The article presents the methodology and results of tests of a prototype controller designed for the electrohydraulic control system of a powered roof support. This controller is the basic part of the developed, innovative control system. The tests were carried out on a custom-designed testing station, equipped with one section of a roof support. The aim of the research was to check the functionality and speed of the controller's response while working with the actual support section. The tested controller and the control system has a modular structure, which greatly facilitates its operation and use. Measurements of control functions were carried out on the controller connected to the electrohydraulic control block. The research mainly focused on determining the period starting from the moment of providing the signal to the moment of switching on the basic functions performed by the support section. The obtained results confirm the assumptions made. The controller's operation is very stable, and its response times are very short. It can therefore be assumed that the tested controller is correctly designed and constructed. This creates great possibilities for its practical application in the built-in system for controlling the roof support. This may be particularly important in the case of high-efficiency longwall complexes, for which wireless control of the support is planned to be used. The presented research methodology and obtained results should therefore be an important source of information in the field of testing controllers for powered roof supports.

One of the major problems of long-distance belt conveyor technology, and not only in the North Bohemian mines, are impacts of rock blocks on the belts which increases the belts wear and reduces their service life. Therefore, in this paper there are widely discussed the rock impacts dynamics, a new type of device - the impact rods intended for significant reducing the number of punctures in the conveyor belts and thus for prolongation of their service life and modeling of the proposed devices. Application of the impact rods is estimated in the impact stands of the systems of conveyors removing the coal extracted by the bucket wheel excavator KU 300.

The process of designing a longwall powered support is extremely complex and requires many operations related to the creation of a complete machine. The powered support section is one of the basic elements of the longwall system. It acts as protection for the working space and takes part in the process of excavating and transporting the spoil. The implementation of the support that meets the guidelines of the manufacturer and user requires an endurance analysis at the design stage conducted according to the regulations in force. The main objective of this research, pursued by the authors, was to perform the analysis of the ultimate strength of selected elements of the designed powered support section. The research was carried out with the use of special software that uses the finite element method. This article presents the analysis of the strength limits conducted with the help of the finite element method, determining the strength of selected elements of the longwall support section. The solutions proposed by the authors include changes in the structure and properties of the material in the design process. The aim of the proposed solution was to obtain a model with strength value that meets safety standards. The research results are a valuable source of knowledge for designers. Solutions of this type set examples for spatial models of the longwall support section being designed currently. The analysis presented in the article, together with the results of the research and the conclusions resulting from them, may improve the safety and effectiveness of powered supports.

In the material transfer area, the belt is exposed to considerable damage, the energy of falling material is lost, and there is significant dust and noise. One of the most common causes of failure is transfer chute blockage, when the flow of material in the free fall or loading zone is disturbed by oversized rock parts or other objects, e.g., rock bolts. The failure of a single transfer point may cause the entire transport route to be excluded from work and associated with costly breakdowns. For this reason, those places require continuous monitoring and special surveillance measures. The number of methods for monitoring this type of blockage is limited. The article presents the research results on the possibility of visual monitoring of the transfer operating status on an object in an underground copper ore mine. A standard industrial RGB camera was used to obtain the video material from the transfer point area, and the recorded frames were processed by a detection algorithm based on a neural network. The CNN autoencoder was taught to reconstruct the image of regular transfer operating conditions. A data set with the recorded transfer blockage state was used for validation.

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