01660522

Component

The importance of eco-driving in reducing cumulative fuel consumption of road vehicles is a well-known and widely treated subject. Eco-driving intends to minimize fuel consumption by maneuvering a vehicle with a human or automated driver. In this work, the problem is cast in an optimal control framework with fixed time horizon. State equations reflect the simple vehicle kinematic equations for position and speed, with the acceleration acting as a control input. Initial and final states (position and speed) are fixed. For the fuel consumption estimation, a number of alternatives are employed. To start with, a realistic, but nonlinear and non-smooth formula from the literature is considered. Simple smoothing procedures are then applied, so as to enable the application of powerful numerical algorithms for the efficient solution of the resulting nonlinear optimal control problem. Furthermore, suitable quadratic approximations of the nonlinear formula are also considered, which enable analytical problem solutions. A comprehensive comparison on the basis of various driving scenarios demonstrates the features of each alternative approach. In particular, it is demonstrated that the often utilized, but sometimes strongly questioned, square-of-acceleration term delivers excellent approximations for fuel-minimizing trajectories in the present setting.

This paper was sponsored by TRB committee ADC20 Standing Committee on Transportation and Air Quality.

18-03953

English

19p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Acceleration (Mechanics); Algorithms; Ecodriving; Fuel consumption; Optimization; Vehicle trajectories

Energy; Highways; Planning and Forecasting; Vehicles and Equipment

Transportation Research Board Annual Meeting 2018 Paper #18-03953

TRIS, TRB, ATRI

Jan 8 2018 10:59AM