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Inspection of the technical condition of load-bearing structural elements of buildings and structures in the process of their construction and operation is an important issue at the present time. A fiber-optic monitoring system is proposed as a solution to the problem of early diagnosis of defects and damage to load-bearing building structures. A scheme has been developed for testing fiber-optic sensors, which make it possible to control the stress-strain state of monolithic reinforced concrete structures. For testing, a series of monolithic concrete beams of rectangular cross section has been made reinforced with fiber optics during their manufacturing. The values of mechanical stresses and deformations arising in beams under loading have been determined. Using the tested samples as an example, it has been established that the proposed fiber-optic monitoring system (FOMS) makes it possible to control stresses and deformations (and to predict the appearance and growth of cracks) in various building structures. The main element of the system is a hardware-software complex capable of estimating the parameters of a light wave at the output of the optical fiber. The distance from the installation site of the data processing unit to the measurement point can cover the area of 30 km. At this, fiber-optic sensors operate without additional power supply from a laser with the power of up to 30 mW. The proposed monitoring system has a low cost of one measurement point, it is easy to install, which is a good alternative to the electronic beacon-recorder device and the development of optical digital technologies in construction.

Currently, there are many enterprises involved in extracting and processing of primary raw materials. The danger of working in this industry consists in the formation of cracks in rocks of the pit side slopes, which can lead to destruction. This article discusses the existing systems for monitoring the pit collapse prevention. The most promising is the use of systems with fiber-optic sensors. However, use of these systems is associated with some difficulties due to high costs, low noise immunity, and in some cases, the requirement for additional equipment to improve the reliability of measurements. A completely new method of processing the data from a fiber-optic sensor that simplifies the design and reduces the cost of the device is proposed considering the experience of previous developments. The system uses artificial intelligence, which improves the data processing. The theoretical part is dedicated to the development of foundations, and the analysis of the nonlinear properties of the physical and mathematical model of optical processes associated with the propagation of an electromagnetic wave in a fiber-optic material was developed. The results of experimental and theoretical applied research, which are important for the development of fiber-optic systems for monitoring the pit collapse prevention, are presented. The dependences of optical losses and the number of pixels on the dis-placement were obtained. The accuracy of the method corresponds to the accuracy of the device by which it is calibrated and is 0.001 mm. The developed hardware-software complex is able to track the rate of changing the derivative of the light wave intensity in time, as well as changing the shape of the spot and transition of pixels from white to black. [ABSTRACT FROM AUTHOR]

This paper presents the results of complex scientific research aimed at developing a prototype fiber-optic system for controlling the technical condition of buildings, structures, and extended objects. The aim is to develop a quasi-distributed type of fiber-optic control system without electrical signals, with the minimum possible cost of one measurement point. The fiber-optic sensors are based on a new method of controlling the parameters of the light spot by means of a hardware-software complex. The proposed monitoring system is quasi-distributed, is able to determine the damaged and most stressed and deformed areas of load-bearing reinforced concrete structures of buildings at the stage of their occurrence, and will allow for the taking of preventive measures for their protection. The research was carried out on a laboratory bench working together with the hardware-software complex; pixel analysis of changes in the area of the spot and its intensity was used as a fiber-optic sensor. A single-mode optical fiber of the G.652.D 9/125 μm standard was used, with a wavelength of 650 nm. The monitoring system can perform the function of pressure measurement on the building structure, establish the damage zone, and signal in case of an abrupt change in parameters in case of structure destruction. Laboratory tests have shown that the number of channels can be increased to 16 or 32. With the help of this system, it is possible to monitor the technical condition of the underground and above-ground parts of buildings or structures and control their integrity in real-time. [ABSTRACT FROM AUTHOR]

This article proposes several solutions for the use of novel AC voltage regulators as electrical energy quality conditioners and for the use of a half-bridge voltage inverter circuit as an active filter. This study was carried out with a real object, and more attention was paid to it. Structural models of electrical energy quality assurance systems, the calculation of control system elements and experimental results are presented. In particular, the use of a half-bridge voltage inverter circuit was considered as a replacement for the passive filter of the battery charger and rectifier device. AC voltage regulators are also used as compensators for higher-current harmonics, namely active filters and reactive power, voltage drop, voltage unbalance and flicker effect compensators. Block diagrams of power quality conditioners are presented, control algorithms are developed and the results of the current high-frequency harmonics compensation, reactive power and signal balancing are presented. The results of an active filter experiment based on the NRT 160.220 charge-rectifier device circuit showed a reduction in ripple of up to 1% with smaller dimensions compared to a passive filter. The control characteristics and external characteristics of the regulators are removed. The dependences of the current THD factor and the power factor are presented depending on the modulation depth for AC voltage regulator circuits used as power quality conditioners. [ABSTRACT FROM AUTHOR]

In the article results of researches of brake devices of lifting machines UD of joint-stock company "ArcelorMittal Temirtau" are resulted. Defects were revealed as a result of the examination. A method and device for the unconditional control of defects and technical condition of the hinged joints of brake devices is developed in terms of the gap size and the angle of rotation between the links of the kinematic pairs "Widget-finger". For the monitoring of gaps, capacitive sensors are installed, mounted on hinged joints. It is substantiated that with the use of capacitive sensors it is possible to control the gaps in the hinged joints in real time. A device has been developed that makes it possible to estimate the magnitude of the gap at several points of the kinematic chain of the mechanism simultaneously.