Department of Electronic and Electrical Engineering, University College London, UK
Making the Case for Switched Control in Systems Science
Since the topic of sliding mode control was introduced to the international control community following early pioneering work in the former Soviet Union in the 1960’s, the methodology has received a great deal of attention across a broad range of application domains. Fundamental to the approach is its total invariance to an important class of parameter variations and uncertainty. A further advantage is that the dynamic behaviour of the system may be directly tailored by the choice of a so-called switching function – essentially this switching function can be thought of as a measure of the desired performance.This presentation will begin with a review of the basic properties and terminology of such discontinuous controllers. By appealing to highly conserved and robust controllers from biology, the case for discontinuous control as an underpinning element for robustness in both the control and observation of large scale and complex systems will be made. Results from current applications of interest including the biological domain will be used to demonstrate the significance of the approach.The environment of the control scientist continues to change rapidly. Coupled with advances in communications, networking, sensing and computing, problems become ever more large scale. This is coupled with an increasing appetite to incorporate data and learning within these systems. The presentation will conclude with some comments on what switched control may have to contribute to this rapidly developing agenda.
Recent advances in state estimation and control of singular systems
Singular systems, also referred as implicit systems or descriptor systems, arise in many applications in practice such as electrical circuits, constrained robot systems, which can describe a larger class of systems other than the normal linear system model. In recent years, considerable amount of research concerning singular systems has been developed in the literature. It is well acknowledged that a linear singular system may possess impulsive modes and a non-singular transfer function, which is remarkably different from a non-singular system. In addition, a solution for the singular system with time-varying uncertainties may not exist even though the system is regular and impulse-free (or causal for discrete-time case). Furthermore, due to the physical constraints, limited capacity communication, the occurrences of abrupt structure or parameter variations and etc., the actuator saturation, data quantization and multi-mode switching are often encountered in practical control systems, which lead some fundamental and challenging issue to be investigated for singular systems. In this talk, we will present the recent advances of our research group in the study of singular systems, including the existence of solution, observer design and stabilization for nonlinear descriptor systems, detection and stabilization for networked singular systems, stability analysis of switched singular systems, etc. Finally, the application to consensus of nonlinear singular multi-agent systems under signed digraph is discussed.
Event-Triggered Communication Schemes in Networked Control Systems
This talk aims to provide recent advances in event-triggered communication and control in networked control systems. First, the background and necessary of event-triggered communications in networked control systems are briefly introduced. Second, some recent results on event-triggered modeling and control for complex networked control systems are reviewed, and the advantages and disadvantages of event-triggered communication schemes and self-triggered communication schemes are analyzed and compared by practical examples. Third, some published results on reporter’s colleague are introduced, for example, the discrete event-triggered communication scheme, the self-triggered communication scheme, the mixed event and self-triggered communication scheme, and the resilient event-triggered communication scheme under consideration of Denial of Services (DoS) attacks. At last, some challenging points on event-triggered communications and networked control systems are discussed for future investigation.
Towards a Distributed Systems Compute Continuum – Understanding the Fabric of IoT, Edge, Fog, and Cloud
As humans, things, software and AI continue to become the entangled fabric of distributed systems, systems engineers and researchers are facing novel challenges. In this talk, we analyze the role of IoT, Edge, and Cloud, as well as AI in the co-evolution of distributed systems for the new decade. We identify challenges and discuss a roadmap that these new distributed systems have to address. We take a closer look at how a cyber-physical fabric will be complemented by AI operationalization to enable seamless end-to-end distributed systems.