Cooperative look-ahead control for fuel-efficient and safe heavy-duty vehicle platooning

The operation of groups of heavy-duty vehicles (HDVs) at a small inter-vehicular distance (known as platoon) allows to lower the overall aerodynamic drag and, therefore, to reduce fuel consumption and greenhouse gas emissions. However, due to the large mass and limited engine power of HDVs, slopes have a significant impact on the feasible and optimal speed profiles that each vehicle can and should follow. Therefore maintaining a short inter-vehicular distance as required by platooning without coordination between vehicles can often result in inefficient or even unfeasible trajectories. In this paper we propose a two-layer control architecture for HDV platooning aimed to safely and fuel-efficiently coordinate the vehicles in the platoon. Here, the layers are responsible for the inclusion of preview information on road topography and the real-time control of the vehicles, respectively. Within this architecture, dynamic programming is used to compute the fuel-optimal speed profile for the entire platoon and a distributed model predictive control framework is developed for the real-time control of the vehicles. The effectiveness of the proposed controller is analyzed by means of simulations of several realistic scenarios that suggest a possible fuel saving of up to 12% for the follower vehicles compared to the use of standard platoon controllers.Comment: 16 pages, 16 figures, submitted to journa

Model reduction of networked passive systems through clustering

In this paper, a model reduction procedure for a network of interconnected identical passive subsystems is presented. Here, rather than performing model reduction on the subsystems, adjacent subsystems are clustered, leading to a reduced-order networked system that allows for a convenient physical interpretation. The identification of the subsystems to be clustered is performed through controllability and observability analysis of an associated edge system and it is shown that the property of synchronization (i.e., the convergence of trajectories of the subsystems to each other) is preserved during reduction. The results are illustrated by means of an example.Comment: 7 pages, 2 figures; minor changes in the final version, as accepted for publication at the 13th European Control Conference, Strasbourg, Franc

Balanced Truncation of Networked Linear Passive Systems

This paper studies model order reduction of multi-agent systems consisting of identical linear passive subsystems, where the interconnection topology is characterized by an undirected weighted graph. Balanced truncation based on a pair of specifically selected generalized Gramians is implemented on the asymptotically stable part of the full-order network model, which leads to a reduced-order system preserving the passivity of each subsystem. Moreover, it is proven that there exists a coordinate transformation to convert the resulting reduced-order model to a state-space model of Laplacian dynamics. Thus, the proposed method simultaneously reduces the complexity of the network structure and individual agent dynamics, and it preserves the passivity of the subsystems and the synchronization of the network. Moreover, it allows for the a priori computation of a bound on the approximation error. Finally, the feasibility of the method is demonstrated by an example

Psychological Effects of ACL Injuries on an Athlete’s Return to Sport

While much attention is paid to physical rehabilitation, a review of the literature indicates that it is the psychological return to sport post-injury that most significantly determines a successful return. That is, with proper rehabilitation and strength training an athlete can achieve a successful physical return however, psychological factors are often unseen, unreported, or ignored and consequently have the greatest impact on performance. Fear of injury is something all athletes face, however, post-injury this fear intensifies impacting an athlete’s cognitions, confidence, and performance. Results from the current inquiry indicate that the ACL injury has specifically been shown to have greater psychological consequences, than other injuries. Factors such as a long recovery time and significant amounts of rehabilitation as well as several months away from competitive sports, are all contributing factors to psychological stress

The primacy of the rule of law and member states’ constitutional identities

This essay discusses the phenomenon of both divergence and convergence in understanding the ‘rule of law’ by EU member states and EU institutions respectively. The potential for constitutional conflict can normatively be located in the relation between articles 2 (on the common foundational values of member states and EU) and 4(2) (on the duty to respect the constitutional identity of member states) of the TEU. The structural nature of the potential for constitutional conflict is explained by the ‘juridictional gap’ between member state courts and the European Court of Justice. By now, however, on the part of national courts which allow for ultra vires or constitutional identity review (like the French and Portuguese) techniques have been developed to reduce the scope for conflict by focussing on convergence of rule of law understandings. These do neither fully reduce the ‘jurisdictional gap’ nor the diversity of authentic (non-abusive) understandings of the rule of law which may be reflected in differences in the constitutional identity of member states. In particular, the revival of a strictly formal and hierarchical understanding of an absolute doctrine of primacy in the case of the Court of Justice which is based on a ‘thin’ concept of the rule of law that outflanks ‘thicker’ concepts obstructs possibilities for resolving constitutional conflict. For resolution of such conflicts, however, it is unavoidable to understand the doctrine of primacy as subject to a ‘thick rule of law’ conditionality, which seems occasionally to be implied in the ECJ’s case law, but is too often missing

The Evolution and <i>Gestalt</i> of the Dutch Constitution

One way of distinguishing constitutions in historical terms is between, on the one hand, modern revolutionary, blue-print, single document constitutions, which have their origin in an identifiable more or less revolutionary constitutional moment—usually connected with some form of political cataclysm (a war or revolution causing political, social and economic collapse)—and, on the other hand, constitutions which are the product of an incremental historical process and in which socio-political developments and evolutions become codified. The constitutional system of the Netherlands is definitely to be grouped in the last category of what one may call ‘evolutionary’ constitutions. It is, in other words, more like the British Constitution and those of the Nordic countries (at least as they were until a few decades ago), and indeed more like that of the European Union than the continental European constitutions of Germany, Italy or France.Among distinctive features that places it in the group of ‘evolutionary’ constitutions is the multi-source nature of which the Constitution (Grondwet, literally Basic Law, but this is never used in translations into English) is but one source, though an important one, between various sources of constitutional law. Another constitutional document, which is of superior rank to the Grondwet, is the Charter for the Kingdom (Statuut voor het Koninkrijk). It regulates the constitutional relations between the European and Caribbean countries that form part of the Kingdom, in a quasi-federal manner. However, as we explain below, also directly effective provisions of international treaties, particularly human rights treaties, are considered to be a source of national constitutional law, with overriding effect towards conflicting norms. Also, there are important rules of customary constitutional law, particularly regarding the parliamentary system, the principle of monism in the relation between international and national law, as well as certain aspects of the principle of judicial deference towards the legislature.Other distinctive features are the absence of constitutional review of acts of parliaments by courts without sovereignty of Parliament, an openness to international law and international society, the lack of an explicit constitutionally relevant concept of sovereignty, and an overall low degree of ideology in the text of the Constitution: it lacks a preamble with its attendant rhetoric. Terms like ‘democracy’, ‘the people’ or ‘nation’ are absent so far. We describe these features below. They can only be properly understood when viewed in historical perspective.Given the evolutionary nature of the Netherlands Constitution, the ‘origin’ of the constitution and its evolution cannot be strictly separated. Which of the texts bearing the name Constitution (Grondwet) should be considered to be the original of the present one is hard to say for reasons that we presently explain, but is not much of an issue. Also, any attempt at identifying original constituent power is meaningless; there has never been a body that could claim to have been a constituent assembly that coined the original, ‘first’ constitution. Most constitutional reforms were the product of political circumstances, often international political circumstances, prepared textually by a committee appointed by the government, only in recent times after consultation and with the approval of the Lower House (Tweede Kamer): the so-called Staatscommissies (Royal Committees). They were not quite like a constituent assembly, though, as we shall see, formally that was called for at the end of the Republic in 1795, by the States-General at its own abolition.The historical evolutionary nature of the constitution necessitates a format that is slightly different from other chapters in this book in the first two parts. In Part B we sketch the outlines of the historical development of the constitution, which is marked by continuity and incrementalism. In Part C, we describe the institutional parameters of constitutional development. Part D looks at the fundamental concepts and structures of the constitutional system, while Part E concludes this contribution with a discussion of the constitutional identity which inheres in these