Distance-Based Ecological Driving Scheme Using a Two-Stage Hierarchy for Long-Term Optimization and Short-Term Adaptation

This paper proposes a distance-based ecological (eco)-driving scheme with two stages: one for long-term speed optimization and the other for short-term adaptation to actual traffic conditions. Before departure, the speed profile for an entire route is optimized in a distance domain by using characteristics of the drivetrain and road conditions. Then, while driving, the speed at only the next location is controlled to follow the optimal speed profile and adapt it for traffic conditions, which allows for real-time adaptation, maintaining optimal driving in the long term. To localize the change of the optimal speed profile due to traffic conditions, models for fuel rate of a conventional vehicle and vehicle propulsion systems were formulated in a distance domain, and a distance-based optimal speed profile was generated. The proposed eco-driving scheme is optimized by the quadratic programming method, and its validity is tested by simulation.