Motorized Seat Belts
A motorized seat belt is a seat belt with a motor coupled to the shoulder belt retractor. The motor performs a reversible, pretightening action (retraction) to reduce the slack in the seat belt. The motorized seat belt provides the driver and passenger a sense of safety and, in the case of severe braking or a crash, more quickly couples the occupant to the vehicle, enhancing the safety to the occupant.
Motorized seat belts monitor vehicle information to determine when to perform each of the following retractions
- Full retraction for such situations but not limited to: panic braking and or skidding
- Dynamic support for lateral and longitudinal dynamics
- Slack removal when the vehicle speed above enable speed
Preconditions for motorized seat belt retractions
- Seat belt buckle is latched
- Vehicle speed greater than or equal to 25 kph (16 mph)
- All messages on serial data are received as valid
Triggers that may cause motorized seat belt retractions
- Emergency Braking
- Sudden Emergency / Panic Braking
- High Vehicle Deceleration Detection
- Ice Braking Detection
- Oversteer and Understeer
Motorized seat belt inputs
- Vehicle Power Mode
- Transmission Gear
- Wheel Speeds
- Vehicle Acceleration
- Accelerator Pedal Position
- Steering Wheel Angle and Gradient
- Yaw Rate and Lat/Long Acceleration
- Brake Pedal Position, Gradient, Pressure, Initial Travel
- Vehicle Stability
Motorized seat belt output signals
- Driver information center message - motorized seat belt Failed "Service Automatic Seatbelt Tightening"
- Driver information center message - motorized seat belt Unavailable "Automatic Seatbelt Tightening Unavailable"
Motorized seat belt retractions are inhibited when seat belt unbuckled
Driver and passenger motorized seat belts operate independently