Safe Documentation of Historical Monuments by an Autonomous Unmanned Aerial Vehicle

Abstract

The use of robotic systems, especially multi-rotor aerial vehicles, in the documentation of historical buildings and cultural heritage monuments has become common in recent years. However, the teleoperated robotic systems have significant limitations encouraging the ongoing development of autonomous unmanned aerial vehicles (UAVs). The autonomous robotic platforms provide a more accurate and safe measurement in distant and difficult to access areas than their teleoperated counterpart. Through the use of autonomous aerial robotic systems, access to such places by humans and building of external infrastructures like scaffolding for documentation purposes is no longer necessary. In this work, we aim to present a novel autonomous unmanned aerial vehicle designed for the documentation of hardly attainable areas of historical buildings. The prototype of this robot was tested in several historical monuments comprising scanned objects located in dark and hardly accessible areas in the upper parts of tall naves. This manuscript presents the results from two specific places: the Church of St. Anne and St. Jacob the Great in Stará Voda, and St. Maurice Church in Olomouc, both in the Czech Republic. Finally, we also compare the three-dimensional map obtained with the measurements made by the 3D laser scanner carried onboard UAV against the ones performed by a 3D terrestrial laser scanner.

New Era in Cultural Heritage Preservation: Cooperative Aerial Autonomy for Fast Digitalization of Difficult-to-Access Interiors of Historical Monuments

“…The orthophotos were used to assess the state of the OoIs for subsequent restoration works and for enhancing the texture of the 3D model of the church 4 . As compared well in [13], the aerial-based orthophotos outperform the ground-based orthophotos in terms of quality of detail, quality of rectification due to perpendicular optical angles, and absence of occlusions.…”

“…Among introduced solutions, the most advanced UAV-based systems with the high level of autonomy required for the interiors of historical buildings were introduced in our recent works [10]- [13]. In these publications, we introduced a preliminary application-tailored autonomous UAV system allowing for safe localization and navigation inside historical structures [10], the methodology and algorithms for the realization of advanced documentation techniques found in reflectance transformation imaging (RTI) [11] and raking light (RAK) [12], and an autonomous single-UAV system for realization of documentation missions [13]. All works provide a fully autonomous solution and the possibility of performing documentation techniques in difficult-to-access areas without using mobile lift platforms or scaffolding installation.…”

MRS Modular UAV Hardware Platforms for Supporting Research in Real-World Outdoor and Indoor Environments

“…For example, for autonomous documentation of historical buildings [12], [13], a platform with high payload is required to carry a full-size camera on a gimbal, Ouster LiDAR for mapping, localization and collision avoidance, and propeller guards to protect the platform and its surroundings. Contrary, the platform has to be as small as possible to maintain its ability to fly in confined environments.…”

“…The MRS platforms have also used actuators, such as manipulators attached to the UAVs [10], gimbals for camera stabilization (NAKI project) [12], [34] and a capsule launcher for fire extinguishing (DOFEC project) [15]. In addition, even a net launcher, mounted on the Eagle.One 5 drone [22], was used to capture invading drones in aerial no-fly zones (for details see Sec.…”

“…Utilization of the safetycritical platforms in tasks documenting interiors of historical monuments by a team of UAVs is part of the Dronument 9 project, showcased in Fig. 9 and summarized in [12], [13], [17], [34], [40], [41].…”