Energy balance of the photovoltaic system is influenced by many factors. In this article the effect of tilt and azimuth angle changes of the photovoltaic system energy production is analyzed. These parameters have significant impact on the amount of solar radiation which hits on the photovoltaic panel surface and therefore also on the energy absorbed by the module surface. The main aim of research was identification of the optimal position of photovoltaic system installation in the southern Slovakia regions. The experimental apparatus had two setups consisting of polycrystalline photovoltaic modules. The first setup was used for identification of the tilt angle changes in the range (0–90°). The second one was focused on the detection of the azimuth angle effect to the energy production. The measurement results were statistically processed and mathematically analyzed. Obtained dependencies are presented as two-dimensional and three-dimensional graphical relations. Regression equations characterize time relations between the tilt or azimuth angle and the energy produced by the photovoltaic system in Southern Slovakia. Obtained simplified mathematical model was verified by analytical model. Presented models can be used for the dimensioning and optimization of the photovoltaic system energy production.

The paper presents the designed system to measurements of gas sensor transient characteristics. Electrochemical oxygen sensor SK-25F was selected for measurements from point of view application in health care and ensuring human safety in industrial production facilities and laboratories. The aim of this work is to design an automatic system for measuring the transient function G(s) of electrochemical sensors and to identify the mathematic model from a sample of sensors. The automatic measurement system based on a microcontroller for the measurements of dynamical characteristics of gas sensors was designed and developed. The result is transfer function with fit to estimation data higher as 99.48 %. The bandwidth of gas sensors was calculated on average at 0.0285763 Hz with a maximum deviation of 0.34 %. Finally, an algorithm for detecting the exceeding of the frequency range of an electrochemical gas sensor is proposed. Its application is in speed control UAV with the aim of accurate measurements of gases in the air by electrochemical sensors.

This study presents a novel multidimensional computational framework for optimising the tilt angle of photovoltaic systems by utilising complex variable modelling, transfer function analysis, and artificial neural network modelling. A 35 kWp photovoltaic system was monitored continuously over one year at a fixed 25° tilt, and comprehensive statistical analyses were conducted to evaluate monthly and seasonal variations in energy output. The proposed methodology makes differential equations with constant coefficients and transfer function models to describe time-dependent energy balance, enabling robust dynamic system identification. Empirical relationships between tilt angle and produced energy yield were effectively quantified, with a negative correlation coefficient value of 0.95 observed between steady-state energy production and tilt angle. Comparative analysis demonstrated negligible differences in annual yield between the 25° and 35° tilt configurations. Validation by neural network, utilising various architectures, revealed that a single hidden layer with 12 neurons achieved optimal model prediction performance value of 99.15%. The results confirm the efficiency of combining complex variable models with AI-based validation for precise and practical PV system modelling. This integrated approach facilitates improved decision-making in PV design by providing accurate predictions of energy yield under varying operational conditions.

Increasing the accuracy of position measurement is an intensively addressed issue in engineering practice. Indirect methods provide satisfactory distance information. For more accurate identification of surface geometry or tilt, systems based on image processing are frequently employed, however, these are more expensive in contrast to devices operating on the basis of acoustic principle. This paper deals with the modelling of the impulse functions of ultrasonic sensors under known geometrical conditions of their distribution. The reflecting surface is a metallic surface. Based on the results, a statistically significant non-linear correlation between the complex integral of the impulse function and the front time of the transient characteristic is shown. The change from the parallel to the perpendicular case of the longitudinal axis of ultrasonic transducer distribution due to the change in the tilt angle of reflected surface is also included in the study. The interval of change in the tilt angle of reflecting surface was from 0° to 30°.