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This paper deals with hardware sensorization and control architectures for nautical applications. The goal is design a sensorization and control network for a new underwater autonomous vehicle (AUV). One of the main objectives is to obtain a network architecture which makes easy the integration of existing marine equipment, sonar, radar, etc. and also makes easy the adaptability to other marine environments.
This paper discusses the algebraic design via Diophantine equations of dual-rate regulators generalizing the well-known interpolation constraints for the reference model in single-rate systems. The results are applicable to unstable plants. A simulation example on a robotic model is presented.
Projects and research lines of the grid computing group at IFIC are presented. These projects can be divided in two main groups related to the subject of research. The first one is related to physics projects in particular to the GRID infrastructure needed to provide solution to the high CPU demanding and huge storage capacity demanding experiments related to the Large Hadron Collider at CERN. Between...
This work presents two applications of a novel tool developed for the approximate calculation of behavior in the domain of the frequency of Multirate Sampled-Data Control Systems. The cases presented here focus on the designing of digital regulators that operate with more than one sampling frequency, the aim being to stabilize the system in closed loop using relatively low sampling frequencies of...
In networked control systems several devices (controllers, sensors and actuators) share a common communication resource. This feature can introduce variable and even random delays when those devices try to transmit information through the shared medium. The limited bandwidth capabilities of the transmission medium also can restrict the freedom to set the sampling periods in the control loop. An attempt...
It has been observed that the inclusion of Dual-Rate regulators in a sampled-data control loop occasionally introduces the phenomenon of intersample ripple in the output of the process being controlled. Several authors have offered explanations for this phenomenon which does not appear to derive from the control method. The aim of this brief report is to demonstrate that, by compensating in frequency...
In this work a new methodology for tracing the frequency response of a multirate system is presented, a multirate system being that in which different blocks appear operating with different sampling periods. Normally, lifting techniques are used to model this kind of system leading to multivariable systems and, in this way, the procedures from this environment are used to obtain the frequency response...
A novel method for the approximation of the frequency response of a sampled data system is presented. Usually the frequency response calculation of sampled-data systems leads to use of the infinite dimension matrices of cumbersome mathematical treatment. The technique presented is based on the inclusion of a fictitious sampler in the continuous process output and on the signal flow analysis in the...
In networked control systems several devices (controller, process and others) share a common communication bus. This feature can suppose delays when those devices try to transmit information through the unique bus, leading to a non- regular behaviour, that is, different variables are sampled and updated in a non-uniform way along the time. As a result, if the control system is designed by means of...
Networked control systems are a special kind of control loops in which the main feedback is closed through a shared communication link. A number of undesirable influences appear when the link to communicate controller and plant is not always available. The aim of this paper is to analyze one of the drawbacks of these systems, irregular conversions that appear when different sampling periods are used...
Nowadays, in industrial control applications, is rather usual to sample and update different variables at different rates, although it is common to consider all these activities equally and regularly spaced on time. These applications can be found, for example, on real-time operating systems by decomposing them into several tasks in such a way that pre-emption and blocking may appear due to task priorities...
In networked control systems (NCS) environments is usual to find restrictions with data-acquisition frequency. If the control action updating can be faster than the output measurement, the use of a dual rate controller is a natural solution. Due to PIDs are useful controllers in industrial applications, in this paper a dual rate PID controller is designed splitting a conventional PID into two parts...
This paper deals with the problem of simulating the sequence of events in the communication through one of the most commonly used fieldbuses: Profibus-DP. Control systems using a fieldbus or any other kind of shared communication medium, are known as Networked Control Systems. A detailed description of the operation of Profibus, when transmitting a signal in a round trip between slave and master devices,...
In networked control systems (NCS) environments is usual to find restrictions with data-acquisition frequency. If the control action updating can be faster than the output measurement, the use of a dual rate controller is a natural solution. Due to PIDs are useful controllers in industrial applications, in this paper a dual rate PID controller is designed splitting a conventional PID into two parts...
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