## 3 Experimental Results and Discussion
The values for \(s\)-control diagram are CL = 0.065,  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & & & & & & \\ \hline  
Figure 14: Control charts for technological parameter vibration signal of acceleration (**a**) diagram of variation range, (**b**) diagram of arithmetic mean, (**c**) diagram of standard deviation, (**d**) diagram of the median. UCL = 0.136, LCL = 0 (see Figure 14c) and for \(\overline{\overline{x}}\)-control chart are CL = 0.038, UCL = 0.075, LCL = 0.151 (see Figure 14d). The technological parameter vibration signal shows strong variability, from which it was concluded that the process is not statistically controlled and is influenced by non-random causes. The value of the center line and the control limits of the moving range for the vibration signal of acceleration are CL = 0.163, UCL = 0.343, LCL = 0 (see Figure 15a), for individual values are CL = \(-\)0.028, UCL = 0.181, LCL = \(-\)0.236 (see Figure 15b) and for moving averages are CL = \(-\)0.028, UCL = 0.066, and LCL = \(-\)0.122 (see Figure 15c). The values of the vibration acceleration signal that exceeded the control limits are shown in Table 11.  
It is clear from the control charts that most of the calculated points lie within the control limits. However, the samples show a rapidly decreasing and increasing time trend. Variability is not under statistical control. It can be stated that the technological parameter vibration signal of drilling acceleration is not in a statistically controlled (stable) state. It is obvious that the input and output technological parameters of the drilling process are not in a statistically stable state. It should be noted that the course of control charts shows strong periodic dependence and time trends. There are several reasons why the drilling process is not in a statistically mastered state for technological parameters. One possible reason is that the operator at the control computer responded late at the experiment's beginning. The second cause may be the rocks' geomechanical properties (i.e., the sudden formation of cracks and fissures during the drilling process). A third possible cause may be \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & \multicolumn{6}{c}{**Vibration-Acceleration**} \\ \hline
**Process Quality Criteria** & \(R\) & \(\overline{x}\) & \(s\) & \(\overline{x}\) & \(R_{MR}\) & \(\overline{X}\) & \(\overline{X}_{MA}\) \\ \hline CL & 0.161 & \(-\)0.033 & 0.065 & \(-\)0.038 & 0.163 & \(-\)0.028 & \(-\)0.028 \\ UCL & 0.342 & 0.0694 & 0.136 & \(-\)0.151 & 0.343 & 0.181 & 0.066 \\ LCL & 0 & \(-\)0.126 & 0 & 0.75 & 0 & \(-\)0.236 & \(-\)0.122 \\ \hline  & \(\succ\)UCL & \(\succ\)UCL & \(\succ\)UCL & \(\succ\)UCL & \(\succ\)UCL & \(\succ\)UCL \\ Violation & 27 (0.44) & & 27 (0.165) & 107–108 (0.365) & 107 (\(-\)0.361) & 107 (\(-\)0.135) \\  & & & & 109–111 (0.423) & & 108 –0.110 (0.422) & & 108 (\(-\)0.133) \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Values of the center line and control limits for the vibration signal acceleration. Figure 15: Control charts for technological parameter vibration signal of acceleration (**a**) diagram of moving range, (**b**) diagram of individual values, (**c**) diagram of moving averages. that the drilling process is very dynamic, and several parts of the drilling rig are underwater; others are exposed to heavy dust. Other reasons are unknown and are the subject of the following research. A prerequisite for bringing the drilling process under control is the identification of identifiable causes in the process and the implementation of corrective measures. However, due to the nature of the experiments and the wear of the drilling rig at the time of drilling, the course is sufficient to ensure the measurement of the monitored control variables. Industrial practice values the control charts because of their preventive nature. They help prevent unnecessary adjustment of equipment, production lines if the technological process is stable.