Georgia Tech Research Corporation

Par Systems, Inc.

William Singhose

Khalid Lief Sorensen

Stephen Lang Dickerson

Dooroo Kim

Raynald F Eloundou

Chen Chih Peng

Methods of detection and prevention for snags or off center lifts, and auto-centering a crane over a load. Snag detection includes monitoring angular deflection of the load with respect to an at-rest position, and halting movement of the crane in a direction of increasing angular deflection. Controlling off center lifting includes detecting a side load condition for a load, and preventing a hoist operation when the side load condition is detected. Auto-centering a load includes determining a position of a block coupled to the load with respect to a trolley of the crane, and centering the trolley over the block prior to a moving operation. Centering includes comparing a position of a block marker using a trolley camera to a known centered position of the marker with respect to the camera, and moving the trolley to match the determined position of the marker to its known centered position.

Crane motion control

The various embodiments of the present disclosure relate generally to crane control systems. An exemplary embodiment of the present invention provides a crane control system comprising a real-time position-location module, an on-off controller module, and an input-shaper module. The real-time position-location module generates a position signal indicative of the distance between crane trolley and a desired location of safety. The on-off controller module maps the position signal to a velocity command signal, wherein the velocity command signal comprises instructions for the crane trolley to move in a vector relative to the desired location in at least a first velocity only if the distance between the crane trolley and the desired location is greater than a cut-off threshold. The at least a first velocity is a substantially constant. The input shaper module manipulates the velocity command signal mapped by the on-off controller module to dampen payload oscillations.

Crane control systems and methods

Disclosed are various embodiments of methods and systems related to double-pendulum crane control. In one embodiment for determining a specified insensitivity (SI) input shaper for a double-pendulum crane, the method using a processor system to implement the steps including determining a plurality of insensitivity ranges based upon operational parameters associated with the double-pendulum crane; and determining SI input shaper parameters based upon tolerances corresponding to the plurality of insensitivity ranges, the SI input shaper parameters including an amplitude and a time corresponding to each impulse of the SI input shaper.

Methods and systems for double-pendulum crane control

Disclosed are algorithms for controlling multiple states of a dynamic system, such as controlling positioning and cable sway in cranes. Exemplary apparatus and methods may be implemented using first and second serially coupled feedback loops coupled to a plant and payload that are to be controlled. The first feedback loop comprises a first control module. It generates a filtered actuator command from an error signal derived from a signal representing a desired system state and a feedback signal indicative of the actual system state. The generated signal is operative to position the payload. The second feedback loop comprises a second control module that generates a second actuator command that is operative to cause the plant to have an output of zero, to eliminate disturbance-induced oscillations. Input shaping may be employed in the first loop for eliminating motion-induced oscillations. The first control module is used for precise payload positioning, and the second control module is used to reject disturbance-induced oscillations. A model reference loop may be employed that outputs a modeled response that is an estimate of the response of the plant in the absence of external disturbances, and which may be used to generate a second actuator command for causing the plant to follow the modeled response.

Combined feedback and command shaping controller for multistate control with application to improving positioning and reducing cable sway in cranes

One preferred embodiment of the invention provides systems and methods for controlling a physical system by generating an input to the physical system that does not excite unwanted dynamics. Briefly described, one embodiment of the system among others, can be broadly summarized by as follows. A control entity generates a desired motion command for a physical system. A command generator then produces a shaped-smooth reference command for the physical system from the desired motion command that will cause the physical system to move in the desired motion without unwanted dynamics. Methods and other systems are also provided.

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Atlanta, GA, United States of America

William Singhose