Concepts of service robots for facade cleaning: Fid-Bau Portal

Concepts of service robots for facade cleaning

Felsch, T. / Elkmann, N. / Sack, M. / Saenz, J.

In the last few years, the Fraunhofer Institute for Factory Operation and Automation in Magdeburg (FRG) has developed a wide variety of concepts and realized systems for facade cleaning. Among these are climbing robots for vertical and horizontal surfaces, as well as for irregular, free-form surfaces. In addition to the existing system for the cleaning of vaulted surfaces and the robot platform, SIRIUS, for vertical facades, there exist other innovative robot concepts such as the flying service robot for cleaning the inner side of atriums and glass roofs, and the semi-automatic, remote-controlled device for cleaning the outer side of glass roofs and atriums. SIRIUS, the robot system for vertical facades was developed in the Fraunhofer Institute. SIRIUS is a climbing robot and has the following characteristics: (1) reliable contact to the surface through vacuum grippers, (2) fast, continual motion, (3) safeguarded against falling through a gantry, and (4) ability to overcome obstacles. SIRIUS is suitable for the following object and/or building types: (1) vertical and/or steeply-inclined surfaces, (2) facades with the load-bearing structure on the inside, (3) even, homogeneous surfaces, (4) facades with window framework, panels, and/or lamellas, (5) ship hulls, and (6) cooling towers. A Siemens PLC (Programmable Logic Controller) was used for the robot control system. The PLC is on-board and controls the entire system. This includes synchronizing the walking mechanism with the trolley as well as the tool, which in this case is the cleaning head. The robot does not start with information about all the obstacles it will face in its path. Rather, it keeps track of the surface and obstacles that are currently under the robot. Obstacles like lamellas or window frames are recognized and measured with sensors. The PLC then generates the corresponding step-lengths so that the robot can successfully walk over the obstacles. The PLC ensures that vacuum grippers that are directly over an obstacle are not engaged, while at the same time maximizing the number of vacuum grippers are in contact with the facade at any given moment. The only manually-inputted information that the robot needs before starting off on a given surface is end-point data as well as the maximum obstacle length.