When it comes to deploying sensors in a suspected CBRNe hazard area, a common question is: How to get them there? Should people be sent in, or is there another way to acquire on-site sensor data without any pre-existing infrastructure? Could a network of novel autonomous air and land-based mobile sensor carriers be a solution? Germany’s Fraunhofer Gesellschaft has looked into the matter as part of its SENEKA research project, where a “sensor network with mobile robots for disaster management” has been developed. This article looks into SENEKA’s basic setup and the benefits that may arise from using such a system. SENEKA includes unmanned aerial systems (UAS) and unmanned ground vehicles (UGV) that are networked with their peers and with a ground control station. UAS and UGV are equipped for autonomous operation, i.e. they do not require joystick-style control commands by a human operator, they rather find their way by themselves. Using a method called SLAM, simultaneous
localization and mapping, they scan their environment while moving, building a digital map of their surroundings that gets more and more detailed and may also serve as an input to a situational picture presented to human experts. SENEKA’s UGVs are four-wheel-drive robust vehicles dubbed “Quanjo”, developed by Fraunhofer for autonomous operation in unknown terrain. UAS are based on commercially available platforms. Following a multi-sensor approach, the carriers may be equipped with cameras and with mission-specific sensors such as gas sensors. They can be used on a fly-in-fly-out (or drive-in-drive out) basis, but some UAS and UGV are additionally designed to drop special low-energy high-endurance sensor nodes at places where they are to remain on a long-term basis during the mission. Those droppable sensor nodes are a new feature of SENEKA and come in two varieties: “High-End” sensor nodes may be deployed by a Quanjo UGV with a robotic arm along its path, so areas may remain under surveillance even when the UGV has moved on. They will be collected again when the mission is over. “Best-price” sensor nodes are disposable sensors shaped like a small ball; they may be dropped by specially equipped UAS while flying e.g. over a heap of debris where sensors have to physically enter the heap in order to obtain meaningful data. Those sensor nodes will not be recovered. Figure 1 shows the SENEKA UAS and UGV sensor carriers, the high-end sensor node, a control station view and some of the communication links. Speaking about sensors, SENEKA nodes may contain commercially available sensors as well as low-energy colorimetric or photo-acoustic “SniffNode” gas sensors developed by Fraunhofer within the project. In order to establish reliable wireless communication links between the carriers, the sensor nodes, and the control station even in a hostile environment, Fraunhofer has come up with a robust radio communication system using a number of frequencies to form a multi-hop redundant network. The SENEKA control station is the hub for mission control and data analysis, normally deployed in a van-sized vehicle.
Fraunhofer believes that, once moved ahead from a research prototype to a fully developed system, SENEKA has the potential to significantly enhance the ability of hazard response teams to get their sensors to where they need to be in order to acquire meaningful data. Due to SENEKA’s autonomous operation features, experts may concentrate on defining the mission and on analyzing the data instead of having to put much effort into controlling the fleet of carriers. Moreover, SENEKA reduces the exposure of responders to risk by keeping them out of the immediate hazard areas, and the SENEKA UAS may even reach otherwise inaccessible areas. Fraunhofer Gesellschaft is Europe’s largest applied research organisation, and as part of its innovation model, prototype results of projects like SENEKA are made available for real-world use by partnering with industry. Approaching the end of the research project phase in late 2014, the SENEKA team is now in the process of establishing such collaboration.