Timed Automata to bridge efficiency and predictability
of event-triggered controllers

Manuel Mazo

TU Delft, Netherlands

Abstract: The last couple of decades has experienced a surge of interest in the study of event-based controller implementation strategies. The vast majority of such studies have been motivated by the goal of reducing the communication footprint, to save bandwidth (and energy). In event-based or event-triggered control (ETC) strategies, communications are triggered by the state of the plant itself, which makes the system communicate only when necessary to retain stability of the closed loop. As a result, transmissions happen following somewhat erratic patterns deviating from the classical periodic paradigm, in which communication events are equally spaced in time. Thus, ETC establishes a form of trade-off between predictability and efficiency (reduction) of communications. Such a tension between predictability and efficiency poses challenges to both the analysis of the actual efficiency of an implementation, and to the design of appropriate schedulers capable of effectively exploiting the communication savings. In practice, these difficulties translate in freed bandwidth that may not be reusable by other (real-time) applications, as well as losing energy efficiency.

In this talk I will describe our advances in the past few years, in the context of the ERC SENTIENT project, to bridge the chasm between efficiency and predictability of ETC communications. I will establish how one can model the resulting communication traffic patterns of a given ETC system by employing ideas from the literature on model abstractions from hybrid systems theory. Next I will elaborate on how such models, which generally take the form of timed automata, enable the analysis of ETC systems in terms of communication efficiency; how they can be used to design schedulers for ETC systems; and how they allow to design efficient periodic (with varying inter-sample times) communication patterns. The talk will conclude with a number of challenges and open problems in the context of modelling and scheduling ETC communications traffic.

Biodata: Manuel Mazo Jr. is an associate professor at the Delft Center for Systems and Control, Delft University of Technology (The Netherlands). He received the Ph.D. and M.Sc. degrees in Electrical Engineering from the University of California,Los Angeles, in 2010 and 2007 respectively. He also holds a Telecommunications Engineering “Ingeniero” degree from the Polytechnic University of Madrid (Spain), and a “Civilingenjör” degree in Electrical Engineering from the Royal Institute of Technology (Sweden), both awarded in 2003. Between 2010 and 2012 he held a joint post-doctoral position at the University of Groningen and the innovation centre INCAS3 (The Netherlands).

Manuel’s main research interest is the formal study of problems emerging in modern control system implementations, and in particular the study of networked control systems and the application of formal verification and synthesis techniques to control. He is an Associate Editor of Nonlinear Analysis: Hybrid Systems, and has served as PC member on multiple conferences on Control, CPS and Hybrid Systems such as HSCC, ICCPS, ECC and EBCCSP. He has been the recipient of a University of Newcastle Research Fellowship (2005), the Spanish Ministry of Education/UCLA Fellowship (2005-2009), the Henry Samueli Scholarship from the UCLA School of Engineering and Applied Sciences (2007/2008) and an ERC Starting Grant (2017).