US Patent 11161430 Vehicle occupant posture detection

A vehicle occupant posture detection (OPD) system, including: a measuring device coupled to a seat back of a seat of a vehicle and adapted to determine an angle (α) between a Z-axis and a torso line of an occupant seated in the seat by measuring an angle of the seat back; a measuring device coupled to a seat bottom of the seat of the vehicle and adapted to determine an angle (β) between the Z-axis and a femoral line of the occupant seated in the seat by measuring an angle of the seat bottom; and means for receiving and using the determined values of α and β to determine an angle (φ) between the torso line and the femoral line of the occupant seated in the seat and thereby characterize a posture state of the occupant seated in the seat.