Comparison between Networked Control System behaviour based on CAN and Switched Ethernet ne.pdfVIP

Comparison between Networked Control System behaviour based on CAN and Switched Ethernet networks B. Brahimi, E. Rondeau, C. Aubrun, Centre de Recherche en Automatique de Nancy (CRAN-UMR- 7039) Nancy-University, CNRS BP 239 54506 Vandoeuvre-lès-Nancy Cedex France Abstract: The distributed control systems are more and more used in many industrial applications. These systems are often referred as “Networked control systems”. The goal of this paper is to show the network influence on feedback control systems. Two networks are considered: Switched Ethernet network and CAN fieldbus. The first one represents the non-deterministic network and second one represents the deterministic one. Several scenarii are studied to analyse the stability of system according to different network parameters (packets losses, congestion and frame priority). The Truetime simulator is used in this work. Keywords: Networked control systems, CAN fieldbus, Switched Ethernet network, Simulation. 1. INTRODUCTION The distributed systems are more and more used in many industrial applications in the context of Flexible Manufacturing Systems (FMS), and Reconfigurable Manufacturing Systems (RMS). In the literature, the distributed control systems are referenced under two acronyms ICCS : Integrated Communication and Control Systems [Ray, 1989, Wittenmark, et al. 1995] and NCS : Networked Control Systems, [Zhang, et al. 2001, branicky, et al. 2000, Walsh, et al. 1999, Nilsson 1998, Lian, et al. 2001]. Now, the second acronym is commonly used. The Networked Control Systems are control systems where controllers, sensors, actuators and other system components communicate over a network. (See figure 1). Network Other applications Controller Physical plant Sensor Actuator Figure 1: Networked Control Systems framework with other applications on the network. The NCS represents a complex research field