The Giant Magellan Telescope (GMT) is a complex observatory with thirty major subsystems, many low-level subsystems, components, external contracts, and interfaces. Almost all subsystems require software and controls to operate. An important goal for GMT is to have software and control subsystems that are easy to develop, test, integrate, operate, and maintain. To provide consistency across all controlled subsystems, a set of standards and a reference architecture are provided. Software components are specified using a Domain Specific Language (DSL), which enables code-generation in several languages and automatic validation of architectural conformance and interfaces. Some of the main observatory control subsystems have already been modeled using this approach, and initial implementations are currently being tested. The most advanced control subsystem is the primary mirror Device Control System (M1 DCS), which is currently under testing before the integration of the optical mirror in the test cell. This paper describes the status of the GMT control system, the main lessons learned, and the future steps in the development of the GMT control system.
The Giant Magellan Telescope is proceeding with design, fabrication, and site construction. Of the seven 8.4 m diameter mirror segments required for the primary mirror, two have been completed and placed in storage, a third has been polished to specification, three more have been cast and are in various stages of fabrication, and glass is in hand to cast the final segment. The telescope structure is nearing final design review and the start of fabrication. Residence buildings and other facilities needed to support construction at the Las Campanas site in Chile are complete. Hard rock excavation of the foundations for the enclosure and telescope pier is complete. The enclosure is in final design. The first off-axis adaptive secondary mirror is being fabricated, and a primary mirror cell has been fabricated and is under test. Two adaptive optics and phasing testbeds are being fabricated for risk reduction testing and component qualification. Our fabrication and construction schedule is being revised in response to evolving programmatic factors, including the US-ELT initiative, which received the top ranking in the National Academies’ ASTRO2020 Decadal Survey.
The Primary Mirror Device Control System (M1 DCS) is one of the many Device Control Systems (DCS) included in the Giant Magellan Telescope (GMT) control system and is responsible for the overall control and operation of the GMT primary mirror segments. The primary mirror is composed of seven 8.4m diameter segments, six off-axis and one in the center. The active support system of each segment comprises 170 support actuators for the off-axis segments and 154 actuators for the center segment to control the mirror figure, and 6 hardpoints to control the six degrees of freedom of rigid body motion. The software design follows a component model-based architecture, implemented using the GMT core software frameworks. Software components of the M1 DCS are specified using a custom Domain Specific Language (DSL) and inherit all key features of the core components such as communication ports, default behaviors, telemetry, logs, alarms, faults, state machines and engineering user-interface without the need of a separate implementation. The communication between the real time software and the controlled devices is implemented by an EtherCAT Fieldbus in a ring topology. This master-slave standard protocol enables the control system to reach 100 Hz closed loop rate for active support control. This paper describes the software of the M1 DCS, the tests performed with different software and hardware simulators, and the strategy to ensure software readiness with the final optical mirror.
The Giant Magellan Telescope project is proceeding with design, fabrication, and site construction. The first two 8.4m primary mirror segments have been completed and placed in storage, three segments are in various stages of grinding and polishing, the sixth segment is in the initial stages of casting, and glass is in hand to cast the seventh segment. An industry contract is in place to complete the design and proceed with fabrication of the telescope structure. Residence buildings and other facilities at the Las Campanas site in Chile are complete. Hard rock excavation of the foundations for the enclosure and telescope pier is complete. Preliminary design of the enclosure has been completed and final design is underway. Seismic isolation system bearings have been tested. A primary mirror segment test cell that will be used to qualify control system components and software is being fabricated. Prototyping continues in several areas, including on-telescope wavefront sensing and control elements, telescope laser metrology, and a subscale Adaptive Secondary Mirror (ASM). Adaptive optics and phasing testbeds are under development. Construction activities were delayed by the global coronavirus pandemic, but work has now resumed.
The Giant Magellan Telescope project is proceeding with design, fabrication, and site construction. The first of the seven required 8.4-m primary mirror segments is completed and in storage, three segments are in various stages of grinding and polishing, and the fifth segment has been cast. Industry contracts are underway to complete the design of the telescope structure. Residence buildings and other facilities needed to support construction at the Las Campanas site in Chile are complete. Hard rock excavation is imminent in preparation for the pouring of concrete for the telescope pier and other foundations. Computational fluid dynamics analysis is informing the design of the telescope enclosure, and further construction work packages are being readied for tender. Seismic design considerations have resulted in the incorporation of a seismic isolation system into the telescope pier, as well as modifications to the primary mirror support system. Designs for the fast-steering and adaptive secondary mirrors, science instruments, and other subsystems are maturing. Prototyping is underway in various aspects, including on-sky testing of wavefront sensing and control elements, and the telescope metrology system. Our fabrication and construction schedule calls for engineering first light with a subset of primary mirror segments in late 2023, with buildout to the full configuration occurring in stages, paced by the availability of primary mirror segments and other components.
The Observatory Control System (OCS) for the Giant Magellan Telescope (GMT) includes all the software and hardware components necessary to control and monitor the GMT optical and electromechanical subsystems and to safely and efficiently operate the GMT observatory. The OCS architecture follows both a component-based and a model-based approaches. Software components are specified using a Domain Specific Language (DSL) which enables codegeneration in several languages and automatic validation of architectural conformance and interfaces. This paper describes the agile development process to generate the final software components from the specifications and the status of the whole development effort.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.