Catálogo de publicaciones - libros

Decentralized control of large-scale systems with uncertain, unmatched interconnections is considered. A stable decentralized adaptive controller is proposed for both linear and nonlinear interconnections. Sufficient conditions under which the overall large-scale system is stable are developed; results from algebraic Riccati equations are used to develop these conditions. The choice of the class of large-scale systems considered is directly motivated by control of web processing machines used in processing of materials. A large experimental web platform is considered for experimental study of the proposed decentralized adaptive controller and its comparison to a decentralized PI controller, which is widely used in the web processing industry. Extensive experiments were conducted; a representative sample of the experiments is presented and discussed.

In this chapter, we stabilize the planar vertical takeoff and landing (PVTOL) aircraft using a camera. The camera is used to measure the position and orientation of the PVTOL moving on an inclined plane. We have developed a simple control strategy to stabilize the system in order to facilitate the real experiments. The proposed control law ensures convergence of the state to the origin.

A neural network model reference adaptive controller for trajectory tracking of nonlinear systems is developed. The proposed control algorithm uses a single layer neural network that bypasses the need for information about the system’s dynamic structure and characteristics and provides portability. Numerical simulations are performed using nonlinear dynamic models of marine vehicles. Results are presented for two separate vehicle models, an autonomous surface vehicle and an autonomous underwater vehicle, to demonstrate the controller performance in terms of tuning, robustness, and tracking.

In maxplus algebra, linear projectors on an image of a morphism B parallel to the kernel of another morphism C can be built under transversality conditions of the two morphisms. The existence of a transverse to an image or a kernel of a morphism is obtained under some regularity conditions. We show that those regularity and transversality conditions can be expressed linearly as soon as the space to which Im( B ) and Ker( C ) belong is free and its order dual is free. The algebraic structure has these two properties. Projectors are constructed following a previous work. Application to aggregation of linear dynamical systems is discussed.

An optimal scheduling problem for a two-part type symmetric manufacturing system subject to nonnegligible setup times and characterized by finite buffer capacity is addressed. The solution method relies on i) restricting the possible control policies to those that respect some general necessary conditions of optimality, ii) exploiting such properties to introduce a two-dimensional sampled version of the original system, and iii) mapping such a planar model onto an equivalent scalar one. This modeling approach makes it possible to derive the analytical solution, which exhibits a simple feedback structure.

In multi-retailer inventory control the possibility of sharing setup costs motivates communication and coordination among the retailers. We solve the problem of finding suboptimal distributed reordering policies that minimize setup, ordering, storage, and shortage costs incurred by the retailers over a finite horizon. Neuro-dynamic programming (NDP) reduces the computational complexity of the solution algorithm from exponential to polynomial on the number of retailers.

This chapter addresses the control of spatially distributed processes via communication networks with a fixed delay. A distributed architecture is utilized in which multiple local controllers coordinate their efforts through a data network that allows information exchange. We focus our work on linear time-invariant processes disturbed by Gaussian white noise and propose several logics to determine when the local controllers should communicate. Necessary conditions are given under which these logics guarantee boundedness and the trade-off is investigated between the amount of information exchanged and the performance achieved. The theoretical results are validated through Monte Carlo simulations. The resulting closed loop systems evolve according to stochastic differential equations with resets triggered by stochastic counters. This type of stochastic hybrid system is interesting on its own.

The vast progress in network technology over the past decade has certainly influenced the area of control systems. Nowadays, it is becoming more common to use networks in systems, especially in those that are large scale and physically distributed or that require extensive cabling. A network-based decentralized control of multirate sampled-data systems approach is introduced and analyzed as an effectiveness solution to the control problem of large-scale continuous-time plant. The main idea is that of information exchange among the various input-output channels of a complex system throughout a local area network. The chapter analyzes the stabilization problem for decentralized control of a large-scale continuous-time plant with different sampling rates in the input-output plant channels. Existence conditions and synthesis procedures are introduced and discussed. The results on the analysis and control of periodic discrete-time systems are used for finding such solutions. The chapter ends with some remarks on the possible extensions to the robust stabilization for the decentralized control of multirate sampled-data systems.

Finite-time stability of nonlinear networked control systems is studied in this chapter. Focusing on packet dropping, a deterministic model for networked control systems is realized by incorporating the network dynamics. This links the fields of control of networks and networked control systems.