Vehicle collision avoidance system (CAS) is a control system that can guide the vehicle into a collision-free safe region in the presence of other objects on road. Common CAS functions, such as forward collision warning and automatic emergency braking, have recently been developed and equipped on production vehicles. However, these CASs focus on mitigating or avoiding potential crashes with the preceding cars and objects. They are not effective fo1β’ crash scenalios with vehicles from the rear-end 01β’ lateral directions. This paper proposes a novel collision avoidance system that will provide the vehicle with all around (360-degree) collision avoidance capability. A lisk evaluation model is developed to calculate potential lisk levels by considering sunounding vehicles (according to their relative positions, velocities, and accelerations) and using a predictive occupancy map (POM). By using the POM, the safest path with the minimum lisk values is chosen from 12 acceleration based trajecto1β’y directions. The global optimal trajectory is then planned using the optimal rapidly explo1β’ing random tree (RRT*) algolithm. The planned vehicle motion profile is generated as the reference for future control. Simulation results show that the developed POM-based CAS demonstrates effective operations to mitigate the potential crashes in both lateral and rear-end crash scenalios.
I. IN1RODUCTIONAutonomous vehicles (AVs) have become a popular research area in both the automotive industty and academia with the objective of minimizing risks and enhancing safety and comfort. Based on the National Highway Traffic Safety Administtβ’ation (NHTSA), smashing into the rear of the car ahead is the top cause of vehicle accidents, contt-ibuting up around 30% of all ttβ’affic accidents annually [I]. Collision avoidance system (CAS) is one of vehicle active safety technologies for dealing with both lane-departure and fo1ward-collision problems, which has been designed and implemented on some production vehicles. D. Sam [2] concluded that most road accidents occured due to human error, and over 90% of those accidents were caused by visual information acquisition problems. However, most of the currently developed CASs were designed to mitigate crashes based on the e1rnrs caused by the ego vehicle (e.g., driver disttβ’action and drowsiness [3]) and static objects on road, such as lane markings, road edges, and parked