Patent ID: 7725287
Filing Date: 2010-05-25
Classification: B66C,G01B

Abstract:
1. A computer-controlled method based on time lapse measurement of pulse emission reflections travelling at a known speed for establishing the location of the edges of a first object having known dimensions, a known shape, a top surface, a bottom surface and capable of movement with six degrees of freedom with respect to a second object having known dimensions, a known shape, a top surface, a bottom surface and a known position based on rectangular coordinates wherein the bottom surface of the second object opposes and is spaced away from the top surface of the first object and a range within which the rectangular coordinates of the first object is expected to be is known comprising: attaching at least three pulse emitters to the bottom surface of the second object, one on each of three sides thereof at known locations and having known orientations, each capable of emitting a sequence of pulses over a known period of time through a sequence of known angles from the perpendicular over a known path; securing at least three three-dimensional target shapes to the top surface of the first object at known locations and in known orientations wherein each target shape has a known configuration, known dimensions and at least one edge or at least one point with an elevation higher than any other edge or point of said target shape; affixing at least three pulse receivers, each of which is co-located with one of said pulse emitters, to the bottom surface of the second object; adjusting the known path of each of said pulse emitters to cross over a highest elevation point of one of the target shapes; storing in the computer's memory data for each target shape its elevation at its highest point or edge, the distance in the x-axis from a highest elevation point of each target shape to an edge of the first object, the y-axis value y associating data for each target shape with a specific pulse emitter; directing a series of pulses at a known speed S from each pulse emitter towards the top surface of the first object wherein each pulse is emitted at a different known angle from the perpendicular at a known point in time over a known path; receiving a reflection from each pulse which has hit the top surface of the first object at a pulse receiver and storing an elapsed time T from emission to reflection reception associated with each pulse; for each pulse emitted, storing the angle α at which that pulse was emitted and calculating the distance d between the pulse emitter and the surface from which the pulse has been reflected according to the formula after a sequence of pulses is completed, selecting the pulses P further calculating the rectangular coordinates x determining the location x further determining the location in the x-axis of three edges of the first object by retrieving the distance of the highest elevation point of each of three target shapes to an edge of the first object from computer memory and adjusting the x combining the x