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Publicatie

Towards unmanned inland shipping

Boek - Dissertatie

Road transport dominates the European and Belgian hinterland freight transport sector. Over the last decades, approximately three quarters of the cargo streams passed by road, whilst inland waterway transport seems to offer a more sustainable alternative. Moreover, the larger inland vessels suffer from an excess of supply over demand, and the amount of smaller inland vessels is diminishing. This negative evolution in the inland waterway transport sector does not align well with the European and Belgian governmental ambitions to transfer more freight transport to their waterways. This thesis aims to investigate a solution for this emerging tension field by studying the technological feasibility of unmanned inland cargo vessels. More precisely, three research questions are answered. The first question explored: "How to design and construct an industrially relevant research vessel for unmanned inland cargo shipping?". To investigate the industrial relevance, the present inland waterway transport sector was examined. Three developments stood out. First, the European Watertruck+ project introduced a novel fleet of modular push boats and barges. Hence, the watertrucks can separate their navigation time from their cargo handling time. Second, Blue Line Logistics built new flat deck vessels with an onboard crane, which enables them to handle their cargo independently from the shoreside infrastructure. These vessels focus on transporting palletized cargo. Finally, smaller urban freight vessels have already successfully transported cargo within several European cities. Next to these industrial developments, the recent research evolution regarding unmanned shipping in general and the specific challenges for inland waterway transport motivated the build of two unmanned research vessels: a scale model self-propelled watertruck barge and a functional scale model of a flat deck barge which focusses on palletized cargo. In addition, both research vessels have a length that facilitates intracity freight transport research. The second question investigated: "How to model and identify the hydrodynamic motion models of an inland cargo vessel?". The modelling part focussed mainly on the decoupled equations of motion in the water plane, i.e., the surge, sway, and yaw degrees of freedom. To identify this decoupled model, experimental data were fetched with the research vessel in its real outdoor environment. Two identification procedures were compared. The first one used the instantaneous force balance, and the second one integrated the differential equations of the decoupled motions. Furthermore, two independent data sources were used to validate the identified models: bollard pull test data, measured inside a towing tank, and longitudinal damping data, calculated via computational fluid dynamics. The third question studied: "How to provide an unmanned inland cargo vessel with perception and motion control?". For this purpose, four navigational environments were differentiated, based on the presence of known or unknown and static or dynamic objects. These environments influence the requirements for the perception and motion control systems of the vessels: exteroceptive sensors are needed to detect unknown objects, and traffic rules need to be implemented in order to avoid dynamic objects. This thesis demonstrates the first successful missions of an unmanned and autonomous vessel navigating on a river with known static obstacles. Furthermore, this work provides an alternative answer for the last two research questions, by the construction of an inland shore control centre to remotely monitor or control vessels. Accordingly, the operator performs the perception and motion control tasks for the vessel, and implicitly models and identifies the behaviour of the ship. A shore control centre, however, raises new research questions: can this centre help the operator to construct a feeling of ship sense, and can the operator keep the ship in harmony with the environment from a remote location? The initial experiments, with an operator in this control centre remotely controlling an unmanned vessel, delivered a first answer for these novel questions. In addition, this thesis includes some preliminary results with an augmented remote control system in the control centre. This augmented system offers the operator extra visualisations and measurements of the vessel on its navigational chart. Evidently, the technological feasibility of the abovementioned research questions alone cannot judge the socio-economic feasibility of unmanned inland shipping in general. Consequently, this work aims to gain insights in order to enable higher resolution socio-economic feasibility studies, with the ambition to guide the course of future investments streams.
Jaar van publicatie:2021
Toegankelijkheid:Open