System and Method for Determining a Load in a Material Handling System

摘要

A system and method for determining the load in a material handling system is disclosed. The load weight detection system measures torque at four operating conditions both at constant speed and during acceleration. The level of torque generated by the motor under each of these operating conditions is stored in the motor drive. The motor drive also receives a signal corresponding to the speed of the hoist motor. Based on the measured torque, as well as the expected torque at no load and at rated load for the measured speed, the motor drive then determines the load present on the hoist. In some systems, two or more hoists are required to operate in tandem to lift a load. Each motor drive determines the weight of the load supported by its respective hoist motor and determines a total weight of the load based on the weights determined by each motor drive.