System and method for maneuvering a mobile drive unit

1. A mobile drive unit for transporting an inventory holder, the mobile drive unit comprising:

at least a first actuator that moves the mobile drive unit and the inventory holder in a first translational direction, wherein the mobile drive unit is operable to dock with the inventory holder; and

at least a second actuator that, while the mobile drive unit is docked with the inventory holder, selectively rotates the inventory holder while the mobile drive unit and the inventory holder continue to move in the first translational direction.

2. The mobile drive unit of claim 1 , the mobile drive unit further operable to rotate in a first rotational direction while selectively rotating the inventory holder in a second rotational direction.

3. The mobile drive unit of claim 2 , the mobile drive unit further operable to rotate in the first rotational direction by an amount calculated to cause the mobile drive unit to change from the first translational direction to a second translational direction.

4. The mobile drive unit of claim 2 , wherein the first and second rotational directions are different.

5. The mobile drive unit of claim 1 , the mobile drive unit further operable to rotate in a first rotational direction at a first rate of movement while selectively rotating the inventory holder in a second rotational direction at a second rate of movement, wherein the first rate of movement and the second rate of movement are different.

6. The mobile drive unit of claim 1 , wherein the inventory holder comprises a first face that is orthogonal to the first translational direction and the mobile drive unit is further operable to:

while continuing translational movement, rotate to a second translational direction while the first face of the inventory holder remains orthogonal to the first translational direction.

7. The mobile drive unit of claim 1 , the mobile drive unit further operable to reserve a space for rotation along a path of the mobile drive unit, wherein the space for rotation is reserved based on a physical dimension of the inventory holder.

8. The mobile drive unit of claim 7 , the mobile drive unit further operable to selectively rotate the inventory holder while continuing to move in the first translational direction while moving through the reserved space for rotation.

9. The mobile drive unit of claim 1 , the mobile drive unit further operable to:

receive a request to present a selected face of the inventory holder to an inventory station; and

while moving, selectively rotate the inventory holder by an amount calculated to present the selected face to the inventory station.

10. The mobile drive unit of claim 1 , the mobile drive unit further operable to:

move to a location of the inventory holder;

dock with the inventory holder at the location;

move the inventory holder to a destination;

undock with the inventory holder at the destination; and

move away from the inventory holder.

11. The mobile drive unit of claim 1 , the mobile drive unit further comprising a docking head; and

the mobile drive unit is further operable to selectively rotate the inventory holder by independently rotating the docking head, the docking head coupling the inventory holder to the mobile drive unit.

12. An inventory system comprising:

an inventory holder comprising a plurality of sides, each side configured to store one or more inventory items;

a mobile drive unit comprising a self-powered robotic device configured to move independently within a workspace and operable to transport the inventory holder;

a management module operable to transmit wireless information to the mobile drive unit;

the mobile drive unit operable to:

receive the wireless information from the management module, the wireless information comprising a first instruction to transport the inventory holder to a remote inventory station and a second instruction to present a selected side of the inventory holder to the inventory station;

in response to receiving the wireless information, initiate transportation of the inventory holder towards the inventory station in a first translational direction and, while moving towards the inventory station in the first translational direction, performing a rotation maneuver calculated to orient the selected side of the inventory holder towards the inventory station.

13. The system of claim 12 , wherein the mobile drive unit is further operable to wirelessly transmit a request to reserve a space to perform the rotation maneuver while traveling along a path towards the inventory station.

14. The system of claim 12 , wherein the mobile drive unit executes the rotation maneuver in response to receiving a reservation grant of the space to perform the rotation maneuver and determining that the mobile drive unit is within the space.

15. The system of claim 12 , wherein the rotation maneuver comprises selectively rotating a docking head of the mobile drive unit that rotates the inventory holder independently of movement in the first translational direction of the mobile drive unit.

16. The system of claim 12 , wherein the mobile drive unit further comprises:

a first actuator operable to control movement in the first translational direction of the mobile drive unit by controlling one or more wheels mounted on the mobile drive unit; and

a second actuator operable to:

control a lifting mechanism connected to a docking head of the mobile drive unit, the second actuator operable to cause the mobile drive unit to lift the docking head against a lower surface of the inventory holder thereby lifting the inventory holder; and

rotate the docking head while the inventory holder is lifted and while the first actuator is causing the movement in the first translational direction of the mobile drive unit.