US3735352A

US3735352A - Communication technique for controlling crane operations

Info

Publication number: US3735352A
Application number: US00165296A
Authority: US
Inventors: L Pease
Original assignee: Eaton Corp
Current assignee: Eaton Corp
Priority date: 1971-07-22
Filing date: 1971-07-22
Publication date: 1973-05-22
Anticipated expiration: 1990-05-22
Also published as: GB1384558A; FR2146332A1; FR2146332B1; DE2235087A1; IT963210B; JPS5430171B1

Abstract

A communication system for controlling a mobile vehicle comprising a trolley system transmitting communication signals between an on-board station carried by said vehicle and a command station and including photoelectric coupling means serving to pass signals between said trolley system and said stations, while electrically isolating said stations from said trolley system.

Description

ite tates Patent 1191 2 qSCHMlTTl messy Pease May 22, 1973 [54] CUMMUNICATION TECHNIQUE FOR 3,552,692 1 1971 Horeczky ..246/l87 B C ONTR LLING RANE PERATI N 0 C O 0 S OTHER PUBLICATIONS [75] Inventor: Logan L. Pease, Bountiful, Utah IBM Technical Disclosure Bulletin Vol. 13, No. 3 Asslgnee! Eaton Corporation, Cleveland, Ohl0 Page 680 August, 1970 Circuit Condition Indica- 22 Filed: July 22,1971 Carey 6131- [21 Appl. No.: 1653296 Primary ExaminerDonald J Yusko Attorney-Lynn G. Foster [52] US. Cl .340/147 R, 246/187 B [57] ABSTRACT [51] Int. Cl. ..B6ll 3/0 1), H03k 17/56 58 Field of Search ..307/9,114,311; A Communication System for controlling a mobile 191/1 4; 340/47 246/167, 187; vehicle comprising a trolley system transmitting com- 256/106 217 S H5/72 82 munication signals between an on-board station carried by said vehicle and a command station and in- [56] References Cited cluding photoelectric coupling means serving to pass signals between said trolley system and said stations, UNITED STATES PATENTS while electrically isolating said stations from said trolley system. 3,315,176 4/1967 Biard ..250/2l7 X 3,594,572 7/1971 Horeczkyn ..246/ 182 R 7 Claims, 2 Drawing Figures 7 T I l l l +sv l i l l 1- *1 I 1 1 287 1 l l 1 l 8 1 l i[ l 5v. l L 34 J V RETURN I T 1 6 s01 l |SCHM|TT 3 l I 1 l l l l l COMMAND STATION RECEIVE ,27' J ON BOARD STATION PATENTEU B I 3,735,352

I SHEET 2 0r 2 Z8\(COMMUNICATIONS) r 4 a 32 (GRND. (PHASE 2) 46 (PHASE 1) 4-4B PHASE 3) i COMMUNICATION TECHNIQUE FOR CONTROLLING CRANE OPERATIONS BACKGROUND 1. Field of Invention This invention relates to communication systems and is particularly directed to communication systems for controlling the operations of stacker cranes and the like.

2. Prior Art In recent years, the trend toward automation or computerized control has touched virtually every area of factory and warehouse operations and the like. However, no satisfactory system has been proposed, heretofore, for communicating with mobile vehicles, such as stacker cranes and the like. Because of the large amounts of iron and steel in such buildings and electrical noise generated by machines operating in the vicinity, radio communications are unreliable. On the other hand, the use of ribbon wires and umbilical cords restricts the mobility of such vehicles and is subject to disruption of communications due to damage or severance of the wire or cable.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION These disadvantages of the prior art are overcome with the present invention and a communications system is proposed which is simple and reliable, which is compatible with either manual or computerized control, and which is substantially unaffected by electrical noise in the vicinity.

The advantages of the present invention are preferably attained by providing a communications system employing a trolley system having an extra conductor in the trolley power rail and sharing the ground conductor between the power and communication systems, together with novel circuitry for transmitting and receiving communications employing photocoupling techniques for noise isolation.

Accordingly, it is an object of the present invention to provide improved communication system for vehicles, such as stacker cranes and the like.

Another object of the present invention is to provide communication systems for vehicles, such as stacker cranes and the like, which are substantially unaffected by electrical noise.

An additional object of the present invention is to provide communication systems for vehicles, such as stacker cranes and the like, which are compatible with either manual or computerized control.

A specific object of the present invention is to provide communication systems for vehicles, such as stacker cranes and the like, employing a trolley system having an extra conductor in the trolley power rail and sharing the ground conductor between the power and communication systems, together with novel circuitry for transmitting and receiving communications employing photocoupling techniques for noise isolation.

These and other objects and features of the present invention will be apparent from the following detailed description, taken with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic representation of a communication system embodying the present invention; and

FIG. 2 is a transverse section through the trolley power rail of the communication system of FIG. 1.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT In that form of the present invention chosen for purposes of illustration, FIG. 1 shows a command station 2 and an on-board station 4 coupled by a trolley system 6. The on-board station 4 is mounted on the vehicle to be controlled and is connected, through the trolley system 6, to the command station 2, which may be located in substantially any desired location.

As will be seen, the circuits of the command station 2 and on-board station 4 are identical. For convenience, the elements of the on-board station 4 are identified by primed reference numerals. Thus, each station 2 and 4 has a signal input 8 and 8' which is connected through the light-emitting diode l0 and 10' of a photocoupling unit 12 and 12' to a suitable voltage source 14 and 14'. The

phototransistor

16 and 16, of the photocoupling unit 12 and 12', passes signals to the base of a transistor 18 and 18' which triggers the

lightemitting diode

20 and 20 of a second photocoupling unit 22 and 22' which causes phototransistor 24 and 24' to apply signals to the output 26 and 26'. The collector of transistor 18 of the command station 2 is also connected to conductor 28 of the trolley system 6, while the collector of transistor 18 of the on-board station 4 is connected to brush 30 which slidably engages conductor 28, as more fully described below. Similarly, the grounded emitter of transistor 18 of the command station 2 is connected to conductor 32 of the trolley system 6, while the grounded emitter of transistor 18 of the on-board station 4 is connected to brush 34 of the trolley system 6 which slidably engages conductor 32. It will be seen that signals passed by either of the transistors 18 or 18' will be applied, either directly or through trolley conductor 28 and brush 30, to actuate both of the photodiodes 20 and 20'. Hence, a signal at either input 8 and 8' will result in the signal being passed to both

outputs

26 and 26. However, each station 2 and 4 includes suitable means for ignoring the signals originating therein, as indicated at 27 and 27'.

FIG. 2 is a transverse section through the power rail, indicated generally at 40, of the trolley system 6. As shown, the power rail 40 comprises an elongated, hollow-duct 42 formed of electrically insulating material and has five electrically

conductive strips

28, 32, 44, 46, and 48 spaced about the interior of the duct 42 and extending longitudinally therein. The duct 42 is disposed adjacent and parallel to all possible routes of the controlled vehicle. A trolley 50 travels within the duct 42 on wheels 52 and is rigidly connected to the controlled vehicle, not shown, by a hollow pigtail 54 which projects through a slot 56 extending along one side of the duct 42. The trolley 50 carries a plurality of electrically

conductive brushes

30, 34, 58, 60, and 62 which are resiliently urged into electrical contact with the

strips

28, 32, 44, 46, and 48 by suitable means, such as springs 64. Each of the

brushes

30, 34, 58, 60, and 62 is connected to a respective conductive wire 66 which passes through trolley 50 and pigtail 54 to appropriate components within the controlled vehicle.

In use,

strips

44, 46, and 48 of power rail 40 of the trolley system 6 each carry electrical power of a respective phase which serves to energize the motors to propel and actuate the controlled vehicle. As described above, conductive strip 28 of power rail 40 provides electrical connection between the command station 2 and on-board station 4 of the communication system, vehicle strip 32 provides ground return for both the power and communication systems. Command signals for the controlled vehicle, such as START, STOP, FORWARD, REVERSE, RAISE, LOWER, rate of speed, etc., are supplied to input 8 of the command station 2 and may be originated from either a manual control panel or a suitable computer. The signals applied to input 8 cause photodiode 10 to emit light which causes phototransistor 16 to conduct and this, in turn, causes transistor 18 to conduct. The signals passed by transistor 18 will be applied directly to photodiode 20 and will also be applied through conductive strip 28 and brush 30 of the trolley system 6 to photodiode 20', causing both of the photodiodes 20 and 20' to emit light. Hence, both

phototransistors

24 and 24 will pass the command signals. Phototransistor 24 will pass the command signals to output 26' of the on-board station 4 where they will be applied to the appropriate components of the controlled vehicle to cause the vehicle to execute the commands.

Signals may be applied to input 8 of the on-board station 4 by any appropriate sensor devices carried by the controlled vehicle to indicate the condition and location of the controlled vehicle. These signals will be transmitted by the on-board station 4 and will be passed through trolley system 6 and applied to output 26 of the command station, in substantially the manner described above, and these signals may then be passed to the computer logic or to appropriate indicators on the manual control panel. It will be seen that, although the trolley system 6 is exposed to electrical noise, the

photocoupling units

12, 12', 22 and 22 serve to completely isolate such noise from the input and output circuits.

Obviously, numerous variations and modifications may be made without departing from the present invention. Accordingly, it should be clearly understood that the form of the present invention described above and shown in the accompanying drawing is illustrative only and is not intended to limit the scope of the invention.

What is claimed is:

1. A communication system for mobile vehicles comprising:

a command station having an input circuit for transmitting command signals to said vehicle and an output circuit for receiving sensor signals from said vehicle,

an on-board station mounted on said vehicle and having an output circuit for receiving command signals from said command station and an input circuit for transmitting sensor signals to said command station,

a trolley system extending adjacent and parallel to desired routes of said vehicle and serving to transmit driving power to said vehicle and to electrically connect and carry said signals between said command station and said on-board station, and

photocoupling means communicating signals between said command station and said on-board station by transmitting signals to and receiving signals from said trolley system while electrically isolating the input and output circuits of said stations from said trolley system.

2. The communication system of claim 1 wherein said command station comprises:

input means for signals to be transmitted;

a first photocoupling unit including a first photodiode connected to receive signals from said input means andserving to emit light signals indicative of the signals received from said input means, and a first phototransistor optically coupled to said first photodiode and serving to pass electrical signals indicative of said light signals;

a transistor connected to said first phototransistor and serving to pass said electrical signals to said trolley system;

a second photocoupling unit including a second photodiode connected to receive said electrical signals from said trolley system and to emit optical signals indicative of said electrical signals, and a second phototransistor optically coupled to said second photodiode and serving to pass electrical output signals indicative of said optical signals; and

output means connected to receive and pass said electrical output signals.

3. The communication system of claim 2 wherein:

said on-board station is substantially identical to said command station in circuit operation.

4. The communication system of claim 2 further comprising:

means for shunting said electrical output signals to ground when signals are being applied to said input means.

5. The communication system of claim 1 wherein said trolley system comprises:

a power rail having an elongated hollow duct composed of electrically insulating material and formed with a slot extending longitudinally along one side thereof;

five electrically conductive strips mounted in spaced relation within said power rail and extending longitudinally thereof,

a trolley movable within said power rail and having a hollow pigtail extending through said slot of said power rail and connected to said vehicle,

a plurality of electrically conductive brushes carried by said trolley and each resiliently urged into electrical contact with a respective one of said conductive strips, and

a plurality of wire means each connected to a respective one of said brushes and extending through said pigtail to respective components of said vehicle.

6. The communication system of claim 5 wherein:

three of said five conductive strips each carry electrical power of a respective phase for energizing the motor of said vehicle,

the fourth of said five conductive strips provides electrical connection between said command station and said on-board station for transmission of communications therebetween, and

the fifth of said five conductive strips is a ground return line common to the power system of said vehicle and to said communication system.

7. A communication system for mobile vehicles comprising:

between said command station and said on-board station by transmitting signals between said input and output circuits of said stations while electrically isolating said stations from external noise.

Claims

1. A communication system for mobile vehicles comprising: a command station having an input circuit for transmitting command signals to said vehicle and an output circuit for receiving sensor signals from said vehicle, an on-board station mounted on said vehicle and having an output circuit for receiving command signals from said command station and an input circuit for transmitting sensor signals to said command station, a trolley system extending adjacent and parallel to desired routes of said vehicle and serving to transmit driving power to said vehicle and to electrically connect and carry said signals between said command station and said on-board station, and photocoupling means communicating signals between said command station and said on-board station by transmitting signals to and receiving signals from said trolley system while electrically isolating the input and output circuits of said stations from said trolley system.

2. The communication system of claim 1 wherein said command station comprises: input means for signals to be transmitted; a first photocoupling unit including a first photodiode connected to receive signals from said input means and serving to emit light signals indicative of the signals received from said input means, and a first phototransistor optically coupled to said first photodiode and serving to pass electrical signals indicative of said light signals; a transistor connected to said first phototransistor and serving to pass said electrical signals to said trolley system; a second photocoupling unit including a second photodiode connected to receive said electrical signals from said trolley system and to emit optical signals indicative of said electrical signals, and a second phototransistor optically coupled to said second photodiode and serving to pass electrical output signals indicative of said optical signals; and output means connected to receive and pass said electrical output signals.

3. The communication system of claim 2 wherein: said on-board station is substantially identical to said command staTion in circuit operation.

4. The communication system of claim 2 further comprising: means for shunting said electrical output signals to ground when signals are being applied to said input means.

5. The communication system of claim 1 wherein said trolley system comprises: a power rail having an elongated hollow duct composed of electrically insulating material and formed with a slot extending longitudinally along one side thereof; five electrically conductive strips mounted in spaced relation within said power rail and extending longitudinally thereof, a trolley movable within said power rail and having a hollow pigtail extending through said slot of said power rail and connected to said vehicle, a plurality of electrically conductive brushes carried by said trolley and each resiliently urged into electrical contact with a respective one of said conductive strips, and a plurality of wire means each connected to a respective one of said brushes and extending through said pigtail to respective components of said vehicle.

6. The communication system of claim 5 wherein: three of said five conductive strips each carry electrical power of a respective phase for energizing the motor of said vehicle, the fourth of said five conductive strips provides electrical connection between said command station and said on-board station for transmission of communications therebetween, and the fifth of said five conductive strips is a ground return line common to the power system of said vehicle and to said communication system.

7. A communication system for mobile vehicles comprising: a command station having an input circuit for transmitting command signals to said vehicle and an output circuit for receiving sensor signals from said vehicle, an on-board station mounted on said vehicle and having an output circuit for receiving command signals from said command station and an input circuit for transmitting sensor signals to said command station, and photocoupling means for providing communication between said command station and said on-board station by transmitting signals between said input and output circuits of said stations while electrically isolating said stations from external noise.