Basis Of Indirect Measurements Research Articles

DIAGNOSTICS OF MECHANICAL ENGINEERING PRODUCTS ON SEVERAL GROUNDS

The article considers methods of non-destructive testing based on various physical laws and phenomena. The possibility of creating a new topical tool for obtaining a wide range of data of mechanical engineering products such as shape, size and location in space is considered. It is proposed to use sound diagnostics using a high-frequency broadband signal to capture the frequency characteristics of the object. The purpose of the study is to develop a method of non-contact measurement of mechanical engineering products on several grounds. With the help of vibroacoustic diagnostics and the method of quantitative control, the distribution of the entire volume of products was 100 pieces. on two parties: the main and control, quantitative parameters of each unit of a product are removed. A signal from 0 to 20,000 Hz was applied by means of a frequency generator. The frequency response of each sample was recorded in the Spectrum Analiyser program. Estimation of the deviation of the product size and its frequency spectrum was performed in the NeuroPro 0.25 software. The created neural network allows is predicted in real time values of several quantitative signs irrespective of their nature. A working model for collecting statistical data for the efficient operation of the neural network is obtained. The developed technique allows detecting the configuration of products on the basis of indirect measurements through the frequency spectrum. This technique can be used to diagnose parts by geometric features, physical properties, defects. This requires an increase in input data for neural network training. With a sufficient selection of parts with different defects of the neural network on the acoustic frequency characteristics will be able to divide the parts into groups of worthy and unworthy on various grounds.

A PCA-based Modeling Approach for Estimation of Road-tire Forces by In-tire Accelerometers

The knowledge of the forces acting between tire and road is crucial for modern vehicle control systems. Typically, such forces are estimated on the basis of indirect measurements and rely on complex mathematical models. Sensors embedded in the tire (e.g. accelerometers) offer the possibility of directly reaching the area of the tire-road interaction, and of delivering signals during the wheel rotation. Such signals reflect the tire state and the force exchanged between tire and road. In this paper an innovative approach to estimate such forces is presented. It exploits the signal delivered during the wheel rotation by an accelerometer glued to the inner side of the tire tread. The approach consists in processing the signal by means of the Principal Component Analysis (PCA). The results of experimental activities employing a real vehicle provide evidence to support the feasibility and the soundness of the proposed approach.

Determination of the Fe−CO Bond Energy in Myoglobin Using Heterodyne-Detected Transient Thermal Phase Grating Spectroscopy

The bond energies at active sites of proteins are intimately coupled to the structure-function relationship in biological systems. Due to the unknown nature of the protein relaxation along a reaction coordinate, it has not been possible to directly determine bond energies relevant to protein function. By embedding proteins in trehalose glasses, it is possible to freeze out protein relaxation on short time scales and determine the bond energies of photolabile ligands using photothermal spectroscopies. As a prototypical example, the photodissociation dynamics and energetics of carboxy-myoglobin (MbCO) in a trehalose glass matrix at room temperature were studied by transient absorption (or pump-probe) and transient thermal phase grating spectroscopy to determine the CO recombination dynamics and associated energetics, respectively. Both the initial energetics of the bond breaking and the energy released upon bond reformation could be used, on a time scale faster than significant protein relaxation, to determine the Fe-CO bond energy as 34 +/- 4 kcal/mol. This bond energy is significantly larger than that typically cited (25 kcal/mol) on the basis of indirect measurements but is in good agreement with recent theoretical predictions (35 kcal/mol) (Rovira, C.; Parrinello, M. Int. J. Quantum Chem. 2000, 80, 1172). This result in combination with the theoretical study suggests that protein structure plays a significant role in the bond energies at active sites which in turn provides a tuning element of the effective barrier heights independent to the transition state region.

Stochastic control for wastewater treatment processes

The sludge load, loading, age, concentration and stock control problems, as well as the treated water quality control problem are formulated and solved. The control algorithm is obtained in an effective computational form. It is shown by simulation that the biological growth and oxidation processes can be satisfactorily controlled on the basis of indirect measurements.

State and parameter estimation for wastewater treatment processes using a stochastic model

A stochastic model of the process is introduced on the basis of an IAWPRC-model and the outlet gas formation description. The original nonlinear model is approximated with a bilinear one as a system of stochastic differential equations separated into two parts for observable and unobservable processes. The state estimation problem is formulated and solved using the normal approximation method. The estimation algorithm is obtained in finite-dimensional form. It is tested on simulated and real data. Unknown parameters of the model are evaluated using a two-stage identification procedure for rough and fine estimation. It is demonstrated that the state of biological growth and oxidation processes can be satisfactorily estimated on the basis of indirect measurements.