Weight measurement system, method and weight sensor

A seat weight measurement system for a seat in a motor vehicle, the motor vehicle having door and a seat belt with a buckle, said system comprising:

• a weight sensor installed in said seat, said weight sensor having a characteristic that varies with the weight of said seat;
• one or more detectors that detect if the seat is empty, if the door is open and the seat belt is unbuckled;
• a computer controller for automatically calibrating said weight sensor by performing the steps of:
• (a) determining that the seat is empty and that a condition is present, where the condition is a member of the group consisting of the door being open and the seat belt being unbuckled;
• (b) if step (a) determines that the seat is empty and that said condition is present, establishing a set of values of said characteristic that define a zero set value;
• and
• (c) presenting the set of values that define a zero set value for in seat weight measurements.

A memory medium for controlling a computer controller of a seat weight measurement system for a motor vehicle having a seat, a door and a seat belt with a buckle, said memory medium comprising:

• means for controlling the computer controller to perform the steps of:
• (a) determining that the seat is empty and that a condition is present, where the condition is a member of the group consisting of the door being open and the seat belt being unbuckled;
• (b) if step (a) determines that the seat is empty and that said condition is present, establishing a set of values of said characteristic that define a zero set value;
• and
• (c) presenting the set of values that define a zero set value for in seat weight measurements.

A method of automatically calibrating a characteristic of a weight sensor installed to sense weight of a seat in a motor vehicle, said method comprising:

• (a) determining that the seat is empty;
• (b) if step (a) determines that the seat is empty, establishing a set of values of said characteristic that define a zero set value;
• and
• (c) presenting the set of values that define a zero set value for in seat weight measurements.