The hardware control system for WEAVE at the William Herschel telescope

Conference item

When an alt-azimuth telescope is tracking at a specific field, it is necessary to use a de-rotator system to compensate the Earth’s rotation of the field of view. In order, to keep the telescope tracking the field of view selected, the instrument will need to a rotation system for compensating it [1]. The new WEAVE [2] two degrees field of view requires a new field de-rotator on the top-end of the telescope. The rotator system has been designed with a direct drive motor which eliminates the need for mechanical transmission elements such as gearboxes, speed reducers, and worm gear drives. This design is a huge advantage for the system performance and lifetime because it eliminates undesirable characteristics such as long-time drift, elasticity, and backlash. The hardware control system has been developed with a Rockwell servo-drive and controller. The rotator has to be controlled by the high-level software which is also responsible for the telescope control. This paper summarizes the model developed for simulating and the software which will be used to accept the rotator system. A performance study is also carried out to test the CIP (Common Industrial Protocol) for communications between the high-level software and the rotator hardware.

Authors: Delgado, J; Mendoza, S; Burgal, J; Herreros, J; Picó, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Society of Photo-optical Instrumentation Engineers
• Host title: Ground-based and Airborne Telescopes VII
• Series number: 10700
• Publication date: 2018-07-06
• Acceptance date: 2018-05-17
• Event title: SPIE Astronomical Telescopes + Instrumentation 2018
• Event location: Austin, Texas, United States
• Event start date: 2018-06-10
• Event end date: 2018-06-15
• DOI: 10.1117/12.2313238
• Language: English
• Keywords: ethernet/IP; rotator; CIP; control system; FFR; system modeling; WEAVE