Adaptive Safety Distance for Collision Avoidance Based on a Full Braking Activation Parameter

In this paper, we propose an adaptive safety distance that is adjusted along the uncertain braking duration of the object vehicle resulting in an improvement of driving comfort. In the real world, the object vehicle decelerates for uncertain duration, while the conventional strategies assume that the object vehicle decelerates until full stop. By imposing a constraint on the ego vehicle to stop simultaneously with the object vehicle, the driving comfort is enhanced by activating full braking (FB) only when it is necessary. To accomplish these, two concepts are proposed; effective collision avoidance (ECA) condition and full braking activation parameter (FBAP). ECA refers to a strategy in which the ego vehicle stops simultaneously with the object vehicle to account for its uncertain deceleration duration. FBAP is suggested to determine when to activate FB by adjusting the duration of partial braking (PB). Virtual experiments are conducted strictly with various scenarios to validate the performance of the proposed FBAP-based safety distance. The test results demonstrate that the suggested FBAP-based safety distance is applicable to a wide range of driving speeds, improving driving comfort and performing collision avoidance compared to conventional methods.