TOKYO (Oct. 28, 2005) — Yokohama Rubber Co. Ltd. has developed an “intelligent” tire pressure monitoring system that can measure tire motion across road surfaces and therefore can help a vehicle's “sideslip prevention system” react quicker and shorten braking distances.
The key technology in the Intelligent TPMS is an acceleration sensor module, called a “G” sensor, that is mounted on the wheel inside the tire and can detect vehicle sideslips 0.2 seconds faster than existing systems used in many vehicles, Yokohama claims. This difference translates into 39 feet of travel at a speed of 62 mph, Yokohama said.
A sideslip prevention system, using input from sensors installed on the vehicle´s body, controls engine power and braking at each wheel as soon as a control computer detects a sideslip, in order to maintain vehicle stability, Yokohama said.
Yokohama found that this process involves a time lag between the actual slipping of a tire and when the sensor detects it. This led the company to researching alternatives, it said.
The Intelligent TPMS also monitors tire pressure and allows the integration of tire pressure monitoring and sideslip prevention into a single system.
From a technical point of view, the G sensor weighs only 0.3 grams and is designed to withstand vehicle speeds up to 186 mph and acceleration of 1,000 Gs, Yokohama said.
The number of vehicles equipped with sideslip prevention systems—known by names such as ESP (Electronic Stability Program) and ESC (Electronic Stability Control)—has been increasing at an average of about 20 percent annually over the past several years, Yokohama said. The penetration level is not high yet, though—over 35 percent in Europe, but only 10 percent or so in the U.S. and Japan.
Such systems are credited by by vehicle makers and others with helping prevent accidents. All Mercedes-Benz models, for example, are fitted with them as standard equipment, and the the Big 3 U.S. auto makers have decided to make them standard, beginning with some 2005 models, primarily large SUVs.
This is Yokohama's third development of a tire pressure monitoring system. In 2003 it released its HiTES system in Japan for trucks and buses, and in 2004 its AIR Watch for passenger cars.