Patent attributes
A system includes a weight sensor and a weight server. The weight sensor generates a signal indicative of a weight of at least one of an item. The weight server detects an event corresponding to a weight change on the weight sensor when a quantity of the item is removed from the weight sensor. The weight server determines the item quantity by calculating a result of dividing the weight change over a unit weight of the item. If the result is within a threshold range from an integer that is closest to the result, the weight server determines that a quantity of the item with the amount of the integer is removed from the weight sensor. If the result is not within the threshold range from the integer, the weight server uses weight change patterns of historically observed signals to determine item quantity that was removed from the weight sensor.