Occupant-classifying system

1. An occupant-classifying system, comprising:

a load-detecting means assembled at a vehicle seat for detecting a load value imposed on the vehicle seat and for outputting the load value; and

a controller for determining whether the vehicle seat is in an occupied state, or in an unoccupied state on a basis of the load value outputted from the load-detecting means; wherein

a seat occupied state is classified into plural modes defined on a basis of plural threshold load values;

the controller is configured to determine the seat occupied state when the load value falls within a specific mode among the plural modes and lasts for a predetermined time duration defined for each specific mode; and wherein

the controller changes one of the threshold load values which define a boundary between the selected mode and another, neighboring mode, whether occupied mode or unoccupied mode.

2. The occupant classifying system according to claim 1 , wherein one of the threshold load values which define a boundary of the selected mode and another, neighboring mode, and the predetermined time duration defined for said another neighboring mode are changed in order to prevent another mode being selected or to prevent an unoccupied state being established.

3. The occupant classifying system according to claim 2 , wherein the plural modes of the seat occupied state include an adult occupied state at which an adult occupies the vehicle seat and a child occupied state at which a child occupies the vehicle seat.

4. The occupant classifying system according to claim 3 , wherein

the plural threshold load values include a first state change load value; and wherein the first state change load value less than one of the threshold load values defined between the adult occupied state and the child occupied state is defined and a time duration longer than one of the time duration defined for the child occupied state is defined when a current judgment that the mode of the seat occupied state is the adult occupied state is changed to a judgment that the mode of the seat occupied state is the child occupied state.

5. The occupant classifying system according to claim 4 , wherein

the plural threshold load values include a second state change load value greater than the first state change load value and less than the threshold value defined between the adult occupied state and the child occupied state; and wherein

the second state change load value greater than the first state change load value and less than the threshold value defined between the adult occupied state and the child occupied state is defined and a time duration shorter than the time duration defined for the child occupied state is defined when a judgment that an occupant is a child is changed to a judgment that the occupant is an adult, and is further changed to a judgment that a child is occupying the vehicle seat.

6. The occupant classifying system according to claim 1 further comprising a detecting means for detecting whether or not a seatbelt is buckled, wherein, depending on whether or not the seatbelt is buckled, a change is made to at least one of the threshold load values which define a boundary of the selected mode and the time duration for the selected mode.

7. The occupant classifying system according to claim 6 , wherein the plural modes of seat occupied state includes an adult occupied state at which an adult occupies the vehicle seat and a child occupied state at which a child occupies the vehicle seat.

8. The occupant classifying system according to claim 7 , wherein at least one of determining a first state change load value smaller level than one of the threshold load values defined between the adult occupied state and the child occupied state, and determining a first state change time longer than the time duration defined for the child occupied state when the seatbelt is buckled and a current judgment that an adult occupies the vehicle seat is changed to a judgment that a child occupies the vehicle seat.

9. The occupant classifying system according to claim 8 , wherein at least one of determining a second state change load value smaller level than the first state change load value and determining a second state change time longer than the first state change time when the seatbelt is unbuckled and a current judgment that an adult occupies the vehicle seat is changed to a judgment that a child occupies the vehicle seat.