Ultrasonic Sensing of Head Position for Head Restraint Automatic Adjustment

In order to provide a safer seating environment, an automatically adjusting head restraint system (AHRS) was developed. The system will serve as a passive head restraint in the event of a rearward impact. Using ultrasonic transducer technology, the AHRS, a microprocessor controlled four way power head restraint mechanism, locates the top of occupant's head and adjusts the head restraint to an appropriate location. This paper demonstrates the effectiveness of employing ultrasonic sensor technology to automatically position a four way power head restraint system. The application and the considerations related to its implementation are discussed.