Suspended load measurement system

Abstract

A power shovel for surface mining operations is equipped with a Suspended Load Measuring (SLM) system. The SLM system determines the net weight of the material in the shovel bucket by sensing the electrical parameters of the drive motors. A microprocessor inputs the drive motor electrical parameters and processes them according to the known geometry of the power shovel. To meet the requisite accuracy of .+-.2% for a load measuring system to be effective, the SLM system utilizes a dynamic model which accounts for both conservative and nonconservative dynamic effects prevalent in power shovel operation. Correction are included for the conservative effects of the rotational inertia of the drive motors and reduction gear train, the stretch of the cables, and the inertia of the bucket. Non-conservative losses due to friction, gear loss and motor inefficiency are also compensated for. During truck loading operations, the SLM system maintains a cumulative total of the net weight of material in the truck based on the individual weights of each shovel bucket load. The total weight in the truck is then displayed to the power shovel operator so that the truck can be accurately loaded to full capacity.

Dependencies are inferred from the claim text.