CURRENT STATUS OF CONSTRUCTION AUTOMATION AND ROBOTICS IN THE UNITED STATES OF AMERICA
Construction automation and robotics research and development in the United States is more than a decade old. A number of research institutions, universities, construction equipment manufacturers and construction engineering firms have been involved in these efforts. This paper summarizes the recent American accomplishments and current efforts in several representative areas. It is concluded that the United States research and development community seems to maintain its leadership primarily in construction automation software design and software engineering. However, a more intensive effort and dedication to automation concepts is needed to capitalize on the potential benefits of automation, particularly in the practicing engineering community and among the industry practitioners. Introduction Automation and robotics has been in all likelihood the most challenging endeavor in the American construction engineering academic community over the past decade. Similar enthusiasm for this field has been shared by several government and private research institutions and laboratories. The industry, including design and construction firms, material suppliers, equipment manufacturers and owners, with a few notable exceptions, was somewhat slower in relating itself to this new field of research and development activity. However, the process of disseminating the early results from the research and development community to industry practice is now slowly beginning to take place. There are no universally adopted definitions for the terms 'construction automation' and 'construction robotics. For the sake of our discussion, we will assume that 'construction automation' refers to the engineering or performance of any construction process, on site or off site, by means of teleoperated, numerically controlled, semiautonomous, or autonomous equipment. 'Construction robotics, as discussed here, refers to advanced construction equipment exhibiting any level of capability related to teleoperation, sensory data collection and processing, numerically controlled, or autonomous task performance. The primary "technology drivers" for introducing robotics to construction sites in the U.S. were health and safety hazards to workers from chemical or radioactive contamination. In extreme cases, where human access to the jobsite is impossible due to excessive levels of contamination, performance of the required work tasks can only be accomplished through the use of robots regardless of the associated cost. On site experience with robotics in these environments, as well as in underwater and outer space tasks, has provided the developers of robotic systems with valuable lessons with respect to the practicality of certain robot design and task implementation solutions. The underlying incentive for automating construction tasks is potential labor savings once the new technology proves successful. Although the U.S. has not experienced acute labor shortages in the construction industry similar to those in a few other developed nations, there appears to be a significantly diminishing number of skilled construction workers at this time. There is also a potential for a shortage of labor in the future due to demographic reasons. Hopes for expanding the construction activity into difficult work environments, improving construction productivity and quality through the use of automation on jobsites are also frequently mentioned. Relevant Systems Developed to Date A number of relevant robotic prototypes have been designed and built in the United States. Table 1 includes a partial listing of some of the robots developed to date. Some of these robots have already found commercial application and some only await commercialization by interested parties. Most of the developed systems have been inspired by either a compelling need to robotize a given task due to inherent hazard to humans associated with its performance, or by potential labor savings due to task simplicity, high volume and repetitiveness. A number of other robotic prototypes and working systems have been developed for applications which are potentially transferable to the construction industry. These include areas of underground mining, underwater inspection and search, nuclear power plant decomissioning, structural assembly in outer space, military applications, and others. Even a summary description of those systems is outside the scope of this paper. Specific information on their details is available from publications by the Robotics Institute of America, commercial vendors, and professional associations such as American Nuclear Society, Institute of Electrical and Electronic Engineers, American Society of Mechanical Engineers, and American Society of Civil Engineers. When analyzing the initial American approach to construction applications of robotics, it is apparent that a significant number of prototypes designed to date have been developed to mimic to a considerable extent the work of humans in unstructured jobsite environments. This approach neglected the need to restructure the jobsite environment to meet the capabilities of relatively unsophisticated, and thus frequently easier to build and more cost effective, construction robotics. As a result, the practical application of the early prototypical systems frequently proved very difficult or prohibitive due to a high cost. On the other hand, the positive side of that approach was valuable experience gained in such areas as sophisticated robot control systems, sensory data processing, artificial intelligence concepts, and machine learning. Significant advances have been made in autonomous navigation, intelligent real time sensing (particularly in robotic vision) 'virtual reality' modeling, and data integration techniques. Future construction robotics have indirectly benefitted from a few one of a kind robot prototypes developed on special orders from government agencies such as the U.S. Department of Energy, pushing robotics technology development to its new heights. This progress in technology has also been helped by the fact that for robot designs intended for disaster handling operations such as a nuclear accident at the Three Mile Island in Pennsylvania financial and economic constraints were not viewed as important. Robot Type Application Developer John Deere Excavator, Model 690C teleoperated excavation for rapid airport runway repair John Deere, Inc. Moline, Illinois Laser Aided Grading System Automatic Slipform Machines Micro Tunneling Machine Robotic Excavator "REX" and Autonomous Pipe Mapper