Continuous System Simulation and Control

ERNESTO KOFMAN; FRANCOIS E. CELLIER; GUSTAVO MIGONI

Discrete Event Simulation and Modeling: Theory and Applications (Model-Based Design)

CRC-Pres

Año: 2009;

Continuous systems are usually represented by sets of ordinary and algebraic differential equations that must be discretized in order to be simulated. Conventional numerical integration methods perform the discretization based on time slicing principles, and the simulation modelsresult of discrete time type. However, there is a new family of numeri cal integration methods that replaces time slicing by state quantization, and the resulting discretized systems are of discrete event type within the DEVS formalism framework. These new algorithms are called QuantizedState System (QSS) methods and exhibit many advantages: unconditional stability, efficient discontinuity handling, intrinsic error control, sparsity exploitation, explicit stiffness treatment, geometric properties, etc. The QSS methods also provide a formal way to approximate continuous systems by DEVS models, allowing to simulate hybrid systems under a unified formalism on standard DEVS simulation software tools.This chapter introduces the QSS methods, discusses their theoretical properties, practical advantages, drawbacks, and shows some examples that illustrate their main features. The chapter concludes showing the application of the QSS methods to the emulation of continuous feedbackcontrollers. This application provides a systematic methodology for the synthesis of DEVS-based digital controllers for continuous systems.