Optimal Sensor Placement

Bayesian Methods for Structural Dynamics and Civil Engineering 

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Keywords ambient vibration correlation function Duffing oscillator hydraulic jump information entropy modal identification optimal sensor placement spectral density structural health monitoring Wishart distribution... 

The present formulation for optimal sensor placement in terms of the information entropy provides a rational procedure for comparing the uncertainty of the estimates of the parameter values for different sensor configurations. Specifically, a direct measure of the uncertainty reduction is provided by the change of the information entropy ... 

Yuen, K.-V, Katafygiotis, L. S., Papadimitriou, C. and Mickleborough, N. C. Optimal sensor placement methodology for identification with unmeasured excitation. Journal of Dynamical Systems, Measurement and Control (ASME) 123(4) (2001), 677-686. 

Among different monitoring techniques like Kalman filters and various Data Reconciliation schemes, Kalman filter presents good variance reduction, estimation of process variables and better tracking in dynamic changes of the process (Benqliiou et al 2002). This performance, however, varies with the position and quality (variance) of the sensors. This paper focuses on the determination of the optimal sensor placement for the use of Kalman filtering. 

Papadimitriou C, Lombaert G (2012) The effect of prediction error correlation on optimal sensor placement in structural dynamics. Mech Syst Signal Process 28 105-127... 

Analysts must recognize the above sensitivity when identifying which measurements are required. For example, atypical use of plant data is to estimate the tray efficiency or HTU of a distillation tower. Certain tray compositions are more important than others in providing an estimate of the efficiency. Unfortunately, sensor placement or sample port location are usually not optimal and, consequently, available measurements are, all too often, of less than optimal use. Uncertainty in the resultant model is not minimized. 

Antoniades, C. and Christofides, P. D. (2001). Integrating nonlinear output feedback control and optimal actuator/sensor placement for transport-reaction processes. Chem. Eng. Sci., 56, 4517-4535. 

In general, the optimal location of measurement points should take into account aspects that improve plant performance such as process variable accuracy, process reliability, resilience, and gross-error detectability (Bagajewicz, 2000). These performance indicators (e.g. estimation precision, reliability) of a sensor network represent the constraints in the sensor placement design problem. 

The centralized control can be approached using different techniques pole-placement, optimal control and loop decoupling. When the whole state is not accessible, a motivation to introduce a state observer is discussed. A detailed example when all state variables are accessible, i.e. when the state observer it is not necessary, has been explained. It is important to remark that the previously cited techniques are not widely used in CSTR control. This is due to the fact that these procedures require non-intuitive matrix tuning and computations, which are not familiar in the process industry. Nevertheless, for complex processes, these procedures can be the only solution to the control problem, when a limited set of sensors are available. 

High-fidelity models are a useful tool for predicting flow over and around the superstructure of naval vessels under a variety of meteorological conditions as such, they provide useful guidance for the optimal placement of onboard sensors. Less work has been done on predicting flow at ports and bases. 

Why are these stated at the beginning This is because of the fact that it has been found that people are more worried about SIL rating of F G detector. It is an important issue but there are a few other critical issues as well. One needs to keep in mind that it is very critical in an FGS that sensors are placed optimally, otherwise hazardous gases and flames are not adequately detected and in that case the SIF/SIS will not be effective. Therefore, it is absolute necessity that proper engineering exercise has been carried out in selecting the detector and their placement. FGS is a subject by itself it is very difficult really to cover all aspects of the same. Here endeavored has been under taken to cover salient features of FGS in reference to SIS. The discussions will be mainly on... 

To date, although a number of articles on structural control for hazard mitigation of civil structures have been investigated, most of the studies have been focused on 2D stmctural models. In particular, almost all articles that study optimal placement of actuators and sensors within large civil stmctures have been mainly dealt with 2D... 

Cha, Y.-J., Raich, A. M., Barroso, L. R., Agrawal, A. K. (2011a). Optimal placements of active control devices and sensors in frame structures using multi-objective genetic algorithms. Jowrna/ ofStructural Control Health Monitoring. DOI 10.1002/stc.468... 

Richardson, A., Abdullah, M. M. (2002). Sensor/ac-tuators placement on civil structures using a real coded genetic algorithm. Proceedings of the SPIE-The International Society for Optimal Engineering, 4696, 244-255. 

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