Survey on Glass And Façade-Cleaning Robots: Climbing Mechanisms, Cleaning Methods, and Applications

Cleaning dirty spaces is a very important task for human beings to maintain their quality of life. Recently, many high-rise buildings have been constructed, and their façades are easily contaminated by dust and pollution, especially in Asian countries such as China and Korea. Human workers are cleaning the façades, which are mostly made of glass, by hanging on to a gondola or rope, which entails spending a long time in midair, and this is dangerous work due to the risk of falling. To help humans avoid this dangerous and hard work, many researchers have tried to develop unmanned façade-cleaning robots; however, there are many issues to be solved before cleaning robots become efficient and popular. In this survey, we investigate and analyze robots used for cleaning building façades and glass. The robot are classified by types of climbing and attaching mechanisms, and their cleaning methods, mobility, and obstacle-overcoming performances are analyzed. In this paper, we also include for discussion some suggestions for making the robots more effective in real environments, and we expect that our work can provide reference to assist in the development of façade-cleaning robots for the real world.