Robotics in Construction      

      The use of robotics or automated equipment in the construction industry is an inevitability. In the near future, the use of these new technologies will create a more productive and safe environment that will reduce overall construction costs. Areas that will benefit greatly from the use of intelligent technologies are the excavation and earth moving phases of the construction process. On any large scale construction process, tons of soil are excavated, with the majority of the process requiring similar tasks performed multiple times. This repetitive nature of excavations screams for efficiency and intelligent equipment is the key. However, the construction site is a dynamic place with obstacles that are difficult for humans to maneuver around, let alone for robotic equpiment to do so.

      Current technologies for automation of excavation equipment lack practical navigation systems. In the first article I read, ( http://www.sciencedirect.com/science/article/pii/S0926580511001105 ), the author suggests two navigation strategies for maneuvering on the construction site: global and local navigation strategies. These navigation strategies use point systems that represent equipment and stationary objects. Then, a work zone and a safety buffer zone are applied to the data to ensure the shape of the object is represented accurately. The global strategy is critical for large scale operations that require large distances and numerous obstacles to avoid. The local strategy works for the actual excavation of areas, which are ideal for optimizing equipment cycles (i.e. dig, rotate, empty bucket, repeat). The main obstacle for the automation of excavation is remote sensing.

      Currently, sensors are struggling to keep real-time, geographical data about the constantly changing construction site. However, new digital correlation technologies are emerging that allow for greater accuracy of the geographical information, as well as faster data processing, which enables realtime analyses. The second article ( http://www.sciencedirect.com/science/article/pii/S0926580511001129 ) discusses the role of image based surveying systems for use in the verification of as-built construction documents. The author tested the accuracy of image-based surveying by comparing it to an existing BIM of the building and to a manual survey of the interior and exterior dimensions. They found that image-based surveys had an error that did not exceed 5%, which would be perfect for excavation work. The author also suggested that modern image correlation technology is rapidly evolving and the error percentage will decrease with further research and development.

      Once an accurate site model is represented, engineers will be able to apply typical work flow algorithms that enable automation of excavation equipment. These algorithms will enable optimization of excavation paths which will save time and money for the contractor. The use of robotics in earthmoving processes also allows for remote operations, and therefore allows earthwork to be performed in radioactive environments and, someday, in extraterrestrial mining.