Abstract: A system for managing inventory items includes a portable inventory holder and an unmanned drive unit configured to move the inventory holder between locations in an inventory facility. The inventory facility includes a plurality of light emitting elements. The drive unit captures an image of a subset of the light emitting elements. The captured image is processed to determine the location of the drive unit within the facility. A path is determined along which the drive unit moves to an inventory holder and moves the inventory holder to another location. The light emitting elements can be provided by optical fibers embedded in the floor of the inventory facility.

Abstract: A system for managing inventory items includes a portable inventory holder and an unmanned drive unit configured to move the inventory holder between locations in an inventory facility. The inventory facility includes a plurality of uniquely identifiable fiducial markers having a small set of values distributed in a pattern. The drive unit captures at least one image of a subset of the plurality of the fiducial markers. The at least one captured image is processed to determine a location of the drive unit within the facility. A path is determined along which the drive unit moves to an inventory holder and moves the inventory holder to another location. The pattern of fiducial markers can include one or more repeated instances of uniquely identifiable fiducial markers. A fiducial marker can encode information using a readable code and at least one attribute of the fiducial marker.

Abstract: An inventory system has mobile drive units that freely and independently move about a facility to transport inventory holders. The mobile drive units may operate through communications with other drive units, or under a more centralized control of a management module. For various operating scenarios, the mobile drive units are directed to shuffle the inventory holders in a manner that minimizes travel of the mobile drive units, thereby improving overall system efficiency. One or more single mobile drive units may be used to transport inventory holders to and from a region, and one or more other mobile drive units may be used to reposition or slide each of the inventory holders back and forth within the region to efficiently place inventory holders before an operator on an as-needed basis.

Abstract: In an infrastructure that uses a mobile order fulfillment system, robotic drive units may be dispatched and instructed to bring inventory holders to a workstation where at least one of the inventory holders is packed and prepared for shipment. The robotic drive units are then instructed to move the prepared inventory holder to a transport vehicle such as a truck. Fiducial marks may be removably placed within the transport vehicle to aid navigation of the robotic drive units. At a destination facility, additional robotic drive units may be instructed to move the inventory holders from the truck and place the inventory holders at appropriate storage locations.

Abstract: In an infrastructure that uses a mobile order fulfillment system, robotic drive units may be dispatched and instructed to bring inventory holders to a workstation where at least one of the inventory holders is packed and prepared for shipment. The robotic drive units are then instructed to move the prepared inventory holder to a transport vehicle such as a truck. Fiducial marks may be removably placed within the transport vehicle to aid navigation of the robotic drive units. At a destination facility, additional robotic drive units may be instructed to move the inventory holders from the truck and place the inventory holders at appropriate storage locations.

Abstract: In an infrastructure that uses a mobile order fulfillment system, robotic drive units may be dispatched and instructed to bring inventory holders to a workstation where at least one of the inventory holders is packed and prepared for shipment. The robotic drive units are then instructed to move the prepared inventory holder to a transport vehicle such as a truck. Fiducial marks may be removably placed within the transport vehicle to aid navigation of the robotic drive units. At a destination facility, additional robotic drive units may be instructed to move the inventory holders from the truck and place the inventory holders at appropriate storage locations.

Abstract: A magazine lock for a firearm, the firearm having a grip, a magazine well, and a hammer, the magazine lock has a body sized and dimensioned to be removeably positioned within the magazine well of the firearm and a locking body retaining mechanism at least intermittently inhibiting removal of the body from the magazine well. The body, when positioned within the magazine well of the firearm, prevents at least one of the following: cocking the hammer of the firearm; removal of the firearm from a tether; removal of a key located inside the magazine well; and accessing any retaining member of the locking body retaining mechanism by disassembling the firearm grip. Unauthorized removal of the firearm can be accomplished by coupling the firearm to a less moveable object via a tether coupled to the firearm via the magazine lock. The firearm can be transported with a key for unlocking the magazine lock locked within the magazine well for later removal through the use of a second key.