This thesis presents a COLREG-compliant collision avoidance and detection algorithm for the safe navigation of autonomous surface vessels. The method builds upon the Velocity Obstacle algorithm and implements the concept of the ship domain and the ship arena into the framework. The International Regulations for Preventing Collision at Sea – the COLREGs – are analyzed individually and incorporated in the designed collision avoidance algorithm. The COLREGs were used to determine the preferred passing side and optimized motion for every possible encounter situation with an obstacle vessel. The ship domain and arena help to perform proactive alterations when required, improving on the apparent shortcomings of the VO algorithm. This framework leads to a more proactive collision avoidance algorithm that guarantees COLREG compliance and safe navigation in mixed-traffic environments. The robustness and wide adaptability of the developed algorithm are validated in different encounter situations, ranging from vessel-to-vessel batch simulations to complex, multi-vessel scenarios.

This thesis presents a COLREG-compliant collision avoidance and detection algorithm for the safe navigation of autonomous surface vessels. The method builds upon the Velocity Obstacle algorithm and implements the concept of the ship domain and the ship arena into the framework. The International Regulations for Preventing Collision at Sea – the COLREGs – are analyzed individually and incorporated in the designed collision avoidance algorithm. The COLREGs were used to determine the preferred passing side and optimized motion for every possible encounter situation with an obstacle vessel. The ship domain and arena help to perform proactive alterations when required, improving on the apparent shortcomings of the VO algorithm. This framework leads to a more proactive collision avoidance algorithm that guarantees COLREG compliance and safe navigation in mixed-traffic environments. The robustness and wide adaptability of the developed algorithm are validated in different encounter situations, ranging from vessel-to-vessel batch simulations to complex, multi-vessel scenarios.

Inland waterway transport is a low CO2 emission alternative to road transport. A shift towards more inland waterway transport could also help reduce road congestion and noise pollution. Infrastructure bottlenecking, particularly at locks, is part of the reasons preventing this shift. Congestion is leading to delays. Locks can be physically improved, or the passage of the vessels through the locks can be optimized through scheduling. Recent work introduced a novel switching-max-plus-linear system approach to scheduling vessels passing through networks of waterways and locks, also introducing a novel routing component to the scheduling problem. Switching max-plus-linear systems are a convenient way to model scheduling systems using max-plus-linear algebra. The switching-max-plus-linear model only considered locks with a single chamber that can only process one vessel at a time. Additionally, it only considered four specific waterway network configurations, rather than any arbitrary network configuration. Real locks can have multiple chambers, and they can process multiple vessels at the same time if they are placed according to regulations in the two-dimensional space of the chamber. The scope of this report was then to build upon this switching max-plus-linear model by adding support for arbitrary network configurations, and multi-chamber, multi-vessel locks with proper twodimensional ship placement, to answer the main research question: How can multi-vessel, multichamber locks with ship placement be integrated into the SMPL IWT scheduling model? Three mathematical scheduling models formulated as SMPL systems were introduced, each subsequent model building on the previous one. The first introduced support for arbitrary network configurations. The second introduced support for multi-chamber locks and allowed vessels to pass through lock chambers at the same time, provided that their assigned one-dimensional sizes fit into the assigned one-dimensional capacity of the chamber. The third introduced support for twodimensional ship placement through a Tetris-like placement sequence also modeled as a switching max-plus-linear system. The models were translated to mixed integer linear programming models, and arrival time and arrival time offset objectives were added, so they could be used as the rules by which a scheduler would build and solve offline scheduling optimization models on a case-by-case basis. Auxiliary objectives to promote vessels slowing down, rather than waiting stationary in the waiting areas, were also added. The models were all found to be working as intended and implemented correctly through the use of a number of verification cases and tests. Complexity tests showed that the solution times for all three models already became larger than a practical limit of 15-20 minutes for simple scenarios with 10-15 vessels. A heuristic model that mimics how vessels are assigned to lockages in practice was built. Comparisons to the scheduling models on the verification cases showed negligible differences for the models in single-lock cases, but it indicated that the multi-vessel, multi-chamber models may outperform practice in multi-lock cases. Future research is recommended to focus on online optimization to account for disturbances, distributed optimization to reduce calculation times, and validation of the model’s performance with real data.

Inland waterways form a natural network infrastructure with the capacity for waterborne transport of people and goods for moving freight from seaports to the hinterland. Recently, Inland Waterway Transport (IWT) has been promoted more extensively by the European Union and various governments as it plays a crucial role in reducing road congestion and CO2 emissions from transport. However, the advantages of IWT are not fully exploited due to inefficiencies in the logistics system, such as long waiting times at locks and sub-optimal navigation on waterways. Currently, no scheduling at infrastructures or routing optimisation of the overall waterway network is happening. The scheduling of vessels through a lock is usually performed on a First In First Out basis, providing an opportunity for improvement. Hence, this thesis aims to design a scheduling strategy for generating an optimal plan for sending inland vessels through a waterway network with minimal delays, yielding a significant positive impact on the modal shift towards IWT. 
A promising approach to scheduling problems is by using Switching Max-Plus-Linear (SMPL) systems. SMPL systems have proven to be effective in various Discrete-Event Systems and transportation networks. Using SMPL models is convenient since non-linear scheduling problems can be described linearly using Max-Plus operators without compromising on the system dynamics. Moreover, as the SMPL systems can be transformed into Mixed-Integer-Linear-Programming (MILP) problems, it is also possible to use fast optimisers for solving the scheduling problems.
This thesis will show how one can describe IWT systems, consisting of; waterways, vessels and locks, as SMPL systems. The optimal schedule for the inland vessels is determined based on multiple input parameters, including waterway network lay-out, the sailing speeds of vessels and arrival deadlines of the vessels. The scheduler will return the individual vessel routing and overall vessel order in the waterway network. This routing and order selection is defined using binary control variables, turning the IWT scheduling problem into a MILP problem, which will allow finding the solution to large scale IWT scheduling problems in a reasonable computation time. Furthermore, this thesis will show how the goal of minimising the cumulative arrival times of all vessels in a network can be achieved. This is done for different types of waterway network cases, for which the results are shown and analysed.

Formation control of autonomous surface vessels (ASVs) is researched extensively in the last years, since it has promising applications. However very few designed strategies have been validated during real experiments. In this research, two
control methods for distributed leader-follower formation control are proposed: A Nonlinear Model Predictive Control (NMPC) method and an MPC method using Feedback Linearization (FL). These two designed methods are compared with a conventional Proportional-Integral (PI) control method. The performance of the proposed strategies is evaluated through simulations and real experiments using small-scale Roboat units. Both designed control methods outperform the conventional PI control method in simulation and real experiments.

Formation control of autonomous surface vessels (ASVs) is researched extensively in the last years, since it has promising applications. However very few designed strategies have been validated during real experiments. In this research, two
control methods for distributed leader-follower formation control are proposed: A Nonlinear Model Predictive Control (NMPC) method and an MPC method using Feedback Linearization (FL). These two designed methods are compared with a conventional Proportional-Integral (PI) control method. The performance of the proposed strategies is evaluated through simulations and real experiments using small-scale Roboat units. Both designed control methods outperform the conventional PI control method in simulation and real experiments.

Damen Shipyards Gorinchem has found deficiencies in the process of developing concept designs of Offshore Patrol Vessels (OPVs). There is a need to increase the efficiency of this process, meaning that (1) the speed has to be increased, (2) the accuracy of designs has to be increased and (3) the risk of deviations of the project plan has to be reduced. Analysis of the current concept design phase shows that the designer should get more insight in the design challenge, and that a more systematic and uniform design approach is required amongst different involved departments. Additionally, the lead time of developing concept designs is mostly delayed by two major bottlenecks: development of the hull shape and obtaining a resistance prediction. In this thesis a conceptual design tool is developed to resolve these deficiencies, by providing a platform for fast hull concept exploration. Key of this approach is to pre-compute time-intensive design aspects such that the most critical activities are done before starting the design process. It uses a set of parent hulls for which the resistance is obtained by RANS CFD simulations. Based on the parents, a semi-parametric modelling technique is used to create new hull geometry. A kriging surrogate model is used to provide a RANS CFD resistance prediction to that new hull geometry. A brute-force approach is then adopted to fill a database with feasible hull shapes, which can be used by the conceptual design tool for hull shape concept exploration. To test this concept a proof-of-concept database of 245.005 hulls of double-ended ferries is generated in a few days on a laptop with good memory capabilities. The geometry results and resistance predictions in the database have been assessed with a sensitivity study, cross-validation and comparison with the parent hulls. It is shown that resulting geometry is smooth and well-faired. The resistance results are sufficiently accurate for use in the concept design phase, but applicability is limited for low prismatic coefficients. For application to OPVs further research into application of this approach to hull geometries with varying local details (bulb shape, tunnels etc.) is necessary. The approach seems promising to improve the concept design phase, as it (1) reduces time pressure in the design process significantly, (2) provides insight in how the resistance is affected by main dimensions of the vessel, and (3) reduces the number of departments which is actively involved in the design process. Putting the design tool in practice should reveal if this is indeed the case.

Damen Shipyards Gorinchem has found deficiencies in the process of developing concept designs of Offshore Patrol Vessels (OPVs). There is a need to increase the efficiency of this process, meaning that (1) the speed has to be increased, (2) the accuracy of designs has to be increased and (3) the risk of deviations of the project plan has to be reduced. Analysis of the current concept design phase shows that the designer should get more insight in the design challenge, and that a more systematic and uniform design approach is required amongst different involved departments. Additionally, the lead time of developing concept designs is mostly delayed by two major bottlenecks: development of the hull shape and obtaining a resistance prediction. In this thesis a conceptual design tool is developed to resolve these deficiencies, by providing a platform for fast hull concept exploration. Key of this approach is to pre-compute time-intensive design aspects such that the most critical activities are done before starting the design process. It uses a set of parent hulls for which the resistance is obtained by RANS CFD simulations. Based on the parents, a semi-parametric modelling technique is used to create new hull geometry. A kriging surrogate model is used to provide a RANS CFD resistance prediction to that new hull geometry. A brute-force approach is then adopted to fill a database with feasible hull shapes, which can be used by the conceptual design tool for hull shape concept exploration. To test this concept a proof-of-concept database of 245.005 hulls of double-ended ferries is generated in a few days on a laptop with good memory capabilities. The geometry results and resistance predictions in the database have been assessed with a sensitivity study, cross-validation and comparison with the parent hulls. It is shown that resulting geometry is smooth and well-faired. The resistance results are sufficiently accurate for use in the concept design phase, but applicability is limited for low prismatic coefficients. For application to OPVs further research into application of this approach to hull geometries with varying local details (bulb shape, tunnels etc.) is necessary. The approach seems promising to improve the concept design phase, as it (1) reduces time pressure in the design process significantly, (2) provides insight in how the resistance is affected by main dimensions of the vessel, and (3) reduces the number of departments which is actively involved in the design process. Putting the design tool in practice should reveal if this is indeed the case.

This thesis presents the design of a performance prediction simulation model for an ship-to-shore crane. Current STS crane models do not take new trends in container terminal operations into account like automation. These models do not predict the performance accurately. This can lead to logistical and financial consequences. Automation systems that are present in the cranes should be taken into account when modelling. State-of-the-art models do not model the cycle path of the crane accurately, crane components are modeled in sequence while in real life the movements between the crane components are parallel. Moreover what is not included in these models are the accelerations/decelerations of these different components of the STS cranes. A new STS crane model is developed that consists of process blocks and all the lacking points. Data was used from a reference crane to verify and validate the new model. To evaluate the performance of the proposed prediction model, a comparison has been made with existing prediction models.

During the start of a project organisations make estimation on the expected amount of work and the corresponding project duration, the lead time. To make these estimations with a low uncertainty is important because a false estimation could result in cost overruns and project delay. This paper proposes an estimation and planning maturity framework where organisation can asses which methods can be used to ensure the estimation and planning are performed to the lowest possible uncertainty. The framework was implemented at a case study organisation, it was found that selecting the correct estimation and planning methods can result in a lead time estimation with a low uncertainty. 

During the start of a project organisations make estimation on the expected amount of work and the corresponding project duration, the lead time. To make these estimations with a low uncertainty is important because a false estimation could result in cost overruns and project delay. This paper proposes an estimation and planning maturity framework where organisation can asses which methods can be used to ensure the estimation and planning are performed to the lowest possible uncertainty. The framework was implemented at a case study organisation, it was found that selecting the correct estimation and planning methods can result in a lead time estimation with a low uncertainty.