This paper presents control and coordination algorithms for groups of vehicles. The focus is on autonomous vehicle networks performing distributed sensing tasks where each vehicle plays the role of a mobile tunable sensor. The paper proposes gradient descent algorithms for a class of utility functions which encode optimal coverage and sensing policies. The resulting closed-loop behavior is adaptive, distributed, asynchronous, and verifiably correct.

Coverage control for mobile sensing networks

Convex bodies: the brunn–minkowski theory

“Multivalued Analysis” is the theory of set-valued maps (called multifonctions) and has important applications in many different areas. Multivalued analysis is a remarkable mixture of many different parts of mathematics such as point-set topology, measure theory and nonlinear functional analysis. It is also closely related to “Nonsmooth Analysis” (Chapter 5) and in fact one of the main motivations behind the development of the theory, was in order to provide necessary analytical tools for the study of problems in nonsmooth analysis. It is not a coincidence that the development of the two fields coincide chronologically and follow parallel paths. Today multivalued analysis is a mature mathematical field with its own methods, techniques and applications that range from social and economic sciences to biological sciences and engineering. There is no doubt that a modern treatise on “Nonlinear Functional Analysis” can not afford the luxury of ignoring multivalued analysis. The omission of the theory of multifunctions will drastically limit the possible applications.

SET-Valued Analysis

Microgrids energy management systems: A critical review on methods, solutions, and prospects

This paper presents a test benchmark model for the evaluation of fault detection and accommodation schemes. This benchmark model deals with the wind turbine on a system level, and it includes sensor, actuator, and system faults, namely faults in the pitch system, the drive train, the generator, and the converter system. Since it is a system-level model, converter and pitch system models are simplified because these are controlled by internal controllers working at higher frequencies than the system model. The model represents a three-bladed pitch-controlled variable-speed wind turbine with a nominal power of 4.8 MW. The fault detection and isolation (FDI) problem was addressed by several teams, and five of the solutions are compared in the second part of this paper. This comparison relies on additional test data in which the faults occur in different operating conditions than in the test data used for the FDI design.

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Fault-Tolerant Control of Wind Turbines: A Benchmark Model

The current paper addresses the problem of minimizing the computational complexity of optimization problems with non-convex and possibly non-connected feasible region of polyhedral type. Using hyperplane arrangements and Mixed-Integer Programming we provide an efficient description of the feasible region in the solution space. Moreover, we exploit the geometric properties of the hyperplane arrangements and adapt this description in order to provide an efficient solution of the mixed-integer optimization problem. Furthermore, a zonotopic representation of the sets appearing in the problem is considered. The advantages of this representation are highlighted and exploited through proof of concepts illustrations as well as simulation results.

Hyperplane arrangements in mixed-integer programming techniques. Collision avoidance application with zonotopic sets

Fault handling in large water networks with online dictionary learning

This paper proposes an interval observer-based actuator fault detection and isolation (FDI) approach. An interval observer matching the healthy system mode is designed to monitor the system. When the system is in different modes, state or output interval vectors predicted by the interval observer manifest different dynamical behaviors. To guarantee reliable FDI, a collection of invariant set-based FDI conditions are established. Under these conditions, actuator faults can be accurately detected and isolated during the transition between different modes. At the end, the effectiveness of this proposed approach is presented by using a numerical example.

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Actuator-fault detection and isolation based on interval observers and invariant sets

The current paper addresses the problem of optimizing a cost function over a non-convex and possibly non-connected feasible region. A classical approach for solving this type of optimization problem is based on Mixed integer technique. The exponential complexity as a function of the number of binary variables used in the problem formulation highlights the importance of reducing them. Previous work which minimize the number of binary variables is revisited and enhanced. Practical limitations of the procedure are discussed and a typical control application, the control of Multi-Agent Systems is exemplified.

/pdf/enhancements-on-the-hyperplane-arrangements-in-mixed-integer-4nwup7zna8.pdf

Enhancements on the hyperplane arrangements in mixed integer techniques

In this paper, the relationship between two settheoretic fault detection (FD) approaches, the interval observer-based and the invariant set-based approaches, is investigated. In FD, interval observers monitor the system dynamic behavior in real time and generates adaptive intervals for system outputs. Invariant sets focus more on steady state behavior of the system rather than the transient behavior. This paper discusses these two approaches, presents the relationship between them and compares them in the FD task. At the end, a numerical example is used to illustrate the relation between these two approaches.

/pdf/on-the-relationship-between-interval-observers-and-invariant-5fwr603j0i.pdf

Florin Stoican

Papers

Hyperplane arrangements in mixed-integer programming techniques. Collision avoidance application with zonotopic sets

Fault handling in large water networks with online dictionary learning

Actuator-fault detection and isolation based on interval observers and invariant sets

Enhancements on the hyperplane arrangements in mixed integer techniques

On the relationship between interval observers and invariant sets in fault detection