Lane change algorithm using rule-based control method based on look-ahead concept for the scenario when emergency vehicle approaching

When an emergency vehicle approaches form behind, the driver must change his/her lane to the left lane and pull over to gave way to the emergency vehicle. However, in most cases the abrupt lane change maneuver of the vehicles in front of the emergency vehicle will cause a traffic congestion, and the emergency vehicles must decelerate as a result. To avoid the above situation, we designed a lane change algorithm based on a look-ahead concept for the vehicle driving in front of the emergency vehicle (defined as the ego vehicle). To reduce calculation load, a rule-based control method is adopted to control the longitudinal motion and a cosine function is adopted to control the lateral motion of the ego vehicle. This lane change algorithm allows the ego vehicle to choose a gap in the left lane or the right lane to merge to as soon as possible, and to change its lane safely without affecting the surrounding vehicles. The objective of the control method is to let the emergency vehicle pass smoothly without deceleration in congested traffic condition. A computer simulation was conducted to validate the effectiveness of the proposed method. The simulation results for 1000 initial conditions show that, for 720 initial conditions the proposed method manages to merge the ego vehicle effectively without collision, and the emergency vehicle does not need to slow down. Compared with a lane change control method without look-ahead concept, the proposed method increases the number of successful lane change maneuver by 555 cases.