NTN Develops Intelligent Wheel Hub Bearing / CV Unit (pic)

NTN Corp. (Japan; TSE: 6472) announced it has developed a unitized wheel bearing hub unit with integral constant velocity joint; in addition, the assembly incorporates advanced force detection sensors. The "intelligent axle unit" provides instantaneous measurement of a vehicle's speed, traction force and cornering force. The sensors allow for the development of more accurate and faster-responding vehicle stability control systems. Electronic vehicle stability control (VSC) systems are increasingly available on passenger cars and trucks, helping prevent excessive slipping or skidding in corners, sliding on slippery surfaces, or loss of control during abrupt maneuvers. In the wheel hub bearing unit, sensors detect the small deflections and distortions caused when the unit is subjected to cornering forces. Sensors in the CV joint detect similar deflections caused by driving torque. Together, the sensors give a picture of how the vehicle, tires, and road are interacting. NTN said vehicle stability control systems currently in use are limited by the fact that the sensors measuring cornering and braking forces are often measuring secondary or tertiary effects -- throttle position, or vehicle speed via yaw rate or lateral acceleration sensors, for example. However, NTN argues, those chassis-mounted sensors are compromised by their location being isolated by the vehicle's entire suspension system. As a result, those sensors necessarily suffer from a significant time lag from when the vehicle interacts with the road and the motion is carried through the vehicle's suspension and chassis to the sensors. By moving the sensors to where they are most directly in contact with the tires and the road, information about the vehicle's interaction with the road is measured virtually instantaneously and without the chassis/suspension damping effects. The result is faster, higher quality information available to the vehicle's stability control system. In addition, by incorporating the sensors at every wheel location rather than at just one central location, more data is available which allows even more precise and immediate control of the VSC system.