In contrast to normal tires for cars and commercial vehicles, the tires of industrial material handling vehicles such as forklifts are not filled with air or gas. Instead, they typically are made of solid rubber. So what is the point of installing a condition monitoring system into such tires? The problem is that the high loads these vehicles are exposed to can lead to temperatures well above 150° - hot enough to liquefy the internal structures of the rubber, destabilising the entire wheel and causing safety problems. In the worst case, such a tire can burst, releasing hot liquid rubber and endangering persons.
The institute of transport and automation technology (ITA) of the Leibniz University in Hannover has now launched a research project that promises remedy. Along with research partner Continental the scientists intend to develop sensors that measure pressure and temperature inside the tire and radio the results to the outside world.
As to the sensor technology, the team around ITA general manager Ludger Overmeyer currently is considering strain gauges or piezo sensors. The sensors will have to withstand high pressure and temperatures, which reduces
The data processing and RF transmitter circuitry will be powered wirelessly by RFID readers outside the tire. The team also pondered the use of energy harvesting schemes, but this would lead to higher complexity - with adverse effects on cost and reliability, said Steffen Kleinert from the ITA team. "But isn't RFID also a kind of energy harvesting?" he asked.
The goal is to develop a system cost-effective enough to convince potential customers that it is better than just take the risk of an accident. In less than two years, results can be expected.