BIG motion: Ultra-precise positioning for the largest telescope in the northern hemisphere

After seven years of construction, the largest optical telescope in the northern hemisphere, the Gran Telescopio Canarias (Grantecan) on La Palma, Spain, has begun trial operation. Heidenhain model ERA 780C angle encoders are being used to position the telescope. The telescope rotates about two axes: elevation (vertical motion) and azimuth (horizontal motion); earth motion also requires compensation during the sometimes hour-long observations.

04/24/2008


Schaumburg, IL — After seven years of construction, the largest optical telescope in the northern hemisphere, the Gran Telescopio Canarias (Grantecan) on La Palma, Spain, has begun trial operation. Heidenhain model ERA 780C angle encoders are being used to position the telescope — a solution that has already proven itself in numerous telescope projects. The telescope rotates about two axes: elevation (vertical motion) and azimuth (horizontal motion). In addition, the motion of the earth has to be compensated during the sometimes hour-long observations.
The angle of the azimuth axis is measured over a diameter of about 15 meters, which requires a scale tape with a length of 48.48 meters. 1,212,000 lines with the scale-tape grating period of 40Calibration and compensation of systematic errors bring a system accuracy of 0.06 arc secs (1.7E-5º) over 13.2°. Each scale is installed in a slot about the respective axis of motion and is provided with a suitable number of measuring heads.
The 105 million euro system is now in a test phase lasting one year. The hyperbolic telescope mirror consisting of 36 hexagonal segments will be expanded segment by segment until it reaches the total diameter of 10.4 meters. At the same time, all instruments will be adjusted. When ready for operation, the telescope will focus four million times more accurately than the human eye. It will enable astronomers to detect more details than ever before.
Edited by C.G. Masi , senior editor
Control Engineering Machine Control eNewsletter
Register here and scroll down to select your choice of eNewsletters free .





No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
2016 Engineering Leaders Under 40; Future vision: Where is manufacturing headed?; Electrical distribution, redefined
Strategic outsourcing delivers efficiency; Sleeve bearing clearance; Causes of water hammer; Improve air quality; Maintenance safety; GAMS preview
World-class maintenance: The three keys to success - Deploy people, process and technology; 2016 Lubrication Guide; Why hydraulic systems get hot
Flexible offshore fire protection; Big Data's impact on operations; Bridging the skills gap; Identifying security risks
The digital oilfield: Utilizing Big Data can yield big savings; Virtualization a real solution; Tracking SIS performance
Getting to the bottom of subsea repairs: Older pipelines need more attention, and operators need a repair strategy; OTC preview; Offshore production difficult - and crucial
Applying network redundancy; Overcoming loop tuning challenges; PID control and networks
Driving motor efficiency; Preventing arc flash in mission critical facilities; Integrating alternative power and existing electrical systems
Package boilers; Natural gas infrared heating; Thermal treasure; Standby generation; Natural gas supports green efforts

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This article collection contains several articles on the vital role that compressed air plays in manufacturing plants.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me