Calculating Position

Once Lewis has identified candidate faces in an image, the information is correlated with the on-board laser range-finder. This sensor returns 180 readings of radial distance from the robot, in one degree intervals, 90 degrees to each side of the front of the robot. We assume that each face has a corresponding pair of legs, and that these legs are more-or-less directly beneath the face. Lewis uses the correspondence between the data from the laser range-finder and the candidate faces to determine the likely xy position of the owners of those faces.. Note that several such positions can be calculated from a single image, since there may be many potential shots. These positions are then passed to the path planner.