An Improved GA-Based Method for Generating Critical Collision Scenarios of AEB on Longitudinal Slope

To accelerate the testing of the function boundary of AEB control strategy on a longitudinal slope, this paper proposed an improved GA-based method for generating critical collision scenarios of AEB on the longitudinal slope. The range constraint of AEB scenario parameters, the longitudinal dynamic constraint of slope and the emergency braking demand constraint of longitudinal slope were analyzed. Furthermore, by examining the collision conditions of AEB when the front vehicle is in three states (parking or maintaining a constant speed, accelerating and decelerating), an objective function for AEB critical collision scenarios with a slope was designed based on the satisfaction criterion model. The reasonable range of each parameter was determined by assessing the degree of constraint between AEB scenario parameters. An iterative operator was then designed to satisfy the constraints of the scene parameters and eliminate invalid scenarios. The results demonstrate that, under identical conditions, the proposed method and the improved GA method with penalty term generated effective scenarios in an average time of 0.45 s and 0.91 s, respectively. This indicates that the proposed method has nearly doubled the generation efficiency. By analyzing the critical collision scenario areas at coverage ratio of 50%, 80% and 100%, it was observed that the scenario area density increased with higher coverage ratio. The critical collision scene domain of the leading vehicle exhibited a distinct boundary under different conditions, with the influence of various longitudinal slopes on the critical collision scenario domain being significant. When employing the AEB function with fixed and adaptive time-to-collision strategies, the AEB systems were activated. In some critical scenarios, the former system resulted in a collision while the latter system successfully avoided a collision. This effectively tests the functional boundary of the AEB control strategy.