Crane Dynamics with Modulated Hoisting

Bockstedte, Andreas; Kreuzer, Edwin

doi:10.1002/pamm.200510022

Cited by 5 publications

(3 citation statements)

References 3 publications

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“…the load swing. The idea is to modify the hoisting velocityṙ ref to reduce load oscillations by adjusting two linearly decoupled oscillations to meet the autoparametric resonance condition (we refer to [2], [3] and [4]). As an illustrative example, the planar elastic pendulum is taken as…”

Section: Load Swing Controlmentioning

confidence: 99%

Modal Coupling for Active Damping of Load Swing of Container Cranes

Kreuzer

Rapp

2010

Proc Appl Math and Mech

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Oscillation control of container handling is dominated by open-loop or closed-loop control of the crane trolley, which highly effects the crane operator's well-being. An alternative actuating approach is presented using the hoists of the crane system. Simulation and test stand results prove the effect of modal coupling control of container handling and its capability to assure improved work environment conditions for the operator of container cranes. MotivationThe container cranes in ports are exposed to disturbances i.e. load oscillations, trolley movement and wind. In order to increase the throughput one has to assure the load oscillations are avoided. The underactuated container crane does not account for direct load oscillation suppression. The present damping strategies only effect the in-plane load oscillations below the boom but not the out-of-plane nor rotational swing. An alternative approach uses the hoists of the crane for modal coupling for active damping of load swing. This contribution first investigates the modal coupling of the structural response of a container crane and the swinging load, represented by an elastic pendulum. The second part is devoted to the design of a load swing control comprising a 2:1 internal resonance and results are presented. Modal Coupling at Container CranesThe investigation of modal coupling at container cranes is based on a loaded (load swing, trolley, wind) finite element beam model of the crane:The structural displacements arise from the effected mode shapes y i , which are identified by mode decomposition. The jth mode shape y j (see Figure 1, solid crane structure) vertically displaces the container crane boom and thereby may lead to nonlinear coupling with the load oscillations (Figure 1, dashed crane and arrows). This idea originates from [1] and is valid for parametrically excited systems for which the internal resonance condition states:The 2:1 autoparametric resonance relates the vertical oscillation ω el to the load oscillation ω p by ω el = 2ω p . This phenomenon takes place for any possible load swing orientation. Figure 2 depicts the lowest container crane eigenfrequencies f i with respect to the trolley position p along the beam (measured from the landside of the crane). Some modes are effected by this position variation and similar effects are observed for the variance of the load mass m and the pendulum's modulus of elasticity E. The highlighted vertical displacement mode is coupled with the pendulum's load oscillation ω p by the resonance condition. The internal 2:1 resonance only occurs for a certain length L of the load displacement from the crane boom, which can be derived from (acceleration due to gravity g):The maximum length L max does not exceed 3m for any of the varied parameters (p, m, E). This value is small compared to actual hoisting distances of container cranes. Thus we conclude that there exists no structural risk from structure-load interaction from nonlinear coupling of structural displacements and load swing. Load Swing ControlNonl...

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Section: Load Swing Controlmentioning

confidence: 99%

Modal Coupling for Active Damping of Load Swing of Container Cranes

Kreuzer

Rapp

2010

Proc Appl Math and Mech

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“…Several models have been proposed for the control problem such as containers and slung loads [4,5,[14][15][16][17][18][19]. However, the sling loads commonly analyzed in these works are large objects, commonly referred to as high-mass sling loads.…”

Section: Table 1 Cpt Medeiros Discusses Medevac Rescues [13]mentioning

confidence: 99%

“…Methods for stabilization of sling loads and hoists include studies of the dynamics of container cranes and are an active area of research in academia [15][16][17][18][19][30][31][32][33][34][35][36][37] and industry [20,[38][39][40]. Currently, for MEDEVAC rescues, the common solution to solving this oscillation is the crew chief of the aircraft grabbing the sling and attempting to stabilize it themselves.…”

Section: Table 1 Cpt Medeiros Discusses Medevac Rescues [13]mentioning

confidence: 99%

Stabilization Environment for Swing Stabilization and MEDEVAC Hoists

Morock

Aldhizer

Lanzerotti

et al. 2021

Aiaa Aviation 2021 Forum

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This paper presents data related to helicopter sling load stabilization and MEDEVAC (Medical Evacuation) rescues collected by cadets performing research in the field at the United States Military Academy (West Point, NY) and Sapienza University of Rome (Rome, Italy) since 2018. The aim of this paper is to identify engineering constraints in MEDEVAC rescues. Constraints in two typical scenarios are presented. This information can then be included in simulations and models of swing stabilization and hoist control methods. Information is obtained through a literature review and interviews with U.S. Army helicopter pilots and crew chiefs who perform MEDEVAC rescues.

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Hoisting Manipulation for Flying Cranes

Bockstedte

Kreuzer

2006

Proc Appl Math and Mech

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A control strategy for hoisting drives of crane systems is discussed. Based on modal coupling control, the desired hoisting velocity is manipulated by superposition of a suitably modulated motion in order to suppress the so–called spaghetti–problem of hoisting–induced pendulations. For a 3–dimensional multibody system featuring the flying–crane –concept the extension of this control strategy to more complicated systems is exemplified. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Crane Dynamics with Modulated Hoisting

Cited by 5 publications

References 3 publications

Modal Coupling for Active Damping of Load Swing of Container Cranes

Modal Coupling for Active Damping of Load Swing of Container Cranes

Stabilization Environment for Swing Stabilization and MEDEVAC Hoists

Hoisting Manipulation for Flying Cranes

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