Learn 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)
— 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 stability(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)
—A self-triggered controller is characterized, in general , by a non-periodic sequence of job activations. And each job execution, apart from performing sampling, control algorithm computation and actuation, calculates the next job activation time as a function of the plant state. This paper describes the implementation of self-triggered controllers in(More)
Embedded control systems are subject to conflicting demands: end-users ask for devices with better capabilities while strong industrial competition impose tight cost constrains that results in devices with limited resources. Current research in the multidisciplinary embedded systems discipline indicates that by combining real-time and control systems it is(More)
Today there is a significant body of results of resource management in real-time systems. However, most of them are based on "open-loop" strategies and techniques that do not take into account application demands to dynamically adjust their behavior. To overcome this problem by focusing on control applications, we show a novel scheduling technique: large(More)
—Maximal-length binary shift register sequences have been known for a long time. They have many interesting properties , one of them is that when taken in blocks of n consecutive positions they form 2 n − 1 different codes in a closed circular sequence. This property can be used for measuring absolute angular positions as the circle can be divided in as(More)
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(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)