process model based methods to detect faults in a hydraulic linear servo axis by measurement of up to five variables are presented. The faults that are detected include gas enclosures in the hydraulic fluid, such as a...
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process model based methods to detect faults in a hydraulic linear servo axis by measurement of up to five variables are presented. The faults that are detected include gas enclosures in the hydraulic fluid, such as air, vapour and foam. The control edges and the valve spool are also monitored in order to detect faults such as erosion of the control edges and grooving of the valve spool. Furthermore, the leakage flow between the cylinder chambers and to the surroundings are monitored, which allows to detect damages of the sealing between the cylinder chambers and between the cylinder and the pushrod. The external mechanical load and the valve spool dynamics are also included in the fault detection and diagnosis approach.
A prediction control algorithm is presented based on least squares support vector machines (LS-SVM) model for a class of complex systems with strong nonlinearity. The nonlinear off-line model of the controlled plant i...
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A prediction control algorithm is presented based on least squares support vector machines (LS-SVM) model for a class of complex systems with strong nonlinearity. The nonlinear off-line model of the controlled plant is built by LS-SVM with radial basis function (RBF) kernel. In the process of system running, the off-line model is linearized at each sampling instant, and the generalized prediction control (GPC) algorithm is employed to implement the prediction control for the controlled *** obtained algorithm is applied to a boiler temperature control system with complicated nonlinearity and large time *** results of the experiment verify the effectiveness and merit of the algorithm.
A synthetical method of multivariable control system performance assessment is proposed in this paper, which uses multivariable minimum variance control (MVC) benchmark to determine the stochastic performance, and nor...
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ISBN:
(纸本)0780382730
A synthetical method of multivariable control system performance assessment is proposed in this paper, which uses multivariable minimum variance control (MVC) benchmark to determine the stochastic performance, and normalized multivariate impulse response (NMIR) curve as an alternative measure of performance to test the dynamic performance, and with the help of auto-correlation function (ACF) and cross-correlation function (CCF) to analyse if there are oscillations exist. The method is applied to assess the performance of multivariable predictive control system of industrial distillation column.
This study is an effort to give a practical solution in the problem of optimizing the structure of the hierarchical mixture of experts model, which is a natural extension of the associative Gaussian mixture of experts...
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This study is an effort to give a practical solution in the problem of optimizing the structure of the hierarchical mixture of experts model, which is a natural extension of the associative Gaussian mixture of experts system. We present two novel methods for optimizing such structures using genetic algorithms. Special concern is taken for reducing the computational time so as to efficiently allow the structure to "grow" while it evolves with the genetic algorithm. The main contribution of the paper lies on the efficient, topologically oriented, representations of such architectures so as to be optimized through involving genetic algorithms.
This paper describes fault detection and diagnosis techniques for a hydraulic passenger car braking system. First, a model of the hydraulic braking system is derived in state space representation. This model is subseq...
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This paper presents the design of a model-based supervision system for the vacuum brake booster of current hydraulic passenger car braking systems. A model is derived, which allows to calculate the pressure in the vac...
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This paper presents the design of a model-based supervision system for the vacuum brake booster of current hydraulic passenger car braking systems. A model is derived, which allows to calculate the pressure in the vac...
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This paper presents the design of a model-based supervision system for the vacuum brake booster of current hydraulic passenger car braking systems. A model is derived, which allows to calculate the pressure in the vacuum chamber and the working chamber of the vacuum brake booster. Based on this model, a real-time supervision system has been implemented. The fidelity of the model has been evaluated by testing the model against experimental data from a braking system test bed. The functioning of the model-based supervision system has also been probed with measurements taken at the aforementioned testbed.
This paper presents an approach to calculate prefilters that are insensitive to parameter deviations. The cost function chosen for this approach is the magnitude of the time-delay filter transfer function. By approxim...
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This paper presents an approach to calculate prefilters that are insensitive to parameter deviations. The cost function chosen for this approach is the magnitude of the time-delay filter transfer function. By approximating the cost function with a polynomial, the effort of calculating minimax robust profiles can be reduced. The resulting control profiles yield a performance similar to the minimax robust controller. This is verified by the numerical results included in this paper.
This paper describes fault detection and diagnosis techniques for a hydraulic passenger car braking system. First, a model of the hydraulic braking system is derived in state space representation. This model is subseq...
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This paper describes fault detection and diagnosis techniques for a hydraulic passenger car braking system. First, a model of the hydraulic braking system is derived in state space representation. This model is subsequentlyemployed for fault detection and diagnosis. Fault detection is based on the calculation of the loss volume, i.e. the amount of brake fluid consumed due to the presence of a fault. The type of fault is determined by means of a correlation analysis approach. Furthermore, the location of the fault can also be determined. This is accomplished by analyzing the master brake cylinder pressure signals. The paper also presents numerical results of data recorded at a braking system testbed which illustrates the feasibility of the proposed approaches.
This paper investigates the possibility of computing the actual position of a passenger car based on different independent internal signals available in a production car. A new front wheel based dead reckoning approac...
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