102,571 research outputs found
Damage Tolerant Active Contro l: Concept and State of the Art
Damage tolerant active control is a new research area relating to fault tolerant control design applied to mechanical structures. It encompasses several techniques already used to design controllers and to detect and to diagnose faults, as well to monitor structural integrity. Brief reviews of the common intersections of these areas are presented, with the purpose to clarify its relations and also to justify the new controller design paradigm. Some examples help to better understand the role of the new area
Fuzzy-logic-based control, filtering, and fault detection for networked systems: A Survey
This paper is concerned with the overview of the recent progress in fuzzy-logic-based filtering, control, and fault detection problems. First, the network technologies are introduced, the networked control systems are categorized from the aspects of fieldbuses and industrial Ethernets, the necessity of utilizing the fuzzy logic is justified, and the network-induced phenomena are discussed. Then, the fuzzy logic control strategies are reviewed in great detail. Special attention is given to the thorough examination on the latest results for fuzzy PID control, fuzzy adaptive control, and fuzzy tracking control problems. Furthermore, recent advances
on the fuzzy-logic-based filtering and fault detection problems are reviewed. Finally, conclusions are given and some possible future research directions are pointed out, for example, topics on two-dimensional networked systems, wireless networked control systems, Quality-of-Service (QoS) of networked systems, and fuzzy access control in open networked systems.This work was supported in part by the National Natural Science Foundation of China under Grants 61329301,
61374039, 61473163, and 61374127, the Hujiang Foundation of China under Grants C14002 andD15009, the Engineering and Physical Sciences Research Council (EPSRC) of the UK, the Royal Society of the UK, and the Alexander von Humboldt Foundation of Germany
On general systems with network-enhanced complexities
In recent years, the study of networked control systems (NCSs) has gradually become an active research area due to the advantages of using networked media in many aspects such as the ease of maintenance and installation, the large flexibility and the low cost. It is well known that the devices in networks are mutually connected via communication cables that are of limited capacity. Therefore, some network-induced phenomena have inevitably emerged in the areas of signal processing and control engineering. These phenomena include, but are not limited to, network-induced communication delays, missing data, signal quantization, saturations, and channel fading. It is of great importance to understand how these phenomena influence the closed-loop stability and performance properties
Predicting respiratory motion for real-time tumour tracking in radiotherapy
Purpose. Radiation therapy is a local treatment aimed at cells in and around
a tumor. The goal of this study is to develop an algorithmic solution for
predicting the position of a target in 3D in real time, aiming for the short
fixed calibration time for each patient at the beginning of the procedure.
Accurate predictions of lung tumor motion are expected to improve the precision
of radiation treatment by controlling the position of a couch or a beam in
order to compensate for respiratory motion during radiation treatment.
Methods. For developing the algorithmic solution, data mining techniques are
used. A model form from the family of exponential smoothing is assumed, and the
model parameters are fitted by minimizing the absolute disposition error, and
the fluctuations of the prediction signal (jitter). The predictive performance
is evaluated retrospectively on clinical datasets capturing different behavior
(being quiet, talking, laughing), and validated in real-time on a prototype
system with respiratory motion imitation.
Results. An algorithmic solution for respiratory motion prediction (called
ExSmi) is designed. ExSmi achieves good accuracy of prediction (error
mm/s) with acceptable jitter values (5-7 mm/s), as tested on out-of-sample
data. The datasets, the code for algorithms and the experiments are openly
available for research purposes on a dedicated website.
Conclusions. The developed algorithmic solution performs well to be
prototyped and deployed in applications of radiotherapy
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