In the paper, there are discussed the backgrounds of unified approach to the analysis and statistical synthesis of optimal (best in the given conditions) analogue- digital measurement systems (MS), working in a presence of noises, random disturbances and observation errors. Methods of derivation of equations and algorithms for optimal estimation of measurands and for adaptive control the measurement experiment are presented. Apart from optimal software, the obtained results determine optimal structure, characteristics, the way of functioning and locked interaction of the main elements of...
In practical situations, the voltage and the current at any supply terminal are not steady-state quantities, since the customers’ load operation and the equivalent impedance of the network vary randomly in time. A search is active for on-line investigation methods able to provide the separation of the responsibility for the electric-power quality degradation. Under nonstationary conditions the methods proposed in the literature require the processing of a great amount of data. In this connection, a statistical approach is recalled in this paper which is aimed to gauge information about the...
RNS arithmetic has received great attention in the literature and its advantages have been clearly pointed out but practical applications are, until now, very poor. This fact is related to different reasons but the most important is the need of a complex conversion from analog or binary quantities to RNS representation (input conversion) and to the necessary final conversion from RNS representation to the classical binary one (output conversion). Recently, some authors have faced the input conversion problem, introducing the MRNS and giving a first hardware implementation for the conversion...
In dynamic calibration on-line quality measurements are improved by using laboratory analysis as a calibration reference. Dynamic calibration is one method of effective use of uncertain measurements other methods include different SPC methods.
The reliability of machining operations is an essential requirement of modern automatic manufacturing system. In the machining operations, in which unbroken chips are the major obstacles for automation, reliability implies chip control as a major aspect. To improve chip control is necessity for automated machining. In turning operation chip control is difficult especially for mild steel because chips are continuous. Chip control is closely related to the chip flow and it plays also a predominant role in the effective control of chip formation and chip breaking for the easy and safe disposal...
A procedure for optimal selection of sample input signals to get the best calibration characteristics of measuring apparatus is proposed. As an example the problem of optimal selection of standart pressure setters when calibrating differential pressure measurer is solved.
Flow curves of metals to be formed must be known if we want to calculate the forces for metal-forming processes. If we can not find flow curve for the material to be formed, we have to carry out an experiment to get flow curve for this material. Instead of expensive and long-time experimental work, flow curve can be determined by using statistical methods. This paper presents determination of flow curves by using multi- regression analysis based on few experimental points of torsion test.
The electromagnetic emissions from a large power rotating machine (synchronous generator) are considered. The results of two measurement campaigns are reported: attention is focused on the measurement methods and on the evaluation of the results, considering the reactive behaviour of the field (the value of the wave impedance and its impact on the limits on the electric field amplitude in the standards), the extension of the source of emissions (the size of the machines is comparable to the measuring distance), the electromagnetic environment (presence of reflecting surfaces and sources of...
Two-parameters double exponential distribution is presented. Maximum likelihood method is applied to estimate the parameters of the distribution. It seems that the maximum likelihood estimates of the double exponential distribution exist only for rather specific collections of data.
An impedance measurement system that is based on a voltmeter with digitising capabilities and on a sine-fit processing is proposed in this paper. The system can be arranged by employing standard instruments that are commonly available in calibration laboratories for the measurement of other electrical quantities. Two different solutions are proposed that differ in the used standards. One solution employs a multifunction calibrator that feeds the unknown impedance and a digital multimeter that acquires the voltage signal across the impedance; the other solution employs the same digital...