Trajectory Planning of Autonomous Vehicle in Freeway Driving

This paper describes trajectory planning for an Autonomous Vehicle (AV) in the freeway path. Three types of driving modes are analyzed. First was free flow, this constitutes that moving at the desired speed is determined at the beginning of the movement. Second case was car following, when overtaking or lane-change was impossible, distance or speed adaptation is executed using the variable acceleration/deceleration strategy. Third case was lane change or overtaking. For lane change or overtaking paths, the 5th degree polynomial is used to create a curvilinear path to changes its path to the left lane and then returns to its default lane. The velocity and relative distances of cars are main factors for decision making. All proper driving decisions algorithm is introduced. According to autonomous car desired velocity, in the two driving cases (fast and slow desired velocity for AV) are studied by simulation and their results analyzed and compared with together.