Abstract: A method is provided for measuring and controlling a cumulative physical property, such as the thickness, of a tubular blown film, wherein the tubular blown film is being extruded from a ring-shaped extruder having a plurality of film physical property controllers disposed around the ring-shaped extruder. Where the physical property is thickness, the method includes the steps of (1) collapsing the tubular film to create a two-ply web and slowly rotating the film while taking a plurality of thickness measurements across the two-play web at various sections of the film, (2) calculating initial estimates of the thickness of each section using a first algorithm, (3) refining the initial estimates of the thicknesses of each section by successive iterations using a second algorithm, and (4) optionally adjusting at least one film physical property controller to control the final estimate of the thicknesses of each longitudinal section.

Abstract: A navigation system for guiding an automatically guided vehicle along a variable, predetermined path defined by a plurality of fixed, spaced-apart points. A target is positioned at each spaced-apart point defining the target which includes first and light sources spaced horizontally apart. A light receiving camera and lens is mounted on the vehicle for receiving the first and second horizontally spaced-apart light beams and focusing the beams on a detector. The detector includes an access on which the light beams are focused. A difference in distance from the vertical axis of the detector of the two spaced-apart points represents a deviation from the proper path of the vehicle to the target and an equality of distance of the two spaced-apart points to the vertically extending axis represents the proper path to the target. A vehicle controller controls the vehicle position in relation to the target based on the information received by the camera and lens.

Abstract: A method for providing destination and vehicle function information to an AGV comprises the steps of providing one or more stationary dynamically codeable passage transducers (5) at predetermined spaced-apart points along an AGV path (220). The AGV path (220) is provided with a separate guidance wire (W1, W2, W3) or other guidance system. Each of the transducers (5) has a digital readable instruction set representing instructions to the vehicle. A transducer reader is provided on each AGV (200) for reading the instruction set of each transducer (5) as the AGV (200) proceeds along path 220 past the transducer (5) in reading relation. The instructions read are interfaced with the control system of the AGV (200) to provide a predetermined AGV (200) response.

Abstract: An automatically guided vehicle (V) having a steering mechanism for enabling the vehicle to follow a guidance wire is disclosed. The vehicle includes a pair of spaced-apart steer drive antennas (S1, S2) and a pair of spaced-apart differential drive antennas (D1, D2). The steer drive antennas and differential drive antennas are in mutual perpendicular relation to each other and are stationarily mounted on the vehicle (V). In a steer drive mode, wheels (12) and (13) are separately controlled by steer drive antennas (S1) and (S2), respectively. The antennas cause the wheels to turn and therefore guides the vehicle (V) so that a wire (W) is followed.In a differential drive mode, wheels (12) and (13) that are positioned in parallel driving relation to each other and are controlled by antennas (D1, D2) respectively by varying the speed of the wheels (12, 13) to cause the vehicle (V) to follow the wire (W).

Abstract: An optical guidance system for remotely controlled, self-propelled vehicles in which a single light source is used as an aiming point by the vehicle. The light source is detected by a camera lens and the vehicle is maneuvered according to the position of the light within the field of view of the lens. A computer is provided to determine the cartesian coordinates of the light source and calculate the position of the vehicle relative to the light source. The light source also transmits optically coded information for controlling the vehicle relative to the position of other vehicles, the condition of the vehicle path or other related information.