Because of missing a-priori information, tolerances of the elements used in microelectronics and other circuits, nonlinearities and to check the results of models and calculations or programs especially in measurement estimation and approximation methods using the physical background are advantageous. Also in education these methods to get a first impression of the solutions of problems should be trained. In the paper a lot of typical examples will be treated as signal analysis and aliasing errors, linearisation, dynamic errors and optimal filtering including consequences for the selection...
The paper relates to the description of Virtual Instrument (VI). A new conceptual model of a virtual instrument is proposed. The model describes not only measuring devices, but also devices that can generate signals both analogue and digital. A compatibility between this model and a model of SCPI devices is shown. A new proposition for description of measurement equipment is also proposed. It makes more clear the classification of measurement equipment and enables one to differ a virtual instrument from a measuring system with a graphic user interface.
Within a formal framework, where each object is characterized by a set of predicates as a binary sequence of 0 and 1, a nominal level of measurement is discussed. The nominal scale is reinterpreted as a set of predicates, and nominal measurement as an assignment of binary sequences to the objects. One remarkable character of this formalization is a reciprocal relationship between the objects and the predicates. Taking this reciprocity as a heuristic guiding principle, a new notion of generalized indiscernibility between two sets of objects is introduced, which enable us to examine various...
The multiple measuring method, that is, the double measuring method or its improved version, provides a precise calibration procedure of linear sensors as well as a linear system identification method, whose results are independent of dynamics of measuring devices. These methods are established on the assumption that measurement noise can be ignored. In practice, however, measurement noise exists and it cannot be ignored. In this paper, the influence of measurement noise is investigated on the result obtained by applying the multiple measuring method. Consequently, the influence is appeared...
In this paper the important problem in measuring system: ”How to eliminate the sensitivity of sensors to the influence quantity?” is replaced by the question: ”How to use this sensitivity to measure both the main and the influence quantities?” As a solution of the second problem the frequency balanced bridges as primary signal processing circuit for parametric sensors are proposed. Structure of such a two-dimensional transducer and possibilities of its realization are described. An example of transfer functions, parameters of linear model, nonlinearity errors is given when typical...
Values of physical quantities are real numbers. These values do not contain information on the physical nature of measured quantity, this information is given by the physical unit. But the physical unit is only a name while the information on the nature of measured quantity is given by physical laws and design of measurement devices (sensors). We propose a topological theory of measurement, which mathematically describes both values of physical quantities and their nature. The model of measurement is fibre bundle space with base space corresponding to topological properties of measured...
The ferrous objects disturb evenly distributed Earth magnetic field. It is possible to detect the ferrous objects by measuring the magnetic field. Detection of objects under water in the Baltic Sea is difficult due to large natural magnetic anomalies. In order to eliminate the anomalies, the prediction technique in measurements was used. Before the prediction, the measured signal is filtered to remove unwanted frequencies and this way the object can be detect using a threshold peak detector. LabVIEW was used to simulate the detection of objects in the Baltic Sea.
Automatic knowledge discloser (AKD) is designed in the field of structures of parametric invariant information converting systems. It allows to reveal in automatic mode the fundamental idea (law, structure) containing in potential form the information on the full set of structures of the class investigated, to build hierarchical forecasting knowledge bases, to synthesize natural classifications and complete deductive theories both of linear, and nonlinear structures of invariant converting systems. These possibilities are provided due to the new approach to equivalent transformation and...
This paper describes a single micro-optical fiber sensor capable of measuring four strains simultaneously in a composite structure. This single transducer is based on cascading four micro Fabry-Pérot cavities to measure three normal strains and one shear strain in the plane of the optical fiber cross-section. The development of the sensor fabrication and signal processing techniques are discussed. This fabrication includes designing and fabricating new optical fibers, optical fiber circuits, and an optical fiber multi-strain sensor head. This paper presents 2D and 3D finite element analysis...
An alternative method of dealing with ill-conditioned problems in model identification is introduced. It consists in estimation of parameters selected on the ground of the sensitivity analysis and fixing remaining ones as constants. Statistical analysis of the resulting estimator in terms of estimate bias and variance is presented together with a realistic simulation example of the maximum expiration model. Results of simulation show that selection of parameters improves numerical conditioning of model identification and decreases variance of estimates.