8/7/2019 Robots Improve Construction Sites

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Sandra Rihs Poster n33

REMEFacult ENAC

Robots improve construction sitesThis research focuses on the potentials given by automation technologies to develop a sustainableconstruction process for buildings. The economic, environmental and social aspects of

automated construction proceses are evaluated. The key factors pushing for a change in the constructionprocess are the declining numbers of construction workers, the increasing schedule and cost pressure onhe construction industry and high material consumption in the Swiss construction sector. This study aims ate-engineering the construction process to make it sustainable. The objectives of this project are: to stimulate research

and implementation of automation technologies in the construction process and to evaluate the potential of construc-ion robots with respect to the economic use of resources in order to provide guidelines for a sustainable stewardship.roject scope The research lies in the intersection of three research fi elds: robotics, architecture and sustainability. The focus within the robotics fi eld is on construction robots and more precisely on different types of construction robots (e.g.: humanoid robot, robotic swarm,contour crafting). In the architecture fi eld this studyoks at the different building types (ex: house-building, non-residential, rehabilitation and maintenance) and at the different construction stages within theses building types (e.g.: primary, secondary and/ or tertiary). The materials used by the construction robots is also relevant(e.g.: concrete,eel, brick etc). Within the sustainability fi eld special attention is given to the economic, social and environmental aspects of the con- struction process accomplished partly or fully by robots. Robot types This chapter will look at classifying different construction robotpes and ana- lyzing their technical abilities to fulfi ll certain tasks. Defi nition of terms and data Within the family of robots the United Nations Economic Commission for Europe (UNECE) and the International Federation of Robotics (IFR) [10] differenti-e between multipurpose manipulating industrial robots and service robots. While industrial robots have a strict international defi nition (ISO 8373), service robots are given a preliminary defi nition by UNECE and IFR: A robothi ch op- e ra tes s emi- o r f ul ly aut onomously t o per fo rm s ervi ces t o t he w el l-be ing o f humans and equ ip- ment, exc luding manuf ac tu ri ng opera ti ons. Acc ording t o t he UNE CE and I FR c lass ifi c at ionithin the service robot category, is done by application areas and types of robots. Three sec- tions describe the different service robots: Section I includes all Personal andomes- tic robots, Section I I Professional service robots and Section I I I is dedicated to Robotics R&D. Section I I inlcudes a subsection called 32-36 Construc-i o n and demolition within which 35 is solely devoted to construction. In this research, robots of other subsections (e.g. Subsection 62 Humanoid robots)r e a ls o t ak en i nt o acc ount f or c onst ruct ion app li ca ti ons. The Const ruct ion Ro- bot Sys tems Cat alogue i n J apan uses f ur ther 17 groups t o

a s- s ify const ruct ion robots. Out of these 17 groups, fi ve are exc luded in this re- search, because they do not relate to const ruct ion ofuild- ings but exclusively to civil engineering works (Mountain and Shield Tun- nel, Dam Construction, Marine Ship/Underwaterork, Pavement Work). The twelve others include: Earthworks, Foundation Works, Crane Work, Concrete Work, Placing ofteel- framework, Fin- ishing Work of Building, Prefabrication of Reinforce- ment, Pneumatic Caisson Work, Survey, Inspec-on & Monitoring, Maintenance and Element Techniques. Three groups are selected for further analysis, which are : Con-r e t e Work, Placing of Steel-framework and Finishing Work of Building. Since not all the chosen robots for this researchan be placed in those three categori es, the three followin g complemen tary classifi cation systems have been defi ned: 1. Ty-

o lo gy, for what type of building is the robot utilized (non-residential, high-rise, residential) 2. Structure, for which structures (pri-a r y , secondary, tertiary) is the robot employed 3. Materials, what materials does the robot handle. A further important indication isether the analyzed robots are commercially available or if it is a university project. In this matrix it is clearly visible that all construction robots cane used for nonresidential, six for high-rise and fi ve for residential buildings. In terms of diffusion, demolition and construction robots of Subsection 32-36ccount for 14% of the total number of worldwide service robots for professional use up to the end of 2003, which adds up to 3030 units int al . A lt hough t he s ubsect ion 35 c onst ruct ion robot s ac- c ount s f or onl y 60 uni ts i n 2003, a f ur ther 95 uni ts a re expec ted t o be i ns ta ll ed unt il 2007. [ 10 ] Anpplication area with strong growth might be hu- manoid robots. quite a few Japanese companies are developing these robots for multiple use. It is further analyzed if theumanoid robots they ,are suitable to work on construction sites.The unit price for professional service robots in general differ from $ 10000 to $ 300000, depending on the type application. Construction robot types Out of the mul- titude of con- struction robot types ten systems have been chosen as samples to be further discussed. The choiceas made so that a great variety of const ruct ion ro- bots is shown, going f rom established systems to promising research solut ions. 1. SurfRobo, concrete compactor,

esigned and implemented by Japanese fi rmTak- enaka 2. Jap- anese WR column-to-col- umn welding robot 3. Contour crafting in-e nte d b y Pr of . Kh osh ne vi s o f t he U ni ve rsi ty o f S ou th- e rn C ali for ni a [4 ] 4 . H ea vy w eig ht ma nip ul ato r fo r cu rt ainall installation by You and Lee,Hanyang Uni- versity and Samsung corpo- ration, South Korea [8] 5. ROC-O a hydraulic 6 DOF robot for brick assem- bly developed as a EU project [2] 6. SMART factory

mp le men ted b y Ja pa ne se fi r m S hi mi zu u se d fo r h ig h- r ise b ui ld in gs [1 2] 7. R ob ot ic sw ar m build a wall tested by Stewart and Russell from Monash Uni- versity, Australia [7] Humanoid Robot to transport light- weight board tested by Japanese Shimizu Corpora-

on [6] 9. Three assembly robots for mounting partition walls, simulated by Prof.Thomasock, TU Mnchen [9] 10. Wall painting robots analyzed by Kahane and Rosenfeld, Technion, Israel [3] Tech-c al an al ysi s Th e di ffe re nt i nf or ma - ti on s a va ila bl e a bo ut th e t en r ob ot sys te ms v ar y si gni fi c an tly. F or th e p ur po se o f t he s tu dy th eost important specifi cations ar e closely tied to the typology and structur e the robots are used for and the mate- rial they areandling. Based on Warszawskis [11] classifi cation the attributes of a construction robot are defi ned as follows: 1. Man ipu la-on of construction materials. The robot arm handles, moves and orients material from one place to another. 2. Effectin g,ippers and various work tools per- form the specifi cally r equired task at the required location. 3. Control of the e ff ec to r

ccording to a specifi ed task program. 4. Sensing through tactile, proximity and vision sensors, the environment ar ou ndand sending appropriate feedback signals to the control mechanism. 5. Mobility of the robotic system within t h e

onstruction site, moving with legs, wheels or tracks. A further study of the technical analysis consists of com- p a ri n ghich energies a robot uses to operate. One can distinguish: Combustion engines (diesel, gasoline) Electri- cal en-nes (Fuel Cell, S olar Energy, Ca- ble...) others . . .Architectural considerations : Architectural typology To a n a -ze use of robots on construction sites this research differentiates between housing, non-residential and high-rise bu il d-gs. The current use of existing robots show, that they are thought to be used for a specifi c typology. Japanese constr uc- t i o n

bots focus mainly on non-residential and high-rise buildings, with the exception of prefabricated buildings for housing, w h i c hll not be further discussed. Construction stages A further and in the future mor e and more important aspect of the con- structionte are the three different construction stage structures. The primary structur e including all the supporting elements. The sec- o n d ar yruc tu re defi ned as s eparat ing w al ls and t he t er - t ia ry s truc tu re des cr ibed as i nt er io r fi n is hing e lement s. I n t erms o f s us ta inab il it y t he du ra ti onf li fe o f th ese t hr ee d iff er ent s tr uct ur es i s o f u tm ost i mp or ta nce a nd mu st b e t ake n i nto co ns id er ati on fo r f utu re r eco ns tr ucti on a nd o r d emo li- ti on o f th euilding.Construction materials The choice of con- struction materials of the building itself also plays a role in decid- ing whichutomation technology to use. Differ- ent robot types special- ize in various material applica- tions. Sus-inability analysis Economica l analysis Based on the research by Warszawski et al. [1] the

comic analy- sis can be described as follows. This method allows calcu- lating the cost produc- ing one work uni t (eg: 1m2 of parti tion).The various costs are taken into account :ro duc- tion Cost = Capital Cost + Direct Cost + Maintenance Cost + Transfer Cost The as- sumptions made forh e analysis for the interior wall painting robot, as described by Kahane et al. [3]: 1. The robotic system is multipurpose and

an be employed for a total of 2000 work-hours/year. 2. The annual interest is assumed to be 7%. 3. The economic life spanf t he r ob ot i s 5 ye ar s. 4 . T he e ner gy co st i n o pe ra ti ng th e r ob ot i s e st i- ma te d at 2 .5 5C HF/ ho ur. 5 . th e a nn ua l co st o f r ep ai r ( in -ud- ing labor, parts and downtime) is assumed to be 10% of the sys- tems initial cost. 6. The rou- tine maintenance of the robot iss - sumed to be 6% of the cost of the working hours. With this given assumpt ions one can calculate at which product ion cost a const ruct iono - bot can compete with an unskilled worker. According to Ka- hane [3] a highly autonomous robotic system for wall painting that costs 127540HF would be profi table even in cheap-labor markets, where an unskilled worker costs 1430.- CHF per month and the robot operator 5100.- CHF per month. This example showsh a t even a h ighl y aut onomous robot ic s ys tem c an be v ery p rofi t - able f or t he Swiss c onst ruct ion marke t, c onsideri ng t he f ac t, t ha t an uns ki ll ed w orker earns as muc h as t he robot

p - erator of Kahanes case study. Other types of robots can be analysed following the same framework. Time analysis Following the case study by Kahane et al. [3] the time usedy the robot and/or the robot operator can be subdivided into the following actions: 1. Actions done autonomously be the robot. 2. Actions that employ the robot and the operator to-eth er. 3. Actions carried out by the operator alone, while the robot is remaining idle. 4. Actions carried out by the operator, while the robot is working on othera s k steps. With a highly autonomous robotic system for wall painting the robot is employed for 94% of the overall task time, while the operator iserely em- ployed for 40% of the overall task time. Which means that the op- erator can simultaneously oper- ate another robotic system. And thetal t ime of the system for two layers of paint was 0.019hr/m2 which corresponds to 70 - 80% of durat ion re- duction for the given task. 4.3aste analysis In the waste analysis special attention will be given to the amount of waste reduction using a robot compared to traditionalchniques. An impor- tant issue will be to analyse the possiblity of recycling the construction waste material (eg.: concrete) as described by Yamazaki2]. Prof. S. Kytzia of the Swiss Federal Insti tute of Technology is current ly leading a project which establishes models to analyse the conse- quences of reorganisa-

on of material fl ow (eg. re-introducing construction waste as construction material or as a secondary energy ressource) in the con-ruction sector, which could be relevant for the waste analysis. Social anal- ysis Another fi eld of re- search focused moren me th od s t o me asu re su sta in ab il ity of th e c on st ru cti on p ro ce ss t ha n o n t he au to ma ti on te ch - n ol og ie s t he mse lve s.

lchrist et al. quantify the social costs associated with con- struction projects by ana- lyzing the adversempacts and defi ning social cost in- dicators. It is stated that more automated meth- ods could contribute l ow er th e to ta l co sts, w hi ch i s d efi n ed a s co nstr uc - ti on co sts + so ci al c os ts. Al th ou gh Gi lch ri st

oncentrates more on social costs borne by the community surr ounding the con- str uction site it is aery interesting method, which could be t rans- posed to defi ne important indicators for the const ruct ionocess with robots. A further study aimed at defi ning social and economical aspects of the constructionocess. Such as the shortage of young labourers, the health risks of the construction workforce and the investment construction in Swit- zerland compared to the EU. First results, according to the Swiss Federal Offi ce of Statistics, were show- ing that the con-ruction workforce has the highest risk of injuries compared to other branches of the secondary sector. In November 2004 the building industries

onsidered their business situation for the fi rst time since 2002 as satisfactory, with a slower recovery noted in the lake of Geneva region. Ac-ording to the Swiss Federal Offi ce of Statistics (2002), Switzerland is clearly at the bottom of the table concerning the number of new con-ruction in housing compared to other countries of the EU, with Spain and Germany leading the list. Another big issue in the construction sectorprice dumping, due to fi erce competition, as stated by the SBV (Swiss Builder Association). Other factors such as the shortage of young build-

g workers and the high construction cost should further more interest con- struction fi rms to invest into new technologies such as robots.ithin the social analysis two topics, which are related to the construc- tion workforce, will be further discussed. One is the impact

n the wages and composition and the other the impact on their health. 1. Impact on the wages and composition of theo n st r u ct i o n workforce Current research main focus is on data analysis of the Swiss construction sector. Following resultsave been sig- nifi cant for further conclusions. The data analysed between 1992 and 2004 was issued by the SBV (Swiss Build-

Association) [5]. The different education levels of construction worker were defi ned by their wages. The average wage in 2004 per month the highly skilled worker (foreman, workmaster, as- sistant foreman) varies between 6828.- and 5920.- CHF, of the middle skilled worker (technician) be-

ween 5326.- and 5226.- CHF and of the unskilled worker between 4780.- and 4244.- CHF per month. These wages are later used to compare the cost of abot with the cost of a construction worker for the same given task. Another indicator is the number of work- ers in the Swiss construc-

on i ndus try. The number o f uns ki ll ed w orkers on c on- s truc ti on s it es d roped by 14% bet ween t he y ear 1992 and 2004.hereas the number of highly skilled workers rose by 2% and the number of middle skilled workers even by 9. Drsteler [5] concludes that the actual enlargement of labour mobility (through east european countries joininge E U) w il l put no press ure on t he employment o f c onst ruc- t ion w orkers , s ince t he new east ern w orkf orce w il l

arge t t he uns ki ll ed w orker marke t, w hich i s dec li ning dra- mat ic al ly any way. 2 . I mpac t on t he hea lt h o f t heonstruct ion workforce Analyzing the reduction of hazardous work by using more automat ion technolo- gies on theonstruct ion s ite. In a further s tep job availabil ity, professional eth- ics, diversi ty and equal ity w il l be taken into account .bliography [1] Y. Rosen- feld A. Warszawski. Economic analysis of robots employment in buildings. In Proceed- ings of the

4th International Sympo- sium on Automation and Robotics in Construction. ISARC, September 1997. 12 [2] J. An- dres. Robot-

systeme fr den Woh- nungsbau. PhD thesis, Universitt Karlsruhe, Fakultt Maschinenbau, June 1998. 7 [3] Y. Rosen- feld B. Ka-ane. Balancing human-and-ro- bot i nt egra ti on i n bui ld ing t as ks . Computer-Aided C iv il and I nf rast ruct ure E ng ineering , 19(6) :393410, Nov embe r004. 8, 12, 13 [4] D. Hwang B. Ko- shnevis. Concrete wall fabrication by contour crafting. In Proceed- ings of the 21th International Symposium on Au- tomation andobot ics in Construct ion. ISARC, Sep- tember 2004. 7 [5] R. Drsteler. Mehr grips, weniger muskelkraft auch auf dem bau!, August 2005. 15 [6] Y. Abe J . Maeda, H. Takada. Appli -able possibi li ty s tudies on a humanoid ro- bot to cooperative work on const ruct ion s ite with a human worker. In Proceedings of the 21th International Symposium on Automat ion and Robot- ics in Construc-on, September 2004. 8 [7] A. Russell R. L. Stew- art. Building a loose wall structure with a robotic swarm using a spatio-temporal varying template. In Proceedings of 2004 IEEE/RSJ International Conference on Intelligent Ro- bots and Systems,eptember 2004. [8] S-Y. Lee S-N. You. Multi-dof con- struction robot for a curtain wall installation of a skyscraper. In Proceedings of the 21th International Symposium on Automation and Robotics in Construction. ISARC, September 2004. [9] K. Kreupl T. Bock. Pro-edure for the implementation of autonomous mobile robots on the construction site. In Proceedings of the 21th International Symposium on Automation and Robotics in Constructionings of the 21th International Symposium on Automation and Robotics in Constructionn. ISARC, September 2004. 8 [10] International Fed-ation of Robotics United Nations economic commission for Europe. World 2004 robotics. statistics, market analysis, forecasts, case studies and profi tability of robot investment, United Nations economic commission for Europe, 2004. 4, 6 [11] A. Warszawski. Industrialization and Robotics in Building. Harper and Row,

990. 8 [12] Y. Yamazaki. Future innovative construction technologies: Directions and strategies to innovate construction industry. In Proceedings of the 21th International Symposium on Automation and Robotics in Construction. ISARC, September 2004. 7, 14

Economical

a n a l y s i sshows that even a highly au-

tonomous robotic system can be

very profi table for the Swissconstruction market consideringthe fact that even unskilled work-

ers earn as much as robotoperators in Switzerland.

Material fl owanalysis

In the material fl ow analysis spe-cial attention will be given to which,

how and how much construction

materialsare economised duringthe different construction stages com-pared to traditional techniques. Animportant issue will be to analyse

the incidence on the recyclingprocess.

S o c i a lanalysis

Within the social analysis twotopics, which are related to the con-

struction workforce, are discussed.

One is the impact on the wages

and composition and the other the im-pact on their health. In a furtherstep job availability, professional

ethics, diversity and equal-ity will be taken into ac-

count.

T i m eanalysis

shows that with the use of

automation technologies a 70-80% duration reduction can beachieved for a given task andit also contributes to lowering

the total time input.

ConclusionsThe economical as well

as the time analysis show thata highly autonomous robot could be

very profi table for Swiss construc-tion fi rms. Furthermore the social analy-sis shows that the supply of unskilledworkers is dramatically decreasingwhich is benefi cial for introducing new

automation technologies.

Technical

analysis

In the technical analysisthe special circumstancesof a construction site andthe resulting technical re-

quirements for robotswill be analysed.