Boundary detection algorithm for embedded devices
First Claim
1. A method for detecting a crossing of a boundary, the method comprising:
- identifying a boundary within a coordinate system, wherein the boundary is defined by at least one rectangle;
identifying a set of coordinates associated with a particular location of a monitored device;
rotating the identified set of coordinates by an angle between a selected side of a particular rectangle of the boundary and an axis of the coordinate system; and
comparing the rotated set of coordinates to a rotated rectangle to determine whether the location of the monitored device is located within the particular rectangle, wherein the particular rectangle is rotated by the angle to form the rotated rectangle such that the selected side of the rotated rectangle is oriented parallel to the axis of the coordinate system.
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Accused Products
Abstract
Techniques for detecting boundary crossings may involve the use of rectangles that approximate a boundary. Data defining the rectangles may be retrieved, and a current location of a monitored device may be identified. The current location may be compared with the rectangles, and a determination that the current location is located within a rectangle may indicate a boundary crossing. To simplify the calculations on the monitored device, certain calculations may be performed in advance. For example, an angle between a selected side of a particular rectangle and an axis of the coordinate system may be determined, and the particular rectangle may be rotated by the angle to orient the rotated rectangle parallel to the axis of the coordinate system. Subsequently, location coordinates for a monitored device may be rotated and compared with a corresponding rotated rectangle to determine whether the monitored device is located within the particular rectangle.
29 Citations
40 Claims
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1. A method for detecting a crossing of a boundary, the method comprising:
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identifying a boundary within a coordinate system, wherein the boundary is defined by at least one rectangle;
identifying a set of coordinates associated with a particular location of a monitored device;
rotating the identified set of coordinates by an angle between a selected side of a particular rectangle of the boundary and an axis of the coordinate system; and
comparing the rotated set of coordinates to a rotated rectangle to determine whether the location of the monitored device is located within the particular rectangle, wherein the particular rectangle is rotated by the angle to form the rotated rectangle such that the selected side of the rotated rectangle is oriented parallel to the axis of the coordinate system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for detecting a crossing of a boundary, the method comprising
retrieving data defining rectangles associated with a boundary; -
identifying a current location of a monitored device; and
comparing the current location with the rectangles using the data defining the rectangles, wherein a determination that the current location is located within a rectangle indicates a boundary crossing. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A system for detecting a crossing of a boundary, the system comprising:
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a locator operable to identify a location of a monitored device;
a memory operable to store at least one angle of rotation and rotated coordinates associated with a predetermined boundary, the rotated coordinates corresponding to original coordinates defining the predetermined boundary in a coordinate system, with each of the original coordinates being rotated by a corresponding angle of rotation to generate the corresponding rotated coordinates prior to storing each of the rotated coordinates in the memory, wherein the rotated coordinates define at least one rectangle of a rotated boundary; and
a processor operable to rotate coordinates representing the identified location by at least one of the stored angles of rotation to calculate rotated location coordinates and to compare the rotated location coordinates with at least two of the rotated coordinates to determine a relative position between the monitored device and the predetermined boundary. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35)
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36. A method for detecting movement across a boundary, the method comprising:
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storing at least two sets of rotated coordinates associated with a predetermined rectangular boundary segment, the at least two sets of rotated coordinates corresponding to at least two sets of original coordinates that define the predetermined rectangular boundary segment in a coordinate system, wherein each set of original coordinates is rotated by an angle of rotation to generate the corresponding set of rotated coordinates prior to storing each set of rotated coordinates, and the at least two sets of rotated coordinates define a rotated boundary segment having sides that are parallel to axis of the coordinate system;
storing the angle of rotation, wherein the angle of rotation is defined by an angle between one of the axes of the coordinate system and a side of the predetermined rectangular boundary segment;
identifying a location of a monitored device;
rotating a set of coordinates representing the identified location of the monitored device by the angle of rotation to generate a rotated set of location coordinates; and
comparing the rotated set of location coordinates with the at least two sets of rotated coordinates to determine a position of the monitored device relative to the predetermined rectangular boundary segment. - View Dependent Claims (37, 38, 39, 40)
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Specification