Yokohama Rubber Unveils Tire Monitoring System Using MEMS Technology
Nov 24, 2005 14:30
The simplified development model to describe the principle of operation
Yokohama Rubber Co., Ltd. has announced the technical details of its next-generation tire pressure monitoring system utilizing MEMS technology. The system not only monitors the air pressure of the tires in order to prevent accidents caused by tire blowouts, but also detects acceleration applied to the tires for more rapid control of the vehicle body.
In this new system, a pressure sensor and three-axis acceleration sensor and the like can be compactly installed inside the tire wheels at low cost by utilizing MEMS technology. Compared to the case where the three-axis acceleration sensor is installed on the vehicle body, the new system is likely to detect the vehicle's posture faster and controls the vehicle more safely. According to a Yokohama Rubber spokesperson, "our system can detect the movement of a vehicle 0.2 second faster than a system with the sensors installed on the vehicle body." This means that at a running speed of 100 km per hour, the former system can start controlling the vehicle 11 meters ahead of the point where the latter starts controlling. As a result, the vehicle control systems such as electric stability program (ESP) system can operate more stably.
Based on the fact that the new system is capable of detecting the tire rotation angle with higher precision, the company also mentioned the possible influences on designing the tread pattern of the tires. In the current ABS system, the rotation angle is detected by dividing one rotation into 48 - 60 segments. Accordingly, when the rotation angle is to be measured by the tire surface, the best precision achieved is only about 3 cm. Considering the width of the tire grounding surface being approximately 15 cm, the braking control at the grounding surface is quite inaccurate. This has been a hamper to the optimum design of the tire tread pattern thus far.
Tsuneyuki Miyake, Nikkei Microdevices
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