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Full-Text Articles in Engineering
Computing Arrival Cost Parameters In Moving Horizon Estimation Using Sampling Based Filters, Sridhar Ungarala
Computing Arrival Cost Parameters In Moving Horizon Estimation Using Sampling Based Filters, Sridhar Ungarala
Chemical & Biomedical Engineering Faculty Publications
Moving horizon estimation (MHE) is a numerical optimization based approach to state estimation, where the joint probability density function (pdf) of a finite state trajectory is sought, which is conditioned on a moving horizon of measurements. The joint conditional pdf depends on the a priori state pdf at the start of the horizon, which is a prediction pdf based on historical data outside the horizon. When the joint pdf is maximized, the arrival cost is a penalty term based on the a priori pdf in the MHE objective function. Traditionally, the a priori pdf is assumed as …
Letter To The Editor, Sridhar Ungarala
Letter To The Editor, Sridhar Ungarala
Chemical & Biomedical Engineering Faculty Publications
No abstract provided.
Comments On "Robust And Reliable Estimation Via Unscented Recursive Nonlinear Dynamic Data Reconciliation", Sridhar Ungarala
Comments On "Robust And Reliable Estimation Via Unscented Recursive Nonlinear Dynamic Data Reconciliation", Sridhar Ungarala
Chemical & Biomedical Engineering Faculty Publications
No abstract provided.
The Use Of A Cell Filter For State Estimation In Closed-Loop Nmpc Of Low Dimensional Systems, Sridhar Ungarala, Keyu Li
The Use Of A Cell Filter For State Estimation In Closed-Loop Nmpc Of Low Dimensional Systems, Sridhar Ungarala, Keyu Li
Chemical & Biomedical Engineering Faculty Publications
Combining variants of the Kalman filter and moving horizon estimation (MHE) with nonlinear MPC has been studied before. The MHE is appealing due to its ability to impose constraints and demonstrated superiority over extended Kalman filter. However, nonlinear MPC based on MHE requires solutions to two back to back nonlinear programs. In this paper we propose to use the cell filter (CF) to provide state feedback to the MPC regulator. The cell filter is a piecewise constant approximation of the conditional probability density of the states, whose temporal evolution is modeled by an aggregate Markov chain. Since the CF …
Effect Of Synthesis Time And Treatment On Porosity Of Mesoporous Silica Materials, Asli Ertan, Pradeep Kodumuri, Orhan Talu, Surendra N. Tewari
Effect Of Synthesis Time And Treatment On Porosity Of Mesoporous Silica Materials, Asli Ertan, Pradeep Kodumuri, Orhan Talu, Surendra N. Tewari
Chemical & Biomedical Engineering Faculty Publications
Nitrogen adsorption at 77 K on mesoporous silica materials (MPS) with varying synthesis time and treatment conditions was investigated. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were also used to characterize the mesoporous materials. This study was performed at 6, 24 and 72-h synthesis times. It is shown that 6-h is not enough for complete formation of the MPS material and at least 24-h is necessary. The pore structure starts decaying for the 72-h synthesis time. The three-after-synthesis treatment conditions used were 1) washed, 2) washed and calcined and 3) directly calcined after synthesis. Ethanol/HCl …