Abstract: An automatic guided vehicle (AGV) system for automatically transporting loads along a predetermined path is provided. The improvement includes a plurality of embedded magnets distant from one another, wherein at least a portion of the plurality of embedded 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 having a plurality of sensors, the sensor system configured for guidance of the AGV based upon simultaneous reading of the embedded magnets under the plurality of sensors, such that a position of the AGV with respect to the sensors can be repeatedly determined with respect to magnetic field peaks of the embedded magnets, and fine positioning markers.

Abstract: A method and apparatus for controlling gaps between articles traveling on a conveyor system includes providing a plurality of tandem conveying surfaces defining a series of sequentially arranged conveying surface interfaces. At least one of the conveying surfaces associated with each of said conveying surface interfaces is an adjustable-speed conveying surface. At least one article sensor is provided adjacent at least one of the conveying surface interfaces. The article sensor provides information on positions of the articles. The speeds of the tandem conveying surfaces are controlled in a manner that establishes controlled gaps between articles, by identifying a controllable gap that can be adjusted between articles at a particular conveying surface interface and adjusting the controllable gap at the particular conveying surface interface.

Abstract: A control architecture for material handling includes multiple tiers of controllers, such as three. The lowest-level controllers interact directly with sensors and actuators used in the material handling system, such as photo-eyes and motors used with conveyors. The lowest-level controllers receive higher level commands from one or more mid-level controllers. The mid-level controllers, in turn, receive still higher level commands and information from at least one upper level controller. Each mid and low level controller is designed to include sufficient intelligence to deal with many of the signals and messages it receives without having to forward those signals or messages to the next higher level controller and await instructions from that higher level controller. The system thus distributes intelligence amongst the controllers. The system is well-adapted for application to conveyor control systems.

Abstract: An induction subsystem for a conveyor sortation system and method of inducting articles includes providing a plurality of tandem conveying surfaces. The speeds of the conveying surfaces are individually controllable. At least one sensor is provided for sensing articles on at least one of the conveying surfaces. A control is responsive to the at least one sensor for controlling the speeds of said conveying surfaces in a manner that controls relative positions of articles. The control defines a plurality of feedback-gapping algorithms. Each of the feedback-gapping algorithms is defined between adjacent conveying surfaces for adjusting relative speeds of those adjacent conveying surfaces as a function of at least one parameter of the articles. The control controls relative positions of articles with the feedback-gapping algorithms beginning with a pair of adjacent conveying surfaces and cascading through adjacent pairs of adjacent conveying surfaces.

Abstract: A control architecture for material handling includes multiple tiers of controllers, such as three. The lowest-level controllers interact directly with sensors and actuators used in the material handling system, such as photo-eyes and motors used with conveyors. The lowest-level controllers receive higher level commands from one or more mid-level controllers. The mid-level controllers, in turn, receive still higher level commands and information from at least one upper level controller. Each mid and low level controller is designed to include sufficient intelligence to deal with many of the signals and messages it receives without having to forward those signals or messages to the next higher level controller and await instructions from that higher level controller. The system thus distributes intelligence amongst the controllers. The system is well-adapted for application to conveyor control systems.

Abstract: A conveyor system, such as an induction subsystem for supplying articles to a sortation subsystem, and method of conveying articles includes providing a conveying surface for conveying a series of articles and at least one sensor for sensing the articles on the conveying surface. A control is provided which establishes at least one parameter for each of the articles and controls the conveying surface as a function of the at least one parameter of each of the articles. The control includes a computer and a program for the computer. The program includes at least one probability estimator. The control determines the at least one parameter of each of the articles at least in part by the at least one probability estimator. The control controls gaps between articles or synchronizes arrival of articles at the sortation system.

Abstract: A positive displacement sorter apparatus and method includes providing a plurality of slats being interconnected in an endless web, an upper run of the web defining a conveying surface, and a plurality of pusher shoes gliding along at least some of the slats to laterally displace articles on the conveying surface. A linear motor system is provided to propel the web and includes a plurality of linear motor secondaries at the slats and at least one primary for propelling the secondaries. A control system controls the primaries.

Abstract: A control architecture for material handling includes multiple tiers of controllers, such as three. The lowest-level controllers interact directly with sensors and actuators used in the material handling system, such as photo-eyes and motors used with conveyors. The lowest-level controllers receive higher level commands from one or more mid-level controllers. The mid-level controllers, in turn, receive still higher level commands and information from at least one upper level controller. Each mid and low level controller is designed to include sufficient intelligence to deal with many of the signals and messages it receives without having to forward those signals or messages to the next higher level controller and await instructions from that higher level controller. The system thus distributes intelligence amongst the controllers. The system is well-adapted for application to conveyor control systems.

Abstract: A positive displacement sorter apparatus and method includes providing a plurality of slats being interconnected in an endless web, an upper run of the web defining a conveying surface, and a plurality of pusher shoes gliding along at least some of the slats to laterally displace articles on the conveying surface. A linear motor system is provided to propel the web and includes a plurality of linear motor secondaries at the slats and at least one primary for propelling the secondaries. A control system controls the primaries.

Abstract: A positive displacement sorter apparatus and method includes providing a plurality of slats being interconnected in an endless web, an upper run of the web defining a conveying surface, and a plurality of pusher shoes gliding along at least some of the slats to laterally displace articles on the conveying surface. A linear motor system is provided to propel the web and includes a plurality of linear motor secondaries at the slats and at least one primary for propelling the secondaries. A control system controls the primaries.

Abstract: A material handling system uses high-frequency location devices for determining the location of mobile units, such as AGVs, overhead mono-rails, conveyor components, or individual articles being transported by such units. The high-frequency location devices may also be used to identify the contents and/or routing information for material being moved within a facility. AGVs may incorporate the high-frequency location devices into their navigation systems to utilize the position and/or heading updates provided by the location devices in guiding the vehicle. The location devices work in cooperation with a number of stationary location devices, such as beacons, that are positioned within the environment at known locations, such as in or adjacent the ceiling of the workplace environment. High-frequency radars may also be used to provide electronic bumpers to the AGVs, allowing them to sense obstacles and take appropriate action to avoid collisions with the obstacles.

Abstract: A positive displacement sorter apparatus and method includes providing a plurality of slats being interconnected in an endless web, an upper run of the web defining a conveying surface, and a plurality of pusher shoes gliding along at least some of the slats to laterally displace articles on the conveying surface. A linear motor system is provided to propel the web and includes a plurality of linear motor secondaries at the slats and at least one primary for propelling the secondaries. A control system controls the primaries.

Abstract: A method and apparatus for controlling the steering of an automatic guided vehicle (AGV) includes simultaneously correcting the vehicle's heading and position errors. The vehicle may include first and second steering control loops that determine the vehicle's position and heading errors, respectively. Separate commands are generated from these control loops to steer the vehicle in a manner that tends to reduce these errors. The vehicle may include a forward and a rearward pair of wheels. For correcting position errors, the first control loop issues the same steering command to both the forward and rearward pair of wheels. For correcting heading errors, the second control loop issues a steering command to the rearward pair of wheels that is summed together with the first control loop's steering command prior to being applied to the rearward pair of wheels.

Abstract: A conveyor induct system includes a control point subsystem for measuring the point at which control of an article transitions from one conveyor to another. The induct system also includes a subsystem for accurately creating or controlling the gaps between articles on the conveyor system. The control point subsystem monitors the location, and changes in the speed, of an article as it passes between two conveyors operating at different speeds. The gap control subsystem provides real time monitoring and measuring of the package gaps. The measured package gaps are fed into a feedback control system which alters the speed of a conveyor in order to change the gapping as desired.

Abstract: A conveyor induct system includes a control point subsystem for measuring the point at which control of an article transitions from one conveyor to another. The induct system also includes a subsystem for accurately creating or controlling the gaps between articles on the conveyor system. The control point subsystem monitors the location, and changes in the speed, of an article as it passes between two conveyors operating at different speeds. The gap control subsystem provides real time monitoring and measuring of the package gaps. The measured package gaps are fed into a feedback control system which alters the speed of a conveyor in order to change the gapping as desired.

Abstract: A method and apparatus for sorting objects includes providing a sorter having a conveying surface, a plurality of pusher shoes capable of traveling laterally of the conveying surface, a plurality of diverting rails extending diagonally under the conveying surface, and a plurality of diverters associated with the diverting rails. The pusher shoes including an article-contacting member extending at least partially above the conveying surface to laterally displace articles on the conveying surface and a transfer assembly having a magnetic member below the conveying surface. The transfer assembly engages ones of the diverting rails to laterally displace the corresponding one of the pusher shoes. Actuators are provided at the diverters. The actuators are selectively energized to attract at least one of the magnetic members towards the associated one of the diverting rails. Residual magnetic attraction between the actuators and the magnetic members is reduced when the actuators are not being energized.

Abstract: A material handling system uses high-frequency location devices for determining the location of mobile units, such as AGVs, overhead mono-rails, conveyor components, or individual articles being transported by such units. The high-frequency location devices may also be used to identify the contents and/or routing information for material being moved within a facility. AGVs may incorporate the high-frequency location devices into their navigation systems to utilize the position and/or heading updates provided by the location devices in guiding the vehicle. The location devices work in cooperation with a number of stationary location devices, such as beacons, that are positioned within the environment at known locations, such as in or adjacent the ceiling of the workplace environment. High-frequency radars may also be used to provide electronic bumpers to the AGVs, allowing them to sense obstacles and take appropriate action to avoid collisions with the obstacles.

Abstract: A control architecture for material handling includes multiple tiers of controllers, such as three. The lowest-level controllers interact directly with sensors and actuators used in the material handling system, such as photo-eyes and motors used with conveyors. The lowest-level controllers receive higher level commands from one or more mid-level controllers. The mid-level controllers, in turn, receive still higher level commands and information from at least one upper level controller. Each mid and low level controller is designed to include sufficient intelligence to deal with many of the signals and messages it receives without having to forward those signals or messages to the next higher level controller and await instructions from that higher level controller. The system thus distributes intelligence amongst the controllers. The system is well-adapted for application to conveyor control systems.

Abstract: A method and apparatus for controlling the steering of an automatic guided vehicle (AGV) includes simultaneously correcting the vehicle's heading and position errors. The vehicle may include first and second steering control loops that determine the vehicle's position and heading errors, respectively. Separate commands are generated from these control loops to steer the vehicle in a manner that tends to reduce these errors. The vehicle may include a forward and a rearward pair of wheels. For correcting position errors, the first control loop issues the same steering command to both the forward and rearward pair of wheels. For correcting heading errors, the second control loop issues a steering command to the rearward pair of wheels that is summed together with the first control loop's steering command prior to being applied to the rearward pair of wheels.

Abstract: A positive displacement sorter apparatus and method includes providing a plurality of slats being interconnected in an endless web, an upper run of the web defining a conveying surface, and a plurality of pusher shoes gliding along at least some of the slats to laterally displace articles on the conveying surface. A linear motor system is provided to propel the web and includes a plurality of linear motor secondaries at the slats and at least one primary for propelling the secondaries. A control system controls the primaries.