Transport system

Abstract

A transport system for linear movements includes at least two sensors configured to determine a position of one or more carriers along a carrier track. Each of the sensors are interconnected with each other and arranged in a daisy-chained manner along the carrier track. The sensors create a position sensor bus configured to transmit a digital position sensor signal. The transport system further includes a motion controller connected to the sensor bus and configured to control at least one position of the carriers along the carrier track.

Claims

1. A transport system for linear movements, comprising: at least two sensors configured to determine a position of one or more carriers along a carrier track, each of the at least two sensors being interconnected with each other and arranged in a daisy-chained manner along the carrier track to create a position sensor bus configured to transmit a digital position sensor signal; a motion controller connected to the sensor bus and configured to control at least one position of the carriers along the carrier track; and a scale including at least two subdivisions, each subdivision corresponds uniquely to one sensor in the at least two sensors, the scale being configured to: add measurement data from each of the at least two sensors into the at least two subdivisions of the scale in response to the one or more carriers passing each sensor; and transmit the scale as an end signal to the motion controller to enable the motion control to identify the measurement data that are specific to each of the at least two sensors based on the at least two subdivisions in the scale.

2. The transport system according to claim 1, wherein the motion controller is furthered configured to determine the position of at least one carrier along the carrier track using sensor data of the at least two sensors.

3. The transport system according to claim 1, wherein the sensor bus is a digital communication bus configured to connect the at least two sensors to the motion controller.

4. The transport system according to claim 1, further comprising: a first sensor connected to a motion system by the position sensor bus and configured to provide a first position sensor signal; and a second sensor connected to the first sensor and configured to provide a second position sensor signal, wherein the first and second position sensor signals are multiplexed digitally.

5. The transport system according claim 4, further comprising: a cable break detection system configured to detect a cable break of at least one of the bus system and of the motion system.

6. The transport system according claim 1, wherein the position sensor bus performs digital multiplexing.

7. The transport system according to claim 1, further comprising configuration parameters of the at least two sensors, wherein the configuration parameters are at least partially stored within each of the at least two sensors.

8. The transport system according to claim 1, wherein the transport system is configured to carry at least one of wafers and wafer products.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a transport system comprising a modular position sensor bus according to the present disclosure.

(2) FIG. 2 shows a principle of the sensor data transmitted from the sensors to the motion controller.

DETAILED DESCRIPTION

(3) Within the embodiment according to FIGS. 1 and 2, the same elements are assigned to same reference signs.

(4) In particular, FIG. 1 shows a transport system 100 for linear movements according to one embodiment of the present disclosure. It can be discerned from FIG. 1 that the transport system 100 comprises a multiplicity of sensors 1 which are each capable and used for determining a position of a carrier 2 along a carrier track 3.

(5) In the present example of FIG. 1 said carrier 3 is moved by electromagnetic forces wherein below each of the carrier 2 and below the carrier track 3, electromagnetic actuators are arranged along the carrier track 3. Said electromagnetic actuators are given the reference sign 5A.

(6) In particular, the sensors 1 are not only arranged on each of the ends of the carrier track 3 but are also arranged between each of the actuators 5A and are interconnected with each other via bus lines so that they are defining a daisy-chained arrangement along the carrier track 3.

(7) In other words, said sensors 1 create a position sensor bus 4 by transmitting, in particular only, a digital position sensor signal, wherein the sensor bus 4 is connected to a motion controller 5, said motion controller 5 controlling at least one position of the carriers 2 along the carrier track 3.

(8) In particular, said multicity of sensors 1 can be subdivided into sensors 1a, 1b 1e, 1d and so on wherein the most left sensor 1a is connected by a first bus line to a further sensor 1b so that along the main extension direction of the carrier 3, the two sensors 1a, 1b generate an arrangement space for a first actuator 5A.

(9) The core of the disclosure isas outlined abovethat signals interchanged are only digital signals instead of being analogue signals so that both the sensors 1 among each other as well as the sensors 1 with the motion controller 5 do communicate only by digital signal communication.

(10) In other words, the sensor bus 4 as well as the transport system 100 is free from analogue multiplexing so that in general a multiplexing can be totally omitted. Instead of the sensors 1 being connected to an analogue multiplexer, said multiplexer being connected to a motion control system, the present disclosure provides the solution that only the first sensor 1a is directly connected to the motion controller 5 and each subsequently arranged sensor 1b, 1e, 1d and so on is in a daisy-chain connection with the previous sensor.

(11) Furthermore, the transport system 100 comprises a cable break detection system 7 detecting a cable break of the bus system 4 and/or a motion system 6 which ensures that the transport system 100 can be driven specifically in a secure manner and without a large monitoring system. In particular, within the hereby described embodiment the cable detection system 7 consists of sub detection systems capable of working independently from each other, wherein in each of the sensors 1 at least one such sub detection system in integrated. This ensures very easy detection of cable breaks also on wires in between neighboring sensors 1.

(12) FIG. 2 teaches the transport system 100 of FIG. 1, however, with particular emphasis towards how the sensor data is transmitted from the sensors 1 to the motion controller 5.

(13) As can be discerned from FIG. 2, the detected signal of each of the sensors 1a, 1b, 1c, 1d and so on can be subdivided in a scale-like manner via a scale 200. Said scale 200 comprises subdivisions 200A wherein each of the subdivisions 200A can be assigned uniquely to a specific sensor 1.

(14) By daisy-chain accumulation of each of the measured signals represented by a corresponding scale-like representation within the scale 200, said signals can be accumulated and added to an end signal 200B.

(15) Said end signal 200B is subsequently transported to the motion controller 5. In that sense, FIG. 2 therefore does not only show how the sensors 1 and in particular the position sensor bus 4 simplify the cable layout but also show the principle how the sensor data is transmitted from the sensors 1 to the motion controller 5.

(16) Therefore, a solution is proposed which leads to less cable means, less chance of cable problems and the like and also simplifies the track design and cable routing so that a transport system 100 in particular for transporting wavers for example within a clean room is provided so that only basic maintenance need to keep the transport system 100 operating.

LIST OF REFERENCE SIGNS

(17) 1, 1a, 1b, 1c, 1d sensors

(18) 2 carrier

(19) 3 carrier track

(20) 4 sensor bus

(21) 5 motion controller

(22) 5A electromagnetic actuators/first actuator

(23) 6 motion system

(24) 7 detection system

(25) 100 transport system

(26) 200 scale

(27) 200A subdivisions

(28) 200B end signal