Tilting platform for stability control

Patent metadata

Field	Value
Publication number	US-2016375813-A1
Application number	US-201514750676-A
Country	US
Kind code	A1
Filing date	Jun 25, 2015
Priority date	Jun 25, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

A mobile drive unit including a docking head assembly is provided. The docking head assembly is configured with two or more actuator assemblies to lift an inventory holder and tilt the inventory holder in two or more directions. The direction of tilt and an associated angle may be determined based on a location of a center of gravity of the inventory holder relative to the mobile drive unit. The direction of tilt and the associated angle may also be determined based on information describing external forces acting on the inventory holder.

First claim

What is claimed is:

1 . A system, comprising:
an inventory holder comprising one or more compartments holding one or more inventory items; and a mobile drive unit comprising:
a base;
a docking head assembly comprising:
a platform moveably attached to the base via a first actuator assembly and a second actuator assembly, the first actuator assembly configured to raise and lower a front portion of the platform and the second actuator assembly configured to raise and lower a rear portion of the platform;
a plurality of sensors disposed about a top surface of the platform; and

a management module configured to:
instruct the first actuator assembly and the second actuator assembly to raise the platform into engagement with the inventory holder and to lift the inventory holder in an initial orientation;
receive sensing information from the plurality of sensors, the sensing information indicating a plurality of relative forces exerted by the inventory holder on the top surface of the platform when the inventory holder is detachably coupled to the mobile drive unit via the platform;
determine, based at least in part on the sensing information, a location of a center of gravity of the inventory holder; and
instruct, based at least in part on the location of the center of gravity, at least one of the first actuator assembly or the second actuator assembly to raise or lower the platform relative to the base to an adjusted orientation, the adjusted orientation being distinct from the initial orientation and comprising a translation of the location of the center of gravity of the inventory holder relative to the base.

2 . The system of claim 1 , wherein the management module is further configured to determine, based at least in part on the location of the center of gravity, an angle of rotation for the platform of the docking head assembly, the angle of rotation comprising a rotation of the platform from the initial orientation to the adjusted orientation.

3 . The system of claim 2 , wherein instructing, based at least in part on the location of the center of gravity, at least one of the first actuator assembly or the second actuator assembly comprises instructing, based at least in part on the angle of rotation, at least one of the first actuator assembly or the second actuator assembly.

4 . The system of claim 1 , wherein the mobile drive unit further comprises a drive motor, and wherein the management module is further configured to:
instruct the drive motor to move the inventory holder along a surface; in response to the drive motor moving the inventory holder along the surface, receive updated sensing information from the plurality of sensors; determine, based at least in part on the updated sensing information, an updated location of the center of gravity of the inventory holder; and instruct, based at least in part on the updated location of the center of gravity, at least one of the first actuator assembly or the second actuator assembly to raise or lower the platform relative to the base to an updated adjusted orientation, the updated adjusted orientation being distinct from the initial orientation and the adjusted orientation.

5 . The system of claim 4 , wherein the updated location of the center of gravity is distinct from the location of the center of gravity as a result of at least one of the one or more inventory items shifting within the inventory holder, at least one inventory item being added to the inventory holder, or at least one of the one or more inventory items being removed from the inventory holder.

6 . A system, comprising:
an inventory holder comprising one or more compartments holding one or more inventory items; and a mobile drive unit comprising:
a docking head assembly comprising:
a platform; and
a plurality of actuator assemblies, the platform moveably attached to the mobile drive unit via the plurality of actuator assemblies, individual actuator assemblies configured to raise and lower respective portions of the platform; and

a management module configured to:
instruct the plurality of actuator assemblies to detachably couple the mobile drive unit to the inventory holder via the platform and move the platform to a first orientation;
receive information indicating a location of a center of gravity of the inventory holder; and
instruct, based at least in part on the location of the center of gravity, at least one of the plurality of actuator assemblies to raise or lower a portion of the platform relative to other portions of the platform to a second orientation, the second orientation comprising a translation of the location of the center of gravity of the inventory holder relative to the mobile drive unit.

7 . The system of claim 6 , wherein the docking head assembly comprises one or more sensors configured to provide sensing information at least when the inventory holder is detachably coupled to the mobile drive unit via the platform, and wherein receiving the information comprises receiving the sensing information.

8 . The system of claim 7 , wherein the one or more sensors are disposed about a top surface of the platform, and wherein the sensing information indicates one or more relative pressures or relative forces exerted by the inventory holder on the top surface of the platform when the inventory holder is detachably coupled to the mobile drive unit via the platform.

9 . The system of claim 7 , wherein the one or more sensors are configured to measure displacement of the individual actuator assemblies of the plurality of actuator assemblies, and wherein the sensing information indicates the displacement of the individual actuator assemblies when the inventory holder is detachably coupled to the mobile drive unit via the platform.

10 . The system of claim 6 , wherein the information comprises inventory location information indicating locations of the one or more inventory items within the one or more compartments of the inventory holder.

11 . The system of claim 6 , wherein the plurality of actuator assemblies comprise two or more scissor actuator assemblies, a first scissor actuator assembly of the two or more scissor actuator assemblies being configured to raise and lower a front portion of the platform relative to a rear portion of the platform, a second scissor actuator assembly of the two or more scissor actuator assemblies being configured to raise and lower the rear portion of the platform relative to the front portion of the platform.

12 . The system of claim 6 , wherein the plurality of actuator assemblies comprise three or more linear actuator assemblies configured to raise or lower respective portions of the platform relative to other portions of the platform to cause the platform to tilt in at least one of a forward direction, a backward direction, or a sideward direction.

13 . The system of claim 6 , wherein the docking head assembly comprises a track bar that is attached to the platform and a base of the mobile drive unit, the track bar at least providing lateral stability for the platform.

14 . The system of claim 6 , wherein the management module is further configured to determine, based at least in part on the location of the center of gravity, an angle of rotation for the platform of the docking head assembly, the angle of rotation comprising a rotation of the platform from the first orientation to the second orientation.

15 . A mobile drive unit, comprising:
a drive motor; a docking head assembly comprising:
a platform; and
a plurality of actuator assemblies, the platform moveably attached to the mobile drive unit

Assignees

• Amazon Tech Inc

Inventors

• Colantonio Peter Thomas
• Katz Allan Andrew
• Wellman Parris S

Classifications

• B66F9/065

  non-masted (mobile jacks of the garage type mounted on wheels or rollers B66F5/00) · CPC title

• A47F5/0018

  Display racks with shelves or receptables (racks per se A47B; storage devices for warehouses B65G1/02) · CPC title

• B60P1/02 Primary

  with parallel up-and-down movement of load supporting or containing element (in combination with tipping B60P1/34; devices for lifting or lowering bulky or heavy goods for loading or unloading purposes, movable on wheels or the like, e.g. fork-lift trucks, B66F9/06 {; suspensions with electronic levelling control during loading or unloading B60G17/0157}) · CPC title

• G06Q10/087

  Inventory or stock management, e.g. order filling, procurement or balancing against orders · CPC title

• G06Q10/08726

  for replenishment processing, procedures, or recommendations using forecasting or optimisation · CPC title