US 7,680,590 B2 · Boundary detection algorithm for embedded devices

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.

Claims33

Dependent claims

A method for detecting a crossing of a boundary, the method comprising:

receiving a representation of a boundary within a coordinate system, wherein the boundary is defined by at least one rectangle;
receiving a set of coordinates associated with a location of a monitored device;
rotating, by a processor, the received 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, by the processor, 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.

2 more elements

A method for detecting movement across a boundary, the method comprising:

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 of the sets 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 an axis of the coordinate system;
storing the angle of rotation, wherein the angle of rotation is defined by an angle between the axis of the coordinate system and a side of the predetermined rectangular boundary segment;
identifying a location of a monitored device;
rotating, by the monitored device, 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, by the monitored device, 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.

3 more elements

Dependencies are inferred from the claim text.

Boundary detection algorithm for embedded devices

Life of this patent

Boundary detection algorithm for embedded devices

Life of this patent

Abstract

Claims33