## 3 Results
### Results Obtained through Statistical Analysis  
The repeatability of measurements refers to the consistency and stability of results obtained when a measurement is repeated under the same conditions. Noise caused by vibrations from external sources, from the electric motor drive, or deviations due to temperature is extremely important [40]. Evaluating repeatability is essential to ensure that a measurement instrument or process produces reliable and consistent results. A total of 36 sets of penetration force measurements were conducted for each variety of cheese, cone geometry (the tip angle), and speed of the cone's movement. The repeatability of the measurements was assessed by testing significant differences between categories (groups) using a \(t\)-test, two-variable analysis of variance (ANOVA), and the ANCOVA method (analysis of covariance). The determination shows whether the average penetration force depends on the cone geometry or the cone movement speed. The average penetration force value for Brie cheese was 1.0520 N, for Camembert cheese it was 1.0434 N, for Dorblue cheese it was 1.1471, and for Roquefort cheese, it was 0.6029 N.  
The box plot charts presented In Figure 8 are used to Identify outliers, the symmetry of the distribution, and the variation in the data, each representing the average penetration force grouped by cone geometry, based on the hypothesis of three force size classes 1.5 N; 2.5 N; 3.5 N.  
Figure 7: Experimental Results for 19-Degree Cone Penetration Tests: (**a**) the average force obtained from the speed of 12 mm/min; (**b**) the average force obtained from the speed of 30 mm/min; (**c**) the average force obtained from the speed of 60 mm/min. The plot in Figure 8a shows the data groups with cone geometries of 9 and 19 degrees (with the acronyms of cone_09_deg and cone_19_deg). The penetration force for the cone_19_degree group is significantly higher than for the cone_09_deg group. The box for cone_19_deg (median value of force around 1.75 N) is positioned much higher than the box for cone_09_deg (the force median value is around 3.1 N), indicating a significant difference in penetration force. The plot in Figure 8b shows the data groups with cone geometries of 9 (cone_09_deg) and 90 (with the acronym of cone_90_deg) degrees. In this case, although the  
Figure 8: Box plot charts of variance analysis ANOVA: (**a**) comparison of data distributions across groups cone of 9 and 19 degrees; (**b**) comparison of data distributions across groups cone of 9 and 90 degrees; (**c**) comparison of data distributions across groups cone of 19 and 90 degrees. difference is not as large as the one observed in the plot in Figure 8a, there is still a notable difference (median of approximately 1.75 N for the cone_09_deg group compared to the median of approximately 2.6 N for the cone_90_deg group). In Figure 8c, it can be observed that the penetration force for con_90_deg is significantly higher than for cone_19_deg. All three plots suggest that there are significant differences in penetration force between the different cone geometries. This visual analysis provides a clear understanding of how cone geometry affects penetration force, suggesting that cones with larger angles require more force for penetration. To perform the multi-factor ANOVA statistical test, we used the built-in Matlab function 'anovan'. Table 3 presents the results of the two-way ANOVA analysis. The probability value (p) for testing the equality of means as an effect of the 'GeometryCONE' variable (cone tip angle) is 0, so the null hypothesis is rejected at a significance level of 0.05. The \(p\)-value for testing the equality of effects of the 'Speed' variable (movement speed) is 0.1188, so this null hypothesis is also rejected. The Analysis of Covariance (ANCOVA) is a statistical technique that combines elements from the ANOVA model and the regression model.