The objectives of dynamic data rectification are wide-ranging and include the estimation of the process states, process signal de-noising, and outlier detection and removal. One approach reported in the literature for...
详细信息
The objectives of dynamic data rectification are wide-ranging and include the estimation of the process states, process signal de-noising, and outlier detection and removal. One approach reported in the literature for dynamic data rectification is the conjunction of the extended Kalman filter (EKF) and the expectation-maximization algorithm. However, this approach is limited in terms of its applicability due to the EKF being less appropriate where the state and measurement functions are highly non-linear or where the posterior distribution of the states is non-Gaussian. This paper proposes an alternative approach whereby particle filters are utilized for dynamic data rectification. By formulating the rectification problem within a probabilistic framework, the particle filters generate Monte Carlo samples from the posterior distribution of the system states, and thus provide the basis for rectifying the process measurements. Furthermore, the proposed technique is capable of detecting changes in process operation and thus complements the task of process fault diagnosis. The appropriateness of particle filters for dynamic data rectification is demonstrated through its application to a benchmark pH neutralization process.
Fault detection and diagnosis are important technologies for the safe and efficient operation of a chemical plant. This paper describes a sensor fault identification approach using variable reconstruction for dynamic ...
详细信息
The importance of the FDA PAT guidelines in pharmaceutical process design space can be influenced by the introduction of robust process malfunction and senor fault detection and diagnosis tools. The paper compares a m...
详细信息
A challenge facing the pharmaceutical and chemical industries is how to understand and identify differences in process behaviour where a product is manufactured at two different sites. Three approaches based on multi-...
详细信息
A challenge facing the pharmaceutical and chemical industries is how to understand and identify differences in process behaviour where a product is manufactured at two different sites. Three approaches based on multi-group principal component analysis are investigated and benchmarked against single site models. The multi-group approach is shown to remove differences between sites such as operational scale thereby enabling the analysis to focus on identifying differences in variation between the two sites that are not a consequence of process configurations. From the analysis it is observed that the multi-group approach can assist in the understanding of manufacturing performance.
Robust fit-for-purpose multivariate calibration models are of critical importance to on-line/in-line quantitative monitoring of bio-chemicals and pharmaceuticals using spectroscopic instruments. Unlike in off-line ass...
详细信息
Robust fit-for-purpose multivariate calibration models are of critical importance to on-line/in-line quantitative monitoring of bio-chemicals and pharmaceuticals using spectroscopic instruments. Unlike in off-line assays, the spectroscopic measurements in on-line/in-line real-time applications are almost inevitably subjected to variations in measurement conditions (e.g. temperature) and samples' physical properties (e.g. cell density, particle size, sample compactness), which can invalidate the assumption of a linear relationship between the spectroscopic measurements and the concentrations of the target chemical components. This Biotech Highlight discusses the effects of such variations on spectroscopic measurements, and presents an overview of recent work on modelling and correcting of the detrimental effects of variations in measurement conditions and samples' physical properties.A number of application studies to complex datasets and an industrial plant demonstrate the methodologies and algorithms discussed.
We present a shared industry-academic perspective on the principles and opportunities for Quality by Digital Design (QbDD) as a framework to accelerate medicines development and enable regulatory innovation for new me...
We present a shared industry-academic perspective on the principles and opportunities for Quality by Digital Design (QbDD) as a framework to accelerate medicines development and enable regulatory innovation for new medicines approvals. This approach exploits emerging capabilities in industrial digital technologies to achieve robust control strategies assuring product quality and patient safety whilst reducing development time/costs, improving research and development efficiency, embedding sustainability into new products and processes, and promoting supply chain resilience. Key QbDD drivers include the opportunity for new scientific understanding and advanced simulation and model-driven, automated experimental approaches. QbDD accelerates the identification and exploration of more robust design spaces. Opportunities to optimise multiple objectives emerge in route selection, manufacturability and sustainability whilst assuring product quality. Challenges to QbDD adoption include siloed data and information sources across development stages, gaps in predictive capabilities, and the current extensive reliance on empirical knowledge and judgement. These challenges can be addressed via QbDD workflows; model-driven experimental design to collect and structure findable, accessible, interoperable and reusable (FAIR) data; and chemistry, manufacturing and control ontologies for shareable and reusable knowledge. Additionally, improved product, process, and performance predictive tools must be developed and exploited to provide a holistic end-to-end development approach.
This paper presents an analysis of nonlinear extensions to Partial Least Squares (PLS) using error-based minimization techniques. The analysis revealed that such algorithms are maximizing the accuracy with which the r...
详细信息
This paper presents an analysis of nonlinear extensions to Partial Least Squares (PLS) using error-based minimization techniques. The analysis revealed that such algorithms are maximizing the accuracy with which the response variables are predicted. Therefore, such algorithms are nonlinear reduced rank regression algorithms rather than nonlinear PLS algorithms
Principal Component Analysis and Partial Least Squares have been used extensively for Multivariate Statistical processcontrol (MSPC) with increasing numbers of applications in the chemical manufacturing industries. I...
详细信息
Principal Component Analysis and Partial Least Squares have been used extensively for Multivariate Statistical processcontrol (MSPC) with increasing numbers of applications in the chemical manufacturing industries. In contrast the multivariate statistical technique of Canonical Correlation Analysis (CCA), despite its conceptual similarities with Principal Component Analysis and Partial Least Squares, has not found analogous applications. In this paper a library of metrics based on Hotelling’s T and the Squared Prediction Error ( SPE ) are developed for CCA. The various monitoring tools and techniques are validated and compared through application to a simulated spray-drying process.
An industrial ethylene propylene rubber compounding process is used to illustrate some of the issues that arise in the monitoring of the manufacturing performance of a process comprising both batch and continuous unit...
详细信息
An industrial ethylene propylene rubber compounding process is used to illustrate some of the issues that arise in the monitoring of the manufacturing performance of a process comprising both batch and continuous unit operations. The key issues relate primarily to the different formats of the data that are routinely collected. For example on batch type processes, measurements are collected for a fixed quantity of produced mass whilst for the continuous units, measurements are recorded for each variable at fixed time points. Thus for the development of a process performance monitoring scheme, it was necessary to provide a common sampling base.
A nonlinear multiscale multivariate statistical processcontrol method is proposed to address fault detection and diagnosis issues at different scales in nonlinear processes. A kernel principal component analysis (KPC...
详细信息
A nonlinear multiscale multivariate statistical processcontrol method is proposed to address fault detection and diagnosis issues at different scales in nonlinear processes. A kernel principal component analysis (KPCA) model is built with the reconstructed data obtained by performing wavelet transform and inverse wavelet transform sequentially on measured data. New variable contributions to monitoring statistics are also derived. A CSTR simulation study compares the proposed approach with several existing methods in terms of false alarm rate, missed alarm rate and detection delay.
暂无评论