System and method for mover self-navigation in an independent cart system
A system for controlling movers in a linear drive system includes a plurality of movers and a track providing segments along which the movers may travel and holding driver coils and a segment controller controlling the driver coils. Some of the segments having switches forming branches between segments. A central controller communicates operates with the segment controllers to route the movers along the track by distributing routing decisions for a given mover to a segment controller for a track on which a given mover is currently traveling.
1 . A system for controlling movers in a linear drive system, comprising:
a plurality of movers associated with mover records; and
a track providing a plurality of segments along which the movers may travel, each segment holding at least one electrically controllable driver coil and a segment controller executing a stored program to energize and deenergize the at least one driver coil for movement of the movers on the segment; wherein at least some of the segments are switch segments forming branches between segments, wherein each switch segment is selectively controllable to direct each of the plurality of movers along either a first route or a second route;
the segment controllers operative to:
(a) circulate mover records among the segment controllers according to physical proximity of a given mover associated with a given record to a given segment controller; and
(b) at each segment controller associated with one of the switch segments, control a switch position to selectively direct each of the plurality of movers along either the first route or the second route according to a data of the mover record corresponding to each of the plurality of movers and its presence at the segment controller corresponding to the switch segment, wherein the data corresponds to a desired destination of the mover.
2 . The system of claim 1 wherein the data of the mover records holds mover destinations and wherein the segment controllers associated with switch segments further hold route listings linking mover destinations to switch positions and control the switch segments according to mover destinations in the mover record of movers present at the switch segment.
3 . The system of claim 1 wherein the data of the mover records holds route listings linking switch segments to switch positions for the associated mover and wherein a given segment controller associated with a switch segment controls the switch segment according to the switch positions linked to the switch of the given segment controller in the mover records of movers present at the switch segment.
4 . The system of claim 1 wherein the data of the mover records holds mover identification and wherein the segment controllers associated with switch segments further hold route listings linking movers to switch positions and control the switch segments according to mover identification in the mover record of movers present at the switch segment.
5 . The system of claim 1 further including a central controller communicating with each of the segment controllers to provide a route listing describing mover routes and triggered by an arrival of the mover at a destination of a previous route listing.
6 . The system of claim 1 further including a central controller communicating with each of the segment controllers to provide the mover records for the movers triggered by an arrival of each mover at a destination of a previous mover record.
7 . The system of claim 1 further including a central controller running an application program to generate control signals for equipment synchronized to an operation of the linear drive system and wherein the application program generates destinations of the movers.
8 . The system of claim 1 further including a central controller receiving from the segment controllers mover location data to dynamically determine traffic flow and to change at least one of the mover records and route listings according to traffic flow.
9 . The system of claim 1 further including an electronic communication bus allowing intercommunication between the segment controllers and wherein the mover record is a data structure communicated along the communication bus to a second segment controller from a first segment controller controlling the given mover.
10 . The system of claim 1 wherein each segment controller associated with a switch segment holds the mover record of each mover present at the switch segment.
11 . The system of claim 1 wherein each segment controller provides a list of mover destination providing information about a distance to that destination whereby motion control may be obtained without necessary intervention of the central controller.
12 . A method of controlling movers in a linear drive system, comprising:
providing a plurality of movers, each mover associated with a mover record;
providing a track providing a plurality of segments along which the movers may travel, each segment holding at least one electrically controllable driver coil and a segment controller executing a stored program to energize and deenergize the at least one driver coil for movement of the movers on the segment; wherein at least some of the segments are switch segments forming branches between segments, wherein each switch segment is selectively controllable to direct each of the plurality of movers along either a first route or a second route;
circulating mover records among the segment controllers according to physical proximity of a given mover associated with a given record to a given segment controller; and
at each segment controller associated with a switch, controlling a switch position to selectively direct each of the plurality of movers along either the first route or the second route according to a data of the mover record corresponding to each of the plurality of movers and its presence at the segment controller corresponding to the switch segment, wherein the data corresponds to a desired destination of the mover.
13 . The method of claim 12 wherein the data of the mover records hold mover destinations and wherein the segment controllers associated with switch segments further hold route listings linking mover destinations to switch positions and control the switch segments according to mover destinations in the mover record of movers present at the switch segment.
14 . The method of claim 12 wherein the data of the mover records hold route listings linking switch segments to switch positions for the associated mover and wherein a given segment controller associated with a switch segment controls the switch segment according to the switch positions linked to the switch of the given segment controller in the mover records of movers present at the switch segment track.
15 . The method of claim 12 wherein the data of the mover records hold mover identification and wherein the segment controllers associated with switch segments further hold route listings linking movers to switch positions and control the switch segments according to mover identification in the mover record of movers present at the switch segment.
16 . The method of claim 12 further including providing a central controller communicating with each of the segment controllers to provide the route listings triggered by an arrival of the mover at a destination of a previous route listing.
17 . The method of claim 12 further including a central controller communicating with each of the segment controllers to provide the mover records for the movers triggered by an arrival of each mover at a destination of a previous mover record.
18 . The method of claim 12 further including providing a central controller running an application program to generate control signals for equipment synchronized to the operation of the linear drive system and wherein the application program generates destinations of the movers.
19 . The method of claim 12 further including providing a central controller receiving from the segment controllers mover location data to dynamically determine traffic flow and to change at least one of the mover records and route listings according to traffic flow.
20 . A system for controlling movers in a linear drive system, comprising:
a plurality of movers;
a track providing a plurality of segments along which the movers may travel, each segment holding at least one electrically controllable driver coil and a segment controller executing a stored program to energize and deenergize the at least one driver coil for movement of the movers on the segment; wherein at least some of the segments are switch segments forming branches between segments, wherein each switch segment is selectively controllable to direct each of the plurality of movers along either a first route or a second route; and
a central controller communicating mover records with the segment controllers, wherein the segment controllers and central controller operate together to route the movers along the track by distributing routing decisions within the mover records for a given mover to a segment controller for a track segment on which a given mover is currently traveling, and wherein a segment controller associated with one of the switch segments on which a mover is present is operative to control a switch position to selectively direct the mover along either the first route or the second route according to the routing decisions within the mover records.