Patent ID: 6070832
Filing Date: 2000-06-06
Classification: B64D,G01S

Abstract:
An ultrasonic angular measurement system for measuring the tip-off angle of a cargo pallet as it is extracted from a rear cargo door of an aircraft, said aircraft having a planar deck adjacent said rear cargo door, said cargo pallet having a planar bottom surface, the combination comprising:means movably supporting said pallet on said planar deck with said planar bottom surface spaced from and parallel to said planar deck, said pallet pivoting on a fixed axis perpendicular to the direction of movement of said pallet as said pallet is moved out of said cargo door; andmeans for measuring the tip-off angle .theta..sub.T defined as the degree of pivoting of said pallet as said pallet exits said cargo door, said measuring means being mounted on said planar deck in the space between said planar deck and said pallet bottom surface, said measuring means comprising:a transducer for transmitting pulses of an ultrasonic beam toward said bottom surface of said pallet, said pulses being transmitted at a fixed angle .theta..sub.B, said beam having a predetermined beam width;a reflector block for intercepting pulses reflected from said surface, said reflector block having a composite surface wherein a portion of said composite surface is always substantially perpendicular to said bottom surface of said pallet, whereby at least a portion of the beam pulse reflected from said bottom surface of said pallet to said reflector block is reflected back to said bottom surface and to said transducer in the path from which it came; andmeans for measuring the round trip time of said pulse from and back to said transducer, said round trip time being a linear function of said tip-off angle .theta..sub.T.