Automatic guided vehicle sensor system and method of using same

摘要

An automatic guided vehicle (AGV) system for automatically transporting loads along a predetermined path is provided that includes a plurality of magnets distant from one another, wherein at least a portion of the plurality of magnets represent a positioning point, and a plurality of AGVs, wherein at least one of the plurality of AGVs includes a drive assembly and a sensor system configured to determine guidance information. The sensor system includes a circuit board, a two-dimensional array of giant magneto resistive (GMR) sensors along a surface of the circuit board, the GMR sensors configured to detect at least one of the plurality of embedded magnets when the GMR sensors are proximate thereto, and an electromagnetic coil extending around the circuit board and at least a portion of the GMR sensors, the electromagnetic coil configured to polarize the GMR sensors.

主权项

1. An automatic guided vehicle (AGV) system for automatically transporting loads over a ground surface along a predetermined path, the improvement comprising:
a plurality of embedded magnets fixed to the ground surface and spaced along the predetermined path distant from one another, wherein a single magnet of the plurality of magnets represent a positioning point; and an AGV comprising:
a drive assembly for moving the AGV relative to the ground surface;a sensor system configured to determine guidance information, the sensor system comprising:
a series of circuit boards;a plurality of giant magneto resistive (GMR) sensors disposed linearly along a surface of each circuit board of the series of circuit boards to define a two-dimensional array of GMR sensors spaced in a grid configuration in a plane generally parallel to the ground surface, wherein the plurality of GMR sensors is configured to detect a coordinate position of the single magnet within a boundary perpendicular to the plane and defined by a periphery of the two-dimensional array of GMR sensors, such that a first 3×3 sub-array of the two-dimensional array of GMR sensors is utilized most proximate the embedded magnet to determine the coordinate position at a first moment in time, and upon movement of the AGV relative to the ground surface, a second 3×3 sub-array of the two-dimensional array of GMR sensors is utilized most proximate the embedded magnet to determine the coordinate position at a second moment in time, and wherein the coordinate position is computed between the first and second moments in time without spatial discontinuities between the first and second 3×3 sub-array using two dimensional interpolated bilinear peak detection; andan electromagnetic coil coupled with at least one of the plurality of GMR sensors to reduce hysteresis thereof; anda controller in communication with the sensor system, wherein the controller is configured to control the drive assembly based upon the guidance information determined from the detected coordinate position, such that the controller controls the drive assembly to stop the AGV within at least one-eighth (⅛) of an inch of the positioning point.