Collision-avoidance lane change control method for enhancing safety for connected vehicle platoon in mixed traffic environment

In a mixed traffic environment, the connected vehicle platoon cannot communicate and collaborate with the surrounding vehicles. In this case, there is a high risk of collision in large vehicle platoon's lane change scenario where the non-connected surrounding vehicle occupies the target lane-changing space of the platoon. This study proposes a collision-avoidance lane change control method for a connected bus platoon to elude the non -connected vehicle in the target lane for completing lane change in the mixed traffic environment safely. A platoon vehicle sensor system with low-cost and low data processing complexity is designed, which equips with multiple sensors in longitudinal and lateral directions. Under control of the proposed platoon controller on the basis of vehicle-to-vehicle (V2V) communication, the platoon following vehicles are fully autonomous in both longitudinal and lateral directions. The safe lane change decision-maker is designed based on the Finite State Machine (FSM). The decision-maker fuses multiple sensor data and determines the lane change operation of the following vehicles. To verify the effectiveness of the proposed method, a three-vehicle platoon is carried out the lane change experiments in a high-fidelity mixed traffic scenario built by the PreScan-Simulink joint simulation platform. Exposure-to-Risk Index (ERI) of the platoon vehicles is adopted to evaluate the collision risk of the platoon during lane changing process. Three typical case scenarios are tested, including unimpeded lane change, passive waiting lane change, and active accelerating lane change. The simulation results show that all platoon vehicles have an excellent success rate in lane change without collision with the non-connected surrounding vehicle in these scenarios. The proposed method exhibits compelling benefits on improving the safety of platoon vehicles in the mixed traffic environment.