibration device and a calibration method. The device of the present invention includes a single star simulator 1, a star sensor 3, a two-dimensional high-precision turntable 4, a data processing computer 5, a platform base 6 and a turntable control lower computer 9, and is characterized in that the data processing computer 5 is inserted with The reflective memory card A7 is inserted with the reflective memory card B8 on the lower computer 9 controlled by the turntable, and the two reflective memory cards A and B are connected by optical fibers to form a reflective memory real-time network. The calibration steps of the dynamic calibration method of the present invention are: static calibration; dynamic data collection; dynamic data processing. The system of the invention is simple in structure, easy to realize and low in cost; the real-time synchronization precision of data collection is relatively high; and the universality is good.

The invention belongs to the positioning and navigation field, and relates to a celestial positioning and satellite positioning cross application subject. The invention is achieved by a positioning resolution terminal device 1. The positioning resolution terminal device 1 comprises a satellite positioning measurement module 2,a celestial satellite historical data base module 3, a liquid crystal display module 4, a keyboard operating module 5, a MCU main control module 6, a power supply module 7 and an optional accurate clock input module 8. When the number of GNSS satellite signals received is less than 3, the positioning resolution terminal device 1 still can resolve a user site under the celestial assistance. The invention is suitable for positioning and navigation under the severe environment, and obtaining user site data with higher accuracy.

The invention discloses a multi-color-temperature and multi-star-magnitude single-star simulator and belongs to the field of aerospace optical remote sensing. In order to reduce the influence of non-matching of color temperatures on calibration precision, the single-star simulator comprises a multi-color-temperature simulative light source system, a star magnitude controller system, a conductive optical fiber, a collimation and calibration system and a control system, wherein the multi-color-temperature simulative light source system is used for generating light with specific color temperature; the light with specific color temperature, emitted by the multi-color-temperature simulative light source system, enters the star magnitude controller system; the input light with specific color temperature is converted into light with specific color temperature and specific star magnitude by the star magnitude controller system; the light with specific color temperature and specific star magnitude is transmitted to the collimation and calibration system by the conductive optical fiber; the collimation and calibration system is used for generating collimating light and calibrating the multi-color-temperature and multi-star-magnitude single-star simulator; the control system is used for controlling the multi-color-temperature and multi-star-magnitude single-star simulator. The multi-color-temperature and multi-star-magnitude single-star simulator can reduce the influence of non-matching of the color temperature of a star simulator for calibration of a star sensor and the color temperature of the star simulator for gazing stars on calibration precision.

The invention belongs to the technical field of vehicle transmission and particularly relates to a seven-gear planet automatic gearbox which can enable two forward gears to become overgears, is large in the range of transmission ratio and good in performance and meets operating requirements of wheeled vehicles. The seven-gear planet automatic gearbox comprises three planet rows, an input component, an output component, four transmission mechanisms, four brakes and two clutches. Therefore, the seven-gear planet automatic gearbox achieves seven forward gears, the range of the transmission ratio can reach 8.941, the three planet rows are all single-star simple planet rows, and the k value is within 1.7-2.6. Furthermore, the seven-gear planet automatic gearbox is compact in structure, and the size and the weight of the seven-gear planet automatic gearbox are reduced.

The invention discloses a star sensor calibration device based on external field star observation and a star observation calibration method thereof. The calibration device comprises a medium-precisionturntable capable of rotating around a zenith, a star sensor arranged on the turntable, and a circuit box connected with the star sensor. The circuit box comprises a data acquisition module and a clock reference module. The calibration method comprises the following steps: step 1, replacing a single-star simulator with starlight, replacing a high-precision turntable with the earth, driving a starsensor through a turntable, simulating a laboratory calibration system, and carrying out a star observation experiment; and step 2, applying a parameter method in laboratory calibration to star observation calibration for data processing; to be specific, constructing an initial alignment error model, compensating an initial alignment error, carrying out nonlinear optimization solution, constructing a distortion correction model, and carrying out least square solution. According to the method provided by the invention, a parameter method in laboratory calibration is applied to star observationcalibration; and especially for a large-field star sensor, the calibration precision is improved.

The invention discloses a method for detecting fault satellites of a satellite navigation system, which comprises the steps: all visible satellites are divided into a first satellite subgroup and a second satellite subgroup according to a satellite top view direction angle in a navigating constellation, and fault detection is carried out on the first satellite subgroup and the second satellite subgroup respectively to obtain the fault satellites. The method adopts the technical scheme that all the visible satellites are grouped according to the satellite top view direction angle in the navigating constellation; the satellites with close or approximately reverse satellite top view direction angles are divided into a group according to the geometric distribution characteristic of the satellites; and LSR detection and MLE recognition are carried out on the grouped satellite subgroups respectively . The invention effectively increases the detection speed and the recognition rate of the fault satellites, is suitable for double-star detection and single-star detection and can be applied to a multiple-constellation satellite navigation system.

The invention discloses a method for testing a porthole-type star sensor system. The method comprises (1) carrying out a porthole-type star sensor static precision test through a single star simulator, (2) comparing the influence caused by a porthole on star sensor detection sensitivity through star sensor picture photographing under the actual sky background, (3) aligning a star sensor having a porthole to a sky area, carrying out continuous working for some time and carrying out statistics on static measuring accuracy, (4) putting the star sensor on a rotary table, carrying out rotation at a certain angle rate and measuring influence caused by the porthole on dynamic tracking performances of the star sensor, and (5) testing the influence caused by the porthole on a stray light protection angle through a solar simulator. The invention provides the method for testing a porthole-type star sensor system for the first time. The method can test the influence caused by the porthole on star sensor functions and performance indexes, can verify whether the design satisfies system task demands, is conducive to specific design improvement of the porthole-type star sensor and provides guidance for on-orbit use strategy of a porthole-type star sensor.

The invention relates to a single star positioning device and a method. The single star positioning device comprises a user terminal and a satellite having a distance measurement function or a single signal resource. The user terminal is provided with an air pressure height measurement chip, an angle measurement part, a pedometer and a trapping atomic clock CPT. The method comprises steps of utilizing an air pressure height measurement chip and a satellite having a distance measurement function or a single base station or a single signal source to obtain an altitude value and a distance measurement value, determining the ring where the user is positioned through the intersection of two curve surfaces, using the angle measurement part to obtain the azimuth information which is constantly extrapolated and corrected based on a navigation position extrapolation theory, and constantly obtaining the three-dimension position coordinate of the user terminal. Different from the traditional GPS satellite system, the positioning theory of the invention gets rid of the limitation of four-star positioning, and can supplement the traditional GPS kind satellite positioning system when the quantity of the satellite is few. Besides, the method disclosed by the invention can also be used as an independent specific method to perform mobile phone positioning which is based on the position service, an ocean buoy, the steamship positioning and monitoring field.

The invention discloses a satellite attitude determination method based on a Samsung sensor. The method comprises the steps of obtaining a matrix of optical axis vectors of three star sensors under a satellite ontology coordinate system; obtaining the matrix of the optical axis vectors of the three star sensors under inertial system coordinates; and based on a transformation matrix of the inertial system coordinates and the satellite ontology coordinate system and a transformation matrix of an orbit coordinate system to the inertial coordinate system, obtaining an attitude matrix of the orbit coordinate system to the satellite ontology coordinate system. The method of the invention is applicable to the installation of the satellites with three or more star sensors, can make full use of on-board resources, can compensate the shortcoming of poor precision of the single-star sensor optical axis, avoids the introduction of a cross-product vector in a double star sensor attitude determination algorithm, reduces attitude determination errors, and is high in reliability, simple in algorithm, and easy in on-board software implementation.

The invention relates to a star sensor measuring coordinate system to prism coordinate system measuring method and system. The method comprises steps that the optical axis direction of a single star simulator is determined through a plane mirror; the mounting position of a photoelectric autocollimator is determined; auto-collimation of the first direction and / or the second direction of the plane mirror and a star sensor reference prism is performed through the photoelectric autocollimator; a rotation angle of the first direction of a coordinate system around the first direction of a prism coordinate system, a rotation angle of the second direction of the coordinate system around the second direction of the prism coordinate system and a rotation angle of the third direction of the coordinate system around the third direction of the prism coordinate system are respectively obtained. The method is advantaged in that high precision measurement equipment is utilized, not only operation is simple and reliable, but also measurement precision is greatly improved.

The invention provides an in-orbit identification method for relative installation error between single star sensors. The method comprises the steps of establishing a mathematical statistic model for star sensor measurement and installation error; establishing a star sensor relative installation error angle observation equation; designing an installation error angle optimal estimation algorithm and designing an installation error angle model nonlinear fitting method. The method is simple and effective, and the attitude and attitude angle speed of a spacecraft are not needed to be calculated. A star sensor relative installation error angle can be estimated under the situation that the dynamical variables are unknown. In the execution process of an actual task, the method is more practical and effective than an installation error angle estimation method which requires real-time acquisition of the attitude of the spacecraft, and compared with a conventional estimation method, the method has the advantages of being simpler and more convenient in data detection and estimation on a star due to the insensitivity for long-period data loss.

The invention relates to a calibrating system and method of a multi-view-field star sensor based on a three-axis turntable. The calibrating system comprises the multi-view-field star sensor, the three-axis turntable, a single-star simulator and a data collecting device. The calibrating method comprises the following steps: step one, collecting data; step two, calibrating a pinhole model; step three, calibrating a complete model; step four, solving a structure parameter; and step five, evaluating a calibrating result. The calibrating method uses a generating angle of a rolling-rotating axis ofthe three-axis turntable to switch a data collecting view field, and uses the other two axes to generate a calibrating track for each view field. Data collection is completed by one time, so an outerparameter model in each view field calibrating model is kept unchanged, and the structure parameter between the view fields can be solved without being affected by an installing error. At the same time, according to an unchanged outer parameter, calibration of each view field can be joint-optimized, and the effect on parameter estimation precision caused by parameter coupling is reduced.

The invention discloses a single-star multilevel modular converter (MMC) structure-based hybrid power electronic transformer and a control method thereof. The hybrid power electronic transformer comprises a three-phase transformer, single-star MMCs, a three-phase full-bridge inverter, a DC bus, an LC filter and a contactor, wherein each phase single-star MMC is connected in parallel to a corresponding transformer primary winding coil via a primary contactor, outputs of three phase single-start MMCs are connected in parallel to a public DC bus, a DC input side of the three-phase full-bridge converter is connected to the public DC bus, and an AC output side of the three-phase full-bridge converter passes through the LC filter and then is connected in series to start connection of a secondarywinding of the three-phase transformer via a secondary contactor. By dynamic compensation on an output voltage of the power grid and reactive power current compensation on an output current, adjustment of electric energy quality of the power grid is achieved, the safety, the reliability and the economy of running of the power grid are guaranteed, and the hybrid power electronic transformer has certain creativeness, practicability and application value.

The invention belongs to the field of satellite communication and satellite navigation technologies and discloses a low-orbit satellite radio ranging signal-based single-star positioning and time service method. According to the method, a non-iteration method is used to solve the approximate coordinates and clock skew of a receiver; on the basis of the approximate coordinates and clock skew of thereceiver, an iteration method is adopted to solve the approximate coordinates and clock skew parameter of a user; and an equation ill-conditioned problem is solved through a regularization method, sothat the stable and reliable three-dimensional coordinates and clock skew of the user can be obtained. With the method of the invention adopted, the cost and power consumption of the receiver can bedecreased; and it only needs the receiver to simultaneously receive ranging signals from a low-orbit satellite at a plurality of time points, so that the three-dimensional coordinates and receiver clock skew of the user can be accurately solved. The low-orbit satellite radio ranging signal-based single-star positioning and time service method is applied to the low-cost location service sensor fields such as the Internet of Things, search and rescue.

The invention discloses a star sensor demarcation method based on region division, comprising steps of (1) placing a star sensor on a two-shaft rotation table and performing imaging observation on a single-star simulator, (2) rotating the rotation table, performing measurement using the approximately uniform angle and choosing a standard grid point, (3) dividing the star sensor vision filed into n mutually independent correction areas according to the grid points, and generating a set of correction functions for each correction area, (4) choosing test points within the range not beyond the distribution boundary of the grid points, and (5) calculating the residual errors of all test points after demarcation. The invention can obtain high demarcation accuracy and is applicable to demarcation test and data processing of a large vision field optical sensor.