Impact of Model Simplification on Optimal Control of Combustion Engine and Electric Vehicles Considering Control Input Constraints

This paper analyzes the impact of model simplification on optimal control for electric and conventional engine-powered vehicles. An optimal control problem is formulated to minimize energy/fuel consumption subject to control input constraints and solved analytically using the Pontryagin's Minimum Principle. We found that simplified solutions without nonlinear aerodynamic drag are sub-optimal, and their loss of optimality increases with average travel speed. The energy/fuel savings of each control approach are evaluated using the intelligent driver model to capture driving behavior of a driver. Simulation case studies are presented for illustration.