Multiple load sensing multi-load cell scale and method

Abstract

The multiple load sensing multi-load cell scale is described that provides improved utility to scales with multiple decks that share load cells near supports so that more than one load may be determined at the same time on a single scale. In more detail, the scale uses the sectional sensitivities to load movement on the scale decks, load position and individual normalized load cell outputs to provide separate load magnitude measurements on these individual decks. According to the present invention, more than two load cells associated to form a single scale provide outputs that are converted to individual digital representations of the relative force magnitude on each. These magnitudes are related to the effective location of each load cell to provide the load centroid location on the scale when the sum of the products of the effective location and magnitude of each is divided by the sum of the magnitudes. The scale in accordance with the invention provides the sensitivity of each load cell to load movement on each deck. In particular, the portion of the total scale load on each deck is resolved when these deck loads are moved equally. Individual deck loads are determined by taking advantage of the fact that the change in total load magnitude across a load bearing section of the scale is the result of the product of the sum of products of sectional moment sensitivity, the deck load and the distance the load moves on the deck to cause the change. Equations for section forces supporting each deck provide a set of simultaneous interdependent equations that have a linear solution for the set of individual deck loads.