Can a refrigerator magnet provide a more accurate and faster sensor that can be used for ABS, stability control, and roll mitigation systems? Although that might be a slight oversimplification, the answer, apparently, is yes. According to Donald Remboski, vice president-power transmission & control technology at the Timken Co. (www.timken.com), the vehicle sensor system they have developed for measuring how much torque is being delivered to a tire patch “is made out of very inexpensive components, essentially a refrigerator magnet with an accurate pattern magnetized into it, which is ready by the sensor.” Heretofore special cost-prohibitive magnetic materials and sensors have been required for the task.
The system they’ve developed at Timken locates a magnetic wheel and a chip at either end of a half shaft. Says Remboski, “We can accurately measure how much torque is going through the shaft itself and the level of torque on the contact patch of the tire.” That torque at the tire patch is the first point of information as to whether something is going amiss. Current systems measure what’s happening later than at that point; they measure when yaw is created in the chassis. According to Remboski, “There’s about a 50 millisecond head start by measuring torque directly.” Which means a 50-millisecond head start in activating a safety system, if necessary.
Besides the safety benefits, Timken is utilizing similar technology to improve the performance of electronic power steering systems for better control of motors, resulting in marginally better fuel economy. Another application being tested is direct installation of the sensors into transmissions, where the technology can monitor shaft position and alert the driver to any potential problems before they reach critical levels—KMK