Aeronautics and astronautics – Aircraft structure – Details
Reexamination Certificate
2002-09-23
2003-10-14
Eldred, J. Woodrow (Department: 3644)
Aeronautics and astronautics
Aircraft structure
Details
C244S075100, C342S359000, C342S354000, C342S164000, C342S164000, C342S164000
Reexamination Certificate
active
06631871
ABSTRACT:
TECHNICAL FIELD
The present invention relates generally to a movable platform or appendage as on an air or space vehicle, and more particularly to a movable platform or appendage that needs to be accurately controlled.
BACKGROUND ART
A reliable communications system depends heavily on the accurate position control of movable platforms or appendages, such as antennas. These movable devices can be mounted on an air or space vehicle, or may be part of a terrestrial system such as an electronically-steered phased array antenna.
In order to provide reliable service, the movable devices must be maintained in certain predetermined, or fixed, positions. This is especially important in air and space vehicles, which are constantly moving and require certain movable devices to maintain relative positions regardless of the motion of the vehicle.
There is a need for a low-cost reliable method of controlling a movable device such as a gimbaled communications platform attached to an unmanned aerospace vehicle.
SUMMARY OF THE INVENTION
It is an object of the present invention to improve the reliability of a communications system. It is another object of the present invention to provide a simple low-cost method for accurately controlling a movable appendage.
It is a further object of the present invention to provide a closed-loop control system for a movable appendage. It is still a further object of the present invention to track the actual position of the device to be controlled and position the device to a desired position.
In carrying out the above objects, the present invention provides a closed-loop control system. Downlink beacons sent from the device being controlled are received by tracking sites on the ground and track the movement of the device. The tracking sites report the device's position information to a computer processor. The processor computes an error that is representative of the actual position of the device from the desired position of the device to be controlled. The computer processor computes a command that is sent back to the device to be controlled to null the error and drive the controlled device to the desired position.
These and other features of the present invention will be better understood with regard to the following description, appended claims, and accompanying drawings.
REFERENCES:
patent: 5790071 (1998-08-01), Silverstein et al.
patent: 5912642 (1999-06-01), Coffin et al.
patent: 6014372 (2000-01-01), Kent et al.
patent: 6150977 (2000-11-01), Wilcoxson
patent: 6513758 (2003-02-01), Lloyd
Oodo, M., et. al, “Onboard DBF Antenna for Stratospheric Platform”, 2000 IEEE International Conference on Phased Array Systems and Technology, Proceedings, May 21-25, 2000, pp. 125-128.
Yokosuka Research Park, “The First Stratospheric Platform Systems Workshop”, May 12-13, 1999 pp. 1-216.
Chan, K. K., et al, “A Circularly Polarized Waveguide Array for Leo Satellite Communications”, Antennas and Propagation Society, 1999, IEEE International Symposium, vol. 1, Jul. 11-16 1999, pp. 154-157.
Duraiswamy V. D.
Eldred J. Woodrow
Hughes Electronics Corporation
Sales M. W.
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