Abstract: A method and device for damping the oscillation of a load suspended from a rope on a crane is presented. A digital filter accepts an arbitrary velocity input signal and produces a velocity signal output similar to the input and that runs a bridge or trolley drive while damping the load's swing. One version of the damping filter may be implemented by programming a microprocessor to output a simple average of the input signal and the input signal delayed by one-half period of the pendulum motion of the load. A second version of the invention averages the input signals over the period of the pendulum motion to producing a damping signal. A third version of the invention averages the input signal with two delayed versions of the input signal. The third version will produce motion that will dampen load swing for a large range of rope lengths. Furthermore, if an additional signal representing rope length is taken, all three versions can be adapted to dampen swing for a full range of rope lengths.

Abstract: A method and device for damping the oscillation of a load suspended from a rope on a crane is presented. A digital filter accepts an arbitrary velocity input signal and produces a velocity signal output similar to the input and that runs a bridge or trolley drive while damping the load's swing. One version of the damping filter may be implemented by programming a microprocessor to output a simple average of the input signal and the input signal delayed by one-half period of the pendulum motion of the load. A second version of the invention averages the input signals over the period of the pendulum motion to producing a damping signal. A third version of the invention averages the input signal with two delayed versions of the input signal. The third version will produce motion that will dampen load swing for a large range of rope lengths. Furthermore, if an additional signal representing rope length is taken, all three versions can be adapted to dampen swing for a full range of rope lengths.