| Popis: |
Nowadays the number of buildings with large glass or flat facades is increasing all over the World. These facades must be periodically cleaned with manual procedures that supposed high cost and risk for the workers that have to develop their work under heavy conditions. Although the cleaning cost depends a lot on several factors as the facade characteristics, the cleaning periodicity or the total surface to be cleaned, the average cost is € 8-9 per square meter. A typical building of 12.000 m2 supposes a total facade cleaning cost of € 100.000 and this task is usually done every year. The use of an automatic or semi-automatic cleaning system can lead to around 60% savings over existing practice (Gambao & Hernando, 2006).Automation and robotics technologies allow environmentally friendly facade cleaning, helping to reduce the cost of these tasks. Additionally, these systems overcome the current worker safety problems associated with difficult and dangerous access, contributing to a zero injury and fatality working practices (Elkman et al., 2002).Because of the increasing number of high-rise buildings and large glass facades and the resulting problem of safe and effective cleaning, a lot of effort has taken place in the last few years to develop automated cleaning systems. The majority of systems conceived and developed thus far are in Japan and Europe (Schraft et al., 2000) (Gambao & Balaguer, 2002).The first automated cleaning systems for high-rise building were used in Japan in the middle of the 80’s. These systems were mainly designed for use on specific buildings. For safety purposes or in order to guide the robot’s movement on the facade, they often required additional construction such as guidance rails to the facade. The practical application of the existing systems mostly failed because of either a weak safety concept, poor cleaning quality, required additional construction to the facade, or simply due to expensive initial or operating costs. At this time, there is only one known system that is in continuous practical operation. That is the automatic system for the cleaning of the vaulted glass hall of the Leipzig Trade Fair, Germany (Figure 1), which was developed by the Fraunhofer Institute IFF, Germany (Elkman et al., 1999). It must also beaded that this system is only applicable to this particular building. Many of previous developed robotic facade cleaning has been designed to operate in a complete automatic way (one example is in figure 2). Although some of these systems have successfully solved the numerous technical problems related to facade climbing operations, in most of the cases they cannot be practically used due to the extremely expensive operating cost of such a complex machines. Many remain as prototypes that are very good demonstrators of high technology but cannot be introduced in the market. |
