Hybrid Control Systems
- Nonlinear and Sampled Data Systems
- Discrete-time Systems
- Emergent and Innovative Control Strategies
- Switching Control Systems
- Sensors and Measurements
- Sensor Networks
Stefano Battilotti, Luca Benvenuti,Claudia Califano, Alessandro De Carli, Paolo Di Giamberardino,
Salvatore Monaco (leader).
Ph D. Students:
Andrea Abelli, Antonio D’Angelo, Enrico Gentili, Marco Paoletti, Daniele Pucci, Fernando Tiefensee.
The hybrid nature of most real control systems strongly demands for the development of a theory for modelling their inherent complexity. From the systems and control theory point of view, the complexity is related to the use of devices which have a different nature, and interact through computational procedures. In particular the research carried out at DIS concerns:
- the proposition of ad hoc methodologies for dealing with sampled data signals as well as representations and design methodologies for discrete time systems – Nonlinear Sampled-Data and Discrete-Time Systems.
- the investigation on new paradigms of representing the knowledge and designing the control strategies – Emergent and Innovative Control Strategies.
- the study of problems related to the presence of quantization and switching, due to the presence of continuous od discrete-time, sampled or quantized variables) - Digital and Switching Control.
- the analysis and design of sensors networks, for solving complex control problems where measurement and data processing of many devices must be handled - Sensors, Measurements and Sensor Networks.
The applicative aspects of the research activities are carried out at the System and Control Laboratory founded in 1995.
Passivity in discrete-time and under sampling
Robust control strategies based on passivity properties or more in general dissipativity concepts are widely investigated from theory to practice in terms of Lyapunov design or H∞ control as many other efficient approaches for capturing and respecting the physical structure of the process.
Specialized studies are needed in discrete. How to define dissipativity in discrete time and how do dissipation inequalities evolve under sampling are challenging problems as they directly affects the related design methods.
In recent works the introduction of output transformations and time scaling transformations has lead to a new trend in the observer design. The use of geometric tools allows to set, in the discrete-time context, constructive necessary and sufficient conditions for the existence of such canonical forms. State estimation of single-output nonlinear systems with semi-Markov jump, a still open problem, will be investigated when a Markov jump process interferes with a deterministic nonlinear dynamics at random times and retains its state for a certain amount of time (dwell time). It is requested that the state estimation error of the switching dynamics asymptotically converges to zero with probability one.
Sensors, Measurements and Sensor Networks
Measurements devices, algorithms, data handling and transmission represent critical aspects in any distributed control problem. The number devices, their location, energy consumption, data-communication links, distributed data handling, are now days classical problems in this context. New issues deal with dynamic sensor networks, where mobile platforms are assimilated to intelligent devices. The formalization of the problem, in an intrinsically hybrid context, is a challenging interdisciplinary area of research towards easier and cheaper solutions to problems like surveillance, monitoring, decentralized and distributed control. Problems under investigation in this field concern sensor and actuator devices, computation algorithms, local and global coordinated control, network communication protocols.
Complex dynamical systems: elements of classification and case studies
January 2007 – June 2008 - UIF/UFI – GALILEO Program
Totally polymeric ionic transducers: applicability study, performance analysis and prototipal realizations for advanced sensor-actuator devices
March 2010 - December 2012 - MIUR PRIN
Parameters identification and algorithms for WAMS in Italian high voltage Transmission network
February 2008 - June 2009 - TERNA