Co-optimization of Speed and Gearshift Control for Battery Electric Vehicles Using Preview Information

TL;DR

This paper presents a hierarchical optimization method for electric vehicle control that combines speed and gearshift strategies using preview traffic information to enhance energy efficiency.

Contribution

It introduces a novel hierarchical approach to jointly optimize continuous speed control and discrete gearshift decisions for electric vehicles.

Findings

Hierarchical method improves energy efficiency in simulations.

Co-optimization outperforms traditional separate control strategies.

Approach effectively handles hybrid discrete-continuous optimization problems.

Abstract

This paper addresses the co-optimization of speed and gearshift control for battery electric vehicles using short-range traffic information. To achieve greater electric motor efficiency, a multi-speed transmission is employed, whose control involves discrete-valued gearshift signals. To overcome the computational difficulties in solving the integrated speed-and-gearshift optimal control problem that involves both continuous and discrete-valued optimization variables, we propose a hierarchical procedure to decompose the integrated hybrid problem into purely continuous and discrete sub-problems, each of which can be efficiently solved. We show, by simulations in various driving scenarios, that the co-optimization of speed and gearshift control using our proposed hierarchical procedure can achieve greater energy efficiency than other typical approaches.