Based on recent advances in control theory, we propose the notion of jitter margin for periodic control tasks. The jitter margin is defined as a function of the amount of constant delay in the control loop, and it describes how much additional time-varying delay can be tolerated before the loop goes unstable. Combined with scheduling theory, the jitter… (More)
R EAL-TIME systems are systems that must respond to external stimuli in a timely fashion. The correctness of a real-time system depends on not only the logical correctness of its tasks but also the timeliness of their executions. The wide adoption of real-time technologies has already resulted in significant impacts on how automated systems are designed and… (More)
After 5 editions of growing number of participants coming from all over Portugal, the Micro-Rato contest has become a well known mobile robotics contest in the country. It promotes a cross fertilization among teams that is strongly educational, appealing and challenging simultaneously for those more or less skilled. In order to improve the robots… (More)
A virtual laboratory is a computing system that allows to share the physical resources available in a laboratory with remote users connected on the internet. This paper describes a particular virtual laboratory environment for running real-time robot control experiments over the internet through a standard web browser. Using the proposed approach, a remote… (More)
S ince the beginnings of computer technology, researchers have speculated about the possibility of building smart machines that could compete with human intelligence. Given the current pace of advances in artificial intelligence and neural computing, such an evolution seems to be a more concrete possibility. Many people now believe that artificial… (More)
We consider an optimal control problem governed by an ODE with memory playing the role of a control. We show the existence of an optimal solution and derive some necessary optimality conditions. Some examples are then discussed.
This report presents a prototype laboratory activity to be integrated in the education of embedded control systems engineers. The laboratory experiment includes the control by means of hard real-time software task of an electronic circuit. The selection of the plant, as well as the selection of the real-time kernel and hardware platform where the control… (More)
• On page 23, Figure 2.2 should not have vertical lines, and the value σ(t) of the schedule function in a context switch time t is equal to σ(t+ε). • On page 25 (last line of the second last paragraph), in the sentence " whereas an aperiodic job by Ji " , the word " job " should be replaced by " task ". • On page 34, the arrow labeled " preemption " in… (More)