Charging systems and methods for autonomous carts

Patent metadata

Field	Value
Publication number	US-11760221-B2
Application number	US-201816020232-A
Country	US
Kind code	B2
Filing date	Jun 27, 2018
Priority date	Jun 27, 2017
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

An autonomous robot moves materials in a warehouse or other industrial environment. It runs on an electric motor powered by a rechargeable battery. When its battery becomes depleted, it maneuvers to a nearby charger. It guides itself to the charger using visual cues, such as a target on or near the charger, until it establishes a good electrical connection with the charger. Proximity sensors on the charger and/or the autonomous robot determine if the autonomous robot is positioned properly; if so, the charger begins charging the autonomous robot's battery. While charging, the charger monitors the resistance of the electrical connection for open- or short-circuit conditions. It also monitors the status of the proximity sensors. If the charger detects an open-circuit or a short-circuit or that the autonomous robot has moved away from the charger, the charger stops charging.

First claim

The invention claimed is:

1. A charger for an autonomous robot, the charger comprising:
a power supply;
a sensor, operably coupled to power supply, to sense a position of the autonomous robot with respect to the charger;
a charging element, in electrical communication with the power supply, to charge the autonomous robot with power from the power supply in response to a signal from the sensor indicating that the autonomous robot is positioned to be charged by the charger;
a visual target, on or in proximity to the charger, wherein the visual target is a physical target that is used by the autonomous robot to guide the autonomous robot to the charger, wherein detection of the visual target triggers a positioning process that is completed when the signal is sent from the sensor, wherein the charger is moveable from a first location to a second location; and
modulating a current supplied to the autonomous robot by the charger based on a selected initial low current output level so as to transmit information from the charger to the autonomous robot.

2. The charger of claim 1 , wherein the sensor comprises:
a magnetic sensor to sense a magnet in or on the autonomous robot.

3. The charger of claim 1 , wherein the sensor comprises:
a momentary switch, disposed on a side of the charger facing the autonomous robot, to complete a circuit between the power supply and the charging element in response to actuation by the autonomous robot.

4. The charger of claim 1 , further comprising:
a voltage sensing element, in electrical communication with the power supply, to measure a voltage at an electrical contact of the autonomous robot.

5. The charger of claim 1 , wherein the charger is configured to stop charging the autonomous robot in response to a fault signal from the sensor, the fault sensor indicating that the autonomous robot is not positioned to be charged by the charger.

6. The charger of claim 1 , further comprising:
a processor, in electrical communication with the charging element, to modulate a current supplied to the autonomous robot via the charging element.

7. The charger of claim 6 , wherein the processor is configured to modulate the current based on a charging cycle of the charger.

8. The charger of claim 1 , further comprising:
a resilient member, supporting the charging element, to push the charging element against an electrical contact of the autonomous robot.

9. The charger of claim 8 , wherein the resilient member comprises a foam pad supporting the charging element.

10. A method of charging an autonomous robot with a charger, the method comprising:
initiating a continuous imaging process that comprises acquiring an image of a physical visual target on or in proximity to the charger;
guiding the autonomous robot to the charger based on the image of the physical visual target;
sensing that the autonomous robot is positioned to be charged by the charger;
in response to sensing that the autonomous robot is positioned to be charged by the charger, (i) charging the autonomous robot with the charger, and (ii) ending the continuous imaging process; and
modulating a current supplied to the autonomous robot by the charger based on a selected initial low current output level so as to transmit information from the charger to the autonomous robot.

11. The method of claim 10 , wherein sensing that the autonomous robot is positioned to be charged by the charger comprises:
sensing a magnet in or on the autonomous robot with a magnetic sensor.

12. The method of claim 10 , wherein sensing that the autonomous robot is positioned to be charged by the charger comprises:
actuating a momentary switch disposed on a side of the charger facing the autonomous robot.

13. The method of claim 10 , further comprising:
measuring a resistance of an electrical connection between the charger and the autonomous robot.

14. The method of claim 13 , further comprising:
sensing corruption or degradation of the electrical connection between the charger and the autonomous robot based on the resistance.

15. The method of claim 10 , further comprising:
wherein the charger is configured to stop charging the autonomous robot in response to a signal indicating that the autonomous robot is not positioned to be charged by the charger.

16. The method of claim 10 , wherein modulating the current supplied to the autonomous robot by the charger comprises modulating the current based on a charging cycle of the charger.

17. A method of charging an autonomous robot with a charger, the method comprising:
sensing that a state-of-charge of a battery of the autonomous robot is within a predetermined range;
in response to determining that the state-of-charge is within the predetermined range, guiding the autonomous robot to within visual range of the charger;
initiating a continuous imaging process that comprises acquiring an image of a physical visual target on or in proximity to the charger;
guiding the autonomous robot to the charger based on the image of the physical visual target;
sensing that the autonomous robot is positioned to be charged by the charger;
in response to sensing that the autonomous robot is positioned to be charged by the charger, (i) supply a current to the autonomous robot from the charger, and (ii) ending the continuous imaging process; and
modulating the current supplied by the charger based on a selected initial low current output level so as to transmit information from the charger to the autonomous robot.

Assignees

• A9 Com Inc

Inventors

• Blacksberg Jacob
• Ventimiglia Matthew
• Mcdowall Karl
• Keivan Nima

Classifications

• H02J7/731

  specially adapted for holding portable devices containing batteries (H02J7/751 takes precedence) · CPC title

• H02J7/485

  with provisions for charging different types of batteries · CPC title

• H02J7/70

  characterised by the mechanical construction · CPC title

• H02J7/50

  acting upon multiple batteries simultaneously or sequentially · CPC title

• H02J7/44

  between battery management systems and power sources · CPC title