Independent cart system and method of operating the same

Patent metadata

Field	Value
Publication number	US-11643120-B2
Application number	US-202117213589-A
Country	US
Kind code	B2
Filing date	Mar 26, 2021
Priority date	Nov 8, 2018
Publication date	May 9, 2023
Grant date	May 9, 2023

Abstract

A method and system for motion control of movers in an independent cart system is disclosed. In one implementation, the independent cart system includes a plurality of track segments, each section having a respective controller. One of the controllers receives a motion command for a plurality of carts, respectively. The controller generates a force command for each of the plurality of carts and transmits the respective commands to the track segments commutating the plurality of carts.

First claim

What is claimed is:

1. A method of controlling operation of a plurality of movers in an independent cart system, the independent cart system including a track having a plurality of track segments, the method comprising the steps of:
obtaining at a first controller a motion command for a first mover;
receiving at the first controller from a segment controller for one of the plurality of track segments a position feedback signal corresponding to a location for the first mover along the track segment corresponding to the segment controller, wherein the first controller is not located along the track segment on which the first mover is present;
determining at the first controller a force command for the first mover based on the motion command and the position feedback signal;
transmitting the force command from the first controller to the segment controller; and
controlling with the segment controller an excitation field to interact with a drive member mounted on the mover based on the force command.

2. The method of claim 1 , and further comprising:
obtaining at the first controller a second motion command for a second mover;
receiving at the first controller from a segment controller for one of the plurality of track segments a second position feedback signal corresponding to a location for the second mover along the track segment corresponding to the segment controller;
determining at the first controller a second force command for the second mover based on the second motion command and the second position feedback signal; and
controlling with the segment controller corresponding to the track segment on which the second mover is located a second excitation field to interact with a second drive member mounted on the second mover based on the second force command.

3. The method of claim 2 , wherein the first mover and the second mover are located on a single track segment and the segment controller corresponding to the first mover and the segment controller corresponding to the second mover are the same.

4. The method of claim 2 , wherein the first mover is located on a first track segment selected from the plurality of track segments and the second mover is located on a second track segment selected from the plurality of track segments and wherein the segment controller corresponding to the first mover is a first segment controller and the segment controller corresponding to the second mover is a second segment controller.

5. The method of claim 1 , wherein the first controller is a second segment controller configured to control excitation fields for a track segment other than the track segment on which the first mover is located.

6. The method of claim 1 , further comprising the steps of:
receiving at the segment controller a second motion command for a second mover;
receiving at the segment controller a second position feedback signal corresponding to a location for the second mover; and
determining at the segment controller a second force command for the second mover based on the second motion command and the second position feedback signal.

7. The method of claim 6 , wherein the second mover is present on the track segment corresponding to the segment controller.

8. The method of claim 6 , wherein the second mover is present on one of the plurality of track segments not corresponding to the segment controller.

9. The method of claim 1 , wherein:
a first portion of the first mover is located on a first track segment;
a second portion of the first mover is located on a second track segment;
the step of determining at the first controller the force command for the first mover further comprises the steps of:
determining at the first controller a first force command for the first track segment, and
determining at the first controller a second force command for the second track segment; and
the step of controlling with the segment controller the excitation field further comprises the steps of:
controlling with a first segment controller a first excitation field on the first track segment to interact with the first mover, and
controlling with a second segment controller a second excitation field on the second track segment to interact with the first mover.

10. An independent cart system, comprising:
a track having a plurality of track segments, wherein each track segment includes:
a plurality of drive coils, and
a segment controller configured to selectively control the plurality of drive coils to generate an excitation field along the corresponding track segment;

a plurality of movers, wherein each mover includes a drive member configured to interact with the excitation field;
a position feedback system configured to generate a plurality of position feedback signals, each position feedback signal corresponding to a location of a first mover, selected from the plurality of movers; and
a first controller configured to:
obtain a motion command for the first mover,
receive from the segment controller for each of the plurality of track segments the position feedback signal corresponding to a location of the first mover as the first mover travels along the track,
determine a force command for each of the plurality of track segments on which the first mover is presently located, and
transmit the force command for the first mover to the segment controller from which the first controller received the position feedback signal.

11. The independent cart system of claim 10 , wherein the first controller is further configured to:
obtain a second motion command for a second mover, the second mover selected from the plurality of movers,
receive from the segment controller for each of the plurality of track segments a second position feedback signal corresponding to a location of the second mover as the second mover travels along the track,
determine a second force command for each of the plurality of track segments on which the second mover is presently located, and
transmit the second force command for the second mover to the segment controller from which the first controller received the second position feedback signal.

12. The independent cart system of claim 11 , wherein:
the first mover and the second mover are located on one track segment, and
the segment controller corresponding to the first mover and the segment controller corresponding to the second mover are the same.

13. The independent cart system of claim 11 , wherein:
the first mover is located on a first track segment,
the second mover is located on a second track segment,
the segment controller corresponding to the first mover is a first segment controller, and
the segment controller corresponding to the second mover is a second segment controller.

14. The independent cart system of claim 10 , wherein the first controller is a second segment controller configured to generate excitation fields for a track segment other than the track segment on which the first mover is located.

15. The independent cart system of claim 10 , wherein the segment controller corresponding to the first mover is further configured to:
receive a second motion command for a second mover,
receive the position feedback signal corresponding to a location for the second mover along the track, and
determine a second force command for the second mover based on the second motion command and the position feedback signal corresponding to the location for the second mover.

16. The independent cart system of claim 15 , wherein the second mover is present on the track segment corresponding to the segment controller.

Assignees

• Rockwell Automation Tech Inc

Inventors

• Cooper Mark R
• Van Dorpe David D
• Ozimek Patrick E
• Ramanarayanan Shankernarayan

Classifications

• G05B19/4189 Primary

  characterised by the transport system · CPC title

• B61C3/00

  Electric locomotives or railcars (characterised by power transmission B61C9/00; electrical features B60L; H02) · CPC title

• B61L25/04

  Indicating or recording train identities · CPC title

• G05B2219/41327

  Linear induction motor · CPC title

• B61L23/14 Primary

  automatically operated · CPC title