Spinning gold - GB cyclists use unique laser timing technology

Materials World magazine
,
25 Sep 2012

Helping Great Britain’s Olympic track cyclists to gold medal glory was BAE Systems, which adapted its military expertise to engineer a unique laser timing technology.     

Great Britain always had high hopes for Victoria Pendleton, Sir Chris Hoy and the rest of the British track cyclists at the London 2012 Olympic Games, but who could have predicted an incredible tally of nine medals? Seven golds, one silver and one bronze later and Great Britain secured itself a place at the top of the track cycling medal table, beating Australia and Germany into second and third places respectively.    

For a small team of engineers at BAE Systems, the triumph was not such a surprise. Their skill and insight helped Pendleton, Hoy et al to the top of the podium through a £1.5 million technology partnership with UK Sport.    

The 18,000 UK-based engineers at BAE Systems are perhaps best known for solving military challenges, but were asked by UK Sport to assist 20 sports in the years running up to the London Games. Kelvin Davies, BAE Systems Project Manager for the UK Sport Technology Partnership, explains, ‘The dream solution for any sport is to know where all of its athletes are all of the time – and in the case of cycling, how fast they’re travelling all of the time’. At the time, coaches were relying on a simple laser break-beam system as a means of timing the cyclists – ‘a little bit like a laser that scans people walking in and out of a shop. Although they knew that a cyclist had passed through the laser beam, they didn’t know which [athlete].’ UK Sport set the brief of detecting where athletes were at five different timing gates around the track in the Manchester velodrome, the home of British Cycling.    

‘They say preparation is everything, and this gives the coaches access to the data with which they can assess changes in interventions such as diet, training programme or the aerodynamics of the bike,’ says Davies. ‘It could be simple things such as getting into the correct slipstream position or the correct aerodynamic pose. It could be changing the bike.’    

Spin doctors    
For BAE Systems, it wasn’t so much a case of adapting its existing piece of military hardware and using it in a sporting context as adapting the expertise and capabilities of its engineers. Indeed, the cycling project largely owes its success to a small team of five who were flexible enough in their thinking to turn their hands to sports technology.    

While engineers toyed with the idea of a RFID system, the engineers decided that an optical system would work best. ‘The solution we decided on was a laser timing system, which tells you where your athletes are at five different places on the track with a high degree of reliability and accuracy,’ says Davies.    

The idea stemmed from an identification system BAE Systems designed for use on the battlefield that allows military personnel to differentiate between friend and foe. While there are no foes on the cycling track (although the athletes might take a different view), the laser timing system uses the same principles to identify individual cyclists via a sophisticated barcode technology.    

A laser beam scans a credit card-sized, retroreflective smart-tag attached to the front forks of each cyclist’s bike, ‘in the same way different products in the supermarket have different barcodes,’ says Davies. ‘While the principle is exactly the same as in the supermarket, the challenges on a cycle in the velodrome are different. You need to be able to reliably read the barcode from a much greater distance than a few centimetres – you try scanning something in a supermarket at 80kph and see what you get. The challenges were to read the tags at speed, to ensure the laser gets reflected back on itself, and to do that uniquely for up to 30 different cyclists.’    

The engineers spent some 18 months developing and testing the tags, first on a laboratory bench ‘where they were spun at appropriate cycling speed to check that the hardware and software could read them,’ says Davies, ‘followed by another six months of testing in the velodrome to verify correct operation’.    

And it was time well spent. Not only did the engineers develop a system that hit the brief, they went one step further and provided an additional piece of information. The system measures not just when an individual cyclist passes a timing gate, but also the speed at which they are travelling. ‘That’s because we can measure the time it takes to scan the retroreflective smart-tag,’ Davies explains. ‘We know when the card began to break the laser beam and we know when it finished breaking it. From that we can deduce exactly how fast a cyclist was travelling, even though the tag is only the size of a credit card.’    

Alongside the development of the tag, specialist software was written particularly for the application, which sits on a central console in the Manchester velodrome allowing real-time viewing by British Cycling coaches as well as pooling the data for later analysis.    

 

Time trials    
The project was not without its challenges – the first being that of alignment. ‘If you imagine a cyclist pedalling furiously, the bike is shaking from side to side,’ Davies explains. ‘The laser beam needs to traverse a small card on the front forks of each bike, so getting the tags to align and scan correctly as they pass the five timing beams in the velodrome was a challenge.’    

Other challenges included accessing the intensively used velodrome for a period of time long enough to allow engineers and cyclists to test the technology. ‘It’s a bit like closing the M25 – not a good thing,’ says Davies, ‘so we had to work long hours, often in the middle of the night, to get the system installed’.    

The system also required a certain amount of structural alterations to the velodrome. The team needed to mount the timing systems on the inside of the track, which meant cutting some potholes into the highly varnished surface, ‘and that isn’t something you do lightly,’ says Davies. Luckily, Manchester City Council, which owns the cycling centre, was happy to accommodate.    

Winning formula    
The medal-winning performance by Great Britain’s cyclists begs the question of whether the system could have an similar use in other sporting disciplines. Says Davies, ‘The system works well on a track where athletes pass a particular timing gate with some precision. Are there other sports that do exactly that? It could work for something like athletics, but that’s a slightly different situation – although the principles of the system could certainly be adapted to other sports.’    

The question on everyone’s lips is how much of a difference did this world-first technology make at the London 2012 Olympics – how many of Great Britain’s gold, bronze and silver medal-winning performances can be attributed to BAE Systems’ engineering feat? ‘That’s the six million dollar question,’ says Davies. ‘It would be great to know the answer, but it’s a marginal gain. ‘It’s also important to remember that the athletes do all the hard work. Our engineers just feel privileged and proud to have contributed to that – even if it’s an infinitesimally small contribution, it is still there. And in the high performance elite cycling world, even an infinitesimal difference can make all the difference between winning and losing.’