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| 2. |
- Chistiakova, Tatiana, et al.
(författare)
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Binary classifiers applied to detect DO sensor faults during washing events
- 2015
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Ingår i: Proc. 2nd IWA Conference on New Developments in IT & Water. - : IWA Publishing.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, several classication techniques are applied for monitoring the status of DO sensors in wastewater treatment plants. In particular, DO sensors during washing events are studied and indication parameters from these events are used. The methods considered are the following: k-Nearest Neighbours, Radial Basis Function and Random Forest classiers. The result shows the comparison and the eligibility of the methods to detect a clogged DO-sensor.
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| 3. |
- Chistiakova, Tatiana, et al.
(författare)
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Nonlinear system identification of the dissolved oxygen to effluent ammonia dynamics in an activated sludge process
- 2017
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Ingår i: IFAC-PapersOnLine. - : Elsevier B.V.. - 2405-8963. ; 50:1, s. 3917-3922
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Tidskriftsartikel (refereegranskat)abstract
- Aeration of biological reactors in wastewater treatment plants is important to obtain a high removal of soluble organic matter as well as for nitrification but requires a significant use of energy. It is hence of importance to control the aeration rate, for example, by ammonium feedback control. The goal of this paper is to model the dynamics from the set point of an existing dissolved oxygen controller to effluent ammonia using two types of system identification methods for a Hammerstein model, including a newly developed recursive variant. The models are estimated and evaluated using noise corrupted data from a complex mechanistic model (Activated Sludge Model no.1). The performance of the estimated nonlinear models are compared with an estimated linear model and it is shown that the nonlinear models give a significantly better fit to the data. The resulting models may be used for adaptive control (using the recursive Hammerstein variant), gain-scheduling control, L2 stability analysis, and model based fault detection.
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| 4. |
- Chistiakova, Tatiana, et al.
(författare)
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Nonlinear system identification of the dissolved oxygen to effluent ammonium dynamics in an activated sludge process
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Aeration of biological reactors in wastewater treatment plants is important to obtain a high removal of soluble organic matter as well as for nitrification but requires a significant use of energy. It is hence of importance to control the aeration rate, for example, by ammonium feedback control. The goal of this report is to model the dynamics from the set point of an existing dissolved oxygen controller to effluent ammonium using two types of system identification methods for a Hammerstein model, including a newly developed recursive variant. The models are estimated and evaluated using noise corrupted data from a complex mechanistic model (Activated Sludge Model no.1). The performances of the estimated nonlinear models are compared with an estimated linear model and it is shown that the nonlinear models give a significantly better fit to the data. The resulting models may be used for adaptive control (using the recursive Hammerstein variant), gain-scheduling control, L2 stability analysis, and model based fault detection.
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| 6. |
- Zambrano, Jesús, et al.
(författare)
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Gaussian process regression for monitoring a secondary settler
- 2015
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Ingår i: Proc. 2nd IWA Conference on New Developments in IT & Water. - : IWA Publishing.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An approach based on Gaussian Process Regression for monitoring the sludge profile of a secondary settler is proposed. Gaussian Process is a probabilistic, nonparametric model with an uncertainty prediction. The approach is illustrated using data from a sensor measuring the sludge concentration in a settler as a function of the settler depth at Bromma wastewater treatment plant (WWTP). Results suggest that the approach is feasible for monitoring and fault detection of the sludge settling process.
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