# Evaluation of the Acceleration Vibration Signal for Aggregates of the Horizontal Drilling Stand
## 6 Conclusions  
Rotary rock disintegration is one of the basic and specific processes of geological and mining activities. Therefore, its research provides useful information that can be used in industrial practice, especially concerning efficiency, economy, and environmental performance in the context of optimization.  
Equipment-generated vibrations have adverse effects on the drilling process, the drilling stand as a whole, and the individual aggregates.  
Nevertheless, their measurement, monitoring, identification, and classification carry essential information about the disintegrating process. Measurements were performed at several selected operating modes.  
This paper proposed methods for processing the vibration signal of acceleration that is generated during the operation of a laboratory horizontal drilling rig.  
Because drilling and rig operation is random and non-linear, their research can be based on time-based statistical methods. In the time domain, significant results were achieved in the statistical characteristics, time waveform, and autocorrelation functions of the vibration signals of the respective modes.  
In the frequency domain, research focused on the use of fast Fourier transform and the construction of signal amplitude and power spectra. As a result, dominant frequency components and bands have been identified.  
The time-frequency domain showed the dynamic properties of individual aggregates and the whole process.  
Based on the knowledge gained from the implementation of processing methods, it can be stated that the measured vibrational signals are deterministic, non-harmonic, and quasi-periodic, with a strong stochastic component and broad-spectrum.  
A more rigorous evaluation of the vibration signal is very complicated because there is a superposition of several signal sources in the area of aggregates but also in the interaction of the drilling tool with the rock. Nevertheless, the presented research results show sufficient differences in autocorrelation functions, spectra, and spectrograms.  
It is also possible to say that signal processing methods have been applied appropriately because the application of the process modeling principle is still unrealistic.  
In addition to processing measured vibration signals, this paper also focused on determining the largest source of vibrations on the drilling stand. This source is the motor itself or in combination with other aggregates.  
Due to the complexity of the horizontal laboratory drilling rig, further research will be needed in the field of signal processing and measurement methods, optimization, and modernization with subsequent reconstruction and innovation of the drilling stand. Therefore, the paper has a highly experimental character with an emphasis on applied research.  
Conceptualization, P.F. and J.K.; Data curation, P.F.; Formal analysis, P.F. and J.K.; Methodology, P.F. and M.D.; Project administration, J.K.; Resources, M.D. and M.L.; Supervision, M.D. and M.L.; Validation, J.K.; Writing--Original draft preparation, P.F. and J.K.; Writing--review and editing M.D. and M.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Slovak Research and Development Agency under contract Nos. APVV-18-0526, APVV-14-0892, and APVV-21-0027. The APC was funded by APVV-18-0526.  
Not applicable.  
No new data were created or analyzed in this study. Data sharing is not applicable to this article.  
This work was supported by the Slovak Grant Agency for Science under grant VEGA 1/0289/22, and by the Slovak Research and Development Agency under contracts No. APVV-14-0892, APVV-18-0526, and APVV-21-0027.  
The authors declare no conflict of interest.