Sway control method and system for rotary cranes
Methods and apparatuses are disclosed for reducing the oscillatory motion of rotary crane payloads during operator-commanded or computer-controlled maneuvers. An Input-shaping filter receives input signals from multiple operator input devices and converts them into output signals readable by the crane controller to dampen the payload tangential and radial sway associated with rotation of the jib. The input signals are characterized by a hub rotation trajectory [gamma](t), which includes a jib angular acceleration [gamma], a trolley acceleration x, and a load-line length velocity L. The system state variables are characterized by a tangential rotation angle [theta](t) and a radial rotation angle [phi](t) of the load-line. The coupled equations of motion governing the filter are non-linear and configuration-dependent. In one embodiment, a filter is provided between the operator and the crane for filtering undesired frequencies from the angular [gamma] and trolley x velocities to suppress payload oscillation. In another embodiment, crane commands are computer generated and controlled to suppress vibration of the payload using a postulated asymmetrical shape for the acceleration profiles of the jib, which profiles are uniquely determined by a set of parameters (including the acceleration pulse amplitude and the duration and coast time between pulses), or a dynamic programming approach. 25 figs.
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- Assignee:
- Sandia Corp., Albuquerque, NM (United States)
- Patent Number(s):
- US 5908122; A
- Application Number:
- PPN: US 8-808821
- OSTI ID:
- 6420220
- Resource Relation:
- Patent File Date: 28 Feb 1997
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COMPUTERIZED CONTROL SYSTEMS
CRANES
DYNAMIC PROGRAMMING
EQUATIONS OF MOTION
MECHANICAL VIBRATIONS
MOTION
SIGNAL CONDITIONERS
CONTROL SYSTEMS
DIFFERENTIAL EQUATIONS
ELECTRONIC CIRCUITS
EQUATIONS
EQUIPMENT
MATERIALS HANDLING EQUIPMENT
ON-LINE CONTROL SYSTEMS
ON-LINE SYSTEMS
PARTIAL DIFFERENTIAL EQUATIONS
PROGRAMMING
PULSE CIRCUITS
420200* - Engineering- Facilities
Equipment
& Techniques