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Technology transfer may prove one of the cornerstones for growth as the UK emerges from recession over the coming months.

However, one company, Sensor Technology, identified the benefits of wireless as far back as the turn of the millennium.

‘We identified a way to measure the torque in a rotating shaft without maintaining physical contact – well, the theory of how to do it.

‘Doing away with the traditional slip rings would be a big advantage in many potential applications and we kept thinking of more and more reasons to develop the concept,’ said Tony Ingham from Sensor Technology.

In the 1990s Sensor Technology had a number of projects running that related to electromagnetic corruption, EMC and its control.

Ingham continued: ‘Computers and electronics were getting everywhere in the 1990s, but they could be susceptible to electrical interference if they were used in proximity to virtually any sort of machine.

‘This included the obvious places such as factory floors, but also hospital wards, offices, broadcast studios, shops full of refrigerators and police command centres.

‘EMC was a big hurdle that had to be overcome if computers were to reach their full potential.

‘We were working hard in the field, as were many other organisations,’ he added.

Sensor Technology had investigated the use of surface acoustic waves (SAWs), or Rayleigh waves, as a way of blocking interference.

These waves are produced by most objects in motion and the theory was that they could be made to interact with the EMC waves and cancel them out.

It is a technique that several teams were working on and with which some success has been achieved.

Ingham added: ‘We were setting up a long-running trial on a lab bench.

‘Things had got a bit messy and we were just tidying up a bit before starting the trial, when we noticed on our instruments that SAWs react to strain.

‘It was hardly a eureka moment, but over the next few days the idea grew that the SAWs could be refined to act as gauges.

‘Even this didn’t get us too excited, but then it struck us that it was a wireless connection and this opened up many practical possibilities,’ he said.

A few weeks and several late nights on and Sensor Technology had a workable proposition.

Soon it had DTi (Department of Trade and Industry) and PERA (Production Engineering Research Association) backing to run a proof-of-concept project.

This was successful and the race was on to develop a marketable product.

‘We protected ourselves with patents and worked out a plan to commercialise the technology.

‘We needed a spread of application projects to work on; some easy, some tough; some commercial, some academic; some mainstream, some specialist.

‘Fortunately, just about every machine in the world uses a rotating shaft to transmit power so there were plenty of contenders,’ Ingham explained.

Universities were fertile grounds.

At University College Dublin, the technology – by now dubbed Torqsense – was used to mix solids into liquids.

It does sound demanding, but there were highly defined targets relating to achieving an even mix in minimum time and with minimum power expenditure.

‘I could see that there were hundreds of industrial applications for this work, but I didn’t predict what it actually turned out to be – stirring meat and other ingredients into curry sauce on an industrial scale.

‘This may sound a bit trivial, but it represents many industrial processes, particularly in Ireland’s food-focussed economy,’ Ingham added.

The University of Greenwich provided a project at the toughest end of the scale – monitoring the torque in high-speed rotating stone saws.

These need to be brought up to speed very quickly; when they first contact the stone, the shock load is incredible, but to get a smooth-cut surface, a constant torque has to be maintained throughout the entire cutting process, with on-the-fly adjustments being made to account for variations in the stone’s density.

Industrial stone cutting is a harsh environment and the Torqsense has to perform faultlessly for hour after hour.

The technology proved itself again and again in fields as diverse as aerospace, marine, nuclear, pharmaceuticals, packaging, pumping, conveying and mixing.

Soon Sensor Technology shifted its focus to developing variations of the basic theme.

‘We designed big and small units; single-piece sensors that are simple to fit; two-part units with a small head that will fit into the tiniest space and communicate to a controller elsewhere on the machine; a pulley replacement unit for direct installation on belt and chain drives, and more,’ Ingham continued.

Another technology transfer is now underway.

Sensor Technology is developing a load sensor that it is building into helicopter cargo hooks.

A wireless connection feeds real-time data through to the pilot and logs it for later management analysis.

Ingham added: ‘The wirelessness is a massive advantage, because it means the hook is legally not part of the aircraft.

‘Therefore users don’t need to spend time and money getting Aviation Authority approval for its installation.

‘The datalogging means exact billing to customers, while an integral GPS means spraying or similar tasks can be done with utter precision.

‘The commercial flying community is very excited about the idea and coming up with more and more avenues for us to explore.

‘This all seems a long way from the drive shafts and industrial plant we usually deal with.

‘But it’s a not-unusual technology-transfer scenario.

‘We come up with an idea, get something working and let people see it.

‘Chances are someone will step out and say: “That’s just what I’ve been looking for,”‘ Ingham finished.

Sensor Technology

Sensor Technology are manufacturers of TORQSENSE Transducers, the world’s first low cost non-contact rotary torque transducers designed for OEM applications. Rotary torque measurement has always been difficult and expensive.

The patented method uses a surface acoustic wave device as a frequency dependent strain gauge and measures the change in resonant frequency caused by the applied strain in the shaft.

The signal is transmitted via an RF couple from the rotating shaft to a fixed pick-up.

By using a frequency-based device, the signal bandwidth is increased, and the problem of electronic interference common with analogue signals is eliminated. The torque sensors are designed to operate direct from a PLC or a PC.

They require minimum length of shaft, have low inertia, no physical contact between shaft and housing, wide bandwidth, high resolution and accuracy resolution to better than one part in a million, and excellent noise immunity.

The technology lends itself to design of OEM transducers for specific customer applications. Applications include automotive, manufacturing machines, condition monitoring where knowledge of torque is critical, torque control of tightening procedures, and monitoring of viscosity during mixing where consistency is required. The technology replaces existing types of rotary torque sensors by providing better performance at a lower price.

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