Formation control in the port-Hamiltonian framework

We all want to keep our feet dry, but at the same time little is known about the composition of more than 17,000km of dikes protecting The Netherlands. Recently, much research has focused on the development of new methods and technologies for the mapping of the composition and failure mechanisms of dikes. This thesis studies the use of a large number of robots for dike mapping in a cooperative fashion. This research is part of the Autonomous Sensor SYStems (ASSYS) program of technology foundation STW and is a collaboration with the University of Twente. The University of Twente focuses on the robot design, while this thesis develops new algorithms for the coordination of the robots. These algorithms ensure that the robots in the team achieve a desired relative displacement, or in other words, achieve a formation. Formations are important for dike inspection to facilitate high resolution, three-dimensional images of the dike. The algorithms are based on assigning virtual springs and dampers between the robots: when robots are too close, springs push them further apart; when robots are too far apart, springs pull them closer together. The use of energy-based models and the physical interpretation of the springs and dampers provides a clear intuition of the technical-mathematical algorithms. Moreover, these models provide robust and energy-efficient results. In addition to the dike application, similar algorithms are developed for the distribution of groups of satellites on planetary orbits (e.g. GPS satellites).