Automatic Lane change system is one of the crucial steps in improving autonomous transportation and the performance of this system especially in the collision avoidance is the important factor in improving the safety of autonomous vehicles. The main problem which has been discussed in this study is the development of trajectory planning algorithms of an automatic lane change based on mathematics functions. Also, Movement of a host vehicle was abstracted into time functions. This algorithm has been developed for two different scenarios: 1- without consideration of other vehicles on the road, 2- without consideration of a vehicle in front of the host vehicle. For the first scenario, the quintic function is used for both x and y trajectory planning. Also, the trajectory planning equation could be solved by using the dynamic constraint of the vehicle on the road. For the second one, a quantic function is used for y trajectory planning and the sextic function is used for x trajectory planning. As the equation of the second scenario is undetermined, the collision avoidance algorithm is used for solving trajectory planning equations. The results illustrate that the algorithm is capable to generate the trajectory without any collision.
Keywords: Autonomous vehicles, Trajectory planning, collision avoidance algorithm, automatic lane change system