Josep M. Fuertes

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In this paper, we first identify the potential violations of control assumptions inherent in standard real-time scheduling approaches (because of the presence of jitters) that causes degradation in control performance and may even lead to instability. We then develop practical approaches founded on control theory to deal with these violations. Our approach(More)
In network-based control systems (NCSs), plant sensor–controller–actuator nodes in closed-loop operation drive principal network traffic. The quality-of-control (QoC) in an NCS, i.e., the performance delivered by each closed-loop operation, depends not only on the controller design but also on the message scheduling strategy. In this paper, we show that the(More)
Abstract— In this paper we study stability properties of networked control systems whose control loops are subject to sampling rates and time delays, both time varying. We represent these time incertitudes as non-static parametric uncertainties in the linear discrete-time closed-loop model. Then we apply robust control techniques, and present a sufficient(More)
In this paper we present an extended state-space representation for closed-loop systems that allows each control task to trigger itself optimizing computing resources and control performance. Using this model, the executing instance informs the scheduler when the next instance should be executed. The next instance execution point in time is dynamically(More)
Closed-loop control systems are dynamic systems subject to perturbations. One of the main concerns of the control is to design controllers to correct or limit the deviation that transient perturbations cause in the controlled system response. The smaller and shorter the deviation, the better the achieved performance. However, such controllers have been(More)
In many application areas, including control systems, careful management of system resources is key to providing the best application performance. Most traditional resource management techniques for real-time systems with multiple control loops are based on open-loop strategies that statically allocate a constant CPU share to each controller, independent of(More)
The performance Distributed Control System (DCS) depends not only on the operation of the individual components, but also on their interaction and cooperation. Therefore, the rules that allow the exchange of messages, i.e. message scheduling policy, is a key issue in terms of system performance. For control applications where control loops are closed over(More)
Bandwidth allocation techniques for control loops closed over communication networks are based on static strategies that ensure average control performance at the expenses of permanently occupy the available bandwidth. In this paper we present a dynamic approach to bandwidth management in networked control systems that allow control loops to consume(More)