Astrophysics · Complex electromechanical systems
ASTRI and SST Cherenkov telescopes
Control software, power panels and automation of the gamma-ray telescopes of the Cherenkov Telescope Array: six ASTRI telescopes installed at the Teide Observatory and more than 35 SST telescopes under construction for the southern site in Chile.
- < 0.07″
- Motion precision
- 50+
- Brushless axes per telescope
- OPC UA
- Communication between controllers
- TwinSAFE
- Functional safety integrated in the controller
The programme
Cherenkov telescopes observe very-high-energy gamma rays and will be part of the Cherenkov Telescope Array, the international observatory for gamma-ray astronomy.
For the ASTRI Mini-Array programme six telescopes with a 4.5-metre primary mirror were built, installed and accepted at the Teide Observatory in Tenerife. More than 35 further SST telescopes are under construction for the southern CTAO site in Chile.
Control and automation
Each telescope is run by a Local Control System (safety, motion control, maintenance), integrated with the Telescope Control System that supervises structure, mirrors and Cherenkov camera. The same control system is used for factory testing and for operation at the observatory.
- Axis control, pointing and tracking
- Active mirror positioning, with over 50 brushless motors and patented actuators
- Metrology to reconstruct the movements
- Safety functions: limit switches, emergency stops and protections
The software is developed in Beckhoff TwinCAT per IEC 61131-3, in a modular, fault-tolerant architecture, with OPC UA communication between controllers and towards the upper level. Function blocks are tested on a simulator before being downloaded to the hardware.
Electrical panels
Power and control panels designed and wired in house, with redundant power supplies, surge protection, thermal management and identified wiring.
The operator interface has two modes. In local mode, control is enabled by a selector in the on-board cabinet, which blocks remote commands. In remote mode the telescope is commanded from the control room via SCADA, over a fibre-optic network, with cameras confirming its position.
Acceptance and commissioning
- Factory and on-site acceptance plans: electrical checks, functional and safety tests, final acceptance
- Electromagnetic compatibility tests on the complete telescope, in the factory
- More than 250 design requirements and more than 100 performance requirements verified
- CE marking under the Machinery Directive (ASTRI)
- Dismantling, shipping and on-site reassembly by teams of electrical technicians and mechanical fitters
