Hardware in the Simulation Loop Framework For Reproducible Testing of Rescue Robot Communications in Constrained Environments

Robotic systems bring significant support in search and rescue missions, especially in disastrous scenarios that harbor significant dangers for rescue forces. In these hazardous areas, remote-controlled rescue robot systems can provide a fast and yet secure way to scout the area and discover survivors. These evolving systems must be tested extensively in various reproducible setups before real-world deployment. Their performance in communication constrained environments, which often induce degrading and even missing network links, is of worth. Therefore, this work presents a concept for an evaluation platform following a Hardware in the Simulation Loop (HiSL) approach to test robotic applications in challenging network environments as well as evaluate communication solutions developed for rescue robotics. An exemplary implementation of the platform concept is provided, which uses extensive raytracing simulations to generate coverage maps of rescue scenarios defined in ROS/Gazebo. These maps are used to simulate the performance of real communication systems. The platform concept implementation is used in a case study based on a sample scenario from the DARPA Subterranean (SubT) challenge, to evaluate SKATES, a communication module of our conception, in its ability to provide reliable network access by leveraging its Multi-Connectivity feature. Results demonstrate the fidelity of the communication behavior in the real-world to the constraints established by the communication environment in the simulation, as well as the robust network behavior of the Multi-Radio Access Technology (Multi-RAT) enabled SKATES module.