CN109932974B - Embedded observation control system of precision measurement type space target telescope - Google Patents
Embedded observation control system of precision measurement type space target telescope Download PDFInfo
- Publication number
- CN109932974B CN109932974B CN201910264270.6A CN201910264270A CN109932974B CN 109932974 B CN109932974 B CN 109932974B CN 201910264270 A CN201910264270 A CN 201910264270A CN 109932974 B CN109932974 B CN 109932974B
- Authority
- CN
- China
- Prior art keywords
- data
- ccd
- image
- space target
- telescope
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Image Analysis (AREA)
- Telescopes (AREA)
Abstract
An embedded observation control system of a precision measurement type space target telescope relates to the technical field of precision measurement of space target photoelectric telescopes, solves the problems that the existing observation control system is realized by a main control computer, has the defects of low efficiency of manually identifying the space target, long identification time and the like, and simultaneously has the defect that remote control can not be realized by LAN, WAN or Internet, and comprises a motion controller, a data collector, a data processor and observation control software. The telescope motion controller is responsible for driving a height axis and an azimuth axis and collecting coded disc data; the data acquisition unit is responsible for acquiring CCD image data, controlling CCD exposure time and latching the CCD exposure time; the data processor is responsible for preprocessing the CCD image, identifying the space target image and positioning the space target astronomically; the observation control software generates an observation plan of the space target, manages the telescope motion controller and the CCD data collector to complete a telescope observation process and guides the data processor to process observation data.
Description
Technical Field
The invention relates to the technical field of precision measurement of space target photoelectric telescopes, in particular to an embedded observation control system of a precision measurement type space target photoelectric telescope.
Background
The ground-based space target photoelectric telescope is a main device for observing space targets, particularly space debris.
The working process of the precision measurement type photoelectric telescope observation space target is approximately as follows: the telescope waits according to the forecast position, guides the telescope driving system to track the target according to the guide data of the target after finding the target, collects the CCD image, collects the code wheel data and the clock signal, gives the position of the calibration star (background fixed star) in addition to the position of the target when processing the CCD image, and gives the right ascension and declination of the target according to the relative position of the target and the calibration star and the star surface position of the calibration star.
As can be seen from the above discussion, the photoelectric telescope realizes the observation of the space target, and the observation control system needs to include the following functions: generating an observation plan of a space target, driving a height axis and an azimuth axis, collecting code disc data, controlling CCD exposure time, latching the CCD exposure time, preprocessing a CCD image, identifying the space target image and positioning the space target astronomically.
These functions are divided into a plurality of systems for telescope control, CCD control and data processing, which are located at different positions. Isolation of the physical location naturally requires that the observation control system be a distributed system. However, most of the observation control systems of the precision measurement type ground-based photoelectric telescopes in China integrate the functions into one piece of software. Is not beneficial to realize remote control through LAN, WAN or Internet, and achieves the aim of centralized management.
With the development of observation technology, the operation mode of the photoelectric telescope gradually tends to unattended operation characterized by observation automation. However, the precise measurement type space target photoelectric telescope needs manual intervention in the aspect of observation automation, namely, an observer identifies a star image of a space target from a large number of punctiform star images by depending on experience within a short time, clicks the star image of the space target in an image by using a mouse to obtain a coordinate of a click position in the image, sets a rectangular area with a fixed size as a gate by taking the position as a center, tracks and calculates the right ascension and declination of the target, completes astronomical positioning, and if the target is lost in the tracking process, the observer needs to newly set the gate to capture the target. The identification mode is influenced by artificial subjective factors, and has the defects of long identification time, low efficiency and the like. Meanwhile, the observer is in a fatigue state for a long time, so that the error rate is gradually increased. This results in low automation and low efficiency of the space target photoelectric telescope.
Disclosure of Invention
The invention aims to solve the problems that the existing observation control system of the precision measurement type space target telescope is realized by a main control computer, the space target is low in efficiency and long in identification time in the manual identification process, and meanwhile, the remote control cannot be realized through LAN, WAN or Internet, so that the aim of centralized management is fulfilled. An embedded observation control system of a precise measurement type space target telescope is provided.
The embedded observation control system of the precision measurement type space target telescope comprises a motion controller, a CCD data collector, a data processor and observation control software; the method is characterized in that: the motion controller and the data processor are both composed of a DSP and an FPGA, and the CCD data collector is composed of an FPGA;
the observation control software transmits a station forecast file to the motion controller, the motion controller tracks the space target according to the received station forecast file to obtain azimuth angle and altitude angle guide data of the space target with the frequency of 1Hz, the motion controller encrypts the guide data with the frequency of 1Hz to 20Hz and then loads the guide data to a servo system of a telescope motor, and meanwhile, the motion controller receives azimuth angle and altitude angle data of an encoder fed back by the servo system; the motion controller transmits the acquired azimuth angle and altitude angle data of the encoder to observation control software;
the observation control software transmits the triggering time, the triggering pulse interval and the triggering pulse number of the CCD to the CCD data collector, and the CCD data collector outputs a pulse signal to the CCD according to the received exposure pulse interval and the triggering pulse number and latches the CCD exposure time; the CCD data collector collects image data obtained by a CCD, and then sends the obtained image data and the CCD exposure time to observation control software;
the observation control software stores image data acquired by the CCD data acquisition device into an FITS file, then writes azimuth angle and altitude angle data of an encoder fed back by a servo system of a motor and exposure time latched by the CCD data acquisition device into the FITS file head, and sends the data to the data processor, and the data processor performs image processing according to the received FITS file and identifies and astronomically positions a space target.
The invention has the beneficial effects that:
the observation control system adopts an embedded architecture and comprises a telescope motion controller, a data acquisition unit, a data processor and observation control software. The telescope motion controller is responsible for driving a height axis and an azimuth axis and collecting coded disc data; the data acquisition unit is responsible for acquiring CCD image data, controlling CCD exposure time and latching the CCD exposure time; the data processor is responsible for preprocessing the CCD image, identifying the space target image and positioning the space target astronomically; the observation control software generates an observation plan of the space target, manages the telescope motion controller and the CCD data collector to complete a telescope observation process and guides the data processor to process observation data.
Secondly, the observation control system is a distributed system. The method avoids the situation that all the functions are concentrated on one control to one software, and is not beneficial to realizing remote control through LAN, WAN or Internet, thereby achieving the aim of centralized management. Compared with a motion control system working in an operating system of Windows, the telescope motion controller adopts an FPGA + DSP heterogeneous processor architecture, avoids the situation of data loss caused by untimely response of the Windows system, and is completely suitable for tracking and observing space targets. The traditional data acquisition system can only acquire image data, and the CCD exposure time control and the CCD exposure time latching are completed by a special time exposure latching device. The CCD data acquisition device is equivalent to a traditional data acquisition system plus a special time exposure latch device. Therefore, the data collector formed by the FPGA simplifies the system and saves the space and the equipment cost.
And the data processor adopts an FPGA + DSP heterogeneous processor architecture, and compared with a data processing system working in an operating system of Windows, the speed of space target identification and positioning is improved because the FPGA is adopted to preprocess the image. Meanwhile, the consistency of the motion direction and the minimum miss distance are used as the identification criterion of the space target, so that the target can be automatically identified, the right ascension and the declination of the target can be calculated, and the astronomical positioning is completed. The identification method solves the problems that the manual identification of the target is influenced by human subjective factors, has the defects of long identification time, low efficiency and the like, and improves the automation degree of the space target photoelectric telescope.
And fourthly, the observation control system adopts an embedded architecture, and is used for upgrading and reconstructing a 1.2-meter telescope of the Changchun people and health station. The upgraded 1.2-meter photoelectric telescope is stable in performance, and in the working process of 4 months, 2593 circles of effective observation data are obtained, so that automatic observation of high, medium and low orbit space targets can be realized. The embedded observation control system developed by the invention can improve the observation automation degree of the 1.2 m photoelectric telescope, realize the unattended observation operation mode of the system, realize remote control through a network, achieve the aim of centralized management and liberate observers from heavy observation tasks.
Drawings
FIG. 1 is a schematic block diagram of an embedded observation control system according to the present invention;
FIG. 2 is a schematic block diagram of interaction data between observation control software and each processor in the embedded observation control system of the precise measurement type space target telescope according to the present invention;
FIG. 3 is a schematic block diagram of a motion controller in the embedded observation control system of the precision measurement type space target telescope according to the present invention;
FIG. 4 is a schematic block diagram of a CCD data collector in the embedded observation control system of the precision measurement type space target telescope of the present invention;
FIG. 5 is a schematic block diagram of a data processor in the embedded observation control system of the precision measurement type space target telescope according to the present invention;
FIG. 6 is a hardware structure diagram of FPGA in a motion controller in the embedded observation control system of the precision measurement type space target telescope according to the present invention;
FIG. 7 is a hardware structure diagram of DSP in the motion controller in the embedded observation control system of the precision measurement type space target telescope according to the present invention;
FIG. 8 is a hardware structure diagram of FPGA in CCD data collector in the embedded observation control system of the precision measurement type space target telescope of the present invention;
FIG. 9 is a hardware structure diagram of FPGA in a data processor in the embedded observation control system of the precision measurement type space target telescope according to the present invention;
fig. 10 is a hardware structure diagram of a DSP in a data processor in the embedded observation control system of the precision measurement type space target telescope according to the present invention.
Detailed Description
In a first embodiment, the present embodiment is described with reference to fig. 1 to 10, in which an embedded observation control system of a precision measurement type space target telescope includes a motion controller, a CCD data collector, a data processor and observation control software; the telescope motion controller and the data processor are composed of a DSP and an FPGA, and the DSP and the FPGA carry out data communication through an SRIO protocol; the CCD data collector consists of an FPGA.
The DSP in the telescope motion controller is used as a core processor of the motion controller to undertake interpolation calculation; the FPGA is used as a co-controller, a time reference is constructed to be used as an independent variable of interpolation calculation, and the DSP and the FPGA carry out data communication through an SRIO protocol;
the observation control software transmits a station forecast file to the motion controller, the motion controller tracks the space target according to the received station forecast file to obtain azimuth angle and altitude angle guide data of the space target with the frequency of 1Hz, the motion controller encrypts the guide data with the frequency of 1Hz to 20Hz and then loads the guide data on a servo system of a telescope motor, the servo system of the motor controls the operation of the telescope to enable the telescope to accurately point to the target, and meanwhile, azimuth angle and altitude angle data of an encoder fed back by the servo system are sent to the observation control software through a UDP (user Datagram protocol); the station forecast file is ephemeris forecast data of a space target,
the observation control software transmits the triggering time, the triggering pulse interval and the triggering pulse number of the CCD to the CCD data collector, and the CCD data collector outputs a pulse signal to the CCD according to the exposure pulse interval and the exposure pulse number, latches the CCD exposure time and sends the CCD exposure time to the observation control software through a PCI Express protocol. The CCD data acquisition device acquires image data and sends the image data to the observation control software through a PCI Express protocol.
The observation control software stores the image data transmitted to the control computer by the CCD data collector into an FITS file, writes azimuth angle and altitude angle information fed back by a servo system of a motor and exposure time latched by the CCD data collector into a file header, and transmits the FITS file into the data processor through a UDP protocol.
And the data processor processes the acquired FITS file, identifies spatial targets in a large number of background stars, and then performs astronomical positioning on the identified spatial targets.
The present embodiment will be described with reference to fig. 3, 6, and 7, and when the observation control system according to the present embodiment observes a spatial target, the telescope is guided in real time to track the target and observe the target in a program tracking manner. The forecasting software carries out orbit forecasting on the observation station by using Two Lines of Elements (TLE), the azimuth angle and the altitude angle guiding data frequency obtained by the observation station forecasting file is 1Hz, the azimuth angle and the altitude angle guiding data frequency are encrypted to 20Hz through an interpolation algorithm and then are loaded on a servo system of a telescope motor, so that the condition that a satellite can be captured and enter a telescope view field is guaranteed.
The invention designs a motion controller based on an FPGA + DSP heterogeneous processor architecture according to the telescope control requirement. The DSP has strong processing performance and flexible programming function, and can conveniently realize a complex speed control algorithm in real time, so the DSP is used as a core processor of the motion controller to undertake interpolation calculation; the FPGA has extremely high parallelism and is suitable for intensive computing application, and the configurable I/O and IP cores support various data transmission interfaces, so the FPGA serves as a co-controller to construct a time reference module. And the SRIO protocol is adopted to realize high-speed data communication between the FPGA and the DSP.
The DSP adopts TI company floating point DSP-TMS320C 6657.
The DSP in the motion controller comprises an interpolation value calculation module, a state quantity output module and a state quantity input module;
the interpolation calculation module adopts a 9-order Lagrange interpolation formula when interpolation is carried out by using the station orbit prediction to generate the real-time tracking prediction, and the Lagrange interpolation basis function is as follows:
the interpolating polynomial is:
wherein n is the order, xkAs epoch time in the forecast, ykThe state quantities (azimuth and height) corresponding to epoch time, x is the current observation time read in FPGA, Ln(x) Is the state quantity corresponding to x.
After the azimuth and the altitude are acquired, the azimuth velocity and the altitude velocity may be further acquired.
The state quantity output module sets a timer of the DSP to be in a continuous counting mode, when the timer is accumulated to 50ms (20Hz), an interrupt service program is entered, the azimuth angle, the altitude angle, the azimuth angle speed and the altitude angle speed are output to a servo system of the motor through a UART interface, and the servo system controls the operation of the telescope to enable the telescope to accurately point to a target.
The state quantity input module acquires azimuth angle and altitude angle information fed back by a servo system of the motor, converts the azimuth angle and altitude angle information into right ascension and declination in a celestial coordinate system, and then sends the right ascension and declination to observation control software through a UDP protocol.
sin(a)＝sin(φ)sin(δ)+cos(φ)cos(δ)cos(h) (4)
In the formula, A and a are an azimuth angle and an elevation angle, respectively, and h and δ are a hour angle and a declination, respectively.
The FPGA in the motion controller adopts Artix-7XC7A100T from Xilinx corporation for the generation of time reference modules.
The time reference module is used for constructing a time reference, and the module constructs a high-precision clock by utilizing a10 MHz signal (provided by a time frequency reference) and a 1PPS signal (provided by the time frequency reference). 2 32-bit counters, namely a second counter and a nanosecond counter, are built in the timing module. The former relies on the 1PPS signal to count more than a second; the latter relies on the 10MHz signal to count the time below seconds while synchronously clearing by means of the 1PPS signal. The clock ensures the precision of accumulated time resolution by externally connecting a time frequency signal and can be used as a time basis of a data epoch, so that the real-time tracking of the satellite can be based on the clock.
In this embodiment, the SRIO program of the motion controller is designed to: the DSP end generates interruption with a period of 50ms by using a timer, a request is sent to the FPGA, the FPGA latches the current time and writes the current time into a cache area predefined by the DSP, and the FPGA informs the DSP to carry out calculation after the writing is finished.
The motion controller and the CCD data collector respectively comprise a time module which is realized by an FPGA.
The embodiment is described by combining fig. 4 and fig. 8, in order to meet the requirement that the imaging device of the photoelectric telescope is physically isolated from the processing device and has a relatively long position, the CCD data collector is designed, the CCD data collector takes the FPGA as a platform, and takes Kintex-7XC7K325T of Xilinx company as a control core to realize two functions, namely, the high-speed acquisition and transmission function of the CCD image data of the optical fiber network and the control function of the CCD.
The first function of the CCD data collector is the collection and transmission of image data, and the CCD data collector is a fiber channel adapter based on a PCI Express bus architecture and can realize the high-speed collection and transmission of image data of a fiber network; the image data acquisition function comprises data receiving and data sending;
the image data receiving is that the FPGA adopts an SFP optical interface module to complete the real-time acquisition of CCD video signals, and the FPGA is used as a controller to carry out logic control on the SFP optical interface module and write the received data into DDR3 SDRAM cache; the image data transmission is that the FPGA transmits the image data cached by the DDR3 SDRAM to observation control software through a PCI Express link by a DMA control module;
the second function of the CCD data acquisition unit is time latching, namely the control function of the CCD, the FPGA is used as a control platform, the Ethernet is used as an interface, and UDP protocol and observation control software are adopted to interactively control data; external triggering of CCD exposure and latching of CCD exposure signals; the external triggering of the CCD exposure and the latching of the CCD exposure signal are realized by the FPGA through an I/O channel control module; the sending of the latched data at the exposure time is that the FPGA transmits the latched data to observation control software through a PCI Express link by a DMA control module; the control function of the CCD also comprises a time reference for controlling the CCD external trigger and the latching of the CCD exposure signal.
The CCD external trigger control is realized, and various cameras can be triggered to expose by controlling an I/O channel to output a fixed pulse width signal; the latching of the CCD exposure signal can continuously and independently record the time (time, minute, second, millisecond and microsecond) corresponding to the rising edge of the pulse signal generated by the CCD exposure, and the latched exposure time can be sent to the observation control software through a PCI Express protocol.
The time reference module is used for constructing a time reference, and the module constructs a high-precision clock by utilizing a10 MHz signal (provided by a time frequency reference) and a 1PPS signal (provided by the time frequency reference). 2 32-bit counters, namely a second counter and a nanosecond counter, are built in the timing module. The former relies on the 1PPS signal to count more than a second; the latter relies on the 10MHz signal to count the time below seconds while synchronously clearing by means of the 1PPS signal. The clock guarantees the precision of accumulated time resolution by externally connecting a time frequency signal and can be used as a time reference for CCD external trigger control and CCD exposure signal latching.
In the embodiment, the objective of space target observation is to realize high-accuracy positioning of a space target, and the space target astronomical positioning is to use a CCD to shoot a series of star maps in a staring imaging mode, perform star point extraction and star map matching, calculate to obtain a position conversion matrix from a CCD body coordinate system to a celestial coordinate system, and then combine the coordinate position of the target on a CCD surface to obtain the position information of the target relative to the stars.
The spatial target astronomical localization algorithm can be divided into three parts of image processing, spatial target recognition and spatial target astronomical localization. In order to accelerate the calculation speed and improve the observation efficiency, the data processor based on the FPGA + DSP heterogeneous processor architecture is provided in the embodiment. The image processing part takes the FPGA as a coprocessor, and improves the speed of image processing by utilizing the characteristics of parallel operation and pipeline processing of the FPGA. The space target identification and space target astronomical positioning part takes the DSP as a core processor to undertake target identification calculation and astronomical positioning calculation, and the DSP and the FPGA carry out data communication through an SRIO protocol.
In this embodiment, the observation control software runs on the control computer, and the task of the observation control software is to manage, coordinate and control the operation of each subsystem, so that the whole telescope system can observe the space target orderly, as planned and as a step. The observation control software comprises the following three functions: firstly, selecting an observation plan, secondly, managing a motion controller and a CCD data collector to complete a telescope observation process, and thirdly, guiding a data processor to process observation data;
the management observation process is that the observation control software stores the image data transmitted to the control computer by the CCD data collector into an FITS file, and writes azimuth angle and altitude angle information fed back by a servo system of a motor and exposure time latched by the CCD data collector into a file header;
the guide data processor processes observation data by sending the stored image FITS file to the data processor according to the stored time sequence by the measurement and control system software;
referring to fig. 5, the embodiment is described, where the FPGA in the data processor uses Kintex-7XC7K325T of Xilinx corporation, and mainly processes the FITS file sent by the observation control software, including four modules, namely saliency detection, iterative threshold segmentation, dilation operation, and contour extraction.
Target detection is a crucial loop of the image processing process of space debris observation. The premise of target detection is to separate the fixed star and the space target from the image so as to carry out subsequent space target detection and precise positioning work. The saliency detection is a bright source for highlighting stars, space targets and the like in the sky background. The generated saliency map can be used for image segmentation and contour extraction.
The significance detection algorithm is as follows:
μ＝mean(I) (5)
SI＝(I-μ)2 (6)
FSI＝255×(SI-min(SI))/(SI-max(SI)) (7)
where I is the original image, μ is the average of I, SIFor processed images, FSIIs the generated saliency image.
Since only two modes of background and target exist in the generated saliency image, iterative threshold segmentation can be adopted.
The iterative threshold solution is as follows:
step one, solving the minimum and maximum gray value Z in the imagelAnd ZkThen threshold value TkInitial value T0Comprises the following steps:
T0＝(Zl+Zk)/2 (8)
step two, dividing the image into a target part and a background part according to a threshold value, and solving the average gray value Z of the two partsoAnd ZB。
Step three, solving a new threshold value Tk+1。
Tk+1＝(Zo+ZB)/2 (9)
Step four if Tk＝Tk+1If yes, ending; otherwise, go to step two.
After the step five and the step four are finished, TkI.e. the optimal threshold.
The closed operation expansion operation has the advantages that after the significance enhancement and the iterative threshold segmentation are adopted, partial star images are cut off, and then the disconnected star images are reconnected by adopting an expansion method.
The extraction of the star image contour only needs to dig out internal pixel points of the star image for the extraction of the binary image contour. All the 8 adjacent pixel points of the bright point are the bright points, and the point is an inner point, otherwise, the point is a contour point. All the interior points are set as background points, contour extraction is completed, and the central coordinates (pixel positions of the image) of the star are solved. All star center coordinates are saved in the FIFO of the FPGA.
In the embodiment, in the design of the SRIO program of the data processor, the FPGA initiates a request to write all the central coordinates of the star image into the predefined cache area of the DSP, and then the FPGA notifies the DSP to perform calculation.
The DSP adopts TI company floating point type DSP-TMS320C 6678.
The DSP in the data processor comprises two functions of space target identification and space target astronomical positioning; the azimuth angle and the elevation angle of the precision tracking measurement of the space target are theoretically the same as the changes of the azimuth angle and the elevation angle of the optical axis center of the telescope. Therefore, the core of the space target identification algorithm is to compare the solved target motion direction with the direction of the telescope by using a similarity function to judge whether the two directions are consistent, and then identify a space target in a background fixed star. The telescope pointing is that observation control software obtains azimuth angle and altitude angle information fed back by a servo system of a motor. In addition, since the space object is pointed to such a state that the deviation angle amount from the optical axis is the smallest among all objects and stars, that is, the miss amount is the smallest, it is possible to distinguish the background stars from the space object by comparing the magnitudes of the miss amounts. The space target recognition is realized by taking the similarity of the pointing direction of the space target and the telescope as a main judgment basis and assisting with the criterion of the minimum miss distance to finish the recognition of the space target from a background fixed star.
The consistency of the motion directions is assumed that m targets exist in the image; RA0,DEC0The right ascension and declination pointed by the current telescope, RA (l), DEC (l) are the right ascension and declination of the stellar, l is 1,2,3 … … m, and m is a positive integer;
the spatial rectangular equatorial coordinate system (x, y, z) of the same star at the same moment is related to the right ascension declination at the equatorial coordinate as follows:
spatial rectangular equatorial coordinate system (x) of telescope pointing at the same moment0,y0,z0) The relationship to right ascension and declination at equatorial coordinates is as follows:
let alpha be the angle between the direction of the star and the direction of the telescope, the similarity function is defined as
If cos alpha is closer to 1, the similarity degree of the star image motion direction and the telescope direction is higher;
the miss distance is defined as the distance function:
D(l)＝|Dl-Do| (13)
the smaller the D (l), the greater the spatial target probability; conversely, the smaller the spatial target probability.
After the position coordinates of the space target on the CCD surface are obtained, the right ascension and the declination of the space target can be calculated.
In this embodiment, the astronomical positioning specifically comprises the following steps: :
step one, after space target identification, finding fixed stars (alpha) in a field of view in Tycho2 ephemerisi,βi) i-1, 2,3, …, J, and queue it up as a star, where αiAnd betaiThe right ascension and the declination under a celestial coordinate system;
step two, adopting a triangular matching method in the CCD image, and obtaining CCD body coordinates (x) of 6 brightest calibration starsi,yi)；
In the third practical work, due to the influence of factors such as an optical system, an algorithm and a star table of the telescope, the relation between the CCD body coordinate system and the celestial coordinate system cannot be accurately deduced, and a polynomial approximate regression method is generally used;
αi＝a0+a1xi+a2yi+a3xi 2+a4xiyi+a5yi 2+a6xi 3 (14)
βi＝b0+b1xi+b2yi+b3xi 2+b4xiyi+b5yi 2+b6xi 3 (15)
in the above formula, xi，yiThe CCD body coordinate is a fixed star; alpha is alphai,βiAll known, finding a0-a6And b0-b6。
Step five, calculating a0-a6And b0-b6Then, the coordinates (x) of the target are calculated0,y0) Substituting the formula to obtain the celestial coordinates (alpha) of the target0,β0)。
Step six, the calculation of one frame of image is completed, and the next frame of image is calculated according to the steps. Solved by each frame of image (alpha)0,β0) And then sent to the observation control software through the UDP protocol.
Claims (5)
1. The embedded observation control system of the precision measurement type space target telescope comprises a motion controller, a CCD data collector, a data processor and observation control software; the method is characterized in that: the motion controller and the data processor are both composed of a DSP and an FPGA, and the CCD data collector is composed of an FPGA;
the observation control software transmits a station forecast file to the motion controller, the motion controller tracks the space target according to the received station forecast file to obtain azimuth angle and altitude angle guide data of the space target with the frequency of 1Hz, the motion controller encrypts the guide data with the frequency of 1Hz to 20Hz and then loads the guide data to a servo system of a telescope motor, and meanwhile, the motion controller receives azimuth angle and altitude angle data of an encoder fed back by the servo system; the motion controller transmits the acquired azimuth angle and altitude angle data of the encoder to observation control software;
the observation control software transmits the triggering time, the triggering pulse interval and the triggering pulse number of the CCD to the CCD data collector, and the CCD data collector outputs a pulse signal to the CCD according to the received exposure pulse interval and the triggering pulse number and latches the CCD exposure time; the CCD data collector collects image data obtained by a CCD, and then sends the obtained image data and the CCD exposure time to observation control software;
the observation control software stores image data acquired by the CCD data acquisition device into an FITS file, then writes azimuth angle and altitude angle data of an encoder fed back by a servo system of a motor and exposure time latched by the CCD data acquisition device into the FITS file head, and sends the data to the data processor, and the data processor performs image processing according to the received FITS file and performs identification and astronomical positioning on a space target;
the FPGA in the data processor performs image processing on the FITS file sent by the observation control software, wherein the image processing comprises significance detection, iteration threshold segmentation, expansion operation and contour extraction; the specific process is as follows:
separating a fixed star and a space target, and obtaining a saliency image through a saliency detection algorithm;
the significance detection algorithm is expressed by the formula:
μ＝mean(I)
SI＝(I-μ)2
FSI＝255×(SI-min(SI))/(SI-max(SI))
where I is the original image, μ is the average of I, SIFor processed images, FSIGenerating a saliency image;
step two, adopting iterative threshold segmentation to the saliency image obtained in the step one; the specific process is as follows:
step two, firstly, the minimum gray value Z in the saliency image is obtainedlAnd maximum gray valueZkInitial value T0Comprises the following steps: t is0＝(Zl+Zk) /2, setting the threshold value as Tk；
Step two, according to the threshold value TkDividing the saliency image into a target part and a background part, and respectively calculating the average gray value Z of the targetoAnd the average gray value Z of the backgroundB；
Step two and step three, the average gray value Z of the target obtained in the step two is used as the gray valueoAnd the average gray value Z of the backgroundBObtaining a new threshold value Tk+1(ii) a The T isk+1＝(Zo+ZB)/2；
Step two, if Tk＝Tk+1Then T iskThe optimal threshold value is obtained, and the process is ended; otherwise, returning to the second step;
and step three, performing closed operation expansion operation and star image contour extraction on the image subjected to threshold segmentation in the step two to obtain the pixel position of the image, namely the central coordinate of the star image.
2. The embedded observation control system of the precision measurement type space target telescope according to claim 1, characterized in that: the DSP in the data processor identifies the space target and performs space target astronomical positioning in parallel through a core0 and a core1 in a DSP kernel, and the process of identifying the space target by the kernel core0 is as follows:
whether the motion direction of the space target is consistent with the direction of the telescope or not is solved by adopting a similar function, and then the space target is identified in a background fixed star;
and then, distinguishing a background fixed star and a space target by comparing the size of the miss distance, and realizing the identification of the space target in the background fixed star, wherein the direction of the telescope is as follows: observing and controlling software to obtain azimuth angle and altitude angle data fed back by a servo system of the motor; the specific process is as follows:
setting m targets in the image, wherein the relation between a spatial rectangular equatorial coordinate system (x, y, z) of the same star image at the same moment and the right ascension and declination of the right ascension under the equatorial coordinate is as follows:
spatial rectangular equatorial coordinate system (x) of telescope pointing at the same moment0,y0,z0) The relationship to right ascension and declination at equatorial coordinates is as follows:
wherein RA is0,DEC0The right ascension and declination pointed by the current telescope, RA (l), DEC (l) are the right ascension and declination of the stellar, l is 1,2,3 … … m, and m is a positive integer;
setting alpha as the included angle between the direction of the star image and the direction of the telescope, the similarity function is defined as:
if cos alpha is closer to 1, the similarity degree of the star image motion direction and the telescope direction is higher;
the miss distance is defined as a distance function:
D(l)＝|Dl-Do|
the smaller the D (l), the greater the spatial target probability, DlImage coordinates of stars, DoObtaining image coordinates (x) of the space object for the coordinates of the center point of the image0,y0)；
The specific steps of the kernel core1 for astronomical positioning of the space target are as follows:
step A, after space targets are identified, finding fixed stars in a telescope view field in a Tycho2 ephemeris, and queuing the fixed stars according to stars and the like;
b, in the CCD image, adopting a triangular matching method to obtain CCD body coordinates (x) of six brightest calibration starsi,yi)；
Step C, adopting a polynomial approximate regression method;
αi＝a0+a1xi+a2yi+a3xi 2+a4xiyi+a5yi 2+a6xi 3
βi＝b0+b1xi+b2yi+b3xi 2+b4xiyi+b5yi 2+b6xi 3
in the formula, xi，yiThe CCD body coordinate of a star, i is 1,2,3, …, J; wherein alpha isiAnd betaiThe right ascension and declination in the celestial coordinate system, and they are known, a0-a6And b0-b6Are all coefficients, find a0-a6And b0-b6；
Step D of determining a0-a6And b0-b6After the value of (c), the image coordinates (x) of the space object are determined0,y0) Substituting into the formula of the step C to obtain the right ascension and declination (alpha) of the space target0,β0) The right ascension and declination (alpha)0,β0) And the UDP protocol is sent to observation control software to realize measurement and control.
3. The embedded observation control system of the precision measurement type space target telescope according to claim 1, characterized in that:
data is transmitted between the observation control software and the motion controller by adopting a UDP (user Datagram protocol) protocol, and image data is transmitted between the observation control software and the CCD data acquisition device by adopting a PCI Express protocol; the observation control software and the CCD data collector transmit control data by adopting a UDP protocol, and the observation control software and the data processor transmit data by adopting the UDP protocol.
4. The embedded observation control system of the precision measurement type space target telescope according to claim 1, characterized in that: the CCD data collector is used for realizing the collection of CCD image data and the control of the CCD;
for the acquisition of image data, the CCD data acquisition device is used as a fiber channel adapter based on a PCI Express bus architecture to realize the high-speed acquisition and transmission of the image data of the fiber network;
the control of the CCD comprises the external triggering moment of the CCD exposure and the latching of CCD exposure signals, and the CCD data acquisition unit is used as an I/O channel controller to realize the control of the CCD through an I/O channel.
5. The embedded observation control system of the precision measurement type space target telescope according to claim 1, characterized in that:
the DSP in the motion controller is used as a core processor and is used for guiding the interpolation calculation of the data frequency; the FPGA is used as a co-controller for constructing a time reference and used as an independent variable for interpolation calculation, and the DSP and the FPGA carry out data communication through an SRIO protocol;
the DSP in the data processor is used as a core processor of the data processor and is used for target identification calculation and astronomical positioning calculation; the FPGA is used as a coprocessor and used for extracting images of the star image and the space target central point for processing, and the DSP and the FPGA carry out data communication through an SRIO protocol.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910264270.6A CN109932974B (en) | 2019-04-03 | 2019-04-03 | Embedded observation control system of precision measurement type space target telescope |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910264270.6A CN109932974B (en) | 2019-04-03 | 2019-04-03 | Embedded observation control system of precision measurement type space target telescope |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109932974A CN109932974A (en) | 2019-06-25 |
| CN109932974B true CN109932974B (en) | 2021-09-24 |
Family
ID=66989183
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910264270.6A Active CN109932974B (en) | 2019-04-03 | 2019-04-03 | Embedded observation control system of precision measurement type space target telescope |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109932974B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110415301A (en) * | 2019-08-08 | 2019-11-05 | 太原理工大学 | A kind of temporary now source real time early warning method of the astronomy based on embedded device |
| CN110889353B (en) * | 2019-11-19 | 2023-04-07 | 中国科学院国家天文台长春人造卫星观测站 | Space target identification method based on primary focus large-visual-field photoelectric telescope |
| CN110887474B (en) * | 2019-11-19 | 2023-03-21 | 中国科学院国家天文台长春人造卫星观测站 | Star map identification method for precision tracking telescope |
| CN111288968B (en) * | 2020-03-26 | 2021-02-26 | 中国科学院长春光学精密机械与物理研究所 | Space target automatic measurement system based on active search strategy |
| CN112631508B (en) * | 2020-11-25 | 2023-04-07 | 广州大学 | Radio astronomical data storage performance optimization method and device, server and storage medium |
| CN116736878B (en) * | 2023-08-15 | 2023-11-21 | 德博睿宇航科技(北京)有限公司 | Full-automatic remote control artificial satellite observation system and method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1693846A (en) * | 2005-06-20 | 2005-11-09 | 中国科学院紫金山天文台 | Precision measuring system for space target |
| CN102374856A (en) * | 2011-11-15 | 2012-03-14 | 中国科学院紫金山天文台 | Measuring method for real-time accurate direction of astronomical telescope |
| CN103559706A (en) * | 2013-10-24 | 2014-02-05 | 华南理工大学 | High-speed image recognition positioning information processor and processing method |
| CN204086992U (en) * | 2014-03-19 | 2015-01-07 | 中国科学院国家天文台 | CCD zenith telescope electric-control system |
| CN107015234A (en) * | 2017-05-19 | 2017-08-04 | 中国科学院国家天文台长春人造卫星观测站 | Embedded satellite laser ranging control system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2536600B (en) * | 2014-01-04 | 2019-01-02 | Chen Jack | Automatic astronomical observation system and observation method |
-
2019
- 2019-04-03 CN CN201910264270.6A patent/CN109932974B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1693846A (en) * | 2005-06-20 | 2005-11-09 | 中国科学院紫金山天文台 | Precision measuring system for space target |
| CN102374856A (en) * | 2011-11-15 | 2012-03-14 | 中国科学院紫金山天文台 | Measuring method for real-time accurate direction of astronomical telescope |
| CN103559706A (en) * | 2013-10-24 | 2014-02-05 | 华南理工大学 | High-speed image recognition positioning information processor and processing method |
| CN204086992U (en) * | 2014-03-19 | 2015-01-07 | 中国科学院国家天文台 | CCD zenith telescope electric-control system |
| CN107015234A (en) * | 2017-05-19 | 2017-08-04 | 中国科学院国家天文台长春人造卫星观测站 | Embedded satellite laser ranging control system |
Non-Patent Citations (1)
| Title |
|---|
| 暗弱空间目标的高精度定位;李振伟 等;《光学精密工程》;20150915;第23卷(第09期);第2627-2634页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109932974A (en) | 2019-06-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109932974B (en) | Embedded observation control system of precision measurement type space target telescope | |
| CN108764187B (en) | Method, device, equipment, storage medium and acquisition entity for extracting lane line | |
| CN110766716B (en) | Method and system for acquiring information of space unknown moving target | |
| CN109991900B (en) | Embedded guide star processing system | |
| CN101581575B (en) | Three-dimensional rebuilding method based on laser and camera data fusion | |
| CN111949111B (en) | Interaction control method and device, electronic equipment and storage medium | |
| CN100487724C (en) | Quick target identification and positioning system and method | |
| WO2016106961A1 (en) | Multi-sensor fusion-based super-near distance autonomous navigation device and method | |
| CN110503713B (en) | Rotation axis estimation method based on combination of trajectory plane normal vector and circle center | |
| CN110880189A (en) | Combined calibration method and combined calibration device thereof and electronic equipment | |
| CN107015234A (en) | Embedded satellite laser ranging control system | |
| CN103544714A (en) | Visual tracking system and method based on high-speed image sensor | |
| CN101419672A (en) | Device and method for synchronistically acquiring human face image and gazing angle | |
| CN110108303B (en) | On-orbit space target detection and identification simulation system and method | |
| CN111401251A (en) | Lane line extraction method and device, electronic equipment and computer-readable storage medium | |
| CN112179357A (en) | Monocular camera-based visual navigation method and system for plane moving target | |
| Zhang et al. | Pose measurement for non-cooperative target based on visual information | |
| CN114659523B (en) | Large-range high-precision attitude measurement method and device | |
| Du et al. | Autonomous measurement and semantic segmentation of non-cooperative targets with deep convolutional neural networks | |
| CN110889353A (en) | Space target identification method based on primary focus large-visual-field photoelectric telescope | |
| Ufuktepe et al. | Learning-based shadow detection in aerial imagery using automatic training supervision from 3D point clouds | |
| CN104217070B (en) | A kind of Space-based Space imaging simulation method and device | |
| CN115937432A (en) | Human body action reconstruction system and method based on multi-modal input | |
| Cao et al. | Recognition and instance segmentation of space non-cooperative satellite components based on deep learning | |
| CN115273070A (en) | Method and device for acquiring initial pose of unmanned vehicle, electronic equipment and storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |