Weight measurement system, method and weight sensor

摘要

A weight measurement system for automatically calibrating weight sensors installed on a motor vehicle seat. The system performs a calibrate operation whenever a valid weight measurement window is found. A valid weight measurement window is defined by the seat being empty, an associated door being open and an associated seat buckle being unlatched. The system operates in a factory install mode to establish a reference zero set value and in a diagnostic mode to establish a temporary zero set value that reflects drift of the weight sensors. The temporary zero set value is used by a weight management program to control occupant restraint devices. The weight sensor has an integral body with two lands connected by an elastomeric beam. The elastomeric beam has a pair of opposed surfaces that define a region of minimum thickness and one or more regions of maximum thickness. A resistive strain gauge element is disposed on the region of minimum thickness. The system measures changes in the resistance of the weight sensor caused by weight of the seat.