A joint fuel consumption and emission optimisation-based lane-changing trajectory planning approach for autonomous vehicles

Lane-changing is a fundamental maneuver for autonomous vehicles. This study proposes a multi-objective joint optimisation-based trajectory planning method for a single vehicle that simultaneously addresses fuel consumption and emission reduction. An optimal control model is established, with acceleration and steering angle as control variables, aiming to minimise both fuel consumption and emissions. By decomposing velocity and acceleration into longitudinal and lateral components, the nonlinear dynamic model is reconstructed into a linearised form. The continuous-time optimal control problem is subsequently transformed into a nonlinear programming problem via time discretization, facilitating numerical solution. Simulation experiments based on the Next Generation Simulation (NGSIM) dataset demonstrate that the proposed method significantly outperforms human-driven and polynomial-fitted trajectories in terms of fuel efficiency and emission reduction. Parameter sensitivity analysis indicates that longitudinal displacement is positively correlated with fuel consumption and emissions, increasing initial speed reduces both indicators, and an optimal lane-change duration exists to minimise emissions.