Aircraft course correction for wind and fuzzy logic course intercept profile based upon accuracy and efficiency
First Claim
1. An automatic flight control system for an aircraft, comprising:
- means for providing a desired course signal indicative of a desired course which the aircraft may fly in order to reach a waypoint;
means for providing a ground track signal as a function of the arctangent of the ratio of the group speed in one direction in each coordinates divided by the groundspeed of the aircraft in a direction in each coordinates which is normal to said one direction, corrected for the quadrant of said ratio;
means for providing a ground track error signal as the difference between said desired course and said ground track; and
means for providing a commanded heading signal as a summation of said desired course signal with proportional and integral functions of said ground track error signal.
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Accused Products
Abstract
An aircraft autopilot system provides a wind correction angle which is added to the desired course to provide commanded heading, the wind correction angle being generated as a proportional and integral function of ground track error. When the aircraft is off its desired course, it can be returned to the desired course by means of a course intercept angle, added to the desired course, to provide a corrected commanded course, the course intercept angle being a proportional function of the perpendicular error (the lateral distance of the aircraft from the original course) suitably limited to some angle within 90° of the desired course. The course correction angle may be generated as a proportion of the perpendicular course error determined by the degree of importance of accuracy, and may be switched over to a course directly toward a waypoint in dependence upon the importance of efficiency. The course intercept angle may be a variable proportion of the perpendicular error as a function of the importance of accuracy, and the limits on the intercept angle determined by the relative importance of efficiency.
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Citations
7 Claims
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1. An automatic flight control system for an aircraft, comprising:
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means for providing a desired course signal indicative of a desired course which the aircraft may fly in order to reach a waypoint; means for providing a ground track signal as a function of the arctangent of the ratio of the group speed in one direction in each coordinates divided by the groundspeed of the aircraft in a direction in each coordinates which is normal to said one direction, corrected for the quadrant of said ratio; means for providing a ground track error signal as the difference between said desired course and said ground track; and means for providing a commanded heading signal as a summation of said desired course signal with proportional and integral functions of said ground track error signal. - View Dependent Claims (2)
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3. An automatic flight control system for an aircraft, comprising:
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means for providing a desired course signal indicative of a desired course which the aircraft may fly in order to reach a waypoint; means for providing a course intercept angle signal as a limited function of a proportion of the perpendicular distance of the aircraft from an original desired flight path to said waypoint; and means for providing, as the summation of said desired course signal and said course intercept angle signal, a commanded heading signal indicative of a course the aircraft should fly to return to the original desired flight path to the waypoint, whereby a smooth interception to the original desired flight path is made. - View Dependent Claims (4, 5, 6, 7)
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Specification