# Simulation of AEBS Applicability by Changing Radar Detection Angle
## 3 Results and Discussion  
Figures 10-12 show the simulation method of PC-Crash for the three AEBS scenarios (City, Inter-Urban, VRU-Pe). For reference, a test vehicle is located on the left side of the picture, while a target vehicle and target pedestrian pile are located on the right. In this study, 71 scenarios were created by increasing the speed of the test vehicle in 5 km/h increments according to the Euro NCAP AEBS test standards [12; 13]. A total of 284 total scenarios were constructed by changing to 4 km/h increments, meaning that the number 284 came about by multiplying 71 times 4. However, not all of them can be shown here. Only the three AEBS scenarios (City, Inter-Urban, VRU-Pe) are shown. Tables 2-4 show the simulation results.  
First, Table 2 shows the simulation results of the AEBS City Scenario by increasing the speed of the test vehicle from 10 km/h to 50 km/h in 5 km/h increments. Here, the \(\Circle\) mark indicates that the test vehicle has stopped without colliding with the stationary target vehicle and thus has avoided collision, regardless of the radar angle and the speed of the test vehicle.  
Table 3 shows the AEBS Inter-Urban scenario simulation results, and the notation of N/A (Not Applicable) means that it is irrelevant to the scenario. Most of the simulations for the three scenarios (CCRs, CCRm, and CCRb) were avoided, but in the case of CCRb, a collision occurred when the distance between the test vehicle and the target vehicle was 12 m and the deceleration of the target vehicle was 6 m/s\({}^{2}\). Table 3 also lists the test vehicle's speed at the time of the crash. All four cases showed the collision speed of the test vehicle at 14 km/h when colliding with the target vehicle regardless of the radar angle but, considering the initial speed of the test vehicle (50 km/h), the speed was reduced by 72%. Therefore, it can be estimated that the shock has been alleviated.  
Table 4 shows the pedestrian collision scenario (AEBS VRU-Pe) results and the different results, depending on the radar angle. In the CVFA scenario, the radar angles of 4\({}^{\circ}\) and 6\({}^{\circ}\) did not avoid pedestrian collision. In the simulation result for the CVNA 25% scenario, the notation X is indicated when the radar angle is 4\({}^{\circ}\), which signifies that the test vehicle collided with the pedestrian, and the collision speed of the test vehicle was the same as the initial speed, indicating that the pedestrian was not recognized. Simulation results for the CVNA 75% scenario show that pedestrian collisions do not occur in all cases.  
On the other hand, simulation for the CVNC scenario showed that a pedestrian collision occurs when the initial speed of the test vehicle is 50 km/h or less when the radar angle is 4\({}^{\circ}\). Based on the simulation results, it was checked whether the traffic accident could have been prevented if the AEBS was applied at the time using the actual traffic accident database (ACCC).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Speed (Km/h)** & **4** & **6** & **8** & **10** \\ \hline
10 & \(\Circle\) & \(\Circle\) & \(\Circle\) & \(\Circle\) \\
15 & \(\Circle\) & \(\Circle\) & \(\Circle\) & \(\Circle\) \\
20 & \(\Circle\) & \(\Circle\) & \(\Circle\) & \(\Circle\) \\
25 & \(\Circle\) & \(\Circle\) &