Fuel and Pollutant Efficient Vehicle Speed Optimization in Real Driving Conditions

Abstract

This paper analyzes the potential benefits in terms of fuel consumption and NOx emissions of an optimized speed trajectory in a real driving situation. The speed management of the vehicle is approached as an optimal control problem, based on a simplified vehicle model supported by experimental measurements. This optimal control problem is addressed twice on a daily commuting route: one for minimum fuel consumption and another for minimum NOx emissions. These speed trajectories are followed in a vehicle test bench, simulating the actual road conditions, with a fully instrumented vehicle. The experimental results are compared to the way two different drivers perform the same route in the same amount of time with their own natural driving styles. Optimal results demonstrate that optimal speed trajectory is strongly dependent on the minimization objective (either fuel or NOx), and that reductions around 4% in fuel consumption and 35% in NOx emissions were possible in the testing route compared to intuitive human driving styles.