situational graph
Situational Graphs for Robotic First Responders: an application to dismantling drug labs
Meijer, W. J., Kemmeren, A. C., van Bruggen, J. M., Haije, T., Fransman, J. E., van Mil, J. D.
In this work, we support experts in the safety domain with safer dismantling of drug labs, by deploying robots for the initial inspection. Being able to act on the discovered environment is key to enabling this (semi-)autonomous inspection, e.g. to open doors or take a closer at suspicious items. Our approach addresses this with a novel environmental representation, the Behavior-Oriented Situational Graph, where we extend on the classical situational graph by merging a perception-driven backbone with prior actionable knowledge via a situational affordance schema. Linking situations to robot behaviors facilitates both autonomous mission planning and situational understanding of the operator. Planning over the graph is easier and faster, since it directly incorporates actionable information, which is critical for online mission systems. Moreover, the representation allows the human operator to seamlessly transition between different levels of autonomy of the robot, from remote control to behavior execution to full autonomous exploration. We test the effectiveness of our approach in a real-world drug lab scenario at a Dutch police training facility using a mobile Spot robot and use the results to iterate on the system design.
Vision-based Situational Graphs Generating Optimizable 3D Scene Representations
Tourani, Ali, Bavle, Hriday, Sanchez-Lopez, Jose Luis, Avsar, Deniz Isinsu, Salinas, Rafael Munoz, Voos, Holger
Abstract-- 3D scene graphs offer a more efficient representation of the environment by hierarchically organizing diverse semantic entities and the topological relationships among them. In the context of Visual SLAM (VSLAM), especially when the reconstructed maps are enriched with practical semantic information, these markers have the potential to enhance the map by augmenting valuable semantic information and fostering meaningful connections among the semantic objects. In this regard, this paper exploits the potential of fiducial markers to incorporate a VSLAM framework with hierarchical representations that generates optimizable multi-layered vision-based situational graphs. The framework comprises a conventional VSLAM system with lowlevel feature tracking and mapping capabilities bolstered by the incorporation of a fiducial marker map. When the goal is to incorporate semantic data, it becomes possible to enrich VSLAM Employing vision sensors for Simultaneous Localization with high-level information about the environment [2], [3] and Mapping (SLAM) applications can bring about several Nonetheless, many of these approaches do not integrate merits, including the ability to achieve rich visual information valuable relational information among pertinent semantic using a low-cost hardware setup, making them attractive entities. This variant of SLAM systems is graphs from underlying SLAM.
Graph-based Global Robot Simultaneous Localization and Mapping using Architectural Plans
Shaheer, Muhammad, Millan-Romera, Jose Andres, Bavle, Hriday, Sanchez-Lopez, Jose Luis, Civera, Javier, Voos, Holger
In this paper, we propose a solution for graph-based global robot simultaneous localization and mapping (SLAM) using architectural plans. Before the start of the robot operation, the previously available architectural plan of the building is converted into our proposed architectural graph (A-Graph). When the robot starts its operation, it uses its onboard LIDAR and odometry to carry out an online SLAM relying on our situational graph (S-Graph), which includes both, a representation of the environment with multiple levels of abstractions, such as walls or rooms, and their relationships, as well as the robot poses with their associated keyframes. Our novel graph-to-graph matching method is used to relate the aforementioned S-Graph and A-Graph, which are aligned and merged, resulting in our novel informed Situational Graph (iS-Graph). Our iS-Graph not only provides graph-based global robot localization, but it extends the graph-based SLAM capabilities of the S-Graph by incorporating into it the prior knowledge of the environment existing in the architectural plan
Graph-based Global Robot Localization Informing Situational Graphs with Architectural Graphs
Shaheer, Muhammad, Millan-Romera, Jose Andres, Bavle, Hriday, Sanchez-Lopez, Jose Luis, Civera, Javier, Voos, Holger
In this paper, we propose a solution for legged robot localization using architectural plans. Our specific contributions towards this goal are several. Firstly, we develop a method for converting the plan of a building into what we denote as an architectural graph (A-Graph). When the robot starts moving in an environment, we assume it has no knowledge about it, and it estimates an online situational graph representation (S-Graph) of its surroundings. We develop a novel graph-to-graph matching method, in order to relate the S-Graph estimated online from the robot sensors and the A-Graph extracted from the building plans. Note the challenge in this, as the S-Graph may show a partial view of the full A-Graph, their nodes are heterogeneous and their reference frames are different. After the matching, both graphs are aligned and merged, resulting in what we denote as an informed Situational Graph (iS-Graph), with which we achieve global robot localization and exploitation of prior knowledge from the building plans. Our experiments show that our pipeline shows a higher robustness and a significantly lower pose error than several LiDAR localization baselines.
Advanced Situational Graphs for Robot Navigation in Structured Indoor Environments
Bavle, Hriday, Sanchez-Lopez, Jose Luis, Shaheer, Muhammad, Civera, Javier, Voos, Holger
Mobile robots extract information from its environment to understand their current situation to enable intelligent decision making and autonomous task execution. In our previous work, we introduced the concept of Situation Graphs (S-Graphs) which combines in a single optimizable graph, the robot keyframes and the representation of the environment with geometric, semantic and topological abstractions. Although S-Graphs were built and optimized in real-time and demonstrated state-of-the-art results, they are limited to specific structured environments with specific hand-tuned dimensions of rooms and corridors. In this work, we present an advanced version of the Situational Graphs (S-Graphs+), consisting of the five layered optimizable graph that includes (1) metric layer along with the graph of free-space clusters (2) keyframe layer where the robot poses are registered (3) metric-semantic layer consisting of the extracted planar walls (4) novel rooms layer constraining the extracted planar walls (5) novel floors layer encompassing the rooms within a given floor level. S-Graphs+ demonstrates improved performance over S-Graphs efficiently extracting the room information while simultaneously improving the pose estimate of the robot, thus extending the robots situational awareness in the form of a five layered environmental model.