Advanced Supervision Laser Based System of the Overhead Cranes

Copyright © IFAC Infonnation Control in Manufacturing, Nancy - Metz, France, 1998

. \D\ · A~CED S(-PER\"JSIO~

L.\SER BASED SYSTE\I OF THE OYERIIEAD CR\~ES

Janusz

Szp~1ko

University of Mining and Metallurgy, Mickiewicza Ave. 30, PL 30-059 Cracow, Poland

Abstract: The paper aim is the integrated monitoring system of the complex metallurgical de,ice quality operation. presented on the metallurgical overhead travelling crane example. Its results industry needs. The paper objectives are method and tools supporting the overhead cranes diagnostics. COp'\righr g;. 1998 IFAC Keywords: automation. diagnostic. laser technique. monitoring. overhead crane.

I. INTRODUCTION

the lifting capacity of 20 t have been around 80% of all operating cranes number.

Material handling devices are an essential element in the Steel Plants. especially into the Computer Integrated Manufacturing (CIM) systems. The key place into the material handling devices are playing overhead cranes: goods displacement support the technological process. limited time goods storage. These functions have been increasing with the higher level of metallurgical system flexibility and automation (Horte and Lindberg. 1991). The overhead crane is an example of the manufacturing high cost unit product operating mostly in the special conditions. Handling facility requirements and quality needs include the necessary safety and reliability. diagnosis ability and accuracy of operational movements. The increasing both complexity of metallurgical process and devices used in the CIM system. required methods and tools supporting the quality operation of the de,ice. The major feature of the de,;ces will be their ability to adopt to an arbitrarily changing emironment and solve problems with less or "ithout human intervention.

Around 67% of all operating cranes number have been the overhead cranes general oriented (hook cranes. grabbing cranes). other are included to the special cranes group. The most large number have been overhead travelling cranes (79%). and portal bridge cranes (18%). The largest number of cranes installed into the Polish steel business are technological cranes (ladle cranes. open-hearth furnace charging cranes. casting cranes. electrodehandling cranes) - app. ~6%. as well as the material handling overhead travelling (transport) cranes app. 23%. The main manufacturing plants of the overhead cranes in Poland arc: Fabryka Urntdzen DZwigowy'ch Minsk Mazowiecki. Gliwickie Zaklady Umtdzen Technicznych. Fabryka Maszyn i Urntdzen FAMAK w K1uczborku. Huta Zabrze. Mostly the O\'erhead cranes failures are around ~3 . 7% of all number of technological de,'ices operating into the metallurgical plants. The results of overhead cranes failures are as follow as: bridge wheel wear (app . .J~%). wear of the rope and rope handling units (e.g.: sheave. rope drum) - app. 26%. As the result of the investigation done at the selected metallurgical plant on the representative group of the 20 t lifting capacity overhead cranes we concluded that:

We estimate the total number of overhead cranes in Poland during 1995 for 60.000. Only approximately 59 % of the total number of the overhead cranes have been under the technical inspection. Left number of cranes have been under the re-design. stand-by. scrapping or selling. (h'erhead cranes "ith

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Its results industry needs. The paper objectives are method and tools supporting the overhead cranes diagnostics.

- results of failures are: overloading, crane operating and maintenance errors - wear of the single crane unit have been around 75% of all failures reasons - the failure have been find out mostly during the inspections (app. 63%) - unit replacement have been the method of fault correction (app.91 %).

2. TIffi INTEGRATED OVERHEAD CRANE TECHNICAL STATE ESTIMATION SYSTEM As a result of applied forces, the realisation of

The cranes are under the technical inspection. Their technical condition is described by the tolerance zones of the selected crane exploitation parameters. The crane exploitation parameters tolerances are based on the standards, for example: ISO 8306 (Cranes. Overhead travelling cranes and portal bridge cranes. Tolerance for cranes and tracks), PN-911M:-45457 (Cranes. Tracks of overhead travelling cranes. Requirements), PN-891M:-45453, as well as manufacturing or branch rules and guidelines (e.g.: VDI 3571, ZN-84/1232-74392).

motion mechanisms control, external influences a time variable force appears and the resulting in device displacements. The estimation of the quality of the device or its assemblies and elements has been developed to check whether forces would not exceed accepted bounding values. The effects of bounding values being infringed are permanent changes in the geometry of the elements/assemblies due to deformation, wear or clearance. Such changes deteriorate at the device quality and in extreme cases result in permanent defects eliminating a device from further operation.

As the results of design characteristics of the overhead cranes (large bridge dimension, small ratio wheel base in end-sill to bridge span, limited bridge displacement into vertical to the crane tracks direction in horizontal plane, mostly continuously operation into limited working space house and long crane track distance) the crane technical inspections (e.g. bridge and railway geometry) are rather between long time period units, mostly when other technological devices involved into the manufacturing process are under the inspection, too. The operational characteristics of the overhead cranes and especially that of the associated units bridge construction and bridge drive mechanism system have operational phenomena that differ principally to those occurring in other handling facilities.

The satisfying user quality level of the overhead crane is possible to obtain through controlling his chosen exploitation parameters during design, manufacture, operation and maintenance life phases of the device (Szpytko, 1996). During the crane operation the device chosen operational parameters should not exceed their designed tolerance zones. To design the tolerance zone of the device operation parameters the crane construction feature, operation needs and surrounding conditions must be calculated. The design process is hard and must be based on the logistic engineering. The integrated approach to the exploitation of the technological devices is described at the book (Szpytko, 1996). The crane technical state estimation approach is based on the selected operational parameters monitoring results and analysis (Szpytko, 1991). Its results with the device necessary maintenance range description and keeping the crane on the required operation quality level. The above is possible as the results of developed the integrated overhead crane technical state estimation system approach - Figure I (Szpytko, 19%).

The low level detection of the backgrounds of the future crane failures during the device is operation results that inspection are mostly during periodical survey. The technical inspection of the crane bridge and track operational parameters are technically difficult. Moreover not always changes of the operation parameters of the crane units or crane track into the suggested by the standards tolerance zone guarantee overlooked device quality operation level. The crane failure reason and results analysis are hard, because mostly data base storage and utilisation system of the overhead cranes events during the exploitation life phase doesn't exist.

During monitoring of the device operation the focus must be oriented to the product running results, which are represented by the exploitation parameters of the crane:

q The running overhead cranes number in each industrial country is rather large, especially into the metallurgical business. Cranes are playing the key position in the technological process, so their high exploitation quality (both operation and financial aspects) is strongly overlooked The paper aim is the integrated mOnitoring system of the complex metallurgical device quality operation, presented on the metallurgical overhead travelling crane example.

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f(m j ±.:1a j • e. c. t)

where: q - device operating characteristics a, - i-th operational parameter of the device m; - nominal value of the i-th operational

parameter a j .:1 a,

- existing error of the i-th operational parameter a j

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The selected parameters have the importance influence at the product actions (metallurgical process). The results coming from the monitoring system are the set-up of the future product quality improvement (through the controlling of the exploitation parameters of the device during its r~ design or design activities).

- controls of the device movement mechanisms - surrounding influences and reactions (e.g .: geometry of the railway of the crane bridge) - time.

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The crane quality estimation is being obtained by the algorithm contain global and local levels. The global level comprises measurement of an device operation (motion) results over the entire work time where the local one measures the errors within the crane units (assemblies and fits), e.g . crane track geometry, angular deviation of the wheel in the horizontal plane. In the integrated monitoring system sensors and control unit are playing the principal position. The crane sensor system has the hierarchical structure following the device operation structure. Through sensor we are observing the operation parameters of the device and supporting control unit. The monitoring system must stop the device operation, when the observed operation parameter(s) is outside his tolerance zone or to correct it when it is necessary. So we are calling that to the sensor a artificial intelligence has been in-build.

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3. OPTOELECTRONIC BASED CRANE MONITORING SYSTEM estimation on the g/obaJ kvel

Theodolites and levelling, as well as a strain gauges are the most popular instruments used into the overhead cranes inspection. Their application at the overhead cranes inspection results metrological and integration difficulties. Moreover the inspection results interpretation and analysis difficulty. To solve the above problems the integrated measurement (monitoring) system of the overhead crane have been work out at the University of Mining and Metallurgy, Cracow - Figure 2 (Szpytko and Stupnicki, 1992a; Szpytko and Stupnicki, 1992b; Szpytko and Stupnicki, 1993; Szpytko, 1996). The monitoring of the overhead crane is based on laser and visual techniques. The system., with a module structure, allows for remote both static and dynamic measurements in noncontact and automatic way with accuracy required for this class of the crane devices, as well as storage measuring results database.

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decision: to stop the device operation decision: to continue the device rvmung operation

Emitted by the laser transmitter (I) optical beam is forming into the constant measuring base. The crane characteristic, as well as the railway characteristic changes are described with regard to the measuring base. The laser transmitter is based on the H~Ne or IR type diodes (ca. 1.0 - 3.0 mW).

Device subsystems tcc!JniuJ state

estimalion

The overhead crane characteristic is recorded by the optoelectronic measurement system (3). The crane railway characteristic is as the outcome of the rails

Fig. 1. The integrated technical state estimation system of the overhead crane (Szpytko, 1996).

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condition of the crane and crane track/rail can be concluded.

geometry testing by the automated guided rails' measuring robot (4). The measuring robot has been developed at the University of Mining and Metallurgy, Cracow. The robot can measure and record in each t moment (or in each rail section on its length): - rails displacements under the crane is running - geometry of the rail: deviations from linearity in the horizontal and vertical plane, width of the rail head, actual distance of measurement section (point) of rail from the beginning of the rail (the first measurement point), - environmental conditions or other additional necessary information.

The recorded examples of the crane rail geometry and movement characteristic of the crane bridge are presented on Figure 3 and Figure 4.

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Fig. 4. Parameters (x, q» of the device operating characteristic (x - movement and q> - rotation in the horizontal plane).

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Fig. 2. Integrated monitoring system of the crane (Szpytko, 1996): 1 - laser transmitter, 2 - laser beam guiding system, 3 - measuring system of the crane, 4 - automated guided rails' measuring robot, 5 - measuring system of the components, 6 - positioning system, 7 - overhead crane, 8 - rails of the crane railway (track), 9 - database transmission system, 10 - CCD camera, 11 strain gauges.

The crane bridge geometry and movement mechanisms geometry changes and their characteristics are recorded by the component measurement system (5). The component measurement system (5) is possible support with the Position Sensing Photo-detectors (PSD) and others (e.g.: strain gauges (11), fiberoptics, etc.). The crane operation precision and the crane with other devices operation co-
The measuring accuracy is ±1,0 mm, range about 30 m. The measurement data are storage in the database system. Using Personal Computer and special image analysis software the technical 358

type, IBEO Lasertechnik system, etc.) and CCD cameras. The distance sensors, updated with in-build feedback system, are useful into the crane bridge bevelling compensation.

measuring results database storage. Has a module structure and artificial intelligence in-build, as well as ability to solve problems with less or without human intervention.

As the results of joint CCD cameras (10) allocation into the crane operation space and supported by the special software, the following are possible to record: 1. the technological operation movements into 3D operation space, 2. the crane selected operation parameters changes, 3. the surrounding influence change (Szpytko, 1993), e.g. : temperature gradient.

The integrated overhead crane technical state estimation system has been supported by measuring tools. The rail (crane track) measuring (automated) robot has been developed. The module robot structure make possible to use his units to measure bridge and travel mechanisms geometry changes. The robot system is based on the laser technique and image analysis. Moreover the measuring results database storage and analysis system (of the crane and track) have been developed.

To help better device accuracy the lifting mechanism of the overhead crane rope swing compensation system has been developed, by the Eurolase and University of Mining and Metallurgy (Hansel, et al., 1996). The non-contact measuring system VeroSowing type, based on the Hall effect sensors, is available for 20-40 mm radius rope. The rope swing (displacements) radius is of ±70 mm, where the temperature change range is of 0-60°C; the measuring error is ±5%.

The crane and handling goods positioning integrated system has been designed The overhead crane rope swing compensation system help better device accuracy the lifting mechanism.

REFERENCES Hansel, J., KwaSniewski, J., Tytko, A , Laokosz, L.

(1996). Sensor for measuring the swing of a cable including a crown with permanent magnets secured to the cable. US Patent No 5.502.379.

4. CONCLUSIONS

Horte, S.A, Lindberg, P. (1991). Implementation of advanced manufacturing technologies: Swedish FMS experiences. International Journal of Human Factors in ManufactUring, 1, no 1, 5573 . Szpytko, J., Stupnicki, S. (1992a). The crane track geometry laser measuring system. Polish Patent no 279895. Szpytko, J., Stupnicki, S. (1992b). The crane bridge movement laser measuring system. Polish Patent no 278644. Szpytko, J. , Stupnicki, S. (1993). The optoelectronic

The overhead travelling cranes are playing the key position in the technological process at the metallurgical plants. Cranes are one of the largest technological metallurgical devices. The number of failures of the cranes into all technological devices operating into the metallurgical plants is rather large and is around 44 % . Increasing quality needs of modern today steel plants results with decreasing level of cranes failures, and their increasing flexibility and automation. Handling facility requirements and quality needs include the necessary safety and reliability, diagnosis ability and accuracy of operational movements. The above needs are possible to obtain as the integrated crane technical state estimation system approach, which should be introduced to the manufacturing plant. The approach is based on the logistic engineering.

displacements measuring based system of the large dimensional devices. Polish Patent no 301555. Szpytko, J. (1991). Analysis of motion trajectory of large-dimensional rails' transport facilities for diagnostic needs. ACTA IMEKO, Measurement

of force, mass, pressure, flow and vibration, 397-402. Szpytko, J. (1993). The diagnostic method of bridge of automated cranes used in metallurgical plants. Proceeding on International Conference on Engineering Software (Staffordshire University ed.), pp.181-185, Stafford. Szpytko, J. (1996). Integrated supervision system of

The integrated diagnostic system of the overhead crane is based on developed at the University of Mining and Metallurgy, Cracow: - the integrated overhead crane technical state estimation system. - monitoring tools supporting diagnostic system, - lifting mechanism of the overhead crane rope swing compensation system.

the chosen exploitation parameters of the largedimensional rails' handling device on the automated overhead crane example. The Science

The integrated overhead crane technical state estimation system is based on the laser technique, and is allows for remote both static and dynamic measurements in noncontact and automatic way with accuracy required for crane devices, as well as

Journal of the UMM Cracow, Dissertation and Monographs, Vol. 46. University of Mining and Metallurgy (UMM) Press, Cracow.

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