Shipboard antenna pointing and alignment system

A method of orienting a mechanism with respect to a target comprising the steps of:

• (a) generating a prescribed coordinate system vector representative signal through which the orientation of said mechanism is to be controlled for orienting said mechanism with respect to a target and translating said vector representative signal through at least one coordinate system transformation;
• (b) generating at least one mechanism orientation parameter representative signal in accordance with which said vector representative signal is translated in step (a);
• (c) modifying said at least one mechanism orientation parameter representative signal in accordance with a correction signal representative of an estimated error in said at least one mechanism orientation parameter and generating therefrom at least one modified signal through which said vector representative signal is translated in step (a);
• (d) applying said translated vector representative signal as a command signal to a mechanism orientation servo control system by way of which the orientation of said mechanism with respect to said target is controlled, said servo control system producing a servo error signal representative of an error in the orientation of said mechanism as sensed by the servo control system with respect to said command signal;
• (e) comparing the actual orientation of said mechanism to the ideal orientation with respect to said target and generating an orientation difference signal representative of the difference therebetween;
• (f) generating an error difference signal representative of a difference between said servo error signal and said orientation difference signal;
• and
• (g) applying said at least one mechanism orientation parameter representative signal and said error difference signal to a Kalman filter error estimator through which said correction signal is generated.

A method of pointing an antenna, that is mounted on a support structure having an orientation that is subject to variation with respect to time, at a target in space comprising the steps of:

• (a) generating a prescribed coordinate system vector representative signal through which said antenna is to be controlled for pointing said antenna at said target and translating said vector representative signal through coordinate system transformations that define the position of said target in space relative to the location of said antenna, the attitude of the structure on which said antenna is mounted, and the orientation of said antenna as mounted on said structure;
• (b) generating respective antenna orientation parameter representative signals representative of the position of said target in space relative to the location of said antenna, the attitude of the structure on which said antenna is mounted, and the orientation of said antenna as mounted on said structure in accordance with which said vector representative signal is translated in step (a);
• (c) modifying said antenna orientation parameter representative signals in accordance with respective correction signals representative of estimated errors in said antenna orientation parameters and generating therefrom respective modified signals through which said vector representative signal is translated in step (a);
• (d) applying said translated vector representative signal as a command signal to an antenna pointing servo control system by way of which said antenna is pointed toward said target, said antenna pointing servo control system producing a servo error signal representative of an error in the actual pointing of said antenna as sensed by the servo control system, relative to the command signal;
• (e) comparing the direction in which said antenna pointing servo control system points said antenna with the actual direction to the target and generating an antenna pointing difference signal representative of the difference therebetween;
• (f) generating an error difference signal representative of a difference between said servo error signal and said antenna pointing difference signal;
• and
• (g) applying said antenna orientation parameter representative signals and said error difference signal to an error estimator through which said correction signals are generated.

A system for orienting a mechanism with respect to a target, said mechanism being mounted on a support structure having an orientation that is subject to variation with respect to time comprising:

• first means for generating a prescribed coordinate system vector representative signal through which the orientation of said mechanism is to be controlled for orientating said mechanism with respect to a target and translating said vector representative signal through at least one coordinate system transformation;
• second means for generating at least one mechanism orientation parameter representative signal in accordance with which said vector representative signal is translated by said first means;
• third means, coupled to said second means, for modifying said at least one mechanism orientation parameter representative signal in accordance with a correction signal representative of an estimated error in said at least one mechanism orientation parameter and generating therefrom at least one modified signal through which said vector representative signal is translated by said first means;
• fourth means, coupled to said first means, for applying said translated vector representative signal as a command signal to a mechanism orientation servo control system by way of which the orientation of said mechanism with respect to said target is controlled, said servo control system producing a servo error signal representative of an error in the actual orientation of said mechanism as sensed by the servo control system, with respect to said command signal;
• fifth means, coupled to said fourth means, for comparing the actual orientation of said mechanism to the ideal orientation with respect to said target and generating an orientation difference signal representative of the difference therebetween;
• sixth means, coupled to said fourth means and said fifth means, for generating an error difference signal representative of a difference between said servo error signal and said orientation difference signal;
• and
• seventh means for generating said correction signal, said seventh means being coupled to receive said at least one mechanism orientation parameter representative signal and said error difference signal.

A system for orienting a mechanism with respect to a target comprising:

• first means for generating a prescribed coordinate system vector representative signal through which the orientation of said mechanism is to be controlled for orienting said mechanism with respect to a target and translating said vector representative signal through at least one coordinate system transformation;
• second means for generating at least one mechanism orientation parameter representative signal in accordance with which said vector representative signal is translated by said first means;
• third means, coupled to said second means, for modifying said at least one mechanism orientation parameter representative signal in accordance with a correction signal representative of an estimated error in said at least one mechanism orientation parameter and generating therefrom at least one modified signal through which said vector representative signal is translated by said first means;
• fourth means, coupled to said first means, for applying said translated vector representative signal as a command signal to a mechanism orientation servo control system by way of which the orientation of said mechanism with respect to said target is controlled, said servo control system producing a servo error signal representative of an error in the actual orientation of said mechanism as sensed by the servo control system, with respect to said command signal;
• fifth means, coupled to said fourth means, for comparing the actual orientation said mechanism to the ideal orientation with respect to said target and generating an orientation difference signal representative of the difference therebetween;
• sixth means, coupled to said fourth means and said fifth means, for generating an error difference signal representative of a difference between said servo error signal and said orientation difference signal;
• and
• seventh means for generating said correction signal, said seventh means being coupled to receive said at least one mechanism orientation parameter representative signal and said error difference signal, said seventh means comprising a Kalman filter error estimator through which said correction signal is generated.

A system for pointing an antenna, that is mounted on a support structure having an orientation that is subject to variation with respect to time, at a target in space comprising:

• first means for generating a prescribed coordinate system vector representative signal through which said antenna is to be controlled for pointing said antenna at said target and translating said vector representative signal through coordinate system transformations that define the position of said target in space relative to the location of said antenna, the attitude of the structure on which said antenna is mounted, and the orientation of said antenna as mounted on said structure;
• second means for generating respective antenna orientation parameter representative signals representative of the position of said target in space relative to the location of said antenna, the attitude of the structure on which said antenna is mounted, and the orientation of said antenna as mounted on said structure in accordance with which said vector representative signal is translated by said first means;
• third means, coupled to said second means, for modifying said antenna orientation parameter representative signals in accordance with respective correction signals representative of estimated errors in said antenna orientation parameters and generating therefrom respective modified signals through which said vector representative signal is translated by said first means;
• fourth means, coupled to said first means, for applying said translated vector representative signal as a command signal to an antenna pointing servo control system by way of which said antenna is pointed toward said target, said antenna pointing servo control system producing a servo error signal representative of an error in the actual pointing of said antenna as sensed by the servo control system, relative to the command signal;
• fifth means, coupled to said fourth means, for comparing the direction in which said antenna pointing servo control system instructs said antenna with the actual direction to the target and generating an antenna pointing difference signal representative of the difference therebetween;
• sixth means, coupled to said fourth means and said fifth means, for generating an error difference signal representative of a difference between said servo error signal and said antenna pointing difference signal;
• and
• seventh means for generating said correction signals in accordance with said antenna orientation parameter representative signals and said error difference signal.