# Development of a Coordinate Measuring Machine--Based Inspection Planning System for Industry 4.0
## 6 Simulation of Measuring Path
### Results of Comparison  
The experiment was performed by simulating three types of measurements. The first measurement simulation was performed in PTC Creo software, the second in STEP-NC Machine software and the third measurement in MatLab software according to the ACO model, presented in Section 5.2. The results of the comparison according to the criterion of the minimum path of the measuring sensor, for individual GFs, are given in Table 2. In this case, as mentioned earlier, the required variables are marked as: \(\mathrm{D_{C}}\) is the measuring path length obtained by PTC Creo; \(\mathrm{D_{S}}\) is the measuring path length obtained by STEP-NC Machine; \(\mathrm{D_{O}}\) is the optimized measuring path length obtained with ACO simulated in MatLab software; \(\mathrm{I_{C}}\) is percentage of saving of the measuring path length \(\mathrm{D_{O}}\) in relation to \(\mathrm{D_{C}}\); \(\mathrm{I_{S}}\) is percentage of saving of the measuring path length \(\mathrm{D_{O}}\) in relation to \(\mathrm{D_{S}}\).  
A realistic comparison is assured by the basic postulate that the measuring process is the same in all three cases (methods), which can be adjusted so that the parameters have the same value in all three methods. The influence of the start and end points is minimised using such a setting that the parameters of measuring process are the same in all three methods.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Name of Path/Impact**} & \multicolumn{5}{c}{**Feature**} \\ \cline{3-6}  & & **Plane** & **Transcated Hemisphere** & **Circ** & **Cylinder** & **Transcated Cone** \\ \hline
1 & PTC Creo (\(\mathrm{D_{C}}\)) [mm] & 202.6522 & 183.6755 & 126.4420 & 228.9870 & 440.1400 \\
2 & STEP-NC (\(\mathrm{D_{S}}\)) [mm] & 172.4683 & 165.2395 & 116.2687 & 195.8100 & 362.5900 \\
3 & Optimized by ACO (\(\mathrm{D_{O}}\)) [mm] & 159.4604 & 159.0962 & 110.2460 & 172.2140 & 307.6090 \\
4 & \(\mathrm{I_{C}}=100-(\mathrm{D_{O}}/\mathrm{D_{C}}\) [\%]) & 21.31 & 13.38 & 12.81 & 24.79 & 30.11 \\
5 & \(\mathrm{I_{S}}=100-(\mathrm{D_{O}}/\mathrm{D_{S}}\) [\%]) & 7.54 & 3.71 & 5.17 & 12.05 & 15.16 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Results of comparison of the three measuring paths for basic GFs.  
The length of the software measuring paths length \(\rm D_{C}\) and \(\rm D_{S}\) are taken from the corresponding CL or DMIS file generated by PTC Creo and STEP-NC Machine, while the optimized path length \(\rm D_{O}\) is the shortest path obtained with the ACO--based model. The software path is obtained by analysing the CL file that shows points used for construction of the measuring path.  
Table 2 shows the values of measuring path lengths (\(\rm D_{C}\), \(\rm D_{S}\) and \(\rm D_{O}\)) obtained with three simulation methods, as well as the results of comparison. For the observed GFs, the impact \(\rm I_{C}=100\,-\,(\rm D_{O}/\rm D_{C}\) [%]) are in the interval 30.11-12.81%, which presents reduction (save) of the measuring path obtained with ACO by at least 12.81%. The impact \(\rm I_{S}=100\,-\,(\rm D_{O}/\rm D_{S}\) [%]) are in the interval 15.16-3.71%, which presents reduction (save) of the measuring path obtained with ACO by at least 3.71%. In accordance with MPE, the results of comparisons were rounded to 2 \(\rm\mu m\).