Robot queueing in order-fulfillment operations

Abstract

A method for queuing robots destined for a target location in an environment, includes determining if a first robot occupies the target location and if it is determined that the first robot occupies the target location, determining if a second robot destined for the target location has entered a predefined target zone proximate the target location. If the second robot has entered the predefined target zone, the method further includes navigating the second robot to a first queue location and causing the second robot to wait at the first queue location until the first robot no longer occupies the target location. The method also includes navigating the second robot to the target location after the first robot leaves the target location.

What is claimed is: 
     
         1 . A method for queuing robots destined for a target location in an environment, comprising:
 Determining if a first robot occupies the target location;   If it is determined that the first robot occupies the target location, determining if at least one other robot destined for the target location has entered a predefined target zone proximate the target location;   If it is determined that the at least one other robot has entered the predefined target zone, assigning the at least one other robot to a que location based on an assigned priority.   
     
     
         2 . The method of  claim 1  wherein the environment is a warehouse space containing items for customer order fulfillment. 
     
     
         3 . The method of  claim 17  wherein the first queue location is offset from the target location by a predetermined distance; the target location being defined by a target pose and the first queue location being defined by a first queue pose; wherein the second robot navigates to the first queue location by navigating to the first queue pose. 
     
     
         4 . The method of  claim 3  wherein the at least one other robot includes a third robot and the method further includees determining if a third robot destined for the target location has entered the predefined target zone when the first robot occupies the target location and the second robot occupies the first queue location, if it is determined that the third robot has entered the predefined target zone while the first robot occupies the target location and the second robot occupies the first queue location, navigating the third robot to a second queue location and causing the third robot to wait at the second queue location until the first robot no longer occupies the target location. 
     
     
         5 . The method of  claim 4  wherein the second queue location is offset from the first queue location by a predetermined distance, the second queue location being defined by a second queue pose; wherein the second robot navigates to the second queue location by navigating to the second queue pose. 
     
     
         6 . The method of  claim 5  further including determining if the first robot continues to occupy the target location and if it does not, navigating the second robot to the target location, navigating the third robot to the first queue location, and causing the third robot to wait at the first queue location until the second robot no longer occupies the target location. 
     
     
         7 . The method of  claim 5  wherein the step of navigating the second robot to the target location includes navigating the second robot to the target pose and navigating the third robot to the first queue location includes navigating the second robot to the first queue pose. 
     
     
         8 . A system for queuing robots destined for a target location, comprising:
 A management system;   At least first robot and at least one other robot destined for a target location;   Wherein the management system is configured to communicate with the first robot and the at least one other robot and to:   determine if the first robot occupies the target location;   If it is determined that the first robot occupies the target location, determine if the at least one other robot has entered a predefined target zone proximate the target location;   If it is determined that the the at least one other robot has entered the predefined target zone, assign the at least one other robot to a que location based on an assigned priority.   
     
     
         9 . The system of  claim 8  wherein the environment is a warehouse space containing items for customer order fulfillment. 
     
     
         10 . The system of  claim 19  wherein the first queue location is offset from the target location by a predetermined distance; the target location being defined by a target pose and the first queue location being defined by a first queue pose;
 wherein the second robot navigates to the first queue location by navigating to the first queue pose. 
 
     
     
         11 . The system of  claim 10  wherein the at least one other robot includes a third robot and the management system is configured to determine if the third robot has entered the predefined target zone when the first robot occupies the target location and the second robot occupies the first queue location, if it is determined that the third robot has entered the predefined target zone while the first robot occupies the target location and the second robot occupies the first queue location, the system directs the third robot to navigate to a second queue location and causes the third robot to wait at the second queue location until the first robot no longer occupies the target location. 
     
     
         12 . The system of  claim 11  wherein the second queue location is offset from the first queue location by a predetermined distance, the second queue location being defined by a second queue pose; wherein the second robot navigates to the second queue location by navigating to the second queue pose. 
     
     
         13 . The system of  claim 12  wherein the management system is further configured to determine if the first robot continues to occupy the target location and if it does not, the system directs the second robot to navigate to the target location, the system directs the third robot to navigate the to the first queue location, and the system causes the third robot to wait at the first queue location until the second robot no longer occupies the target location. 
     
     
         14 . The system of  claim 13  wherein the management system is further configured direct the second robot to the target location by navigating it to the target pose and to direct the third robot to the first queue location by navigating it to the first queue pose. 
     
     
         15 . A robot capable of navigating to predefined locations in an environment containing a plurality of other robots, the robot and the plurality of other robots capable of interacting with a management system, the robot comprising:
 A mobile base;   A communication device enabling communication between the robot and the management system;   A processor, responsive to communications with the management system, configured to:   Navigate the robot to a target location in the environment;   Determine if at least one of the plurality of other robots occupies the target location;   If it is determined that at least one of the plurality of other robots occupies the target location, determine if the robot has entered a predefined target zone proximate the target location;   If it is determined that the robot has entered the predefined target zone, assign the robot to a que location based on an assigned priority.   
     
     
         16 . The method of  claim 1  wherein the assigned priority is determined by the order of entry of the at least one other robot into the target zone. 
     
     
         17 . The system of  claim 16  wherein the at least one other robot includes a second robot and the method further includes:
 Navigating the second robot to a first queue location; 
 Causing the second robot to wait at the first queue location until the first robot no longer occupies the target location; and 
 Navigating the second robot to the target location after the first robot leaves the target location. 
 
     
     
         18 . The system of  claim 8  wherein the assigned priority is determined by the order of entry of the at least one other robot into the target zone. 
     
     
         19 . The system of  claim 18  wherein the at least one other robot includes a second robot and the management system is further configured to:
 Navigate the second robot to a first queue location; 
 Cause the second robot to wait at the first queue location until the first robot no longer occupies the target location; and 
 Navigate the second robot to the target location after the first robot leaves the target location. 
 
     
     
         20 . The system of  claim 15  wherein the assigned priority is determined by the order of entry of the robot and at the plurality of other robots into the target zone. 
     
     
         21 . The system of  claim 20  wherein the management system is further configured to:
 Navigate the robot to a queue location associated with its assigned priority; 
 Cause the robot to wait at said queue location until the at least one of the plurality of robots no longer occupies the target location; and 
 Navigate the robot to one of the target location or another que location associated with a higher priority after the at least one of the plurality of robots leaves the target location. 
 
     
     
         22 . A method for queuing robots destined for a target location in an environment, comprising:
 Determining if a plurality of robots destined for the target location have entered a predefined target zone proximate the target location; and   Assigning each of the robots to one of the target location or a que location based on an assigned priority.   
     
     
         23 . The system of  claim 22  wherein the assigned priority is determined by the order of entry of each of the plurality of other robots into the target zone, and wherein the first robot to enter the target zone is assigned the highest priority.