SUSPENSION INNOVATION FOR A SAFER JOURNEY Engineering and Physical Sciences Research Council I Case study 14
An innovative suspension-system component that is boosting the performance of Formula 1 cars could improve comfort and safety in road cars, motorbikes and trains. Called the inerter, it emerged from EPSRC-funded theoretical research undertaken at the University of Cambridge.
≥O.4s The inerter is said to be capable of reducing lap times by up to four tenths of a second – a huge amount by Formula 1 standards. The first Formula 1 car equipped with inerters – a McLaren-Mercedes at the 2005 Spanish Grand Prix – won the race by nearly half a minute.
Where the quest for success in Formula 1 is concerned, the issue of ‘grip’ is never far away. The better the traction, the faster the car can travel. The inerter helps to control a car’s oscillations, improving mechanical grip and cutting lap times. It was developed by the McLaren team under an exclusive licensing agreement with the university. IMPACT ON TRANSPORT > The inerter could be used in motorbikes to control steering oscillations and improve safety. > The technology could be used in trains, helping to aid stability at high speeds and reduce track wear caused by cornering. > The inerter is boosting the excitement, appeal and ongoing success of Formula 1, a sport which employs thousands of people and makes an important contribution to the UK economy. First steps The idea began with abstract circuit theory. In electrical networks, three components are needed to build the most general passive impedances: the resistor, inductor and capacitor. In passive suspension systems only two components are used: the spring and damper. Professor Malcolm Smith realised that more freedom could be gained if a third component could be added. Professor Smith christened his invention the inerter, a patent application was filed and McLaren Formula 1 signed a licensing agreement.
Formula for success After design studies, computer simulations, prototype development and track tests, a McLaren-Mercedes equipped with inerters debuted at the 2005 Spanish Grand Prix. The car powered to victory, nearly half a minute ahead of the field. For the next three years, McLaren spared no effort keeping the inerter secret, until it was ‘outed’ in a magazine article in 2008. The inerter is now licensed to Penske Racing Shocks for supply to any Formula 1 team. Professor Smith is working with McLaren’s sports car division to explore other uses in motor sport. But there may be scope to incorporate inerters in ordinary cars, leading to improved handling and passenger comfort, and in motorcycles to control steering oscillations. Other applications could include train suspension systems, where inerters could aid stability at high speeds and minimise track damage. The inerter has demonstrated how theoretical research can lead to real-world inventions which have a beneficial impact on many people’s lives. For more information about EPSRC and the impact it is making visit www.epsrc.ac.uk
Engineering and Physical Sciences Research Council
IMPROVING TRANSPORT THROUGH TECHNOLOGY
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