# A Study on Highway Driving Assist Evaluation Method Using the Theoretical Formula and Dual Cameras
## 5 Conclusions  
In this paper, to verify the evaluation method of the HDA function using the theoretical formula and dual cameras, a formula capable of calculating the distance to the lead vehicle was proposed. The HDA scenario and dual camera installation location proposed in the preceding study were used. In addition, the HDA scenario-based test was conducted on the actual highway. Thus, the results of inter-vehicle distance using the theoretical formula and the results of the inter-vehicle distance using measuring instruments were compared and analyzed, and the results of the distance from the lane using dual cameras and the results of the distance from the lane using measuring instruments were compared and analyzed. The conclusions were drawn accordingly, and the conclusions are summarized as follows. 1. The formula proposed a new theoretical formula applicable to the safety evaluation of HDA. The proposed formula is a longitudinal theoretical formula capable of calculating the inter-vehicle distance, and a lateral theoretical formula capable of calculating the distance to the lane using a dual camera; the formula from previous studies was cited. 2. The actual vehicle test was conducted on the Dongdaeugt TG-Gyeongsan TG section on the Gyeongbu Expressway of the Republic of Korea. To secure the objectivity of the test results, repeated tests were conducted three times with the same number of people, and same equipment and location (site). GENESIS G90 of company H** was used for the subject vehicle. 3. The HDA test and evaluation scenarios were selected according to the characteristics of each section of the highway and the results were analyzed. The analysis compared and evaluated the proposed longitudinal theoretical formula, the cited lateral theoretical formula, and the measured values of the measurement equipment by the actual vehicle test conducted on the highway. 4. The test results of the scenario were compared. As a result of the analysis of the lead vehicle and the relative distance by scenario, most of the maximum errors were within 10%, and the average error rate was within 5%. In the second and third test cases of scenario 7, the maximum error rate between 10% and 12% occurred momentarily. As  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Scenario**} & \multirow{2}{*}{**Case**} & \multicolumn{3}{c}{**Result (Error Factor) (\%)**} & \multirow{2}{*}{**Scenario**} & \multirow{2}{*}{**Case**} & \multicolumn{3}{c}{**Result (Error Factor) (\%)**} \\ \cline{3-3} \cline{5-8}  & & **Minimum** & & & & **Maximum** & **Average** \\ \hline \multirow{3}{*}{1} & 1 & 0.053 & 9.970 & 4.250 & & 1 & 0.046 & 9.930 & 3.870 \\  & 2 & 0.013 & 9  
a result of the analysis of the distance from the lane by scenario, the maximum errors were within 10%, and the average error rate was within 6%. 5. Compared with the precision measuring instrument through actual difference testing, the proposed theoretical formula showed that the longitudinal error rate was at least 0.005% and the maximum was 9.798%, and the lateral error rate was at least 0.007% and the maximum was 9.997%. Using the proposed theoretical formula, safety trends can be identified before development when studying an HDA system and reliability can be predicted in an environment where the actual test of the system is impossible. Currently, HDA applied to mass-produced vehicles is implemented based on sensors such as radar and cameras. Due to expensive sensors such as radars and riders, there is a disadvantage of the high cost burden. However, based on the above results, it was judged that the proposed theoretical formula and dual camera alone could derive the results of the HDA test. In the development stage of ADAS such as HDA, it is judged that only theoretical formula and dual cameras might reduce the cost burden due to the derivation of test results. In the future, it is necessary to evaluate the safety in bad weather conditions and night conditions.