Technology: Black box gives Indy racing a crash course in safety

时间:2019-02-28 03:20:15166网络整理admin

By ELISABETH GEAKE As the new Formula 1 motor racing champion Nigel Mansell sets off to the US to join the Indy racing circuit, his newly adopted sport is completing trials of a crash recorder which could help to make races safer. The recorder, similar to ‘black box’ flight data recorders in aircraft, records the deceleration of the car for 10 seconds at the time of an impact. The data recorded in real crashes will be used to improve crash testing in the laboratory. Concern about the safety of Indy racing was highlighted last May during practice for the Indianapolis 500, the most famous race of the season. There were eight crashes and one death on Indianapolis’s 4-kilometre oval track, which is bounded by concrete walls. Formula 1 racetracks have cushioned walls or runoff areas to reduce the impact of an accident. Average speeds during the Indianapolis 500 reach 350 kilometres per hour (220 miles per hour), whereas Formula 1 circuits have many bends to limit speeds. The Motorsports Technology Group of General Motors has just finished trials of several accelerometer recorders, including one commissioned from Cranfield Impact Centre (CIC) in Bedfordshire, part of Cranfield Institute of Technology. It contains three commercial piezoelectric accelerometers arranged at 90 degrees to each other which together record acceleration of up to 100g. From this data, the velocity, position and kinetic energy of the car can be calculated. The data is stored in a memory chip which can hold half a million samples collected over a 10-second period. The recorder continually loads data into the chip which simply overwrites the oldest data, so that the last 10 seconds are always recorded. Mike Bessant of CIC, who designed the hardware, says the clever part is distinguishing when a car has crashed. ‘You select in software beforehand what you consider to be an impact – you get bottom-ing (of the chassis on the track) and quite a lot of banging about.’ If the reading from an accelerometer exceeds a preset g-force for more than a certain time, there has been a crash. ‘You have to record thedata quickly – the energy is dissipated in 10 to 20 milliseconds. You see a big spike as the car decelerates, then the car begins to crumple and the deceleration dies away,’ Bessant says. Once a crash is detected, the recorder permanently stores data for a second before the impact and nine seconds afterwards, allowing for a ricochet from the walls. John Melvin of General Motors’ biomedical science department in Warren, Michigan, says that if such a recorder is carried in races, the data will be used to improve the tests done on crash test sleds. Sleds carry car bodies and crash dummies, and accelerate them at high speeds into walls to test their crash resistance and look for ways of reducing injury. But at present the energy of the impact can only be guessed. Kirk Russell of the sport’s governing body, called CART, says it is pressing for compulsory impact monitoring, as are General Motors and car manufacturers Penske and Lola. The Indycar designers are meeting in Indianapolis next week to discuss safety,