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In this study, we consider a model free control technique for a class of minimum phase nonlinear systems with unknown dynamics. We propose a timescale transformation approach that can be used to estimate the drift and the high frequency gain of the output dynamics of nonlinear systems with a well de ned relative degree. The proposed controller provides an e ective output regulation mechanism that avoids the need for direct disturbance model estimation and high gain output feedback controllers. A simulation study is conducted to demonstrate the e ectiveness of the proposed approach.

Heat exchangers are generally described by two coupled partial differential equations (PDEs), and belong to the class of systems of conservation laws. In this paper we propose a result on the regulation of heat exchangers, in which we are choosing a proportional-integral (PI)-controller implemented on an output feedback from a boundary condition. First, a study on the existence and uniqueness of solutions of uncontrolled system is carried out, and we give a condition on the parameters of the system that ensures that the control-observation problem is well-posedness. Secondly we successively study the stability of the system controlled by a proportional and integral action, when the gains are adjusted following respectively a classic Lyapunov approach, and using a recent result that combines Lyapunov’s approach and operator perturbation theory.

Complex balanced mass-action systems (CBMASs) are of great importance in the filed of biochemical reaction networks. However analyzing the persistence of these networks with high dimensions and time delays poses significant challenges. To tackle this, we propose a novel approach that combines 1-dimensional (1d) or 2d delayed CBMASs (DeCBMASs) and introduces inheritable combination methods based on the relationship between semilocking sets and intersecting species. These methods account for various scenarios, including cases where the set of intersecting species is empty, or there are no common species in non-trivial semilocking sets and the intersecting species set, or when special forms are present. By utilizing these combination methods, we derive sufficient conditions for the persistence of high-dimensional DeCBMASs. This significantly expands the known class of delayed chemical reaction network systems that exhibit persistence. The effectiveness of our proposed approach is also demonstrated through several examples, highlighting its practical applicability in real-world scenarios. This research contributes to advancing the understanding of high-dimensional DeCBMASs and offers insights into their persistent behavior.

In this paper, we propose a model reduction method for semistable Laplacian dynamics, which describe the behaviors of network systems. In the method, the original semistable system is split into an average system and asymptotically stable part. We only implement the balanced truncation to reduce the dimension of the stable part and obtain the reduced-order model preserving the semistability. Then, a specific coordinate transform enables to convert the resulting reduced-order model to the lower-dimensional network system that represents a simplified complete network with less vertices. The reduction procedure allows for the a priori computation of a bound on the approximation error between the original and reduced Laplacian dynamics. Finally, the proposed method is illustrated by an example.

Nuclear norm based subspace identification methods have recently gained importance due to their ability to find low rank solutions while maintaining accuracy through convex optimization. However, their heavy computational burden typically precludes the use in an online, recursive manner, such as may be required for adaptive control. This paper deals with the formulation of a recursive version of a nuclear norm based subspace identification method with an emphasis on reducing the computational complexity. The developed methodology is analyzed through simulations on Linear Time-Varying (LTV) systems particularly in terms of convergence rate, tracking speed and the accuracy of identification and it is shown to be computationally lighter and effective for such systems, with the considered rate of change of dynamics.

Implementation of a liquid cooling transforms a refrigeration system into a combined cooling and heating system. Reclaimed heat can be used for building heating purposes or can be sold. Carbon dioxide based refrigeration systems are considered to have a particularly high potential for becoming efficient heat energy producers. In this paper, a CO2 system that operates in the subcritical region is examined. The modelling approach is presented, and used for operation optimisation by way of non-linear model predictive control techniques. Assuming that the heat is sold, it turns out that the system has negative operational cost. Depending on the choice of objective function daily revenue varies from about 7.9 [eur] to 11.9 [eur].

In this paper, we investigate a novel distributed behavioral control scheme for second-order nonlinear multi-agent systems (MAS) directed network topologies. Unlike most existing behavioral control algorithms which require global information of the underlying network, we develop a distributed adaptive behavioral control using a local adaptive strategy via distributed state estimator, null-space-based behavioral projection, and neural-network-based approximation. Some simple behaviors for each agent are defined and properly arranged according to their priority to achieve the assigned overall behavior. In particular, tracking is performed in a distributed manner, in which the behaviors of each agent only depend on local information concerning the agent’s neighbors. Finally, we present a simulation example to verify and illustrate the theoretical results.

In this paper, we consider empirical balancing of a nonlinear system by using its prolonged system, which consists of the original nonlinear system and its variational system. For the prolonged system, we define differential reachability and observability Gramians, which are matrix valued functions of the state trajectory (i.e. the initial state and input trajectory) of the original system. The main result of this paper is showing that for a fixed state trajectory, it is possible to compute the values of these Gramians by using impulse and initial state responses of the variational system. By using the obtained values of the Gramians, balanced truncation is doable along the fixed state trajectory without solving nonlinear partial differential equations. An example demonstrates our proposed method to compute a reduced order model along a limit cycle of a coupled van der Pol oscillator.

This paper considers two different control problems for deterministic systems with stochastic initial conditions where, in addition to the usual asymptotic behavior requirement, we are interested in the transient behavior of the state distribution evolution. For the first one, we study control design such that the state trajectories enter target set at a given transient time with a prescribed minimum cumulative distribution. For the second one, we propose control design where the distribution of state variable at transient time is close to the target distribution. We illustrate the efficacy of the proposed solutions to the aforementioned control problems through numerical examples.

The state of the art in automotive control has proposed several analytical, simulation and experimental studies of longitudinal adaptive cruise control strategies, and of lateral control strategies. However, methodical integration of these two strategies is to a large extent missing, as well as validation in real-time computing environment of the safety and performance of longitudinal and lateral integrated solutions. This work proposes a real-time validation of an integrated vehicle dynamic control strategy, designed to create safe interaction between longitudinal and lateral controllers: the integrated system is designed, implemented and tested through Dynacar, a real-time simulation environment for the development and validation of vehicle embedded functionalities. The results show that the proposed integrated controller satisfies the performance in terms of real-time computation, path tracking and collision avoidance for various driving situations.

This contribution discusses open and closed reacting systems. In recent years, this subject has attracted the attention of many researchers, studying the problems of stability characterization exploiting thermodynamics potentials and reacting invariant structures description using a graph-theoretic approach. Here, we outline an approach to these problems from the expression of mass-action kinetics as potential-driven reacting forces.

This paper investigates four questions related to ethical issues associated with the involvement of engineers and scientists in 'military work', including the influence of ethical values and beliefs, the role of gendered perspectives and moves beyond the purely technical. It fits strongly into a human (and planet)-centred systems perspective and extends my previous AI and Society papers on othering and narrative ethics, and ethics and social responsibility. It has two main contributions. The first involves an analysis of the literature through the application of different ethical theories and the application of gendered analysis to discussion of masculinities in engineering and the military. The second is a survey of scientists and engineers to investigate their opinions and experiences. The conclusions draw together the results of these two contributions to provide preliminary responses to the four questions and include a series of recommendations covering education and training, ethical approval of work not involving human participants or animals, the need for organisational support, approaches covering wider perspectives and the encouragement of individual ethical commitment.

Model Predictive Control (MPC) is a promising algorithm for building climate control. However, the construction of an accurate building model is very challenging since identification experiments on buildings are, due to time and usage constraints, difficult to conduct and the construction data are often only known approximately. This paper proposes the use of a recently developed robust, adaptive MPC as a possible solution for handling this model uncertainty. Starting from an initial set of possible models, the algorithm relies on recursive set membership identification to shrink this set in each step of the closed-loop operation. The MPC enforces comfort constraints for all the models in the current set and hence achieves robust constraint satisfaction even during the adaptation phase. The proposed algorithm is compared to a standard, non-robust, non-adaptive MPC and to a non-robust, adaptive MPC in simulations using the EnergyPlus building simulation software., IFAC-PapersOnLine, 50 (1), ISSN:2405-8963, 20th IFAC World Congress. Proceedings

A linear model predictive control (LMPC) based framework is developed for underactuated marine vehicles' kinematic line following while moving at a constant depth in the presence of disturbance. LMPC is used as a high level controller which sets the reference surge and yaw velocities for the low level PID tracking controllers. Used ACADO optimization toolbox solves the optimal problem at hand in real-time. This framework has shown good results both in simulation environment and in on-sea experiments. (C) 2017, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

The class of isotherm lumped process systems with constant overall mass in each of its balance volumes is considered in this paper. It is shown that the convection and transfer mechanisms can be described by a mass action law chemical reaction network (MAL CRN) with only linear kinetics where the in- and outflow terms are represented using the zero complex. This gives rise to a convection and transfer reaction sub-graph that connects atomic complexes consisting of the components in the balance volumes of the system. The real chemical reactions in each of the balance volumes can be described by their own CRNs, where the chemical reaction sub-graphs may be disconnected from the convection and transfer reaction sub-graph when nonlinear reactions occur. In the case of chemical reactions with a finite number of steady state points, the underlying linear dynamical system enables us to construct a dynamically similar linear overall reaction graph for the whole process system. The resulting overall reaction graph can be used for structural stability analysis by applying its graph theoretical properties.

8th International Conference on Computer Applications in Biotechnology. Modelling and Control of Biotechnological Processes, Québec City, Canada, June 24-27, 2001

We consider a problem of information structure design in team decision problems and team games. We propose simple, scalable greedy algorithms for adding a set of extra information links to optimize team performance and resilience to non-cooperative and adversarial agents. We show via a simple counterexample that the set function mapping additional information links to team performance is in general not supermodular. Although this implies that the greedy algorithm is not accompanied by worst-case performance guarantees, we illustrate through numerical experiments that it can produce effective and often optimal or near optimal information structure modifications., IFAC-PapersOnLine, 50 (1), ISSN:2405-8963, 20th IFAC World Congress. Proceedings