Abstract: In one illustrative embodiment, the present subject matter is directed to a device adapted to determine the position of a target magnet, wherein the device includes a pair of orthogonal magnetic field sensors laterally disposed along an axis that is substantially transverse to an axis defined by one that is nominally parallel to the direction of the target magnet. In another illustrative embodiment, the subject matter is adapted for use on an automated guided vehicle (AGV), whereby detection of the target magnet's location facilitates correction of the vehicle's heading and position while traversing an AGV system. The present subject matter is also directed to a method whereby the position of a target magnet may be determined by triangulation, utilizing trigonometric calculations based upon the strength and direction of the magnet field to determine the magnet's position relative to the magnetic field sensors.

Abstract: A guidance system for guiding an automated guided vehicle along a pathway is disclosed which includes rails for holding the AGV to the generally straight portions of the pathway and a non-rail guidance system for directing the AGV from the end of a first rail segment to the beginning of another. The rails provide the necessary level of control to allow an unmanned vehicle to move at high speeds while the non-rail guidance system eliminates the need for the rail switches that would otherwise be needed to shift a rail guided vehicle from one rail portion to another.

Abstract: A guidance system for guiding an automated guided vehicle along a pathway is disclosed which includes rails for holding the AGV to the generally straight portions of the pathway and a non-rail guidance system for directing the AGV from the end of a first rail segment to the beginning of another. The rails provide the necessary level of control to allow an unmanned vehicle to move at high speeds while the non-rail guidance system eliminates the need for the rail switches that would otherwise be needed to shift a rail guided vehicle from one rail portion to another.

Abstract: A method and system for controlling the movement of one or more automatic guided vehicles includes a system controller, a number of non-wire automatic guided vehicles (AGV's) and location markers positioned on a floor. The system controller serves as a dispatcher and traffic controller for the system, providing, in one embodiment, two way wireless communication to each AGV in the system. Each AGV is equipped with a navigation and guidance system for controlling the AGV's movement along a predefined guidepath. Differential X, Y-coordinates from a path point database stored in the system controller are communicated to a given AGV which can then follow the predefined guidepath. Communicating just the differential X, Y-coordinates allows for improved control over systems utilizing a large number of AGV's.

Abstract: This invention relates to a swivel caster fitted with rotational and swivel angle measurement sensors mounted to a driverless vehicle so that the lateral motion of the vehicle can be detected and accounted for by the vehicle's navigation and guidance system. A preferred embodiment of the present invention is a driverless vehicle comprising a navigation and guidance system having an angular motion sensor and a track wheel caster assembly equipped with a caster pivot sensor and a wheel rotation sensor to determine the relative position of the vehicle by taking into account substantially all movement of the vehicle along the surface upon which the vehicle is travelling. These sensors enable the navigation system to more accurately determine the vehicles current position and enable the guidance system to better guide the vehicle.

Abstract: The present invention involves an apparatus and a method for optically detecting and determining the angular position of a target. The apparatus comprises a pair of optic sensors arranged so that at least a portion of their sensing areas overlap. Their overlapping areas define the total sensing, or active sensing, area for the apparatus. Each of the optic sensors in the apparatus senses light, or other optically sensible transmission, either projected or reflected from a target positioned within the total sensing area and produces a signal relative to the amount of light sensed. The signals are then interpreted to determine the angular position of the target based on the relative signals from the optic sensors. The method of the present invention determines the angular position of a target within an area, defined by the overlapping sensing areas of a pair of optic sensors, by interpreting the relative signal intensities from the pair of optic sensors.

Abstract: Apparatus for determining the position of a mobile vehicle relative to a fixed location marker device which comprises a coil energized to emit a magnetic field composed of lines of magnetic flux extending radially and arcuately from the ends of the coil's longitudinal axis. A sensor unit mounted on the mobile vehicle comprises four identical sensing coils each responsive to the frequency of the magnetic field of the marker device and each having a major axis. These sensor coils are supported in two pairs with the major axes of the sensor coils of each pair disposed on either side of a common central plane and extending parallel thereto, this common central plane extending transversely to the longitudinal axis of the marker device coil. Each pair of sensor coils is arranged in an X pattern in which their major axes cross each other medially and perpendicularly to define a center for the coil pair.

Abstract: A method and apparatus for guiding a driverless vehicle along a path defined by a guide cable carrying a current in a horizontal road surface includes mounting a first coil, having a major coil axis, at +45 degrees relative to the horizontal on said vehicle, mounting a second coil, having a major coil axis, at -45 degrees relative to the horizontal on said vehicle such that the axes of said first and second coils intersect, sensing both the radial and circular field vectors of the electromagnetic field with each coil, comparing the magnitude of the radial vector with the magnitude of the circular vector for each coil whereby the lateral position of the intersection point of the axes of the coils is determined relative to the guide cable to indicate the lateral displacement of the vehicle relative to said path, and using the displacement information in the vehicle steering system.