Seat occupancy determination apparatus

A seat occupancy determination apparatus comprising:

• a seat belt detection portion configured to detect an engagement of a tongue plate with a buckle of a seat belt;
• first and second load sensors arranged at one end of a lower side of a seat in a width direction thereof in a state where the first and second load sensors are positioned away from each other, each of the first and second load sensors detecting a portion of a load applied to the seat;
• a determination portion determining whether an occupancy state of the seat is an occupant seated state in which an occupant is seated on the seat or the occupancy state is a no occupant state in which the occupant is not seated on the seat;
• a load decrease determination process portion determining a load decrease caused by a turning of the vehicle to inhibit a determination of the determination portion from being shifted to the no occupant state in a case where an inclination of a decrease of a load detected by the first and second load sensors is gentle in a state where the seat belt detection portion detects a disengagement state of the seat belt while the occupant seated state is determined by the determination portion, the load decrease determination process portion determining the load decrease caused by the occupant moving away from the seat and that the occupant is not seated on the seat in a case where the inclination of the decrease of the load detected by the first and second load sensors is steep;
• a negative load determination process portion determining the load decrease caused by the turning of the vehicle to inhibit the determination of the determination portion from being shifted to the no occupant state in a case where a negative load is detected by the first and second load sensors while the occupant seated state is determined by the determination portion;
• and
• an occupant moving-away determination process portion causing the determination of the determination portion to be shifted to the no occupant state in a case where the determination of the determination portion was inhibited from being shifted to the no occupant state by the load decrease determination process portion and the negative load determination process portion, and a load value detected by the first and second load sensors is equal to or smaller than a predetermined load value for a predetermined time period.