Hazard detection for a travel plan
First Claim
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1. A method of evaluating a predicted plan for conflict with a hazard, comprising:
- defining the predicted plan as a trajectory including a set of segments having parameters denoting finite spatial extents, the parameters for all segments being specifiable arbitrarily and independently of those for any others of the segments;
representing a hazard as a collection of features having finite spatial extents;
determining whether at least a portion of at least one of the segments conflicts with any of the features of the hazard;
if so, signaling a conflict.
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Abstract
A flight plan is modeled by a trajectory with a set of segments having finite lateral and altitude extents between nominal way points. A terrain database stores hierarchical patches with maximum and minimum altitudes and pointers or altitudes for subpatches. Linear-programming inequality constraints match segments with patches. A search finds any terrain locations that impinge upon the trajectory tube, indicating an error condition for the plan. Moving hazards are modeled with segmented trajectories. Conflict with a moving hazard occurs when moving bubbles within both of the trajectories overlap in both space and time.
119 Citations
57 Claims
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1. A method of evaluating a predicted plan for conflict with a hazard, comprising:
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defining the predicted plan as a trajectory including a set of segments having parameters denoting finite spatial extents, the parameters for all segments being specifiable arbitrarily and independently of those for any others of the segments;
representing a hazard as a collection of features having finite spatial extents;
determining whether at least a portion of at least one of the segments conflicts with any of the features of the hazard;
if so, signaling a conflict. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of evaluating a predicted plan for conflict with a hazard, comprising:
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defining the predicted plan as a trajectory including a plurality of segments each having independently and arbitrarily specifiable parameters denoting finite spatial extents;
storing a database of data representing terrain;
for each segment, determining whether at least a portion of at least one of the segments intersects the terrain represented by the data;
if so, signaling an error condition. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
determining whether a first altitude of terrain in a certain area bears a first relation to a first altitude of one of the segments;
if not, repeating the above step for each of a plurality of subareas;
if so, signaling the error condition.
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18. The method of claim 17 wherein determining whether at least a portion of at least one of the segments intersects the terrain represented by the data further comprises:
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calculating a first altitude of the one segment associated with the certain area;
determining whether the first altitude associated with the area bears the first relation to the first altitude of one of the segments;
if so, omitting the signaling step.
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19. The method of claim 11 further comprising:
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modeling the segments as systems of inequality constraints;
modeling a plurality of patches of the terrain as systems of inequality constraints;
determining portions of the patches associated with particular ones of the segments as those portions that satisfy the systems of constraints.
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20. The method of claim 19 wherein the determining step comprises:
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constructing a cost function associated with the segments;
minimizing the cost function within the portions of the patches.
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21. The method of claim 11 wherein the plan includes time information, and wherein at least one of the parameters of each segment denotes the time information.
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22. The method of claim 11 further comprising:
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constructing in the plan trajectory a plan bubble having parameters denoting finite spatial extents and times;
defining a hazard trajectory including a set of segments and a hazard bubble having parameters denoting finite spatial extents and times;
for each segment of the plan trajectory, determining whether the plan bubble overlaps the hazard bubble in both space and time;
if so, signaling the error condition.
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23. The method of claim 11 wherein determining whether at least a portion of at least one of the segments intersects the terrain represented by the data is performed only in spatial coordinates, independently of time.
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24. A method of evaluating a plan for conflict with a hazard, comprising:
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defining the predicted plan as a plan trajectory including a set of segments each having parameters denoting finite spatial extents;
defining the hazard as a hazard trajectory including a set of segments each having separate and independently specifiable parameters denoting finite spatial extents;
for each segment, determining whether the plan bubble overlaps the hazard bubble in both space and time;
if so, signaling the error condition. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32)
modeling the bubbles as systems of inequality constraints;
determining bubble overlap as regions that satisfy all the systems of constraints.
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29. The method of claim 28 where determining bubble overlap comprises:
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constructing a cost function associated with the bubbles;
detecting a certain value of the cost function within the regions.
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30. The method of claim 24 where one of the spatial extents of a hazard bubble depends upon at least one of the spatial extents of the hazard-trajectory segment in which it is located, and another of the spatial extents of the hazard bubble is independent of the spatial extents of such hazard segment.
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31. The method of claim 30 where the other of the hazard-bubble spatial extents is constant for all segments of the hazard trajectory.
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32. The method of claim 30 where the other of the hazard-bubble spatial extents depends upon a characteristic of the hazard.
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33. A system for evaluating a predicted plan with a hazard, comprising:
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a trajectory model including a set of segments within a geographic area, each of the segments having a finite extent in a plurality of dimensions;
a hazard model including data representing predetennined features of a hazard as a plurality of nested patches and subpatches within the geographic area of the trajectory model;
a detector for determining whether at least a portion of any of the segments conflicts with the hazard model within any portion of the geographic area;
an indicator responsive to the detector for producing an error condition indicating the conflict. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40)
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41. A system for evaluating a predicted plan with a hazard, comprising:
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means for modeling a trajectory including a set of segments within a geographic area, each of the segments having a finite independently specifiable extent in a plurality of dimensions;
means for modeling a hazard including data representing predetermined features of a hazard within the geographic area of the trajectory model;
means for determining whether at least a portion of any of the segments conflicts with the hazard model within any portion of the geographic area;
means responsive to the determining means for producing an error condition indicating the conflict. - View Dependent Claims (42, 43)
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- 44. A data structure for evaluating a predicted plan, comprising a predicted trajectory including a plurality of segments defined by waypoints, each of the segments including a horizontal path having a lateral extent parameter and a vertical path including an altitude extent parameter, at least one of the parameters for each segment is independent of the corresponding parameter for all other segments in the same trajectory.
- 54. A data structure for evaluating a predicted plan, comprising a hierarchical plurality of patches and subpatches together forming a geographic area, each patch containing an altitude parameter and at least one pointer to a subpatch representing a smaller portion of the area covered by its parent patch.
Specification