Automation in Construction Volume 9 issue 5-6 2000 [doi 10.1016%2Fs0926-5805%2800%2900060-1] R.D...

8/13/2019 Automation in Construction Volume 9 issue 5-6 2000 [doi 10.1016%2Fs0926-5805%2800%2900060-1] R.D Schraft

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Automated cleaning of windows on standard facades

Abstract

The aim of this applied research project is a cleaning robot which automatically cleans the outside of windows on a facadewith vertical jambs and horizontal bars. The facade has to possess certain constructive properties. This interface enablesthe cleaning robotwhich is detachable from the building and portableto operate on any respectively designed facade onseveral buildings. A special cleaning-head keeps the water used for cleaning in a constant cycle. It is wielded through a filterand reused. The cleaning robot in operation is quicker, safer and cheaper than manual cleaning. Its use is environment-friendly and considerate with regard to resources.

1. Introduction

The architecture of modern buildings reflectsincreasingly complicated and extravagant forms andmaterials. Often, a buildings geometry is so complexthat it is impossible to reach every corner of it forcleaning, maintenance and repairs with common

meansw

2x.

In particular, the cleaning of large glass facades isa very important task, which has to be carried outregularly.

Large, expensive and extravagant buildings moreand more require the development and realization ofspecial devices in order to reach and clean them

properly. In addition to that, a survey made by

Fraunhofer IPAw

4x

in 1998 shows that the personalcosts for cleaning the facades windows. of buildingsare up to 70%. To reduce these expenses by using an

) Corresponding author. Tel.: q49-711-970-1330; fax: q49711-970-1008.

E-mail address:[email protected]. Brauning

.

.

automated facade cleaning robot will open hugeeconomy savings.

The Standard Facade cleaning Robot SFR. is a

low-costw

1x

and tough alternative for facades withvertical jambs and horizontal bars that means withregularly repeating geometric forms e.g. see Fig. 1..

As the survey of the Fraunhofer IPAw

2,4x

andmarket analyses have shown the most useful andeconomic relevant system would be a cleaningsystem for buildings with a height up to eight stories.

This development of a cleaning system for facadeswill confirm the change within the fields of researchfrom the regular industrial use to the use in thefields of services with very high requirements to

sensors and data processingw

3,5x.

2. Occurring problems

Nowadays, the problems occurring in manual

cleaning especially medium and large sized buildings0926-5805r00r$ - see front matter q2000 Elsevier Science B.V. All rights reserved.


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490 R.D. Schraft et al.rAutomation in Construction 9 (2000) 489501

PII: S0926-580500.00060-1

Fig. 1. The front view of a exemplary facade with vertical jambsand horizontal bars.

are encountered very often and nearly everywhere.Even if there is a system fixed to the building to givethe workers access during their cleaning job, themanual work is physically hard and the effective

cleaning speed and quality is very loww

4x.

If there are no such systems for manual access tothe building available because of saving money,

precipitate planning or because there are no technicalsolutions at all. this may entail intricate anduncomfortable constructions and work conditions forthe workers as shown in Fig. 2 or Fig. 3. However,

very often no other possibilities to clean suchbuildings are left at the moment.

Fig. 2. Manual cleaning with a special truck mounted lifting rampand two workers.


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R.D. Schraft et al.rAutomation in Construction 9 (2000) 489501 491

Fig. 3. Manual cleaning with a ladder bounded to the building byseven workers.

These pictures show two examples how nowadaysthe windows of facades are cleaned sometimes.

With the possibilities of the actual, moderntechnologies kinematics, sensors, computers, etc.

.

this kind of work has to be replaced by automatedsolutions.

3.Cleaning3.1. Basics

To meet the wide-ranged requirements in thefields of cleaning, the Fraunhofer IPA is carrying outresearch and development in the following domains:

production agriculture food

productionand trade

motor industry chemistryand pharmaceutics buildingsindoor and outdoor. printingindustry.

To obtain the best possible and best economicsolutions for cleaning problems, specific research and

development is done in three different stepsw

6x.

3.1.1. Aoiding cleaning tasks

For reasons of economy, it is desired to avoid asmany cleaning tasks as possible. This can be done,e.g. by using different or changing processes. Toanalyze problems and to develop and define solutions

Fraunhofer IPA is using different tools: for examplebenchmarking, different methods for analyzing andinvestigating the structure of the cleaning problem.

3.1.2. Reducing cleaning tasks

If it is not possible to avoid all cleaning tasks,Fraunhofer IPA tries to reduce at least the number or

the extend of cleaning tasks e.g. by frequency,complexity, duration andror hazardousness.. Possibleactions for reducing cleaning tasks are determined by

performing analyses and studies.

3.1.3. Automating cleaning tasks

If it is neither possible to reduce cleaning tasks thethird step is to automate these cleaning tasks. Bychanging or developing new systems, it is aimed todecrease manual work. The aim is to reduce costs,cleaning time, hard and hazardous manual work.

3.2. Cleaning windows

Within the large field of cleaning the inside andthe outside of buildings, the cleaning of windows isan important field for research and development.Fraunhofer IPA has considerably researched ondifferent cleaning methods and principles. Differentmanual and automated cleaning devices have beentested. With an experimental setup as it is shown inFig. 4, it is possible to investigate these differentcleaning methods.

By changing repeatable and selected boundaryconditions and process parameters, the cleaningresults can be described in their quality and quantity.

Fig. 4. Experimental setup.

Thus, for each cleaning problem in windowcleaning, depending for example on the situation ofdirt and environmental situations, the best cleaningmethod and procedure can be determined.


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4. Other principles for cleaning windows of

facades

At the moment, there are three unique systems,which are bounded to one building, for automated

cleaning of the windows of facadesw

5x

:

The cleaning robot for the fair of LeipzigFraunhofer IFF, Germany.

A prototype of Siriusc IFF. shown at the HMI 99in Hannover, Germany

The cleaning robot for the Louvre in Paris, Francecompany: Comatec..

However, there are no automated systems whichstart from the ground and going up to the roof toclean the facades, without using any roof-boundedconstructions and which are not fixed bounded toonly one building. One of the most obviousadvantage of such a system would be that there is noneed for lifting the whole system on top of the roof ofthe buildings by mans help.

5. Quality function deployment (QFD) 5.1.

QFD

QFDw

7,8x

is a method to meet and increasecustomer satisfaction. With the help of this method, it

is possible to determine the customers needs andrequirements. For the developers and designers, theseneeds and requirements are transformed in qualitycharacteristics. These are technical definitions andattributes of the new system. The customers needs

and the quality characteristics are evaluated andassessed depending on their importance. The basicelements which are used in applying QFD are:

customer requirements

quality characteristics

functions new concepts

components single element work procedures.

The use of the elements depends on the tasks fordeveloping. The more precise the solutions have to

be, the more elements have to be used. Then, it ismade sure that all customer requirements aretransformed all the way down to the whole productdevelopment and the production.

Therefore, QFD offers different tools like:

lists

comparison one by one.

triangle matrixes

matrixes

tables

diagrams

To unburden the developers there are some

software tools to guide the user, calculate and printout the results e.g. different kinds of graphs, tables,roadmaps and overviews..

There are two principle ways of proceeding. The

principle of Akaow

9x

which is called waterfallmodelis linear and done step by step.

To react on problem specific situations there is asecond way of carrying out the QFD-process. Thedeveloper chooses the necessary matrixes out of thematrix of matrixes. This proceeding was defined

by Kingw

10x

. So this leads to more freedom, userspecific and faster work. The disadvantage is that theuser needs more experience to get good enoughresults.

5.2. Deeloping the cleaning robot with QFD

At the beginning of concepting and developing therobot system, the general requirements, theguidelines and the customer requests andrequirements are recorded.

The determining of quality characteristics and

their importance takes place with the help of the QFDmethod.

One of the Houses of Quality HoQ. is shown asan example in Fig. 5. The correlation of the qualityfeatures have been determined and can be seen in thetable.


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As a result, the table shows the sensitivity of thewhole system, the critical components and the

positive and negative correlation of the qualityfeatures. So in the ongoing research and developmentit is very easily possible to concentrate on thesecritical and sensitive components.

The tables of the QFD lead to the most importantcustomer requirements, which are:

a safe system, no danger or hazardous for persons

workers and passers-by. and buildings

high quality of the cleaning result

good and easy service

no molestation for the people living in thebuilding.

Fig. 5. Sample table taken from the QFD method qualitycharacteristics..

The tables of the QFD lead also to the mostimportant quality characteristics, which are:

safety

cleaning robots stability cleaning robots torsion

supply and disposal of cleaning medium

maximum loadedrunloaded weight

dimension of the cleaning robot length, heightand width..

These customer requirements and qualitycharacteristics play a determinant role in the furtherongoing research and development.

6. First drafts and system conception

After determining customer-related features, firstideas and various principles are developed andworked out see example sketches in Fig. 6..

The research and development was focused on asystem for facades with regularly repeating geometryand a system with uncomplicated and robustkinematics.

As the customer requirements ask for a systemwhich is usable on several buildings and without theneed to go on the roof of the buildings, the focus of

the further project work is on the question of how toconnect and drive the robot to and on the facades.

The first ideas and drafts have been leading to firstsimulations and computer models Fig. 7..

Not only the customer and technical requirementshave to be met and fulfilled but also the needs ofarchitects and the users of the building in future.

The derived requirements for the kinematics arethe following: modular, easy to control, adjustable

Fig. 6. First ideas and drafts of the principles, I.

Fig. 7. Computer model.


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and robust. One idea in this respect is shown in Fig. 6third picture..

The various solutions for partial systems andcomplete systems are assessed according to whatdegree these solutions match the quality featureswhich were determined beforehand. Then the choice

is made. The chosen solution with the mostadvantages for the final users according to therequirements is now tested with a series of furthersimulations and experiments in order to find out whatits realization would be like.

7.SimulationFor a better and quicker development, there have

been made simulations to check first ideas andconcepts without any expensive field tests.

7.1.Simulation robotThe pictures Figs. 8 and 9. of a simulation show

the pragmatic solution.

Fig. 8. Simulation robot, excerpt 1.


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Fig. 9. Simulation robot, excerpt 2.

7.2.Simulation modular facade kit (MFK)As mentioned in Section 4, to use the cleaningrobot on several facades and different buildings, the

facades have to posses certain requirements andconstruction features. Especially the two sides of theinterface between the facade and the robot have to fittogether. Therefore, the pre-experimental setup haselements for guidance and elements for the traction.This interface is the main part of the further ongoingresearch and development for obtaining a cheaper,easier and lighter solution.

In a next step, a MFK should be defined anddeveloped. This MFK will consist of certain basicelements for example: straight elements, elementsfor corners, roofs or domes.. With these basicelements it will be possible to compose the desirede.g. by architects and end-users. facade. Possibleexamples of such basic elements are shown in thenext pictures Fig. 10..

Fig. 10. MFK, basic elements.

Fig. 11. MFK, facade 1.

To increase the freedom of designing the facades,it is possible to add new and different elements.

With the four shown basic elements it will bepossible to build facades like seen in Figs. 11 and 12.These facades are representing a huge spectrum ofthe used an build facades for cost-sensitiveconstruction.

The resulting aim is to have these kinds of facadesrespectively, these kinds of elements. cleaned by theSFR.

8.The technical implementation8.1. Technical implementation robot (SFR I)

The first experimental setup Fig. 13. of aprototype of the SFR I serves the purpose ofmechanical


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Fig. 12. MFK, facade 2.Fig. 13. The initial experimental setup SFR I..

pre-experiments and various cleaning experiments, aswell as the exhibit at the IRW fair in Cologne,Germany.

Within this first prototype, the kinematics aredesigned for cleaning one window with differentcleaning methods cleaning heads, end effectors. anddifferent cleaning procedures e.g. linear, circular or

randomized.

. The control and the supply unit powerand water. is designed as an external module see

behind the window of the facade element in Fig. 13..

The result of the work with prototype SFR I is aknowledge of cleaning methods e.g. different data

bases. and cleaning procedures first experiences..

8.2. Technical implementation robot (SFR II)

These results determine the further interpretation,the details and the design of the second robot SFR

II.. A simulation is produced first as described inSection 7., in order to show and verify an entirecleaning cycle.

The facade has to be slightly modified in order to

tie the cleaning robot to it.Fig. 14 shows in a total view all the components

of the whole cleaning system for cleaning standardfacades in its second experimental setup: the robotsystem itself 1., the facade 2. built up in thelaboratory of Fraunhofer IPA, the supply unit 3., the

Fig. 14. Total view of the standard cleaning robot SFR II.

control unit 4. and the umbilical cord 5.. Figs. 1523 show details of the facade and the robot system.

The SFR II possesses three degrees of freedom.The kinematics is designed like a portable robot with


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Fig. 15. A camouflage prototype of a cleaning head of theDornier-Technology.

Fig. 16. Picture 1 outside view..

three linear axis. The robot runs up and down the rowof windows with the y-axis. The x-axis ensures thatthe cleaning head moves on the pane from the left tothe right. Thez-axis enables the delivery to the pane,over and across the horizontal bars, any kind of sun

blinds or other obstacles. Safety precautions orroadblocks and Emergency-Stop functions are

provided and implemented.The standard cleaning robot SFR II is put up at the

joint interface on this modified facade. The controland supply unit is connected via the umbilical cord.

After starting the system, the robot now fullyautomated cleans the three test windows. These areseparated by horizontal bars which stick out from the

surface. These are to be overcome by the cleaninghead during the cleaning process.

Fig. 17. Picture 2 outside view..Fig. 18. Picture 3 outside view..

The cleaning robot is connected to a supply unitand a control unit through hoses and cables. Itsupplies the cleaning head with water and processesthe sucked off used water. It consists of a pressure

pump, a suction device, a filter and a tank. Thecontrol unit is in charge of the regulation and controlof the entire system. It is connected with the sensors

and the servo motors of the robot throughinformation and performance cables. The computerwill calculate in advance the necessary movementsaccording to the facade which is to be cleaned.

During the experiment, optimization potentials areworked out and collected for the further developmentof the facade cleaning robot.


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The next step of development consists ofminimizing the components, making the robot systemsuitable for manufacturing and assembly.

Fig. 19. Outside focused view.


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Fig. 20. Inside view.

The user interface ManMachine-Interface,

MMI.

has to be designed simple and safe. Safety hasto be ensured at all times for people, as well as forthe building itself.

8.3. Technical implementation of the cleaning head

The cleaning head is a special development of theDornier-Technology and protected by copyright. Fig.15 shows the view of one of the first camouflaged

prototypes of a cleaning head through a window fromthe inside of a building.

The cleaning consists of an abrasive procedurewith rotating brushes, water and cleansing agent,measured out according to the need and the degree ofdirt. The area of cleaning is watertight. The cleaninghead floats on a thin surface of water and

Fig. 21. Overcoming obstacles 1.

Fig. 22. Overcoming obstacles 2.

does not scratch the panes. Since the water is suckedoff at the outer edge, it is possible to reuse it several

times by recycling it through a filter. The cleanedwindows are immediately dry and free of streaks.

With the described one and other types of cleaningheads, various cleaning experiments have beenexecuted, taken down and analyzed: individual testsand endurance tests, varying kinds and degrees ofdirt, varying panes and kinds of glass, varyingstainresistant or nonstick coatings.

9.Cleaning experimentsAs described in the last section, several cleaning

experiments have been made. The following picturesFigs. 1618. show the movement and the results ofthe standard cleaning robot SFR II. The robot begins


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Fig. 23. Overcoming obstacles 3.its cleaning cycle in the upper left corner of thefacade element. Then the cleaning head is movedmeandering going right, down, left, down, right andso on. downwards. The robot is cleaning windowafter window until it reaches the bottom of the

building here: the facade element.

.

9.1. Cleaning cycle (outside iew)

In Fig. 16, the robot has moved the cleaning headonto the window. The brushes are rotating, water andcleansing medium are injected and the used water isremoved and sucked off.

Now the robot is moving the best cleaning cycle.The speed is adjusted to the grade of pollution withdifferent kinds of dirt. In Fig. 17, the cleaning head is

being moved all the way to the right.

After reaching the right end of the window, therobot moves one cleaning head height downwards.

After reaching the next row to be cleaned, the nextlinear cleaning movement can be fulfilled all the wayto the left.

According to the above described movement tothe right, the SFR is moving to the left.

After reaching the left end of the window, the

downwards movement exactly the height of thecleaning head. will be started. Then the next cycle ofthe meandering path will be executed.

The overcoming of the horizontal bars and otherobstacles is shown in Section 9.4.

9.2. Cleaning cycle (outside focused iew)

To demonstrate the very good cleaning results,Fig. 19 shows details of the described cleaning

procedure. It can be seen that the area under thecleaning head is the area to be cleaned and the area

over the cleaning head is the window with a newshine and a clear view.

9.3. Cleaning cycle (inside iew)

The same cleaning process is now seen in Fig. 20from the inside of the building that means theexperimental setup SFR II in the testing fields of theFraunhofer IPA..

The people living or working in the building caneasily see and recognize the ongoing cleaningprocess. But they will not be disturbed by any loudcleaning noises or electric devices.

9.4. Oercoming obstacles

The next three pictures Figs. 2123. show howthe cleaning robot is going over obstacles. In thisexample, it is a horizontal bar of the facade. Thishorizontal bar is a periodical occurring element.

In addition to that, the robot is as well able to

overcome obstacles e.g. tilted windows, devices forshading and air conditioning and all elements

projecting from the window-layer, if they do notexceed a maximum height. This maximum heightdepends on the robots construction and kinematics.

10. Results

The tests show that it is possible to realize thecontrol, sensoring and kinematics but it still needsmore research that goes beyond the current state-ofthe-art. Last but not least, the progress in thetechnical fields is steadily going on, so the aim ofminimization of the systems geometric extension

will be reachable.

Business economic studies give clear evidence forthe economic advantage of the SFR in comparison tothe existing manual cleaning.


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Hannover, Germany. was outstandingly positive,and further development of the SFR is expected.

By switching the cleaning head for other effectors,the robot is enabled to perform other important tasks,so it can broaden its field of operation. According tothe chosen system, it can perform maintenance tasks,

inspection or painting tasks, the renewal of sealingcompounds or the cleaning of sun protection systemsas well as bars or window seats.

Another possibility, and with a huge demandw

4x,

is to develop a system which can be mounted toexisting building during renovations Fig. 24..

The possibility to offer a modular system that canbe used with little changes on new and old existing.buildings is the main concern of the further andongoing research and development of the FraunhoferIPA.

Especially the development of a cleaning robotwhich can easily be integrated and fixed on existing,old buildings seems to be very important. Such a

Fig. 24. Vision of a cleaning system to be mounted to existingbuildings during renovations.

system could integrate in addition to the cleaningfeature the possibilities of shading systems Fig. 25.to give a better feeling of convenience for the peopleinside the building.

This kind of cleaning robot would need specialkinematics to fulfill all the existing boundary

requirements.

14. A deduced special solution

Based on research results of the SFR, it is possibleto deduce quickly individual special solutions for

Fig. 25. Cleaning robot for existing buildings.

Fig. 26. The vision of the cleaning robot Lehrter Bahnhof,Berlin.

new immediate employment with relatively little

effort of development.On this basis, the future inside cleaning robot of

the glass roofing of the train station Lehrter

Bahnhof in Berlin, Germany Fig. 26. is developedby the Fraunhofer IPA.

The basic operational principles of this specialsolution are corresponding to the basic principles of


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the SFR, e.g. integration and guidance in thestructural elements of the building, main linear axisfor covering all windows above the cleaning robotand the special kinematics for moving the cleaninghead onto the window and for surmounting obstaclessee on possible solution in Fig. 27 .. In this case,obstacles are not only horizontal bars but steel cablesfor a lighter construction of the glass roof.

Fig. 27. Functional view of the cleaning robot.


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References

w1x

U. Brauning, M. Hornemann, Automatische Reinigung,Spektrum der Wissenschaft, Dossier 4r1998.

w2x

S. Brosch, Automatisierte Reinigung von Standard-fassaden-Bauseitige Voraussetzungen und Perspektiven Dresden,Stuttgart; Juli 1998.

w3x

M. u.a. Hagele, Serviceroboter ein Beitrag zurInnovation im Dienstleistungswesen Stuttgart: FraunhoferIPA, September 1994.

w4x

R.A. Leonhardt, Kundenorientierte Produktneuentwicklungunter Integration von Marketingaspekten und erweiterten

QFD Fraunhofer-Institut fur Produktionstechnik undAutomatisierung IPA. Stuttgart; Dezember 1998.

w5x

R.D. Schraft, G. Schmierer, Serviceroboter: Produkte,

Szenarien, Visionen. Berlin; Heidelberg: Springer, 1998.

w

6

x

R.D. Schraft, M. Hagele, Serviceroboter Perspektiven derAutomatisierung des Dienstleistungsbereiches, wt Januar 1993,Springer Verlag.w

7x

QFD-Capture, User Manual, International Technegroup,

Milford, OH, USA, 1996.w

8x

J. Saatweber, QFD, International Technegroup, Milford, OH,USA, 1996.

w9x

Y. Akao, QFD Wie die Japaner Kundenwunsche in

Qualitatsprodukte umsetzen. Hrsg. Prof. Gunther Liesegang

LandsbergrLech, verlag moderne industrie, 1992.w10

xB. King, Doppelt so schnell wie die Konkurrenz, Kossmann,

Hofstetter, Lange, Grohn St. Gallen, gfmt, 1994.

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Automation in Construction Volume 9 issue 5-6 2000 [doi 10.1016%2Fs0926-5805%2800%2900060-1] R.D...

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