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- Introduction
Australia has always had a reputation for being innovative and for being an early adopter of good, new technology. Starting from a few years ago, there are now clear signs that the country is beginning to take up technology associated with the general domain of construction automation and robotics. Ultimately this technology can be expected to totally revolutionise practice [1].
- Autonomous Machines
To give some illustration of the kind of technology currently being introduced, we might consider the subject of autonomous construction machines. Driverless and operatorless construction machinery technology has been under development in the USA and Japan for some time now, but Australia is perhaps the first country in the world to begin seriously to try to implement this technology commercially. The Australian mining and heavy civil construction industry is committed to field automation because of its cost-effectiveness and currently is in the process of introducing a number of large off-road driverless trucks into full production operation. Autonomous machine technology is also being applied to more difficult applications such as the operation of load-haul-dump vehicles (in underground operations) and the automated operation of hydraulic excavators and draglines.
The primary difficulty associated with the development of autonomous vehicles lies in the development of low cost instrumentation and sensing systems and rugged on-board computer equipment. Work at the University of Sydney and at the Centre for Mining Technology and Equipment in Queensland (CMTE) has largely focused on these problems. A review of the activities of these groups can be obtained from their web site [2-3].
Figure 1. Autonomous LHD vehicle
In perhaps the most demanding machinery application being explored at the moment, fully autonomous operations of large load-haul-dump (LHD) machines for underground applications are being developed. A driverless machine of a type similar to that illustrated in Figure1 is currently undergoing extensive trialing at Mt. Isa Mines in Queensland. The machine is able to do autonomous operation using on-board inertial guidance systems, laser ranging, millimetre radar and acoustic sensing systems and has many types of redundant safety systems as well as a transputer based ruggedised on-board computer. Auto-dig and auto dump operations as well as auto tramming functions are being investigated. High speed travel in tunnels under low clearance conditions has already been demonstrated. The work is a joint venture between Mt. Isa Mines, CMTE and Sydney University.
Further, Sydney University, working with Komatsu, has developed a full sensor equipped hydraulic excavator for autonomous operation testing. The machine [2] is equipped with millimetre radar, inertial navigation and on-board computer systems similar to the Mt. Isa LHD machine.
In other automated earthworks/roadworks field applications, in 1994 Spectra Physics demonstrated a fully automated paver that can operate at 4 km/hr with grade control in x-y-z of +/- 3 mm using a AGA Geotronics robotic total survey station. Automated motor grader operations at higher speeds has been demonstrated but at grading speeds accuracies of +/-2.5 cm in vertical control could only be achieved.
In relation to earthmoving machinery blade control Caterpillar is working with Elphingstone of Tasmania in the development of smart and computer and sensor assisted earthmoving and tunnelling machinery systems. In these systems satellite surveying systems are put on the ends of a grader or dozer blade as position sensors.
- Robotised Physical Testing
Physical testing of materials and other parameters for quality control and assurance purposed can be a very tedious and expensive process. Many firms in Australia have turned to automation technology for improvements in this area. In the north west of Australia, for example, Hamersley Iron has adapted a general purpose robot to do sophisticated large volume routine chemical and physical tests on aggregates and crushed rock.
Figure 2. Robotised testing cell for QA/QC
Figure 2 shows a standard industrial robot which has been adapted to do a complex series of physical tests of blasted and crushed material in accordance with Australian Standard Specification. The software programmable machine is able to do most of the normal physical testing activities required - eg sampling, sieve analyses, moisture content through oven drying, chemical analyses etc.. The results are provided on-line to the head-office - which is thousands of kilometres away. The robotised process is more than cost-effective in comparison with human based testing laboratory operations.
From this application it can be seen that industrial robot technology can be simply developed to handle many types of civil and building quality control and inspection processes and laboratory testing operations. Allied to industrial robot technology, advanced vision systems have been developed for quality control and real-time process management by agencies such as the CSIRO's advanced vision laboratories in Melbourne [4].
At the University of NSW advanced close-range photogrammetry systems have been developed for geometry control of manufactured products. These systems yield accuracies of +/- 0.4 mm and can handle objects of complex shape.
- Assets Maintenance
Physical assets maintenance and infrastructure condition monitoring is a major applications area for construction automation and robotics technology. Worldwide, societal assets management and infrastructure maintenance are of increasing economic concern. Assets management as a process however requires detailed information of the physical state of the systems to be developed and this is often very expensive and tedious to obtain. These conditions favour the development of automated solutions to the physical inspection and assets maintenance problem.
Australian industry is well advanced in the beginning application of integrated and highly automated systems for advanced assets management. In relation to underground pipe systems maintenance, Melbourne Water has spent some A$ 5 million developing an advanced sewer inspection and condition monitoring systems [5]. This system uses an in-sewer traveller vehicle with laser ranging and sonar sensors. The system captures quantitative data about the state of the sewer at the rate of about 100 000 cross sections per linear metre of pipe.
Figure 3. False colour map of conduit data
The data from the geometrical measurements may be plotted as colour enhanced unwrapped maps of the sewer cross section such as Figure 3. Alternately, the captured data can be analysed automatically using artificial intelligence based examination methods. In tests of over 4 km of real sewer the automated inspection method has been shown to be clearly superior to human operated inspection systems which are typically based on examination of the direct output of closed circuit TV pictures.
In the roads and pavement maintenance arena new pavement inspection and measurement systems have been developed by the Road Research Board and an advanced pavement management system has recently been implemented in Sydney by the contractor Transfield [6]. The systems developed by Transfield Pty. Ltd. uses a data base comprised of video pictures of every square meter of the pavement being managed.
In relation to building and structures maintenance large multi-degree of freedom manipulator arms have great potential for expediting and cheapening structural inspection and condition monitoring work.
Figure 4. Facade inspection and repair robot
- Site Robotics
The idea that the use of large manipulators, such as shown in Figure 4, and the use of high dexterity robotic arms (Figure 5) can improve the efficiency of on-site construction processes is now well advanced in Australia and the author's work at UNSW is possibly of some significance here [7-8].
Figure 5. High dexterity robotic arm
With the introduction of such technology the materials handling aspects of many construction operations can be much simplified. Indeed, detailed economic analyses have shown that large scale manipulators/robotic erector arms can be highly cost-effective in the erection of industrial structures such as is shown in Figure 6.
Figure 6. Robot erection compatible industrial building.
Manipulators are also very useful in the execution of many other site tasks such as reinforcement bar placement and within trench site operations. They also have great potential for safety and OH&S risk reduction [9]. Typically also, time and cost saving of more that 50% in the erection process can be achieved .
On the Olympic Rail project in Sydney, Australia's largest construction Group Leighton Contactors are currently investigating the use of large manipulators with a capacity of around 2 000 kg for heavy steelwork handling on cut and cover tunnel operations. By the combined use of precision robotic arm technology and automated positioning systems, activities such as the installation of mechanical building services to buildings can be simplified. For the job fire sprinkler installation, detailed cost studies have shown that the erection of sprinkler systems to the undersides of the concrete slab on this job allowed labour cost to be reduced by 92%.
The use of more complex forms of site robotics to reduce the cost of general construction and on-site concrete work are discussed in [7 &10].
- Electronically Integrated Construction
It has long been recognised that major improvements in the construction process can be achieved through the electronic data-integration of the various stages of the design and construction process. This process is sometimes referred to as computer integrated construction or CIC.
The economic benefits of electronic integration can be large. A recent cost study on the cost of production of industrial process pipework on a large project outside Sydney, for example indicated that the cost to produce steel pipes can be cut by around 60% by electronic integration of the design and pipework manufacturing processes.
In the timber structure industry Pryda Pty. Ltd. of Victoria is using electronically integrated production processes. Pryda is a major national supplier of timber roof trusswork and timber framed housing. In their manufacturing process, trusses are designed on computer and then the output data from these CAD programs is used to direct drive numerically controlled Omni-saws and computer controlled indexing and set-out tables for the timber layout. Nail-plate technology is used to join the timber sections. A fixed position large robotic arm is used for final truss pick-up and stacking (Figure 7). Currently, Pryda is examining the use of large scale erector arms for the site installation of the trusses.
Figure 7. CIC generated timber roof truss-work
- Simulation and Virtue Reality Planning Tools
Through the use of advanced computer graphics and very high speed computing systems it is now possible to do real time, interactive, visual simulation of many forms of construction process and to do high fidelity virtual prototyping of products and facilities [11]. High resolution virtual prototyping of products and buildings is well stablished in Australia through use of CAD systems such as CATIA and walk-through computer graphics is now being used relatively extensively by the architecture profession.
Through the use of more advanced forms of graphic output simulation, the first author has developed high fidelity earthmoving machinery modelling systems and plant operator training simulators of various kinds (Figure 8).
Figure 8. Low cost simulator trainer
This type of technology has the capacity to transform construction operator training and site process planning [11]. Simulator based training machines are currently in daily use around Australia (Figure 9) and may be transported in a caravan to the teaching site.
Figure 10. Mobile skills centre in Tasmania
The simulation system is fully general and can be used to model any form of construction and operations sequence. Such technology is being used now by major contractors in Australia to explore construction processes and to develop a range of virtual reality planning tools and construction process visualisation technologies for tasks such as process plant erection, crane hook productivity studies and alternative erection methodologies.
- Intra-project Networked Telecommunications and Distributed Decision-making
As is well known, computer technology and telecommunications developments are having a big impact on the way business is being conducted around the world. A particular worldwide trend that is now emerging in construction is to introduce high bandwidth digital telecommunications links and network systems between the parties in civil and engineering projects. Direct connection between the parties to a project or process allows for improved distributed decision making [11].
The large Australian based contractor Group, Leighton is considering the installation of project wide intranets with digital communications links between all project participants including to roving field operatives. In Sydney, the central Road Transport Authority has just finished building a large Intranet operation to link its 2 500 field units across the large of New South Wales State in Australia, to head office and to major data bases. The systems has been cheap to install and has already proved very cost-effective. A significant decision has also been made by the Local Government Authority in New South Wales to the affect that all communications between Municipal Authorities and allied organisations are to be in direct electronic form and are to be sent by email.
A further recent development in Australia has been to develop cost-effective procedures for the simultaneous linking of field operations to head office and design functions so that tele-conferencing and project-wide group decision-making is possible. A trial use of system has been developed by the CSIRO and the Australian telecommunications giant Telstra [11-12]. The use of such systems allows for increased knowledge worker productivity and a large reduction in travel to and from sites by project personnel and increased organisational design flexibility.
- Automated Field Data Acquisition Systems
A neglected and very under-appreciated aspect of construction and management is the topic of field intelligence gathering and analysis. The quality and quantity of data available for decision-making has a significant affect on productivity and field performance. Further, much expensive-to-acquire field date is typically necessary for the physical execution of any project. However, despite a widespread industry disinterest in the development of systematised approaches to this problem there is growing evidence that automated technology has begun to penetrate this sector of construction. Thus, within Australia, there has been a rapid uptake in technology such as computer aided positioning systems. These technologies have been applied to both static and moving systems. Bar coding and other discrete item tracking technologies are also in solid evidence on sites within Australia.
- Electronic Commerce
Electronic processing of on-site commercial data and electronic funds transfer between business entities is an emerging aspect of modern business worldwide. The trend to electronic commerce is well evident in Australia with, for example, the National Government in Canberra actively pushing for total application of these ideas on major government projects [13].
- Conclusions
From the examples cited above it can perhaps be appreciated that construction robotics and automation technology is beginning to be taken up by Australian industry as a serious tool and the uses of this technology can only increase. The author is of the opinion that this technology trend will accelerate with time and will ultimately come to revolutionise the industry. The next decade in Australian and world-wide construction engineering can be expected to see many major technological changes.
- References
Please note that the Editor and IAARC cannot guarantee the integrity of the URLs given below.
[1] O'Brien, J.B. Construction robotics and the upcoming technology-based revolution in construction. Aust. Institute of Project Management. Annual Papers. 1997.
[2] Sydney University Mechatronic group home page: http://www.me.su.oz.au/research/mechtron/mechtron.html#projects
[3] CMTE home page: http://www.dem.csiro.au/dmt/programs/autom/index.html
[4] CSIRO industrial vision dept home page: http://www.mlb.dmt.csiro.au/IVT/IVT.html
[5] CSIRO home page: http://www.dbce.csiro.au/dbr/pirat/pirat.htm
[6] The Earthmover and Civil Contractor, August 1996, p52.
[7] O'Brien, J. B. Construction Robotics In Australia - A State Of The Art Report. Proc.13th ISARC, Tokyo, 1996, pp15-22.
[8] See [7]
[9] UNSW home page: http://www.civeng.unsw.edu.au/ CENTRES/ MUNRO/ PUBLICATIONS/ RISKENG/ paper12.htm#ROBOTICS
[10] O'Brien, J. B. Robotic systems for general Concrete Construction. Proc. Intl. Conf. Concrete Institute of Australia: Concrete-95, Brisbane, 4-7 Sept 1995, pp787-792.
[11] See [7].
[12] CSIRO home page http://www.dbce.csiro.au/divserv/capabil/comcon/comcon.htm
[13] See: www.navy.gov.au
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