Transport system

Abstract

The invention relates to a transport system, in particular to a multi-carrier system, comprising a central control; a plurality of drive units, wherein the drive units are coupled to the central control by means of a data link; and a plurality of transport elements that are movable by means of the drive units, wherein the central control is configured to communicate control commands to the drive units, with the control commands causing the drive units to make a movement of the transport elements in dependence on the control commands. The transport system in accordance with the invention is characterized in that at least two of the drive units, preferably all the drive units, receive the same control commands.

Claims

1. A transport system comprising: a central control; a plurality of drive units, wherein the drive units are coupled to the central control by means of a data link; and a plurality of transport elements that are movable by means of the drive units, wherein the central control communicates control commands to the drive units, with the control commands causing the drive units to make a movement of the transport elements in dependence on the control commands, and wherein at least two of the drive units receive the same control commands.

2. The transport system in accordance with claim 1, wherein the transport system is a multi-carrier system.

3. The transport system in accordance with claim 1, wherein all the drive units receive the same control commands.

4. The transport system in accordance with claim 1, wherein there is a communication link between at least two of the drive units.

5. The transport system in accordance with claim 1, wherein the data link is based on a fieldbus connection.

6. The transport system in accordance with claim 1, wherein the data link is based on the Sercos III fieldbus, with the filter in the drive units comprising a Sercos descriptor table that carries out an association of commands included in the control commands with transport elements located in the region of the respective drive unit.

7. The transport system in accordance with claim 1, wherein at least two of the drive units respectively comprise a plurality of regulators, with a respective one of the regulators carrying out a regulation for one of the transport elements.

8. The transport system in accordance with claim 1, wherein the central control for at least two of the transport elements specifies a movement profile and transmits it to the drive units by means of the data link.

9. The transport system in accordance with claim 1, wherein the drive units are directly connected to the central control by means of the data link.

10. The transport system in accordance with claim 1, wherein the transport system is a multi-carrier system that comprises a plurality of transport elements movable independently of one another, with the transport elements being guided on a guide path and being moved along the guide path by means of the drive units.

11. The transport system in accordance with claim 1, wherein the drive units comprise linear motors.

12. The transport system in accordance with claim 1, wherein the drive units send status information on the transport elements back to the central control, with the status information of at least two drive units and/or of at least two transport elements being combined in a datagram.

13. The transport system in accordance with claim 12, wherein a respective drive unit is configured only to add status information on a transport element to the datagram when the transport element can currently be moved by the respective drive unit.

14. The transport system in accordance with claim 13, wherein the status information for a respective transport element is stored at a predetermined position in the datagram.

15. The transport system in accordance with claim 1, wherein the control commands comprise commands to move at least two transport elements, with the drive units processing the control commands in dependence on a position of the transport elements.

16. The transport system in accordance with claim 15, wherein at least two of the drive units comprise a filter that filters the commands.

17. The transport system in accordance with claim 16, wherein at least two of the drive units comprise a filter that filters only the commands relevant to the respective drive unit from the control commands.

18. The transport system in accordance with claim 17, wherein the relevant commands only relate to those transport elements that can instantaneously be moved by the respective drive unit.

19. The transport system in accordance with claim 16, wherein the drive units are configured to initiate a change of the filter when a transport element is no longer movable by means of the respective drive unit and/or when a transport element is movable by means of the drive unit.

20. A method of controlling a transport system, wherein the transport system comprises a central control; a plurality of drive units, wherein the drive units are coupled to the central control by means of a data link; and a plurality of transport elements, and wherein the transport elements are moved by means of the drive units, the method comprising: communicating, by the central control, control commands to the drive units, with the control commands causing the drive units to make a movement of the transport elements in dependence on the control commands; and receiving, by at least two of the drive units, the same control commands.

Description

(1) The invention will be described in the following purely by way of example with reference to the drawing. There is shown:

(2) FIG. 1 schematically, a multi-carrier system.

(3) FIG. 1 shows a multi-carrier system 10 in a schematic view. The multi-carrier system 10 comprises a central control 12 and at least three drive units 14a, 14b, 14c.

(4) The central control 12 is coupled to the drive units 14 by means of a Sercos III fieldbus 16 in a ring connection. In addition to the Sercos III fieldbus 16, the drive units 14 are each connected to adjacent drive units 14 by means of a communication link 18. The communication link 18 is configured to transmit data faster between two drive units 14 than is possible by means of the Sercos III field bus 16. The communication link 18 can, for example, require 125 μs, whereas the Sercos III fieldbus 16 can require 1 ms.

(5) The Sercos III fieldbus 16 is configured such that every drive unit 14 receives all the real time data transmitted over the Sercos III fieldbus 16 and forwards them to the further drive units 14.

(6) A respective segment controller 20 is arranged in every drive unit 14a, 14b, 14c. Each segment controller 20 has a filter 22 in the form of a Sercos descriptor table.

(7) The drive units 14 additionally each comprise three regulators which control field coils 26 of the drive units 14 via power stages (not shown). The regulators 24 are in turn controlled by the respective segment controller 20.

(8) A changeable and/or migrating magnetic field is generated by the field coils 26 by means of which so-called movers 28 (i.e. transport elements) can be moved on a guide path 30. The movers 28 comprise permanent magnets (not shown) for this purpose.

(9) FIG. 1 shows a total of five movers 28, with a first mover 28a, a second mover 28b, and a third mover 28c being arranged in the region of the first drive unit 14a. A fourth mover 28d and a fifth mover 28e are in contrast located in the region of the second drive unit 14b.

(10) In operation, the central control 12 now transmits Ethernet frames 32a, 32b cyclically over the Sercos III fieldbus 16. The Ethernet frames 32a, 32b here comprise either control commands 34 or status information 35.

(11) The control commands 34 are divided within the Ethernet frames 32a into—here by way of example—five control command sections 36a, 36b, 36c, 36d, 36e. Each control command section 36 is here associated with a respective mover 28 and includes control commands for the respective mover. A first control command section 36a, for example, includes control commands for the first mover 28a.

(12) In a corresponding manner, five predetermined status information sections 37a, 37b, 37c, 37d, 37e are e.g. arranged within another Ethernet frame 32b. A respective mover 28 is here also associated with each status information section 37, with e.g. the first status information section 37a being filled with status information on the first mover 28a.

(13) The drive units 14 now know (e.g. by determining by means of an encoder, not shown) which movers 28 are located in the region of the respective drive unit 14. The segment controllers 20 of the drive units 14 adapt their filters 22 accordingly.

(14) In operation, one Ethernet frame 32 having the same control commands 34 is now received from all drive units 14 (more precisely from the respective segment controller 20). It should be understood that only the control commands 34 are respectively identically received. Further data contained in the Ethernet frame 32a can in contrast be changed by the drive units 14.

(15) The filter 22 is now set in the first drive unit 14a such that the control command sections 36a, 36b, 36c relevant to the three movers 28a, 28b, 28c located in the region of the first drive unit 14a are processed, which is indicated by processing arrows 38 in FIG. 1. It is effected by the processing that the regulators 24 in the first drive unit 14a e.g. carry out a movement of the movers 28a, 28b, 28c. The remaining control command sections 36d, 36e are not taken into account by the first drive unit 14a.

(16) In a corresponding manner, only the control command sections 36d and 36e are forwarded by the filter 22 of the second drive unit 14b for processing since they belong to the movers 28d, 28e located in the region of the second drive unit 14b.

(17) There are initially no movers 28 in the region of the third control unit 14c so that the filter 22 there initially does not initiate any processing of control command sections 36.

(18) If now the fifth mover 28e is moved by the second drive unit 14b into the region of the third drive unit 14c, the second drive unit 14b communicates this to the third drive unit 14c by means of the communication link 18. The filters 22 of the second and third drive units 14b, 14c are thereupon changed. The execution of control commands for the fifth mover 28e is blocked in the filter 22 of the second drive unit, whereas the execution of control commands for the mover 28c is released for processing in the third drive unit 14c.

(19) If the central control 12 now transmits a further command to move the fifth mover 28e in the control commands 34 (in the fifth control command section 36e), this command is automatically processed by the third drive unit 14c without the central control 12 thus being strained to set up or initialize a communication or a data path with respect to the respective drive unit 14. In this manner, the control of the multi-carrier system 10 becomes possible in a simple manner and thereby permits a flexible use of the multi-carrier system 10.

(20) The sending back of status information 35 from the drive units 14 to the central control 12 takes place in a simple manner.

(21) The Ethernet frame 32b for communicating the status information is first received by first drive unit 14a. The Ethernet frame 32b for communicating the status information in the use of the Sercos III fieldbus 16 is a different Ethernet frame 32 than the Ethernet frame 32a that communicates the control commands 34.

(22) In the first drive unit 14a, the filter 22 is set such that the status information sections 37a, 37b, 37c for the three movers 28a, 28b, 28c located in the region of the first drive unit 14a are “filled” (i.e. written) by the first drive unit 14a, which is likewise indicated by the processing arrows 38.

(23) In a corresponding manner, the remaining status information sections 37d, 37e are written by the second and third drive units 14b, 14c. Finally, the central control 12 receives the Ethernet frame 32b again and thus obtains the complete status information 35 that was determined without the necessity of a high transmission bandwidth of the fieldbus 16.

REFERENCE NUMERAL LIST

(24) 10 multi-carrier system

(25) 12 central control

(26) 14a-14c drive units

(27) 16 Sercos III fieldbus

(28) 18 communication link

(29) 20 segment controller

(30) 22 filter

(31) 24 regulator

(32) 26 field coil

(33) 28a-28e movers

(34) 30 guide path

(35) 32a, 32b Ethernet frame

(36) 34 control command

(37) 35 status information

(38) 36a-36e control command section

(39) 37a-37e status information section

(40) 38 processing