## 4 System Verification with Full-Vehicle Simulation
### Results and Discussions
Furthermore, as shown in Figure 17a, since the previous system decelerated rapidly at \(-8\) m/s\({}^{2}\), there was a rear-end collision risk if the following vehicle could not brake at the same level as the ego vehicle in time. On the other hand, as shown in Figure 17b, the new system decelerated more slowly at accelerations higher than \(-2\) m/s\({}^{2}\). Therefore, the new system could reduce the rear-end collision risk, since the following vehicle would not need to brake suddenly. As described in Section 2.2, this system is designed to avoid collisions with vehicles darting out at the determined virtual velocity \(V_{\mathit{vir}}\) or under. On the other hand, a study of naturalistic driving data at intersections in Japan and Germany by [PERSON] et al. shows that darting-out vehicles exceed the speed limit at a certain rate [31]. Therefore, we simulated the case of darting out at a higher velocity than the assumed virtual velocity \(V_{\mathit{vir}}\). Figure 18 shows the results of maximum deceleration with PBS and AEBS. The assumed virtual velocity \(V_{\mathit{vir}}\) was 50 km/h, and the velocity of object \(V_{obj}\) varied from 50 km to 70 km/h. The magnitude of deceleration was indicated by blue-to-white shading. In Figure 18, the dark blue cells with deceleration under \(-6\) m/s\({}^{2}\) indicate that AEBS was activated, the light  
Figure 16: Collision case and distance to the closest point of approach (DCPA) heat map. (**a**) AEBS (Black dots indicate the collision cases); (**b**) PBS and AEBS. blue cells with deceleration between \(-4\) m/s\({}^{2}\) and \(-1\) m/s\({}^{2}\) indicate mild deceleration by PBS, and the white cells between \(0\) m/s\({}^{2}\) and \(-1\) m/s\({}^{2}\) indicate that the ego vehicle escaped the intersection before coming into contact with the object. Figure 18 shows that AEBS was activated for cases where darting-out occurs at 53 km/h or higher. In addition, the number of AEBS activation cases increased as the object velocity became higher than \(V_{vir}\). On the other hand, even at velocities exceeding \(V_{vir}\), collisions were avoided in all cases by activating PBS or AEBS. These results suggest that this system has a high possibility of avoiding a collision even when a darting-out occurs at a velocity exceeding prediction. However, it was also confirmed that in some cases, the system was not able to achieve its design goal of mild deceleration without emergency braking. This is because the system predicted that there was no dilemma zone and determined that the ego vehicle could escape, but the detected velocity was higher than predicted. As a result, the ego vehicle was in a dilemma zone and it was necessary to activate the AEBS to stop in time. This result shows that it is necessary to accurately predict and set the parameters of the logical scenario such as the determined virtual velocity of the oncoming objects \(V_{vir}\) in this system. Figure 17: Time history of the ego vehicle in the simulation (\(V_{obj}\)= 50 km/h, \(D_{obj\_offset}\) = 40 m). (**a**) Previous system (PBS\({}_{t}\) and AEBS); (**b**) new system (PBS and AEBS). Figure 18: Maximum deceleration in cases of darting out at a higher-than-expected velocity.