An exhaust gas recirculation (EGR) control system for automotive application is briefly presented. Robustness is one of the main issues in this particular system due to nonlinearities, time delays, and the effects of ...
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An exhaust gas recirculation (EGR) control system for automotive application is briefly presented. Robustness is one of the main issues in this particular system due to nonlinearities, time delays, and the effects of complex exhaust gas dynamics. It was found that a good approximation of the system dynamics consists of a first order transfer function with a time delay where both transfer function coefficients and the time delay depend on the reference signal (desired EGR(%)). Moreover, it is sufficient to identify only four models corresponding to four different values of desired EGR (%) and assume interpolation for transfer function coefficients to characterize the system dynamics. Since the value of the reference signal is available in real time the controller design can be reduced to four controllers corresponding to four identified models and interpolation for coefficients of the controller transfer function in cases when the value of desired EGR (%) is between the assumed values. Simulation results for such designs are presented.
This paper reports the application of evolutionary computation in the automatic generation of a neural network architecture. It is a usual practice to use trial and error to find a suitable neural network architecture...
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This paper reports the application of evolutionary computation in the automatic generation of a neural network architecture. It is a usual practice to use trial and error to find a suitable neural network architecture. This is not only time consuming but may not generate an optimal solution for a given problem. The use of evolutionary computation is a step towards automation in architecture generation. In this paper a brief introduction to the field is given as well as an implementation of automatic neural network generation using genetic programming.< >
Iterative least-squares estimation requires accurate reflectance models to retrieve geometrical parameters of 3-D objects from an image projection. We investigate the use of separating the diffuse (body) reflection fr...
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Iterative least-squares estimation requires accurate reflectance models to retrieve geometrical parameters of 3-D objects from an image projection. We investigate the use of separating the diffuse (body) reflection from the specular (surface) reflection, where the latter is responsible for image highlights. The performance of several models has been analysed by comparing local higher-order derivatives of the least-squares error function. Experiments show that the (smooth) diffuse component yields the best convergence properties, while the (sharp) specular component cast be utilized to improve noise insensitivity.
This paper deals with simultaneous control of acceleration transmission, wheel load fluctuation, suspension deflection and sprung mass displacement. The control theory is based on the robust H/sub /spl infin// control...
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This paper deals with simultaneous control of acceleration transmission, wheel load fluctuation, suspension deflection and sprung mass displacement. The control theory is based on the robust H/sub /spl infin// control theory with the consideration of the modeling errors lumped into an unstructured uncertainty acting on the unperturbed plant. The design method is new and powerful for electronic car suspension's controlsystems, as it presents a new approach to the designers for the computation of a controller maintaining robust stability while guaranteeing the performance in a wide frequency range, even in the case of the controller is applied to the actual plant. Additionally, the paper emphasizes that the assumptions in the modeling step may lead to unrealistic control designs and, as an example, the effect of the rigidity assumption on the behavior of the open loop system is discussed.
The problem of design and evaluation of binary hypothesis tests based on a set of available observations is considered. A so-called structured adaptive network (SAN) configuration for the modeling and implementation o...
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The problem of design and evaluation of binary hypothesis tests based on a set of available observations is considered. A so-called structured adaptive network (SAN) configuration for the modeling and implementation of a wide class of such tests is introduced. A general framework for the analysis and performance evaluation of a SAN is developed.
We consider the problem of multisensor detection in the presence of misalignment. We assume that the region that is covered by the sensors contains subregions that constitute blind spots in the sensors' fields of ...
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We consider the problem of multisensor detection in the presence of misalignment. We assume that the region that is covered by the sensors contains subregions that constitute blind spots in the sensors' fields of view. For analytical simplicity and numerical convenience, we consider the two-sensor case only, and describe the misalignment mathematically using a model that we have developed earlier. Preliminary assumptions involve a known geometry of the regions covered by each sensor and symmetric coverage. We formulate and analyze the distributed decision problem in the presence of misalignment when the sensors transmit only local decisions to the fusion. Different combining roles are considered at the fusion and compared with a centralized fusion scheme. Numerical results in the Gaussian channel indicate that for two sensors and under the imposed assumptions, only the OR combining rule at the fusion results in performance that degrades gracefully as the coverage factor decreases. The performance of the fusion under the OR rule is comparable-although inferior-to the performance of the centralized scheme. However, the AND combining rule yields very poor performance that degrades rapidly as the coverage factor varies.
Grey box modeling is a widely used term, which presently reflects that both a priori and experimental knowledge is being incorporated into the model building process. A brief investigation into various uses of grey bo...
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Grey box modeling is a widely used term, which presently reflects that both a priori and experimental knowledge is being incorporated into the model building process. A brief investigation into various uses of grey box modeling approaches reveals that they mainly differ with respect to the required model accuracy. The goal of the model application also has to be considered in the model building, since it constrains the necessary accuracy required by the model. In this paper these two viewpoints are combined thus leading to a proposed new definition of grey box modeling.
This paper outlines some preliminary work on the stability analysis of switched and hybrid systems. The hybrid systems considered are those that combine continuous dynamics, represented by differential or difference e...
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This paper outlines some preliminary work on the stability analysis of switched and hybrid systems. The hybrid systems considered are those that combine continuous dynamics, represented by differential or difference equations, with finite dynamics usually thought of as being a finite automaton. Here, we concentrate on the continuous dynamics and model the finite dynamics as switching among finitely many continuous systems. We introduce multiple Lyapunov functions as a tool for analyzing Lyapunov stability of such "switched systems". We use iterated function systems theory as a tool for Lagrange stability. We also discuss the case where the switched systems are indexed by an arbitrary compact set.< >
作者:
S.V. GaikwadD.E. RiveraDepartment of Chemical
Bio and Materials Engineering and Control Systems Engineering Laboratory Computer-Integrated Manufacturing Systems Research Center Arizona State University Tempe AZ USA
control-ID is a computer aided controlengineering (CACE) tool serving as a support environment for computer aided control system design (CACSD) in the chemical process industry. The fundamental basis for this tool is...
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control-ID is a computer aided controlengineering (CACE) tool serving as a support environment for computer aided control system design (CACSD) in the chemical process industry. The fundamental basis for this tool is the theory of control-relevant system identification, which takes advantage of the interplay between identification and control design. control-ID is implemented using MATLAB on a VAXStation 4000 cluster, which is integrated in real-time to an industrial-scale Honeywell TDC 3000 plant information and control system. control action is computed on the TDC 3000 system using low-order difference equations, which yield superior performance over traditional PID control while resembling the behavior of model predictive controlsystems. Results from a simulation study using a gas/oil furnace are reported.< >
In this paper a fast spatial adaptive algorithm is presented for the efficient least squares (LS), autoregressive exogenous (ARX), two-dimensional (2-D) modeling. Filter masks of general boundaries are allowed. Effici...
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In this paper a fast spatial adaptive algorithm is presented for the efficient least squares (LS), autoregressive exogenous (ARX), two-dimensional (2-D) modeling. Filter masks of general boundaries are allowed. Efficient space updating recursions are developed by exploiting the spatial shift invariance property of the 2-D data set.< >
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