Abstract: In one embodiment, a method for displaying an image comprises moving a color filter through a source light beam, modulating the source light beam into a plurality of image segments, modifying the source light beam to each of the plurality of image segments in a sequential manner such that each particular image segment is off at least when an uncertain region is co-incidental with the particular image segment. The color filter has at least two color filter elements that form at least two interfaces. The uncertain region is created by each interface when moved through the source light beam. The plurality of image segments are contiguously arranged with one another in order to form the image.

Abstract: A device (10) identifies a defective object (12) from an image of the object (12) stored as pixel data in a pixel-data memory (52, 54, 56, 58). An inspection-point memory (72, 74, 76, 78) stores inspection-point data for the object (12). The inspection-point data represents inspection points (122, 124, . . . ) that are arranged in circuital (112, 136) and transverse (110) groups, where member inspection points of the circuital groups (112, 136) are also members of different ones of the transverse groups (110). A program memory (84) stores a program, which is executed by a processor (64, 66, 68, 70).

Abstract: The invention is a modular and hierarchically organized set of computer programs which comprise methods for controlling a system of semi-autonomous automatically guided vehicles, such as mobile robots. The methods include control programs which: execute in stationary control computers; communicate between the stationary control computer programs and corresponding programs which execute in mobile control computers aboard the vehicles; operate independently in mobile control computers aboard the vehicles. The invention allows the system executive program to command the mobile vehicles to start, to stop, to transfer material to or from the vehicles, to change batteries in the vehicles, to park the vehicles at specific points in a factory, to move the vehicles from point to point in a factory, and to remove the vehicles from the factory.

Abstract: The invention is a method of static collision avoidance for multiple automatically guided vehicles (AGVs) on bidirectional paths. It defines the allowable travel path for an AGV as a series of path segments through or between possible destination points (called nodes) which are defined for the factory floor. AGVs can move to or through any of these nodes and can arrive in a predetermined order, according to "rules" defined by the method. The invention provides better performance than conventional AGV systems by allowing multiple AGVs to coexist in the same pathways without collision or excessive queueing in systems which use free-roving AGVs having programmable bidirectional paths. This new ability maximizes the degrees of freedom of AGV movement while minimizing collisions and "deadlock.

Abstract: The invention provides a method for communicating the need to move a mobile robot, such as an AGV, from one location (node) to another, on a node-by-node basis, incrementally, among the nodes established in a physical environment such as a factory. The invention also provides the means to generate the commands necessary to accomplish this motion, by providing specific steering and drive information such as angle and speed to the mobile robot or AGV. The invention accomplishes these tasks in response to direct commands from a stationary controller as well as in response to continuous node-by-node position updates provided by an external navigation system, such as a visual navigation system, or an internal dead-reckoning navigation system, or both.

Abstract: A visual navigation system provides absolute position information to multiple automatically guided vehicles (AGVs) such as mobile robots. The beacon-equipped AGVs emit light visible to overhead television cameras. The beacons are arranged and controlled so that the vision systems can acquire, measure, and report the locations of multiple AGVs. The system controller incorporates a programmable "factory map", or knowledge base, of allowable paths of travel for the AGVs, which navigate by dead reckoning with periodic position updates from the visual navigation system. The visual navigation system notifies the autonomous AGVs and the system controller when an AGV strays from its command path. The combination of computer controls in the elements of the system provides the means to stop and to recover straying AGVs. The navigation system visually monitors normal AGV travel, off-course corrections, "lost" AGV searches, and recovery. Thus, it provides closed-loop, servo-like operation.

Abstract: The invention is a method of dynamic collision avoidance for multiple automatically guided vehicles (AGVs) on bidirectional paths. It calculates windows, or areas of computer memory, against which it matches the reported positions of AGVs. The invention acts on information from a central data base in which the factory or operating space of the AGVs is mapped and from AGV position updates supplied by an independently operating visual navigation system. The invention dynamically calculates the locations and dimensions of the windows for each position update. Since these position updates occur in real time, many times each second, the invention provides the means for the AGV system's controller to prevent collisions between the AGVs and other objects without minimizing the degrees of freedom of AGV movement.

Abstract: A communication system for a mobile apparatus includes a means for communicating commanded destination to the mobile apparatus. The mobile apparatus includes a plurality of beacons that are used for both communicating with a master station and as a means of locating the mobile apparatus by the master station. The location of the mobile apparatus is used to generate commands which are transmitted to the mobile apparatus by light emitting diodes such that the light emitting diodes mounted on the mobile apparatus are used for both navigation purposes and communication.