Navigation using planned robot travel paths

Patent metadata

Field	Value
Publication number	US-9864377-B2
Application number	US-201615088474-A
Country	US
Kind code	B2
Filing date	Apr 1, 2016
Priority date	Apr 1, 2016
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A method for generating a navigation map of an environment in which a plurality of robots will navigate, includes obtaining an image of the environment defined by a plurality of pixels, each having a cost value. The environment includes an image of a fixed object having a set of pixels corresponding to its location and having a first defined cost value. The method includes obtaining a planned path image for the robots, which include a first set of pixels corresponding to the location of each robot in the environment and a second set of pixels adjacent to the first set of pixels and extending along a planned path of travel toward a destination. The first set of pixels of each robot having the first defined cost value and the second set of pixels having a second defined cost value. The second defined cost value is less than the first defined cost value.

First claim

Having described the invention, and a preferred embodiment thereof, what is claimed as new and secured by Letters Patent is:

1. A method for generating a navigation map of an environment in which a plurality of robots will navigate, the method comprising:
Obtaining an image of the environment, the image defined by a plurality of pixels, each pixel having a cost value associated with it; wherein the image of the environment includes an image of at least one fixed object comprising a set of pixels corresponding to the location of the at least one fixed object in the environment, the set of pixels corresponding to the location of the at least one fixed object having a first defined cost value; and
Obtaining a planned path image for each of the plurality of robots in the environment, the planned path image including for each robot a first set of pixels corresponding to the location of each robot in the environment and a second set of pixels adjacent to the first set of pixels and extending along a planned path of travel of each robot toward a destination; the pixels in the first set of pixels of each robot having the first defined cost value and the second set of pixels of each robot comprising pixels having cost values which are less than the first defined cost value;
wherein the image of the environment including the image of at least one fixed object is stored locally with each of the plurality of robots;
wherein each of the plurality of robots produces its own planned path and communicates its own planned path to the other of the plurality of robots;
wherein each robot combines the image of the environment including the image of at least one fixed object with images representing the planned paths received from other of the plurality of robots to form a navigation map; and
wherein each robot uses the navigation map to plan a path from its current location to its destination.

2. The method of claim 1 , wherein each of the plurality of robots produces its own updated planned path at regular time intervals as each robot traverses its path to its destination and communicates its own updated planned path to the other of the plurality of robots at such regular intervals; and wherein each robot uses the updated planned path of the other of the plurality of robots to produce an updated navigation map and updates its planned path to its destination using the updated navigation map.

3. The method of claim 1 wherein the second set of pixels of each robot comprises pixels having plurality of cost values less than the first cost value, and wherein the cost values of the pixels decrease proportionally in value as they extend from adjacent to the first set of pixels out along the planned path of travel of each robot toward a destination.

4. The method of claim 3 wherein the second set of pixels of each robot is formed by producing a plurality of regions along the planned path of travel of each robot toward a destination and wherein each region successively comprises pixels having cost values less than the preceding region.

5. The method of claim 4 wherein the plurality of regions are circular in shape and the regions have a radius corresponding to the size of at least one of the robots.

6. The method of claim 1 wherein the environment is a warehouse.

7. A method for navigating a robot in an environment from a current location to a destination, the environment including at least one fixed object and at least one other robot, the method comprising:
Obtaining an image of the environment, the image defined by a plurality of pixels, each pixel having a cost value associated with it; wherein the image of the environment includes an image of the at least one fixed object comprising a set of pixels corresponding to the location of the at least one fixed object in the environment, the set of pixels corresponding to the location of the at least one fixed object having a first defined cost value;
Obtaining an image of the at least one other robot in the environment, the image of the at least one other robot including a first set of pixels corresponding to the location of the at least one other robot in the environment and a second set of pixels adjacent to the first set of pixels and extending along a planned path of travel of the at least one other robot toward a destination; the pixels in the first set of pixels of the at least one other robot having the first defined cost value and the second set of pixels of the at least one other robot comprising pixels having cost values which are less than the first defined cost value; and
Planning a path from the current location of the robot to the destination of the robot based on the image of the at least one fixed object and the image of the at least one other robot.

8. The method of claim 7 , wherein the image of the environment including the image of at least one fixed object is stored locally within the robot.

9. The method of claim 8 , wherein the at least one other robot produces its own planned path from a current location to a destination and communicates its own planned path to the robot.

10. The method of claim 9 , wherein the robot combines the image of the environment including the image of at least one fixed object with an image of the planned path received from the at least one other robot to form a navigation map.

11. The method of claim 10 , wherein the robot uses the navigation map to plan a path from its current location to its destination.

12. The method of claim 11 , wherein the at least one other robot produces its own updated planned path at regular time intervals as it traverses its path to its destination and communicates its own updated planned path to the robot at such regular intervals; and wherein the robot uses the updated planned path of the at least one other robot to produce an updated navigation map and updates its planned path to its destination using the updated navigation map.

13. The method of claim 7 , wherein the second set of pixels of the at least one other robot comprises pixels having plurality of cost values less than the first cost value, and wherein the cost values of the pixels decrease proportionally in value as they extend from adjacent to the first set of pixels out along the planned path of travel of the at least one other robot toward its destination.

14. The method of claim 13 , wherein the second set of pixels of the at least one other robot is formed by producing a plurality of regions along the planned path of travel of the at least one other robot toward its destination and wherein each region successively comprises pixels having cost values less than the preceding region.

15. The method of claim 14 , wherein the plurality of regions are circular in shape and the plurality of regions have a radius corresponding to the size of the robot or the at least one other robot.

16. The method of claim 7 , wherein the environment is a warehouse.

17. A robot configured to navigate an environment, the environment including at least one fixed object and a plurality of other robots, the robot comprising:
A mobile base for propelling the robot throughout the environment;
A communication device enabling communication between the robot and the plurality of other robots; and
A processor, in communication with the communication device, configured to:
Obtain an image of the environment, the image defined by a plurality of pixels, each pixel having a cost value associated with it; wherein the image of the environment includes an image of the at least one fixed object comprising a set of pixels corresponding to the location of

Assignees

• Locus Robotics Corp

Inventors

• Welty Bruce
• Powers Bradley
• Tappan Eric

Classifications

• Y10S901/01

  Mobile robot · CPC title

• G06Q10/087

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

• B25J11/008

  Manipulators for service tasks · CPC title

• B25J5/007

  mounted on wheels · CPC title

• G05D2111/50

  Internal signals, i.e. from sensors located in the vehicle, e.g. from compasses or angular sensors · CPC title