Product category:
Industrial Drives/Controls
News Release from: Control Techniques | Subject: Unidrive
Edited by the Engineeringtalk Editorial
Team on 02 December 2002
Universal drive meets special
requirements
A new design of airport baggage carousels by Leicester-based market leader Alstec Systems Technology offers major user benefits of quiet running and reduced maintenance.
A new design of airport baggage carousels by Leicester-based market leader Alstec Systems Technology offers major user benefits of quiet running and reduced maintenance These benefits stem from the motor/drive system at the heart of each carousel - Force Engineering's linear induction motors teamed up with a dedicated version of the Unidrive variable AC drive from Control Techniques
This article was originally published on Engineeringtalk on 8 Jun 2000 at 8.00am (UK)
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A retrofit drive package, comprising Control Techniques' Unidrive, UD70 soft logic module and a flux vector motor, is achieving 20% more output from a 25 year old yarn winding machine.
A number of successful installations at Attaturk Airport in Turkey, Basle-Mulhouse Airport, Terminal 3 at Heathrow and Aberdeen Airport have proved the new system 's reliability and operational benefits.
Alan Foster, Managing Director of Force Engineering of Shepshed in Leicestershire explains how it all came about.
"At an early installation using linear induction motors (LIMs) on a baggage carousel at Leeds/Bradford Airport, we installed a voltage control system with fixed 50Hz frequency to solve an operational noise problem.
We used proximity detectors to give feedback for speed control and it proved very successful.
However, we felt that the efficiency could be improved further if the system operated on a lower frequency, 18-20Hz, in order to minimise the supply current required.
Further reading
Ski innovation helped by versatile digital drives
Mantec in Italy has developed a form-grinder which uses Control Techniques Unidrives and Unimotors to drive 4 servo axes that combine to grind tiny profiles into skis.
Form-grinder which uses Control Techniques drives
Mantec, a high tech company near Milan, has developed a form-grinder which uses Control Techniques Unidrives and Unimotors to drive 4 servo axes that combine to grind tiny profiles into skis
Drives star at the refitted Royal Opera House
At the Royal Opera house, the majority of the motion, to move backdrops, light bridges, scenery wagons, and even the Proscenium Arch, is provided by 316 Unidrive and Dinverter AC drives
This was when Control Techniques came into the picture".
A survey of the capabilities of a number of variable-speed drives suppliers showed that Control Techniques was the only company who could provide voltage control combined low frequency, without having to resort to external PCBs that were less than satisfactory.
On the Unidrive 'universal' AC drive, Control Techniques was able to offer a plug-in coprocessor that was programmed to meet Force Engineering's special control requirements.
"This dedicated programming module has been developed over several contracts", says Alan Foster, "with a basic control structure and special requirements as additional programming blocks to meet virtually any customer requirements that may arise.
The basic control allows both frequency and voltage control, with frequency being adjustable between 10 and 100Hz for particular requirements.
It allows us to offer a bespoke solution at a competitive price".
The package now being offered by Alstec, using the Force Engineering's LIM package, which uses these dedicated Unidrive variable speed linear drive solutions as standard, offers the end user tremendous operational benefits.
"Although the initial capital cost is a little higher, the payback is very rapid", says Alstec Engineering Manager, Neil Goldsworthy.
"The overall life cost is significantly lower, with minimal maintenance (the maintenance schedule is 90% routine cleaning) as the only moving parts are the free-running wheels and the flight carriers.
There's next to no lubrication required, the carousels run exceptionally quietly and the projected life is at least 15-20 years.
The financial logic of the package is very compelling.
Add to that our modular design, which means that carousels can be broken down and reassembled in a different configuration in a matter of hours and we believe that we have a world-beating product".
A typical installation can be seen at the Basle-Mulhouse Airport that straddles the Swiss/French border.
As part of a larger contract to expand the check-in and baggage-screening facilities, Alstec provided a big arrivals carousel, that itself sat across the border, with one side in France, the other in Switzerland.
A total of 22 Force Engineering LIMs were controlled by just one 90kW Unidrive, fitted with a UD70 coprocessor on which resides the special linear drive program.
By contrast, the arrivals carousel installed in the British Midlands Terminal (Building 39) at London Heathrow has been designed with multiple redundancy.
"This is because it has multiple conveyors converging at this point - effectively it is at a bottleneck", says Neil Goldsworthy, "and a breakdown is not an option".
In this case, a total of 12 Force Engineering LIMs has been split into six pairs, each with a Unidrive variable speed control.
Again, each Unidrive has the special linear drive control program, but this time loaded onto UD75 plug-in units, that also provide networking using Control Techniques' own high-speed network CT-Net.
Each drive is given a node number and operates on a master/slave basis, the lowest node number being the master.
If one drive should fail, the carousel will still continue to operate.
Feedback to drives for speed control is by digital signal from photocells.
"This new motor/drive arrangement is unique in the market", concludes Neil Goldsworthy, "and has given us the flexibility to develop new products such as the inclined multi-level arrivals carousels to meet virtually any site requirement that a customer may have.
The input from both Force Engineering and Control Techniques has been superb and it is reassuring to know that Control Techniques' international network of drives centres can provide rapid on-site support wherever it may be needed throughout the world".
With great experience in airport contracts worldwide, Alstec can provide everything from preliminary designs right up to turnkey projects.
The company is a world leader in the provision of baggage, cargo and unit handling facilities.
Force Engineering is a world leader in linear induction motor technology.
Hundreds of designs have been turned into practical solutions and more than 13,000 LIMs have been built, with a total capacity in excess of 500MVA.
Applications span conveying, transportation, leisure rides, defence projects and metal separation. Request a free brochure from Control Techniques ...
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