A vehicle occupant sensor which utilizes an acoustic system for determining
object range, extent, and direction. The system is composed of an
ultrasonic transmitter formed from an array of air chamber resonator
elements driven in relative phase to each other to produce a steered
acoustic beam. Electrical excitation circuitry converts waveform data
stored in memory elements to electrical signals to drive the transmitter.
One or more ultrasonic receivers receives the acoustic waves reflected
from objects, and a processor determines the range, extent and direction
of the objects based on the received acoustic waves.