DRoB - Drones and robotics for efficient monitoring and management of green facades or roofs

Green infrastructure is increasingly appreciated in contemporary urban planning. The associated increase in green roofs and green façades requires clear framework conditions concerning maintenance and care. One of the long-standing tasks is the reduction of the growth of climbing plants on vertical surfaces. The use of cost-effective methods for assessment and maintenance, including the use of drones and/or robots, represents great potential. Methods and areas of application from other specialist disciplines already show available technical possibilities but must be adapted for use in this purpose. A robot for maintaining green facades currently goes beyond the state of the art. The image recognition of plants and a robotic reaction such as pruning young shoots are innovative and in principle also feasible.

The objectives of the present project include (1) analysis of the current market and collection of costs for monitoring and maintenance of green façades, (2) evaluation of different remote sensing sensors for issues relevant to vegetation and care, (3) investigation of the use of drones as a new and innovative method for monitoring greening of buildings, (4) assessment of the potential of robotics for the care of green façades and roofs, (5) designing rail-guided cutting robots for the care of climbing plants, (6) assessing the acceptance of the use of drones and robotics for monitoring and maintenance of green façades and roofs.

The growing market for green facades results in a higher maintenance volume overall. In order to continue this trend, acceptance for care and monitoring measures must be increased and the costs for this must be made as efficient as possible. When maintaining green facades, care must be taken to ensure that specialized and qualified companies are used for maintenance. Therefore, companies will likely specialize in the future, which will also increase the acceptance and necessity for more efficient work processes, e.g. through the use of robots and drones. Furthermore, it shows that resilient and low-maintenance forms of greenery are gaining ground and driving the dissemination of greening in buildings.

The sensor evaluation included RGB, multispectral and thermal cameras and showed that several relevant parameters for evaluating the plant condition can be collected. The vegetation coverage, 3D-modelling of the plants, but also vitality changes and water stress were surveyed. The data transfer of the sensor evaluation carried out under laboratory conditions is made more difficult by additional challenges in data acquisition using drones. The tests showed that the precise planning of an aerial survey in coordination with the orientation of the façades and the position of the sun is essential. In addition to the derivation of the relevant parameters, data images represent objective records for comprehensible documentation. Drone flights will be useful if it is essential to record the entire greenery, e.g. for higher buildings or green roofs. The further research need in the field of sensors and drones for the monitoring of green façades and roofs is seen in the evaluation of the possible uses with a focus on the economic utilization options. The inclusion of image data to record the degree of coverage on green roofs and vertical green roofs could also provide significant support for ongoing remote monitoring by care officers.

Automated maintenance must be tailored to a large number of greening systems used, which is why the design of a robot is challenging. The data-based location on the building would allow digital documentation for defect rectification, maintenance and inspection, since both damage detection and the care and maintenance requirements would be more comprehensible. In this project, a rail-guided cutting robot was designed for the care of climbing plants. The overgrowth bar already in use could be used to guide the robot. For other applications or care interventions on the entire area, additional sensors and rails or ropes are necessary for safe movement. The future goal is the development of a robot that differentiates between species, growth, positioning, condition and care needs of the plants and adjusts the care intervention accordingly. Another recommendation is to expand the area of robot use to include green roofs, especially in combination with photovoltaic systems (pruning, nutrient supply, control activities). The project team will use the data obtained to carry out further research in the direction of professional service robots for the automated maintenance of green walls. The focus will be on the application on as many different greening systems as possible, as well as data management using clouds and self-learning algorithms.

The surveys on green facades clearly show that acceptance for the use of robots and drones in the current care industry is still low. However, due to the generally growing market for green facades, there will also be more maintenance volume in the future and companies are more likely to specialize. This will also increase the acceptance and need for more efficient operations, e.g. through the use of robots and drones.

Paper: Water-Stressed Plants Do Not Cool: Leaf Surface Temperature of Living Wall Plants under Drought Stress (Februar 2021)

Project management

University of Natural Resources and Life Sciences, Vienna,

• Institute of Geomatics
• Institute of Soil Bioengineering and Landscape Construction (IBLB)

Project or cooperation partners

• LEHI - Copters KG
• GrünStattGrau Forschungs- und Innovations-GmbH
• alchemia-nova GmbH

University of Natural Resources and Life Sciences, Vienna,
Institute of Geomatics
Markus Immitzer
Peter-Jordan-Str 82
A-1190 Vienna
Tel.: +43 (1) 47654 85732
Fax: +43 (1) 47654 85709
E-mail: markus.immitzer@boku.ac.at
Web: http://short.boku.ac.at/DRoB