Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from parts through vibration of the powder, the parts, and/or structures mechanically connected to the powder and/or parts. For instance, the application of vibration may dislodge, aerate and/or otherwise increase the flowability of regions of the powder, thereby making it easier to remove the powder with a suitable means. Techniques for depowdering through vibration may be automated, thereby mitigating challenges associated with manual depowdering operations.

Abstract: Techniques for depowdering additively fabricated parts are described. The techniques utilize various mechanisms to separate powder from parts. For instance, techniques for depowdering described herein may include fabrication of auxiliary structures in addition to fabrication of parts. Certain auxiliary structures may aid with depowdering operations, and may be fabricated along with parts during an additive fabrication process. The auxiliary structures may be shaped and/or have positional and/or geometrical relationships to the parts during fabrication. For instance, an auxiliary structure may include a cage structure fabricated around one or more parts.

Abstract: Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from parts through vibration of the powder, the parts, and/or structures mechanically connected to the powder and/or parts. For instance, the application of vibration may dislodge, aerate and/or otherwise increase the flowability of regions of the powder, thereby making it easier to remove the powder with a suitable means. Techniques for depowdering through vibration may be automated, thereby mitigating challenges associated with manual depowdering operations.

Abstract: A build box associated with a powder bed fabrication system may comprise a housing defining a housing cavity, and a powder print bed disposed within the housing cavity. The powder print bed may be characterized by state information. The build box may further comprise a medium configured to facilitate access to the state information, and a coupling interface for removably engaging the build box with at least one subsystem of the powder bed fabrication system. The state information may comprise one or more state information elements of object identification, object location, current processing state, next subsystem processing step, previous subsystem processing step, object model information, object material composition, and current powder print bed temperature profile. The medium may comprise a memory device coupled with a transceiver. The medium may alternatively comprise an RFID device, or an optically perceivable designator, such as a bar code or QR code.

Abstract: Techniques for providing a signal processing feature in an inventory management system are described herein. For example, instructions may be received by a computer system of an autonomous vehicle that identify a path to move inventory within a materials handling facility. Further, the computer system of the autonomous vehicle may reduce a current traveling speed of the autonomous vehicle in response to receiving a first signal that is provided by a transmitter coupled with an entity moving within the materials handling facility. The first signal may be span a first distance. In embodiments, the computer system of the autonomous vehicle may stop movement of the autonomous vehicle in response to receiving a second signal provided by the transmitter coupled with the entity. The second signal may span a second distance from the entity that is less than the first distance.

Abstract: An additive manufacturing method including depositing a first amount of metal powder on a print bed, the first amount metal powder forming a first layer, depositing a first binder component to the first layer in a first region, and depositing a second binder component to the first layer in a second region.

Abstract: A system for de-powdering one or more objects within a powder print bed comprises a build box configured to contain the powder print bed, and a de-powdering subsystem configured to engage the build box. The de-powdering subsystem comprises a vacuum device configured to withdraw loose powder agitated by the air jet device, and a robotic arm configured to convey the vacuum device to one or more locations on the powder print bed. The system may further comprise an air jet device disposed on the robotic arm, the air jet device configured to agitate, with a jet of air, unbound powder within the powder print bed. The system may further comprise a mechanical agitation instrument configured to facilitate agitation of the unbound powder within the powder print bed. The mechanical agitation instrument may be used in conjunction with one or both of the vacuum device and the air jet device.

Abstract: A system for separating objects within a stacked powder print bed of nested objects comprises a build box configured to contain the powder print bed. The build box has a build box top and a build box floor. The system further includes an elongated aperture formed in a side wall of the build box, and a de-powdering subsystem configured to mechanically and electrically engage the build box. A separating blade associated with the de-powdering subsystem is configured to be inserted through the elongated aperture and into the powder print bed between a top-most print bed layer of the nested objects and a second print bed layer directly below and contiguous with the top-most layer, thereby forming an isolated powder print bed between the separating blade and the build box top. The unbound powder may be agitated by various techniques and subsequently removed from the objects.

Abstract: An inventory system includes an inventory holder and an actively balanced mobile drive unit. A control module of the mobile drive unit can receive sensing information about the inventory holder and/or the mobile drive unit and use the sensing information to control a drive module of the mobile drive unit so as to maintain the inventory holder and/or the mobile drive unit within a predetermined deviation amount from an equilibrium state.

Abstract: Techniques for providing a signal processing feature in an inventory management system are described herein. For example, instructions may be received by a computer system of an autonomous vehicle that identify a path to move inventory within a materials handling facility. Further, the computer system of the autonomous vehicle may reduce a current traveling speed of the autonomous vehicle in response to receiving a first signal that is provided by a transmitter coupled with an entity moving within the materials handling facility. The first signal may be span a first distance. In embodiments, the computer system of the autonomous vehicle may stop movement of the autonomous vehicle in response to receiving a second signal provided by the transmitter coupled with the entity. The second signal may span a second distance from the entity that is less than the first distance.

Abstract: Robotic arms or manipulators can be utilized to grasp inventory items within an inventory system. Information can be obtained about constraints relative to relevant elements of a process of transferring the item from place to place. Examples of such elements may include a grasping location from which an item is to be grasped, a receiving location in which a grasped item is to be placed, or a space between the grasping location and the receiving location. The information about the constraints can be used to select from multiple possible grasping options, such as by eliminating options that conflict with the constraints or preferring options that outperform others given the constraints.

Abstract: Techniques for providing an entity monitoring safety feature in an inventory management system are described herein. For example, instructions may be received by a computer system of an autonomous vehicle that identify a path to move inventory within a materials handling facility. Further, the computer system of the autonomous vehicle may reduce a current traveling speed of the autonomous vehicle in response to receiving a first signal that is provided by a transmitter coupled with an entity moving with the materials handling facility. The first signal may be provided up to a first distance from the entity. In embodiments, the computer system of the autonomous vehicle may stop movement of the autonomous vehicle in response to receiving a second signal provided by the transmitter coupled with the entity. The second signal may be provided up to a second distance from the entity that is less than the first distance.

Abstract: A system for de-powdering one or more objects within a powder print bed comprises a build box configured to contain the powder print bed, and a de-powdering subsystem configured to engage the build box. The de-powdering subsystem comprises a vacuum device configured to withdraw loose powder agitated by the air jet device, and a robotic arm configured to convey the vacuum device to one or more locations on the powder print bed. The system may further comprise an air jet device disposed on the robotic arm, the air jet device configured to agitate, with a jet of air, unbound powder within the powder print bed. The system may further comprise a mechanical agitation instrument configured to facilitate agitation of the unbound powder within the powder print bed.

Abstract: Features are disclosed for a mobile drive unit and systems including mobile drive units that eliminate the need for dedicated lifting motors. The mobile drive unit arrangements described leverage existing motors used to drive the rolling elements (e.g., wheels) of the mobile drive unit to perform the lifting. For example, a mobile drive unit may include four locomotion motors. Because each motor can be individually controlled, the distance between front and rear (or left and right) rolling elements can be used to actuate mechanisms for lifting payloads without requiring a dedicated lifting motor.

Abstract: A robot equipped with an object detection system and an object identification system is used to move inventory holders throughout a warehouse or other environment. The robot can detect objects in its path using the object detection system, which can include one or more sensors for this purpose. The robot can then classify the object using the object identification system to determine an appropriate course of action. The robot can classify the object as an inventory item, warehouse equipment, or a person, among other things. The robot can take action based on the object classification. The robot can reroute around inventory items and warehouse equipment. When encountering people or objects that cannot be classified, the robot can stop and await further instructions. In some cases, the robot may wait for a manual reset before continuing along its path.

Abstract: A build box associated with a powder bed fabrication system may comprise a housing defining a housing cavity, and a powder print bed disposed within the housing cavity. The powder print bed may be characterized by state information. The build box may further comprise a medium configured to facilitate access to the state information, and a coupling interface for removably engaging the build box with at least one subsystem of the powder bed fabrication system. The state information may comprise one or more state information elements of object identification, object location, current processing state, next subsystem processing step, previous subsystem processing step, object model information, object material composition, and current powder print bed temperature profile. The medium may comprise a memory device coupled with a transceiver. The medium may alternatively comprise an RFID device, or an optically perceivable designator, such as a bar code or QR code.

Abstract: A system for separating objects within a stacked powder print bed of nested objects comprises a build box configured to contain the powder print bed. The build box has a build box top and a build box floor. The system further includes an elongated aperture formed in a side wall of the build box, and a de-powdering subsystem configured to mechanically and electrically engage the build box. A separating blade associated with the de-powdering subsystem is configured to be inserted through the elongated aperture and into the powder print bed between a top-most print bed layer of the nested objects and a second print bed layer directly below and contiguous with the top-most layer, thereby forming an isolated powder print bed between the separating blade and the build box top. The unbound powder may be agitated by various techniques and subsequently removed from the objects.

Abstract: Disclosed are various embodiments for an integrated obstacle detection and payload centering sensor system. A robotic drive unit (RDU) captures, with a downward facing camera mounted to itself, an image of fiducial located on the ground. The RDU then positions itself over the fiducial and subsequently rotates. As it rotates, the RDU captures a point cloud of the surround vicinity a forward-facing three-dimensional camera mounted to itself. The RDU then identifies in the point cloud at least two legs of a storage unit positioned over the robotic drive unit. Subsequently, the RDU determines a location for each of the at least two legs relative to the fiducial and triangulates a center of the storage unit based at least in part on the location of each of the at least two legs. The RDU then centers itself underneath the storage unit.

Abstract: Robotic arms or manipulators can be utilized to grasp inventory items within an inventory system. Information can be obtained about constraints relative to relevant elements of a process of transferring the item from place to place. Examples of such elements may include a grasping location from which an item is to be grasped, a receiving location in which a grasped item is to be placed, or a space between the grasping location and the receiving location. The information about the constraints can be used to select from multiple possible grasping options, such as by eliminating options that conflict with the constraints or preferring options that outperform others given the constraints.

Abstract: Features are disclosed for a mobile drive unit and systems including mobile drive units that eliminate the need for dedicated lifting motors. The mobile drive unit arrangements described leverage existing motors used to drive the rolling elements (e.g., wheels) of the mobile drive unit to perform the lifting. For example, a mobile drive unit may include four locomotion motors. Because each motor can be individually controlled, the distance between front and rear (or left and right) rolling elements can be used to actuate mechanisms for lifting payloads without requiring a dedicated lifting motor.