A vehicle occupant restraint
system includes an
airbag system and a
seat belt harness with pretensioner and
retractor mechanisms. Multiple sensors are mounted within the vehicle to measure and monitor various occupant and vehicle characteristics, which are entered into a
central processing unit (CPU). These sensors include an occupant presence sensor for determining whether there is an occupant present within the
airbag deployment area, a child seat sensor for determining whether a child seat is properly installed in the
airbag deployment area, and a
seat belt usage sensor for determining whether a
seat belt is in an engaged position. The occupant presence, child seat, and seat belt usage sensors generate
system modifier signals that can disable the airbag system or seat belt mechanisms if certain predetermined conditions are not satisfied. Other sensors include an occupant weight sensor, an occupant
proximity sensor for determining occupant position relative to the
airbag deployment area, a
crash severity sensor, and a pre-
crash sensor for providing vehicle speed and orientation characteristics prior to the collision. All of these sensors provide input signals that are received by the CPU. The CPU processes these
multiple input signals with a hizzy
logic control system to generate multiple output signals for controlling the airbag and seat belt mechanisms. The multiple output signals can include a multi-stage airbag inflation
signal, a variable venting
signal, a seat belt pretensioner
signal, and a seat belt
retractor signal.