KEYWORDS: Mathematical optimization, Detection and tracking algorithms, Data modeling, Telescopes, Large telescopes, Feature selection, Random forests, Education and training, Device simulation, Computer simulations
A method for unanticipated fault diagnosis based on IGWO-iForest (Improved Grey Wolf Optimizer-Isolation Forest) is proposed to address various unpredictable problems faced by large telescopes in extreme environments. First, the random forest feature selection algorithm is used to identify the features of the original dataset and eliminate redundant features. Secondly, the differential evolution strategy is introduced into the GWO (Grey Wolf Optimizer) to improve the local search efficiency and accuracy, and the Levy flight strategy is introduced into the GWO to improve the global search ability of the algorithm. Then, the improved IGWO is used to optimize the parameters of the iForest model. Finally, the performance of the model is verified through data collected from a fault diagnosis and self-healing hardware-in-the-loop simulation platform. The experimental results show that the IGWO-iForest algorithm achieves a fault diagnosis accuracy of 99.1%, which demonstrates its higher sensitivity to a small number of unanticipated fault data compared with other anomaly detection algorithms, proving the effectiveness of this method in accurately diagnosing unanticipated faults in telescopes
KEYWORDS: Data modeling, Astronomy, Telescopes, Control systems, Domes, Optical telescopes, Data storage, Reliability, Instrument modeling, Software development
Due to the high complexity of the system and the variety of influencing factors of large astronomical telescopes, the current control system could be improved largely. It’s difficult for traditional automatic control technologies to ensure reliable and highly efficient operation. The key problem is such a system which needs to consider not only the various internal factors but also the various external factors. In addition, some factors are difficult to be digitized. Thus, it’s hard to make mathematical models to represent such complex and dynamic systems. The first goal of this project is to construct a software experimental platform for the intelligentization. The second goal is to develop an intelligent reliability management system, and an optimization system for observation quality. These application systems will be running using the historical data of LAMOST operation. The evaluation of such systems will be based on the simulation of these data.
More and more astronomical instruments have been installed in extreme environment such as Antarctica because of good seeing. However it’s not good for electromechanical system of astronomical telescope due to the harsh environment. This paper presents the study of the unanticipated states of direct drive system of extremely large telescope in extreme environment. The unanticipated states which are short of priori knowledge will degrade the reliability of monitor system significantly and put the self-diagnosis system into trouble.
The Antarctic Survey Telescope-AST3 consists of three optical telescopes with 680mm primary mirror and 8 square degree field of view, mainly for observations of supernovas and extrasolar planets searching from Antarctic Dome A. The first two AST3 telescopes (AST3-1 and AST3-2) were successfully installed on Dome A by Chinese expedition team in Jan. 2012 and Jan. 2015 separately. Multi-anti-frost methods were designed for AST3-2 and the automatic observations are keeping on from March 2016. The best limited magnitude is 19.4m with exposure time 60s in G band. The third AST3 will have switchable interface for both optical camera and near infrared camera optimized for k dark band survey. Now the telescope is under development in NIAOT and the K-band camera is under development in AAO.
Chinese Antarctic Observatory has been listed as National large research infrastructure during twelfth five-year plan. Kunlun Dark Universe Survey Telescope, one of two major facility of Chinese Antarctic Observatory, is a 2.5-meter optic/infrared telescope and will be built at the Chinese Antarctic Kunlun Station. It is intended to take advantage of the exceptional seeing conditions, as well as the low temperature reducing background for infrared observations. KDUST will adopt an innovative optical system, which can deliver very good image quality over a 2 square degree flat field of view. All of parts of it have been designed carefully to endure the extremely harsh environment. KDUST will be perched on a 14.5-meter-high tower to lift it above the turbulence layer. In this paper, preliminary design and key technology pre-research of KDUST will be introduced.
The AST3 project consists of three large field of view survey telescopes with 680mm primary mirror, mainly for observations of supernovas and extrasolar planets searching from Antarctic Dome A where is very likely to be the best astronomical site on earth for astronomical observations from optical wavelength to thermal infrared and beyond, according to the four years site testing works by CCAA, UNSW and PRIC. The first AST3 was mounted on Dome A in Jan. 2012 and automatically run from March to May 2012. Based on the onsite winterization performance of the first AST3, some improvements such as the usage of high resolution encoders, defrosting method, better thermal control and easier onsite assembly et al were done for the second one. The winterization observation of AST3-2 in Mohe was carried on from Nov. 2013 to Apr. 2014, where is the most northern and coldest part of China with the lowest temperature around -50°. The technical modifications and testing observation results will be given in this paper. The third AST3 will be optimized from optical to thermal infrared aiming diffraction limited imaging with K band. Thus the whole AST3 project will be a good test bench for the development of future larger aperture optical/infrared Antarctic telescopes such as the proposed 2.5m Kunlun Dark Universe Survey Telescope project.
SONG (Stellar Oscillation Network Group) is an international project to form a global observing network of eight 1- meter class telescopes. China joined this project and funded one node telescope for this network. By the end of 2013, the Chinese SONG telescope has been installed on the Delinha observing site of Purple Mountain Observatory in Qinghai province. This paper will give the introduction of this telescope, including its optical system, structure and control system. Besides, the preliminary observing performance of the telescope on site will be given in the second part of this paper.
The extreme environment of Antarctic is valuable for astronomical observations. Dome C is proved has excellent seeing
and transmission by site testing works. While the higher, colder inland plateau Dome A is widely predicted as even better
astronomical site than Dome C. Preliminary site testing developed since the beginning of 2008 shows that Dome A has
lower boundary layer and lower precipitable water vapour. Now the automated seeing monitor is urgently needed to
quantify the site's optical character which is necessary for the telescope design and deployment. In addition, it has the
requirement that DIMM must realize automatic measurement for nearly one year under the case of unmanned
intervention during which a great quantity of data will be generated because of the limitation of Dome A. This paper
aims at researching how to use the method of mining association rules to automatically analyze observation data, what
the relationship between various parameters effecting on optical quality is, and improving the efficiency of telescope
observation by parameter optimization. We have modified a commercial telescope with diameter of 35cm to function as
site testing DIMM which has been installed at XingLong observation station of National Astronomical Observatories,
Chinese Academy of Sciences, acquired long term observation data, and identified that this method is suitable for
optimizing the parameters of DIMM system.
The Chinese astronomical exploration in Antarctic region has been initialized and stepped forward. The R&D roadmap in this regard identifies each progressive step. For the past several years China has set up Kunlun station at Antarctic Dome-A, and Chinese Small Telescope ARray (CSTAR) has already been up and running regularly. In addition, Antarctic Schmidt Telescopes (AST3_1) was transported to the area in the year of 2011 and has recently been placed in service for some time and followed with telescopes in larger size predictably more to come. Antarctic region is one of a few best sites left on the Earth for astronomical telescope observation, yet with worst fundamental living conditions for human survival and activities. To meet such a tough challenge it is essential to establish an efficient and reliable means of remote access for telescope routine observation. This paper outlines the remote communication for CSTAR and AST3_1, and further proposes an intercontinental network control platform for Chinese Antarctic telescope array with remote full-automatic control and robotic observation and management. A number of technical issues for telescope access such as the unattended operation, the bandwidth based on iridium satellite transmission as well as the means of reliable and secure communication among other things are all reviewed and further analyzed.
The first Three Antarctic Survey Telescope (AST3-1), a 50/68cm Schmidt-like equatorial-mount telescope, is the first
automated Chinese telescope operating on the Antarctic plateau. It is planned to be in operations at Dome A, the highest
peak on the Antarctic plateau, in 2012. The telescope is unmanned during night-time operations in the Austral winter.
The telescope optics and mechanics, as well as the motors and position sensors, are exposed to a very harsh environment.
The mechanics is enclosed with a foldable tent-like dome to prevent snow, diamond dust and ice. While the drive boxes,
most circuit, power supply and computers are located inside the warm instrumental cabin. This article describes the
challenges the telescope control system encountered in night-time operations, such as the power supply limit, the harsh
meteorological condition, unattended testing, automatic operation, remote control and telemetry, etc. Some solutions are
also discussed in this paper, which are applied on the AST3-1 and waiting for validation. AST3-1 is also an exploration
of a larger telescope on the Antarctic.
The preliminary site testing carried out since the beginning of 2008 shows the Antarctic Dome A is very likely to be the
best astronomical site on earth even better than Dome C and suitable for observations ranging from optical wavelength to
infrared and sub-millimeter. After the Chinese Small Telescope Array (CSTAR) which is composed of four small fixed
telescopes with diameter of 145mm and mounted on Dome A in 2008 for site testing and variable star monitor, three
Antarctic Survey Telescopes (AST3) were proposed for observations of supernovas and extrasolar planets searching.
AST3 is composed of 3 large field of view catadioptric telescopes with 500mm entrance diameter and G, R, I filter for
each. The telescopes can point and track autonomously along with a light and foldable dome to keep the snow and icing
build up. A precise auto-focusing mechanism is designed to make the telescope work at the right focus under large
temperature difference. The control and tracking components and assembly were successfully tested at from normal
temperature down to -80 Celsius degree. Testing observations of the first AST3 showed it can deliver good and uniform
images over the field of 8 square degrees. The first telescope was successfully mounted on Dome A in Jan. 2012 and the
automatic observations were started from Mar. 2012.
Prelimenary site testing led by Chinese Center of Antarctic Astronomy (CCAA) shows that the highest point of the
Antarctic Plateau Dome A has very clear sky, good seeing, slow wind, low boundary layer and very low precipitable
water vapour which make it the best site on earth for optical/IR and sub-mm observations. Chinese Small Telescope
ARray (CSTAR) was installed at Dome A in 2008 and have automatically observed for about 3 antarctic winters. The
three Antarctic Schmidt telescopes(AST3) with entrance pupil diameter 500mm are the second antarctic project
proposed by CCAA and the first AST are being constructed in NIAOT now which is planned to be mounted on Dome A
at the beginning of 2011. All the tracking components were tested in the low temperature chamber and an adaptive
defrosting method is designed to prevent the frost building up on the schmidt plate.
KEYWORDS: Control systems, Telescopes, Space telescopes, Astronomical telescopes, Astronomical imaging, Control systems design, Servomechanisms, Astronomy, Mirrors, Active optics
The project of much-anticipated LAMOST (Large sky Area Multi-Object fibre Spectroscopic Telescope) has
successfully been inspected and accepted at national-level evaluation. It will become the world's most powerful
meter-class level ground astronomical optical survey telescope. The ever-ambitious project throughout the development
history of Chinese astronomical optics telescopes has brought an extraordinary challenge to its control system from
all-round aspects. Painstaking effort has been made to the R&D of the control system from its design strategy,
functionality analyses to most subtle technical solutions, and of course efficient engineering management is also
included. A number of papers highlighting the anticipated LAMOST control system have previously been published
during the course of the project evolving. However, much lesson and experience have been learned since 10 years ago.
Now the telescope with all its facilities and observation chamber has been put into trial observation. This is the time to
review the past and ponder over the future of the control system as a whole against the functional telescope in current
reality. Lesson and experience are discussed. Some considerations for improving the system efficiency and the
accessibility are presented too in this paper.
KEYWORDS: Process modeling, Control systems, Telescopes, Astronomical imaging, Mirrors, Stars, Systems modeling, Astronomical telescopes, Astronomy, Domes
The Chinese ever-ambitious project LAMOST (Large sky Area Multi-Object fibre Spectroscopic Telescope) has now
come to its final completion of R&D stage. Major functions of the telescope have successfully passed a serial of pilot
observation recently, and various kinds of applications integrated into the automation of the telescope chamber are being
under vigorous site tests too. The TCS (Telescope Control System) is built on multi-layer distributed network platform
with many sub-systems at different levels. How to efficiently process the enormous amount of message with particular
implications running in and out the TCS is one of the major issues of the TCS software package. The paper focuses on
the modelling of control system for LAMOST based on Petri net workflow. The model is also analyzed and verified with
the matrix equation.
KEYWORDS: Satellites, Iridium, Satellite communications, Telescopes, Data communications, Receivers, Internet, Telecommunications, Data transmission, Adaptive control
Astronomers are ever dreaming of sites with best seeing on the Earth surface for celestial observation, and the Antarctica
is one of a few such sites only left owing to the global air pollution. However, Antarctica region is largely unaccessible
for human being due to lacking of fundamental living conditions, travel facilities and effective ways of communication.
Worst of all, the popular internet source as a general way of communication scarcely exists there. Facing such a dilemma
and as a solution remote control and data transmission for telescopes through iridium satellite communication has been
put forward for the Chinese network Antarctic Schmidt Telescopes 3 (AST3), which is currently under all round research
and development. This paper presents iridium satellite-based remote control application adapted to telescope control. The
pioneer work in China involves hardware and software configuration utilizing techniques for reliable and secure
communication, which is outlined in the paper too.
The LAMOST (Large sky Area Multi-Object fibre Spectroscopic Telescope) has now come to its final
completion of R&D stage. Major functions of the telescope have successfully passed a serial site tests
recently, and various kinds of applications integrated into the automation of the telescope chamber is
being under vigorous tests too. The TCS (Telescope Control System) is built on multi-layer distributed
network platform with many sub-systems at different levels. How to efficiently process the enormous
amount of message with particular implications running in and out the TCS is one of the major issues
of the TCS software programming. The paper describes the mechanism and methodology of the
LAMOST message bus structure. The realisation of message bus architecture as a result of years of
research and site test is presented in general, and dealing with the message priority and manipulating
smallest piece of message in parallel or in serial sequence are elaborated in particular.
KEYWORDS: Telescopes, Control systems, Global system for mobile communications, Astronomy, Mobile communications, Astronomical telescopes, Lithium, Astronomical imaging, Information technology, Cell phones
The R and D of the Chinese 4-m ever-ambitious telescope, Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), has advanced towards a new stage, and first light is expected by the end of 2006. As one of national scientific and engineering projects the telescope will become national facility and accommodate maximum accessibility for public reach in general and for the astronomical community in particular. Thus remote or even robotic control of the telescope is put under careful exploration. With the rapid development of IT technology one of the fashions is the mobile telephone carried around by average people mainly for daily communication, and mobile notes application has become a real hit. This paper presents GSM based remote wireless application adapted to telescope control, which can be utilized for greatly enhancing LAMOST' accessibility. The novel technique has recently been developed in LAMOST control lab. Test has demonstrated successful execution of Monitor and Control (M and C) commands for LAMOST through remote wireless mobile. The hardware and software configuration with techniques involved for reliable and secure communication is outlined in this paper too.
The ongoing Chinese ever-ambitious project of Large Sky Area
Multi-Object Fiber Spectroscopic Telescope (LAMOST) has brought about a tremendous challenge for the control engineers. To the bottom line the giant 4-meter class ground telescope is a comprehensive optomechatronic platform to achieve high performance and functionality, such as its capability of observing 4000 stars simultaneously, which will set a world record in contemporary ground survey telescopes. This paper outlines the R&D stages of the control system for the project along with its integrated strategy of
optomechatronic components in general and network control framework in particular. The approach is to make a careful investigation with respect to the time crucialness for execution of different tasks so as to utilize different networks. However, the overall network framework is based on a distributed platform, hierarchical structure and open architecture to boost the flexibility. Vigorous study has been invested and a number of cutting edge techniques have been applied to meet the tough network control requirements, such as
real-time database, powerful interfaces, sophisticated controllers,
remote control, etc.
KEYWORDS: Databases, Human-machine interfaces, Control systems, Telescopes, Computer programming, Data communications, Astronomical telescopes, Digital signal processing, Data storage, Servomechanisms
The QNX based real time database is one of main features for Large sky Area Multi-Object fiber Spectroscopic Telescope's (LAMOST) control system, which serves as a storage and platform for data flow, recording and updating timely various status of moving components in the telescope structure as well as environmental parameters around it. The database joins harmonically in the administration of the Telescope Control System (TCS). The paper presents methodology and technique tips in designing the EMPRESS database GUI software package, such as the dynamic creation of control widgets, dynamic query and share memory. The seamless connection between EMPRESS and the graphical development tool of QNX’s Photon Application Builder (PhAB) has been realized, and so have the Windows look and feel yet under Unix-like operating system. In particular, the real time feature of the database is analyzed that satisfies the needs of the control system.
Based on an unconventional design concept the LAMOST telescope will become the world's most powerful meter-class level ground astronomical optical survey telescope when it is completed. From technical perspective the goal with such a high profile has brought an extraordinary challenge to its control system. For better image quality the telescope's segmented reflecting Schmidt mirror has to be actively controlled by nanometer technique. At the same time the mirror is driven on both azimuth and altitude axes in subarcsecond accuracy for tracking the star. Vigorous study has been done and a number of cutting edge techniques are applied to meet the tough requirements. This paper gives the overview of LAMOST control system, outlines its distributed, real time, reliable and expansible configuration and the simulation approach. The current status of the control system is briefly reported in this paper too.
The Chinese ever-ambitious project of Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) has brought about a tremendous challenge for the software engineers. This paper describes the strategy of software simulation for the telescope control system as a whole, which is vital before the actual integration at the telescope with electronics, and mechanics. The development process of the simulator itself is envisioned from level-0 upgrade to level-2, and a demonstration of such a simulator at its level-0 phase is illustrated in detail in this paper.
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