## 5 Field Test Configuration and Results
### Credibility Evaluation Results
#### 5.2.1 Results of Key Parameter-Based Evaluation  
Following the parameter-based reliability evaluation methodology presented in Section 3.2, we comparatively analyzed the results of the real-vehicle (Real) and VILS (Sim) tests across the 12 key parameters listed in Table 2. All tests were repeated five times, and the graphs of the real-vehicle data (Real) and VILS data (Sim) are represented by dashed and solid lines, respectively, to ensure an intuitive comparison (Figures 7 and 8). In Scenario B, the yaw angle (\(\psi\)), lateral acceleration (\(a_{y}\)), yaw rate (\(\gamma\)), desired steering angle (\(\delta_{des}\)), and driving trajectory (\(X,\ Y\)) were analyzed (Figure 7), with the trajectory data being presented in two separate plots [31]. The first plot shows the results of the repeated real-vehicle tests conducted on the actual road, while the second (\"synchronized\") plot shows all test runs aligned to the origin (0,0) via rotation and translation. This synchronization is necessary because the VILS tests were performed in multiple areas of the PG environment. Since each area had a different initial position and orientation, the trajectory and yaw angle were both reset to (0,0). The synchronized yaw angle and trajectory \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**ParameterIndex** & \(p_{1}\) & \(p_{2}\) & \(p_{3}\) & \(p_{4}\) & \(p_{5}\) & \(p_{6}\) & \(p_{7}\) & \(p_{8}\) & \(p_{9}\) & \(p_{10}\) & \(p_{11}\) & \(p_{12}\) \\ \hline \(P_{m}(r)\) & 0.811 & 0.844 & 0.886 & 0.972 & 0.947 & 0.852 & 0.866 & 0.963 & 0.902 & 0.964 & 0.774 & 0.867 \\ \hline \(P_{m}(v)\) & 0.848 & 0.868 & 0.91 & 0.971 & 0.961 & 0.94 & 0.898 & 0.963 & 0.915 & 0.967 & 0.924 & 0.912 \\ \hline \(P_{m}(v,r)\) & 0.706 & 0.746 & 0.748 & 0.943 & 0.877 & 0.747 & 0.794 & 0.922 & 0.805 & 0.916 & 0.683 & 0.814 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Consistency indices of key parameters. Figure 6: Test field at KATRI K-City (real) and proving ground (VILS). plots for the real-vehicle and VILS tests both show a consistent S-shaped pattern; specifically, the two trajectory patterns are nearly identical, which indicates accurate coordinate synchronization. In contrast, some subtle differences are observed between the synchronized yaw graphs, which are attributed to errors during the generation of the virtual road model reflecting the actual road geometry based on the high-precision map. The lateral acceleration, yaw rate, and desired steering angle plots show minor oscillations within each test iteration, attributable to road-surface irregularities and sensor noise during real-world driving. Notably, the yaw rate peak around 30 s appears almost identical between the real-vehicle and VILS tests, which demonstrates that the VILS system accurately replicated the real vehicle's dynamic maneuvers. In Scenario C, the longitudinal acceleration (\(a_{x}\)), vehicle speed (\(V_{c}\)), desired longitudinal acceleration (\(a_{x,des}\)), relative longitudinal distance (\(RD_{x}\)), relative lateral distance (\(RD_{y}\)), and relative velocity (\(RV\)) were analyzed (Figure 8). The test was conducted from 0 to 35 s, with the subject vehicle and the target vehicle both starting from rest. The subject vehicle reached approximately 15 m/s at around 10 s. The target vehicle performed a cut-in maneuver between 12 and 15 s, causing the relative lateral distance to drop sharply from about 3 m to 0 m. In response, the autonomous driving controller of the subject vehicle issued a deceleration command of about -2.5 m/s\({}^{2}\). In the desired acceleration plot, the close match between real-vehicle and VILS results confirms that the control algorithm behaved identically in both environments.