Dynamic discharge compensation for a sortation system
View Patent ↗The discharge accuracy of unit sortation is improved by making real time adjustments to the discharge timing of the carrier based on the determined actual position of each article on respective carriers. The adjustments are applied at the time the discharge command is given.
1. A material handling system comprising:
a sortation system;
an image device for detecting an image of an article at an off-center location on a selected moving carrier of the sortation system;
a controller in communication with the image device and the sortation system to perform operations to:
determine the off-center location by performing image processing of the image;
determine a change to a discharge command that compensates for the off-center location to discharge the article to a selected stationary discharge location; and
execute the changed discharge command to discharge the article at the selected stationary discharge location.
2. The material handling system of claim 1 , wherein:
the sortation system comprises an endless conveyor having more than one moving carrier that moves past more than one stationary discharge location;
the controller performs operations to:
determine the change to the discharge command by determining a release point for discharging to the selected stationary discharge location; and
determine whether the release point has been reached; and
in response to determining that the release point has been reached, executing the changed discharge command by initiating discharge of the article positioned off-center by the selected moving carrier.
3. The material handling system of claim 1 , wherein the off-center location comprises a longitudinal component.
4. The material handling system of claim 1 , wherein the off-center location comprises a lateral component.
5. The material handling system of claim 1 , wherein the controller determines the change to the discharge command that compensates for the off-center location to discharge the article to the selected stationary discharge location by:
determining a longitudinal speed of the sortation system; and
determining the change in the discharge command to compensate at least in part for the longitudinal speed of the sortation system.
6. The material handling system of claim 5 , wherein:
the carrier comprises a cross belt carrier; and
the controller determines the change to the discharge command that compensates at least in part for the off-center location to discharge the article to the selected stationary discharge location by:
determining a motor profile of cross belt carrier; and
determining the change in the discharge command to compensate at least in part for the motor profile of the cross belt carrier of the sortation system to effect discharge of the article from the off-center location.
7. The material handling system of claim 1 , wherein determining the change to the discharge command comprises determining an amount of time required to actuate the selected mobile carrier to discharge the article to the selected stationary discharge location.
8. The material handling system of claim 1 , wherein determining the change to the discharge command comprises determining a release location of the selected mobile carrier required to actuate the selected mobile carrier to discharge the article to the selected stationary discharge location.
9. A controller of a material handling system, the controller comprising:
an interface in communication with a sortation system; and
a processor in communication with an image device positioned to image articles on carriers of a sortation system and the interface and comprising a processor to perform operations to:
determine an off-center location of an article on a selected carrier of the sortation system by performing image processing of the image;
determine a change to a discharge command that compensates for the off-center location to discharge the article to a selected stationary discharge location; and
execute the changed discharge command to discharge the article at the selected stationary discharge location.
10. The controller of claim 9 , wherein:
the sortation system comprises an endless conveyor having more than one moving carrier that moves past more than one stationary discharge location;
the controller performs the operations to:
determine the change to the discharge command by determining a release point for discharging to the selected stationary discharge location;
determine whether the release point has been reached; and
in response to determining that the release point has been reached, executing the changed discharge command by initiating discharge of the article positioned off-center by the selected moving carrier.
11. The controller of claim 9 , wherein the off-center location comprises a longitudinal component.
12. The controller of claim 9 , wherein the off-center location comprises a lateral component.
13. The controller of claim 9 , wherein the controller determines the change to the discharge command that compensates for the off-center location to discharge the article to the selected stationary discharge location by:
determining a longitudinal speed of the sortation system; and
determining the change in the discharge command to compensate at least in part for the longitudinal speed of the sortation system.
14. The controller of claim 13 , wherein:
the carrier comprises a cross belt carrier; and
the controller determines the change to the discharge command that compensates at least in part for the off-center location to discharge the article to the selected stationary discharge location by:
determining a motor profile of cross belt carrier; and
determining the change in the discharge command to compensate at least in part for the motor profile of the cross belt carrier of the sortation system to effect discharge of the article from the off-center location.
15. The controller of claim 9 , wherein determining the change to the discharge command comprises determining an amount of time required to actuate the selected mobile carrier to discharge the article to the selected stationary discharge location.
16. The controller of claim 9 , wherein determining the change to the discharge command comprises determining a release location of the selected mobile carrier required to actuate the selected mobile carrier to discharge the article to the selected stationary discharge location.
17. A method of controlling a material handling system, the method comprising:
imaging by an image device an article on a selected carrier of a sortation system;
determining an off-center location of the article on the selected carrier of the sortation system by performing image processing of the image;
determining a change to a discharge command that compensates for the off-center location to discharge the article to a selected stationary discharge location; and
executing the changed discharge command to discharge the article at the selected stationary discharge location.
18. The controller of claim 17 , wherein:
the sortation system comprises an endless conveyor having more than one moving carrier that moves past more than one stationary discharge location;
determining the change to the discharge command comprises determining a release point for discharging to the selected stationary discharge location and determining whether the release point has been reached; and
in response to determining that the release point has been reached, executing the changed discharge command by initiating discharge of the article positioned off-center by the selected moving carrier.
19. The method of claim 17 , wherein the off-center location comprises a longitudinal component.
20. The method of claim 17 , wherein the off-center location comprises a lateral component.
21. The method of claim 17 , wherein determining the change to the discharge command that compensates for the off-center location to discharge the article to the selected stationary discharge location further comprises:
determining a longitudinal speed of the sortation system; and
determining the change in the discharge command to compensate at least in part for the longitudinal speed of the sortation system.
22. The method of claim 21 , wherein:
the carrier comprises a cross belt carrier; and
determining the change to the discharge command that compensates at least in part for the off-center location to discharge the article to the selected stationary discharge location further comprises:
determining a motor profile of cross belt carrier; and
determining the change in the discharge command to compensate at least in part for the motor profile of the cross belt carrier of the sortation system to effect discharge of the article from the off-center location.
23. The method of claim 17 , wherein determining the change to the discharge command comprises determining an amount of time required to actuate the selected mobile carrier to discharge the article to the selected stationary discharge location.
24. The method of claim 17 , wherein determining the change to the discharge command comprises determining a release location of the selected mobile carrier required to actuate the selected mobile carrier to discharge the article to the selected stationary discharge location.