Tilting platform for stability control

Patent metadata

Field	Value
Publication number	US-9731641-B2
Application number	US-201715418540-A
Country	US
Kind code	B2
Filing date	Jan 27, 2017
Priority date	Jun 25, 2015
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A mobile drive unit including a docking head assembly is provided. The docking head assembly is configured with a set of actuator assemblies to lift an holder structure and tilt the holder structure in at least one direction. The direction of tilt and an associated angle may be determined based on a location of a center of gravity of the holder structure 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 holder structure.

First claim

What is claimed is:

1. A mobile drive unit, comprising:
a frame;
a docking head assembly comprising:
a platform moveably attached to the frame via a set of actuator assemblies that is configured to raise and lower the platform and to tilt the platform; and
a sensor disposed at or adjacent to a top surface of the platform; and

a management module configured to:
receive sensing information from the sensor after the set of actuator assemblies has raised the platform so as to lift a holder structure into an initial orientation, the sensing information indicating at least one force exerted by the holder structure on the top surface of the platform when the holder structure is in the initial orientation;
determine, based at least in part on the sensing information, one or more characteristics of a load of the holder structure; and
cause, based at least in part on the one or more characteristics of the load, at least one actuator assembly of the set of actuator assemblies to tilt the platform into an adjusted orientation, the adjusted orientation being distinct from the initial orientation.

2. The mobile drive unit of claim 1 , wherein the management module is further configured to determine, based at least in part on the one or more characteristics of the load, a tilting angle for tilting the platform from the initial orientation to the adjusted orientation.

3. The mobile drive unit of claim 2 , wherein causing the at least one actuator assembly to tilt the platform comprises causing the at least one actuator assembly to tilt the platform based at least in part on the tilting angle.

4. The mobile drive unit of claim 1 , further comprising a drive motor, and wherein the management module is further configured to:
cause the drive motor to move the holder structure along a surface;
in response to the drive motor moving the holder structure along the surface, receive updated sensing information from the sensor;
determine, based at least in part on the updated sensing information, one or more updated characteristics of the load the holder structure; and
cause, based at least in part on the one or more updated characteristics, the at least one actuator assembly to tilt the platform to an updated adjusted orientation, the updated adjusted orientation being distinct from the initial orientation and the adjusted orientation.

5. The mobile drive unit of claim 1 , wherein the one or more characteristics comprise a location of a center of gravity of the holder structure.

6. A computer-implemented method, comprising:
causing a docking head assembly of a mobile drive unit to couple with a holder structure by adjusting a set of actuator assemblies of the docking head assembly to raise a platform of the docking head assembly into a first orientation in which the platform supports the holder structure;
receiving information indicating a load of the holder structure; and
causing, based at least in part on the load, the docking head assembly to tilt the holder structure by adjusting at least one actuator assembly to raise or lower a portion of the platform relative to other portions of the platform into a second orientation that is distinct from the first orientation.

7. The computer-implemented method of claim 6 , wherein the docking head assembly comprises one or more sensors configured to provide sensing information at least when the holder structure is coupled to the mobile drive unit via the platform, and wherein the information comprises the sensing information.

8. The computer-implemented method 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 holder structure on the top surface of the platform when the holder structure is coupled to the mobile drive unit via the platform.

9. The computer-implemented method of claim 7 , wherein the one or more sensors are configured to measure displacement of the at least one actuator assembly, and wherein the sensing information indicates the displacement of the at least one actuator assembly when the holder structure is detachably coupled to the mobile drive unit via the platform.

10. The computer-implemented method of claim 6 , wherein the information comprises item location information identifying locations of one or more items stowed in the holder structure.

11. The computer-implemented method of claim 6 , wherein the set of actuator assemblies comprises a first scissor actuator assembly and a second scissor actuator assembly, the first scissor actuator assembly configured to raise and lower a front portion of the platform relative to a rear portion of the platform, the second scissor actuator assembly configured to raise and lower the rear portion of the platform relative to the front portion of the platform.

12. The computer-implemented method of claim 6 , wherein the set of actuator assemblies comprises 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 computer-implemented method of claim 6 , wherein the docking head assembly comprises a track bar that is attached to the platform and a frame of the mobile drive unit, the track bar at least providing lateral stability for the platform.

14. The computer-implemented method of claim 6 , further comprising determining, based at least in part on the load, a tilting angle for tilting the platform, the tilting angle 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 configured to tilt the platform in at least one direction; and
a management module configured to:
cause the drive motor to move along a surface when the mobile drive unit is supporting a holder structure via the platform, the holder structure configured to hold one or more items;
receive information regarding the one or more items held in the holder structure;
determine, based at least in part on the information, an angular adjustment for the platform; and
cause the docking head assembly to perform the angular adjustment by raising or lowering at least one portion of the platform, the angular adjustment changing an angle of the platform relative to the mobile drive unit.

16. The mobile drive unit of claim 15 , wherein:
the management module is further configured to identify a location of a center of gravity of the holder structure based at least in part on the information; and
determining the angular adjustment comprises determining the angular adjustment based at least in part on the location of the center of gravity.

17. The mobile drive unit of claim 15 , wherein the information comprises:
mass information identifying a mass value of the one or more items; and
item location information identifying locations of the one or more items with respect to the holder structure.

18. The mobile drive unit of claim 15 , wherein causing the docking head assembly to perform the angular adjustment comprises causing the docking head assembly to perform an adjustment to an orientation of a center of gravity of the holder structure with respect to the mobile drive unit.

19. The mobile drive unit of claim 15 , wherein:
the management module is further configured to receive movem

Assignees

• Amazon Tech Inc

Inventors

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

Classifications

• 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

• B66F9/065

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

• G06Q10/087

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

• G05D1/021

  specially adapted to land vehicles · CPC title