The accuracy of current measurements can be increased by appropriate amplification of the signal to within the measurement range. Accurate current measurement is important for energy monitoring and in power converter control systems. Resistance and inductive current transducers are used to measure the major current in AC/DC power converters. The output value of the current transducer depends on the load motor, and changes across the whole measurement range. Modern current measurement circuits are equipped with operational amplifiers with constant or programmable gain. These circuits are not able to measure small input currents with high resolution. This article proposes a precise loop gain system that can be implemented with various algorithms. Computer analysis of various automatic gain control (AGC) systems proved the effectiveness of the Mamdani controller, which was implemented in an MCU (microprocessor). The proposed fuzzy controller continuously determines the value of the conversion factor. The system also enables high resolution measurements of the current emitted from small electric loads (≥1 A) when the electric motor is stationary.

Currently computer programs are known to predict what value of desflurane concentration will be required during general anesthesia. None of them are coupled with the vaporizer of this anesthetic. The authors of the article presented the possibilities of automating the selection of desflurane concentration for vaporizers equipped with an adjustable knob during the conduction phase of balanced anesthesia. The value of the delivered concentration of the volatile anesthetic should be such as to ensure the hemodynamic stability of the anesthetized patient. The above-mentioned solution is based on the values of circulatory parameters such as: mean blood arterial pressure (MAP) and heart rate (HR). The proposed system is equipped with limiters containing upper and lower limits to prevent decrease or excessive deepening of anesthesia which resulting in hemodynamic instability. The system also reacts to rapid changes in blood circulation values adjusting the concentration of anesthetic to the strength of the surgical stimulus and the circulatory response to the course of anesthesia and the surgical procedure. The authors of the article showed the usefulness of automating the selection of desflurane concentration in low-flow anesthesia. The algorithm controlling the setting of the desflurane vaporizer knob does not bind the input and output spaces with mathematical relationships.

This paper presents the theory about generating the braking curve and the analysis of the influence of the braking controller parameters on the generation of the braking curve of the train. In this paper, computed examples of braking quality developed using generic quality factor are shown, and on the basis of the calculations, weight components of the factor and an additional criterion for assessing the quality of braking were proposed. It has been demonstrated that the developed algorithms can be used to verify the effectiveness of the braking controller and the adjustment of the terms, and the change of these algorithms affects the shape of the generated braking curve of the train. It has been shown that the analysis of a failure of the propulsion car revealed the existence of a safe braking area. The performed statistical analysis confirmed the normal distribution of the scatter of braking results, for which the regression model fitted.

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Summary. This paper presents the possibility of using a fuzzy controller to correct metrological properties of an electric traction energy meter. So far, no algorithms based on fuzzy logic to determine the desired conversion value of the current channel of the electricity meter have been applied. Currently, for the mentioned channel, conventional methods of gain determination are used, based on a sequential algorithm that controls operation of the programmable gain amplifier. The proposed corrector is designed for smart and continuous modification of the conversion factor of the low-voltage input part of the current channel in the electric energy meter. The authors have performed an accurate analysis of the current function in the main circuit of an electric locomotive by creating a model of a traction inverter subject to asynchronous motor load. An essential concept is this paper is to present the possibility of having a multi-input fuzzy controller split into two-input controllers connected in parallel and cascade. By performing a computer simulation of systems used for correcting metrological properties of electric traction energy meters, it has been proven that the applied fuzzy systems, based on an expert's knowledge of digitally controlled PGA (Programmable Gain Amplifier) type operational amplifiers, are advantageous.