PL
 |
EN
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 10

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Robustness of iterative learning control - algorithms with experimental benchmarking
100%
Rogers E.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2008
|
tom Vol. 56, nr 3
205-215
EN
Iterative learning control is a technique especially developed for application to processes which are required to repeat the same operation over a finite duration. The exact sequence of operation is that the task is completed, the process is reset and then the operation is repeated. Applications are widespread among many industries, e.g. a gantry robot which is required to place items on a conveyor under synchronization as part of a food manufacturing process. In effect, iterative learning control exploits the fact that once a single execution of the task is complete then the input control action and output response produced are available to update the control input for the next trial and thereby sequentially improve performance. Moreover, it may be possible to undertake the required computations during the time between completing one trial and the start of the next. This paper gives an overview of some very significant recent progress in this general area, including results from experimental benchmarking, and also some areas for on-going/future research are outlined.
2
Content available Assessing the impacts to vessel traffic from offshore wind farms in the Thames Estuary
63%
Rawson A. , Rogers E.
Zeszyty Naukowe Akademii Morskiej w Szczecinie
|
2015
|
tom nr 43 (115)
99--107
EN
The development of offshore renewable energy installations can introduce additional hazards to the safe navigation of shipping in often already crowded waterways. Developers and decision makers must predict and properly manage the potential risks imposed on navigating vessels from wind farm developments, in a complex and uncertain environment. Considerable analysis has been undertaken to model navigational risks to vessel traffic around wind farms; however this work is generally predictive and there is little understanding as to whether the modelling, central to the consideration of navigation safety, accurately reflects the postconstructed navigation risks. It is therefore important for decision makers to understand the uncertainties present in the analysis, both in terms of the assessment of risk and the implementation of any risk reduction measures. This paper presents a comparative analysis of the change in vessel traffic in the Thames Estuary before and after the construction of five offshore wind farms. The analysis demonstrates how the impact on vessel traffic is specific to the location of each development, driven by traffic management measures and other local constraints. Therefore the accurate modelling of this impact requires the input of experienced navigators, regulators and other knowledgeable stakeholders. The results of this analysis can be used to improve the predictive modelling of vessel traffic around offshore wind farms and other offshore installations, leading to a reduction in the uncertainty of vessel traffic modelling in the future.
3
Content available remote Robust stabilization of discrete linear repetitive processes with switched dynamics
51%
Bochniak J. , Gałkowski K. , Rogers E. , Kummert A.
International Journal of Applied Mathematics and Computer Science
|
2006
|
tom Vol. 16, no 4
441-462
EN
Repetitive processes constitute a distinct class of 2D systems, i.e., systems characterized by information propagation in two independent directions, which are interesting in both theory and applications. They cannot be controlled by a direct extension of the existing techniques from either standard (termed 1D here) or 2D systems theories. Here we give new results on the design of physically based control laws. These results are for a sub-class of discrete linear repetitive processes with switched dynamics in both independent directions of information propagation.
4
Some observations on degradation processes in roller and polymer based bridge bearings
51%
Hooper R. M. , Henshall J. L. , Rogers E.
Applied Mechanics and Engineering
|
1999
|
tom Vol. 4, no spec.
219-224
EN
The investigation of failed roller bearings from two bridges has shown that the main source of failure is associated with the materials selection where a low toughness material has lead to significant failures. Laboratory tests show that in the contact of the stainless steel plate and PTFE bearing, creep effects will contribute to the interaction of asperities for extended periods of time and lead to a more intimate contact between the two components. In addition there may be problems with fretting/corrosion of stainless steel in PTFE bearings.
5
Content available remote On the development of SCILAB compatible software for the analysis and control of repetitive processes
51%
Hładowski Ł. , Cichy B. , Gałkowski K. , Rogers E.
International Journal of Applied Mathematics and Computer Science
|
2008
|
tom Vol. 18, no 3
377-387
EN
In this paper further results on the development of a SCILAB compatible software package for the analysis and control of repetitive processes is described. The core of the package consists of a simulation tool which enables the user to inspect the response of a given example to an input, design a control law for stability and/or performance, and also simulate the response of a controlled process to a specified reference signal.
6
Content available remote Linear Repetitive Process Control Theory Applied to a Physical Example
51%
Gałkowski K. , Rogers E. , Paszke W. , Owens D. H.
International Journal of Applied Mathematics and Computer Science
|
2003
|
tom Vol. 13, no 1
87-99
EN
In the case of linear dynamics, repetitive processes are a distinct class of 2D linear systems with uses in areas ranging from long-wall coal cutting and metal rolling operations to iterative learning control schemes. The main feature which makes them distinct from other classes of 2D linear systems is that information propagation in one of the two independent directions only occurs over a finite duration. This, in turn, means that a distinct systems theory must be developed for them for onward translation into efficient routinely applicable controller design algorithms for applications domains. In this paper, we introduce the dynamics of these processes by outlining the development of models for various metal rolling operations. These models are then used to illustrate some recent results on the development of a comprehensive control theory for these processes.
7
Content available remote From Continuous to Discrete Models of Linear Repetitive Processes
45%
Gramacki A. , Gramacki J. , Gałkowski K. , Rogers E. , Owens D. H.
Archives of Control Sciences
|
2002
|
tom Vol. 12, no. 1/2
151-185
EN
Differential linear repetitive processes are a distinct class of 2D linear systems which pose problems which cannot (except in a few very restrictive special cases) be solved by application for computer aided annalysis and simulation. One such problem area is the construction of accurate numerically well conditioned discrete approximations of the dynamics of differential processes which could, as one example of number of immediate applications areas, from the basis for digital implementation of control laws. In this paper, we undertake a detailed investigation of the critical problems which arise when attempting to construct usefull discrete approximations of the dynamics of differential linear repetitive processes and develop solutions to them. Numerical examples to support the results obtained are also given using a specially developed MATLAB based toolbox.
8
Stability and controllability properties of extended discrete linear repetitive processes.
45%
Gałkowski K. , Sulikowski B. , Paszke W. , Rogers E. , Owens D.
Prace Naukowe Instytutu Cybernetyki Technicznej Politechniki Wrocławskiej. Konferencje
|
2001
|
tom Vol. 103, nr 47
5-14
EN
This paper develops an extension of the state space model for discrete linear repetitive processes which, in addition to their theoretical interest, are also relevant to robotics applications. In particular, the effects of an additional term in the basie state space model of these processes, which represents a direct cross-dependence between successive passes, are investigated. The main results given are the extensions of the existing 2D global-state, and ID equivalent state space model approaches to stability and controllability analysis of this new model. Finally, the role of MATLAB based numerical analysis in this context is also illustrated.
9
Content available Robust control of distributed parameter mechanical systems using a multidimensional systems approach
45%
Cichy B. , Augusta P. , Rogers E. , Gałkowski K. , Hurak Z.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2010
|
tom Vol. 58, nr 1
67-75
EN
The unique characteristic of a repetitive processes is a series of sweeps, termed passes, through a set of dynamics defined over a finite duration. On each pass an output, termed the pass profile is produced which acts as on forcing function, and hence contributes to, the dynamics of the next pass profile. This leads to the possibility that the output, i.e. the sequence of pass profiles, will contain oscillations that increase in amplitude in the pass-to-pass direction. Such behavior cannot be controlled by application of standard linear systems control laws and instead they must be treated as two-dimensional (2D) systems where information propagation in two independent directions, termed passto-pass and along the pass respectively, is the defining feature. Physical examples of such processes include long-wall coal cutting and metal rolling. In this paper, stability analysis and control law design algorithms are developed for discrete linear repetitive processes where a plane, or rectangle, of information is propagated in the pass-to-pass direction. The possible use of such a model in the control of distributed parameter systems has been investigated in previous work and this paper considers an extension to allow for uncertainty in the model description.
10
Content available Robustness of iterative learning control - algorithms with experimental benchmarking
26%
Rogers E.
|
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.