Patent ID: 6442439
Filing Date: 2002-08-27
Classification: B66C

Abstract:
A control system for filtering input commands to a rotary boom crane to reduce payload pendulation, wherein the rotary boom crane comprises a crane column horizontally rotatable about a vertical axis, a luffing boom mounted with the crane column, a variable-length hoist-line attached to the distal end of the luffing boom, and an operator input device for the input commands, wherein a payload suspended from the hoist-line is moveable in a horizontal and a vertical plane responsive to the operator input device, the payload having a tangential pendulation and a radial pendulation, wherein the control system comprises:a) an input command sensor, responsive to the input commands from the operator input device, the input commands comprising a commanded hoist velocity {dot over (L)}c, a commanded luff velocity {dot over (&bgr;)}c, and a commanded slew velocity {dot over (&agr;)}c; b) a pendulation frequency identifier, indicative of residual payload pendulation frequency of the rotary boom crane; and c) a command shaping filter, adapted to generate a plurality of filtered signals to reduce payload pendulation in the rotary boom crane by filtering out the residual payload pendulation frequency from the input commands.