Planning flexible and smooth paths for lane‐changing manoeuvres of autonomous vehicles

Lane‐changing manoeuvres are essential for daily driving tasks. Safety and comfort are the primary issues to be considered during the lane‐changing manoeuvres of autonomous vehicles. However, because the traffic environment is complicated and changeable, executing fixed lane‐changing manoeuvres cannot guarantee safety and comfort. Thus, it is important to find a flexible method that can plan and re‐plan a lane‐changing path according to the traffic environment in real time. But that remains smooth to ensure the vehicle occupants stay comfortable. Therefore, this paper proposes a method for planning a flexible and smooth lane‐changing path in real time. The proposed method uses the bi‐elementary paths to ensure comfort, and clothoid and arc curves are superimposed on the bi‐elementary paths to add re‐planning flexibility. Additionally, lookup tables and reasonable approximations are employed to quickly generate and evaluate lane‐changing paths. The results of the simulations demonstrate that the proposed method is able to plan and re‐plan a smooth lane‐changing path. Then, the results of vehicle experiments performed based on the embedded controller platform show that the proposed method guarantees real‐time performance, that the planned path is easy to follow, and that the planned paths make autonomous vehicle lane‐changing manoeuvres safe and comfortable.