Transport of Water versus Transport over Water

In this chapter, a methodology for the optimal management of combined water supply and navigability/sustainability in river systems based on model predictive control (MPC) is proposed. A control-oriented modeling methodology for this type of systems is presented as well. MPC is used to generate flow-control strategies from the sources to both the farmers and urban consumers in order to meet future demands with appropriate flows, optimizing operational goals such as network safety volumes in dams and smooth operations of actuators (valves, gates and pumps). At the same time, the generated flow-control strategies should allow maintaining the appropriate river water levels that, in turn, allows to preserve the ecological flows and the navigability of the downstream part of the river. The case study of the Guadiana river is used to show and verify the proposed optimal management methodology.

The dams and the hydropower plants on the Rhône River, managed by the Companie Nationale du Rhône (CNR), are controller in real-time by Model Predictive Controllers (MPC) since the early 2000s. The control objectives and constraints are manyfold: optimize electrical production, allow navigation, protect the banks from erosion, prevent or reduce the damages during flood events, supply water to industries, cities and irrigation districts. In case the outputs of the embedded model used by MPC do not fit the field measurements, some questions are raised on: how to interpret this, and what can be done to solve this problem? We will present recent developments, carried out and illustrated on the Rhône River allowing to address these issues. The framework we will use is the one of Kalman filtering. We will see that this framework is very powerful to solve the above described problems. But, in some cases the obtained solution is not the one we would expect. The conditions of success can be expressed and checked from some mathematical tests, and linked to some physical properties (number and location of sensors, uncertainties of the measurements and of the model, hydraulic configuration of the hydraulic system).

This chapter addresses distributed LQG control of multipurpose open water channels, used both for water delivery and vehicle transportation. The use of a local control agent structure of the so called local upstream control type ensures that the water level is kept close to a desired level, even in the presence of disturbances caused by water turnout at side offtakes, so as to ensure navigability. Local control agents are modified LQG controllers coupled with a nonlinear compensation of the nonlinearities induced by the gates nonlinear models. The coordination among local controllers is achieved through an algorithm based on game theory that drives the local decisions to a Nash equilibrium. Experimental results in a large scale pilot canal are included to demonstrate the control concepts proposed.

Everywhere in the world where canal systems have been constructed, often the main purpose was transportation. But for most canal systems it was inevitable that they also started to play a role in the hydrology of the regions the canals crossed. In normal situations the canals have a drainage function, but in dry periods the systems can provide fresh water. An important goal for the operators is to maintain water levels on setpoint for navigation purposes. Their target is to minimize operating costs, while giving operation for navigation the highest priority. Thereby they have to take into account that the control structures have a limited operating range. A short-term optimization approach for the operational management of the canal system can increase efficiency of the water management, thereby decreasing operation costs. For the Twente Canal system, located in the eastern part of The Netherlands, such an short-term optimization approach was implemented in the operational system. This advisory module calculates the optimal operation of the available structures, given expected fluxes and system boundaries. The approach is based on Model Predictive Control and integrates observations from a gauge network and forecasted fluxes to calculate the best use of pumps and gates. The approach anticipates future lateral inflow and lock operation. The future lateral inflow in the canal sections is calculated by a rainfall-runoff model, which uses observed and forecast precipitation and evaporation. Future lock operation is estimated based on the expertise of the operators. Both have a large impact on the water balance and contain related uncertainties. The short-term optimization is implemented in the Operational Monitoring System for regulated water systems under authority of the National Water Authority (Rijkswaterstaat). This monitoring system advises operating staff on the operation of the related hydraulic structures.

Hydraulic performance has largely benefited from recent advances in canal control. Nonetheless, taking account of water quality criteria at the same time is more challenging due to longer delay times for particular transport than for wave transport, and to poorly quantified interactions between flow and substratum. This chapter is first illustrated with a typical situation where both water quality and discharge are expected to be controlled. Different approaches of modeling are then introduced, leading to the definition of different delay times that must be considered in the perspective of real-time control. Open-loop and closed-loop control strategies of water quality in open-channels are finally presented and discussed. Research perspectives are suggested regarding combined hydraulic and water quality control.

Transport and supply water networks are two types of systems which have received a significant amount of attention in the recent years. Issues on how to obtain the best performance for a given transport or supply water systems, or how to coordinate interactions between them are still open and need more research. This chapter presents a hierarchical Model Predictive Control (MPC) scheme with a supervisor that coordinates transport and supply water systems. First, a two-level hierarchical control structure resulting from a functional decomposition of water network is briefly presented. Inside each hierarchy, an MPC controller is used. In the two-level hierarchy, a supervisory coordinating mechanism is used to generate control strategies which consider objectives at different time scales. The first level, in charge of managing the transport system, works in a daily scale in order to achieve the global management policies for the transport over water (e.g., navigation, vessels and barges) in different rivers and balance management of different reservoirs. The second level, in charge of managing the supply system, works in a hourly scale and manipulates actuator (pumps and valves) set-point to satisfy the local water supplying objectives (e.g., minimizing economic cost, handling emergency storage and smoothing actuator operation). The results of the modeling will be applied to the Catalunya Regional Water Network and based on an aggregate model.

During the 2010 and 2011, extreme flooding events affected the low Magdalena River catchment, Colombia, with devastating consequences. This triggered the urgency of adjusting the new river basing planning framework for the country, in which the generation and use of flood risk maps, was lacking. Recent efforts include the generation of probabilistic flood maps, based on the generation of a hydraulic model and an uncertainty analysis related to the wetland-river connections. Although this effort is a step forward to the definition of design criteria for flood risk prevention measures and for the land-use planning process in general, an integrated vision is still missing. In particular, depending on the hydraulic and hydrological condition of the river-wetland system, the operation of the existing hydraulic structures is sometimes decided illegally by the water users with the strongest economical power and not by the local authority, with the consequent biased water use. The research objective of this study is to analyze the control strategy for the operation of hydraulic structures in the region of the Low Magdalena River, considering uncertain control due to self-operation of the structures by non-official actors. The study includes a literature review on existing methodologies and cases where control structures are significant and where conflicting interests are present. A number of different scenarios are analyzed different control scenarios are tested. The study uses the recently developed 1D–2D model of the region that simulates the Magdalena River Channel with side structures that replicate the river-wetland connections. Conclusions and recommendations of the study are drawn, as well as indications of activities for future research.

The underlining philosophical statement of this chapter is that the promotion of automatic control for open-channel hydraulic systems will be greatly facilitated when simple algorithms and tuning procedures are available and adapted to this type of systems. The objective is therefore to contribute to an “automation for hydraulic systems for dummies” approach. In this chapter, we propose an automatic method to tune a series of distant downstream PI controllers for a cascade of pools. The methodology we present could also be used for local upstream controllers, with minor changes. The method is based on the Auto-Tuned Variation principle (ATV) carrying out a relay experiment. The information obtained from this experiment allows to estimate the parameters of a simplified integrator-delay model of each pool. Finally this allows tuning automatically a series of feedback PI controllers, with given gain and phase robustness margins, and a feedforward controller based on simple time delay. This relay experiment is performed for each pool of the canal or river, in sequence, with automatic activation of the previously tuned PI controllers. Different decoupling configurations, in order to reduce interactions between pools, are evaluated in simulation on the benchmark canal 2 of the ASCE Task Committee on Canal Automation Algorithms.

We discuss the problem of controlling an irrigation canal to accommodate fast changes in the canal state in response to events such as offtakes announced with no time lag or sudden weather changes. Our proposed approach comprises a hierarchical controller consisting of two layers with decentralized PI controllers in the lower layer and a centralized MPC-based event-driven controller in the higher layer. By incorporating the hierarchical controller structure we achieve a better performance than with the PI controllers only as currently in use in the real world, while barely increasing the communication requirements and remaining robust to temporary communication link breakdowns as the lower layer can work independently of the higher layer when the links are being restored. The operation of the higher-layer controller relies on controlling the head gate and modifying the settings of the local controllers. This way, an acceleration of water transporting is attained as the controller allows for rapid reactions to the need for more water or less water at a location. Specifically, when there is a sudden need for water, the storage in some of the pools is used to temporarily borrow water. Alternatively, when there is too much water at a location, it can be stored for some time in upstream or downstream pools before the PI controllers manage to remove the water.

The Netherlands lies in the delta area, which is formed by the Rivers Rhine, Meuse and Scheldt. Being a low-lying country, dikes and other water-retaining structures have been constructed for the purposes of flood protection (transport of water), water supply (transport of water), and navigation (transport over water). All of these objectives are important within the total operational water management. In order to achieve these objectives and make them explicit, we propose a water management approach in which each goal is addressed specifically by a term in a cost function. We assume one centralized Model Predictive Controller, which can determine the balance among the different objectives, as the control strategy for determining which actions to take when controlling the Dutch water system, especially in droughts. Simulation experiments are used to illustrate the potential of this approach under different scenarios in the dry season.

Navigation canals are used for transport purposes. In order to allow safe navigation the water level should be kept in a certain range around the Normal Navigation Level (NNL). The water level is disturbed by known and unknown inputs, like tributaries, municipal water flows, rain, etc. Some of these inputs can be used to control the water level. If the geometry requires it, canal reaches are connected by locks. The operation of these locks sometimes can disturb the water level, if the difference between the upstream and downstream water level is large. The objective is to minimize the disturbances caused by these lock operations on the water level in order to maintain the NNL. In this work the global management of the canal reach is discussed and an option to maintain the NNL by active control is introduced. Some inputs to the system, such as other confluences or gates on the side of the locks, can be controlled automatically to react to the disturbances caused by the lock operations using model predictive control to maintain the desired water level.

Controlling the transport of water by adjusting water flows in rivers and canals, inevitably will have an effect on the transport over water by vessels as well. We will discuss the effect of flowing water on scheduling micro-ferries (small autonomous water-taxis) using the least amount of energy, while aiming at satisfying customer demands with respect to pick-up times. This trade-off will be made by optimizing the assignment of micro-ferries to customers in a specific order, and by searching for the best travel speeds. The interplay between controlling transport of water and scheduling transport over water will become clear by the explicit relation between the speed of the water (influenced by water management) on travel times and energy consumption, derived in this chapter. It is shown that on average the travel times (and thereby the energy consumption) will increase with increasing magnitudes of the current. Hence, decisions made on water management have a direct effect on the performance of the transport system, and the interests of both parties should be taken into account to obtain a well-functioning water transport system.

Without an explicit road-like regulation, following the proper sailing routes and practices is still a challenge mostly addressed using seamen’s know-how and experience. This chapter focuses on the problem of modeling ship movements over water with the aim to extract and represent this kind of knowledge. The purpose of the developed modeling method, inspired by the theory of potential fields, is to capture the process of navigation and piloting through the observation of ship behaviors in transport over water on narrow waterways. When successfully modeled, that knowledge can be subsequently used for various purposes. Here, the models of typical ship movements and behaviors are used to provide a visual insight into the actual normal traffic properties (maritime situational awareness) and to warn about potentially dangerous traffic behaviors (anomaly detection). A traffic modeling and anomaly detection prototype system STRAND implements the potential field based method for a collected set of AIS data. A quantitative case study is taken out to evaluate the applicability and performance of the implemented modeling method. The case study focuses on quantifying the detections for varying geographical resolution of the detection process. The potential fields extract and visualize the actual behavior patterns, such as right-hand sailing rule and speed limits, without any prior assumptions or information introduced in advance. The display of patterns of correct (normal) behavior aids the choice of an optimal path, in contrast to the anomaly detection which notifies about possible traffic incidents. A tool visualizing the potential fields may aid traffic surveillance and incident response, help recognize traffic regulation and legislative issues, and facilitate the process of waterways development and maintenance.

The vast majority of global transports are managed by waterborne transport and continuous trade increase calls for always more productive transport means and methods. Port approaches and waterways cannot become increased along with the increase of vessel size, especially in the container trade, and limits cannot become experienced by trial and error. Navigation errors may result in ship accidents with catastrophic consequences for man, material and environment. Therefore scientific methods are required to amend navigational expertise in order to enable management of waterborne traffic by exhausting the available infrastructure capacity without violating risk boundaries. Navigational requirements and conditions depend on manifold parameters which all must be taken into account when establishing an effective traffic management system as a further development of the existing vessel traffic service (VTS) systems. The paper elucidates the multidisciplinary views and contributions and provides an outlook into the current research path based on comprehensive experience from VTS-operations and the availability of advanced information and communication technologies.

In many parts of the world, vast quantities of goods are transported over rivers and canals by means of ships and pushed convoys. This makes these waterways important transport corridors. Of all modes of transport, inland waterway transport has the strongest interaction between infrastructure and the vessels/vehicles that perform the transport. Locks, bridges and waterway depth limit the dimensions of vessels that are used in all directions, while the water depth, fairway cross-section and flow speed of the water have a significant impact on the speed and fuel consumption of these vessels. This in turn influences the cost of transport and thereby the economic viability of transport over water. In this chapter, the interaction between ship and waterway and its impact on the economic viability of inland shipping is highlighted, followed by a discussion of the recent and ongoing efforts to innovate the design of inland ships with the aim of minimizing transport cost and emissions. This is followed by a case study in which the dimensions of inland tank ships that are intended for operation on the river Rhine are optimized, taking into account the properties of the waterway and the boundary conditions that are imposed by the transport chain in which the ship operates. Finally, on the basis of this case study and the discussion of recent and ongoing innovations, possible approaches for optimization of inland waterway transport and inland ships are discussed.

This chapter describes a procedure to obtain an improved design model of ships subjected to the influence of currents and sea waves. The model structure is at the heart of the application of new techniques in control and estimation theory to the problem of Dynamic Positioning (DP) and wave filtering of marine vessels. The model proposed captures the physics of the problem at hand in an effective manner and includes the sea state as an uncertain parameter. This allows for the design of advanced control and estimation algorithms to solve the DP and wave filtering problems under different sea conditions. Numerical simulations, carried out using a high fidelity nonlinear DP system simulator, illustrate the performance improvement in wave filtering as a result of the use of the proposed model. Furthermore, using Monte-Carlo simulations the performance of three DP controllers, designed based on the plant model developed, is evaluated for different sea conditions. The first controller is a nonlinear multivariable PID controller with a passive observer. The second controller is of the Linear Quadratic Gaussian type and the third controller builds on \(\mathcal{H}_{\infty }\) control techniques using the mixed-μ synthesis methodology. The theoretical results are experimentally verified and the performance of wave filtering in DP systems operated with the controllers designed for different sea conditions are further examined by model testing a DP operated ship, the Cybership III, in a towing tank equipped with a hydraulic wavemaker.

Extensive research has been conducted on a navigation system for inland vessels at the University of Stuttgart and at the Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg (Focus Max Planck Gesellschaft, Computer at the helm, http://​www.​mpg.​de/​942027). As part of this navigation system, a model-based track-keeping controller has been developed. A high performance controller is required because of the reduced space available on rivers and canals. The control structure consists of two components, a feedback and a feedforward block, where the former is provided by a linear quadratic gaussian controller. Both components require the ship dynamics model and thus, the parameter estimation of the underlying model is a key issue to achieve high performance. In this chapter, we firstly consider Monte Carlo simulations to generate data of the closed-loop system and then the parameters of a continuous-time steering dynamics model are identified. The parameter estimation problem is solved applying an instrumental variable method, which takes into account the control structure. Parameter identification using real closed-loop experiments is also considered. Additionally, we evaluate the experiments for parameter estimation through a sensitivity analysis.

This chapter addresses the problem of control design and implementation of a nonlinear marine vessel manoeuvring model. The chapter includes a thorough literature review of the current state of the art in the nonlinear control of marine vessels field. Then, the model will be presented; the authors will consider a highly nonlinear vessel 4 DOF model as the basis of the work. The control algorithm will be introduced providing the adequate mathematical description. The control algorithm here proposed consists of a combination of two methodologies: (i) An iteration technique that approximates the original nonlinear model by a sequence of linear time varying equations whose solution converge to the solution of the original nonlinear problem and, (ii) A lead compensation design in which for each of the iterated linear time varying systems generated, the controller is optimized at each time on the interval for better tracking performance. The control designed for the last iteration is then applied to the original nonlinear problem. Simulations and results will be presented and will show an accurate performance of the approximation methodology to the non linear manoeuvring model and also an accurate tracking for certain manoeuvring cases under the control of the designed lead controller. The main characteristics of the nonlinear systems response are the reduction of the settling time and the elimination of the steady state error and overshoot.

In order to meet the future exhaust gas emission standards on European inland waterways, ship owners are facing challenges when selecting the optimal power configuration and/or retrofit option. While there are many variations of power configurations for an inland vessel, a typical ship owner is not certain which of those possibilities is the best one. To help tackling these challenges, a comprehensive study has been carried out where various power configurations have been evaluated against the operational profile of an inland pusher on river Rhine. The operational profile was obtained by measuring the fuel rack position and ship speed during the period of 6 months. Comparing the transport efficiency (i.e., fuel consumed versus cargo transported) with the recorded water levels it was shown that the transport efficiency doubles in deep water periods. Furthermore, it was argued that a more flexible power configuration, with an additional shaft line, could contribute to the total efficiency. Based on the operational profile, seven alternative power configurations have been selected. They include: diesel-direct, diesel-electric, gas engine-electric, and a combination of diesel-direct and diesel-electric. Afterwards, an estimate of the total exhaust emissions during one typical voyage was made for all alternative configurations using dynamic models. For the investigated vessel, the diesel direct configuration still is the most efficient configuration regarding the energy consumption. However, regarding NOx and PM the performance of power configurations based on gas engines is superior. As an alternative for NOx reduction, the effect of SCR installation was also considered which appears to be practical solution for retrofitting as well.

Urban freight transport became a specific research topic as the general awareness on the increasing negative effects of these freight delivery activities on the local livability grows. The awareness for external costs (congestion, emissions, noise and road safety) by the public grew. As a result, (local) governments implemented specific policies. Often, these limit the free, flow of traffic, put limits on (un)loading activities and limit urban road capacity. As a result, logistics entrepreneurs innovate their last mile transport operations. An under-investigated opportunity is the use of waterways for urban freight delivery purposes. This chapter lists best practices found in Western Europe. These transport freight towards or in the city. In this chapter, a Dutch concept was translated into a specific case for the Belgian city of Ghent. A cost simulation of an urban delivery concept with an electrically-powered vessel is developed and gives us insight in the actual competitiveness. Based on our own simulation, conclusions are drawn. Further research opportunities are indicated.

Inland shipping in North Western Europe is a well known transportation mode which can make use of a large and dense inland waterway network. However in the last 50 years no new small inland ships have been built. The reasons why these small inland ships are disappearing are explained. In order to deal with the diminished supply on the small inland waterways a new type of inland navigation system is proposed. A methodology is developed to research this new inland navigation system. In the developed methodology a network design, tug and barge design, transportation costs and competition models are combined into a single model. The main goal of the total model is to determine the profitability, expressed in the Net Present Value (NPV), of the investment in a specific ship and network design. Also the link between transport function of waterway and the actual design of the waterway network is made. Lastly the role of the government is discussed in how it could facilitate the reactivation of the small inland waterway network.

Inland waterway transport is an important economic activity in the Netherlands and in Europe. Especially in the hinterland transport of containers, inland shipping is expected to form the backbone of a multimodal transport system. To support and strengthen the inland waterway industry in the Netherlands, the Dutch Government conducted a stimulus program called Impuls Dynamic Traffic Management Waterways. As part of this stimulus program, research was carried out into the economic structure of the inland waterway transport industry, and the potential for cooperation in certain geographical areas in the hinterland. To support the development of new logistics concepts for inland waterway transport, we developed a simulator, in which market parties can develop new transport and logistics concepts, and investigate the impact of implementing these concepts. Several gaming sessions with industry representatives were conducted for six of the main geographical areas in the Dutch waterway system. From the sessions, we can conclude that further cooperation is possible in certain geographical areas, which can result in a concept that can prove to be beneficial for the partners in the transport network, as well as their customers. A second conclusion is that the combination of simulation and gaming in an interactive workshop setting proved to be a very effective way to stimulate discussions on innovations in the inland waterway transportation sector.