Energy reduction by power loss minimisation through wheel torque allocation in electric vehicles: a simulation-based approach
Journal article, 2021

As vehicles become increasingly electrified, electrical machines for propulsion can be divided into many sources making the vehicle highly over-actuated. For over-actuated vehicles, the allocation of a propulsive force is an underdetermined process with respect to both the number of wheels and electrical machines. Hence, the allocation can be made to favour particular attributes such as energy consumption. In this study, a vehicle equipped with four identical electric motors with a fixed transmission ratio connected through a half-shaft and a coupling to one wheel respectively is driven a 2-h-long city cycle in the vicinity of Göteborg. Two different control allocation methods are presented to distribute torque momentaneously based on driver request while minimising power losses in electric motor and inverter as well as tyres. One method is a quadratic programming optimisation and the other is an offline exhaustive search method resulting in a look-up table based on requested torque and actual speed. The two methods are compared to other torque distribution strategies based on fixed distribution ratio and equal tyre-to-road friction utilisation. It was found that using the developed optimisation algorithms, a reduction of up to 3.9% in energy consumption can be obtained.

control allocation

electric vehicles

vehicle motion control

wheel torque distribution

Energy optimisation

Author

Juliette Torinsson

Chalmers, Mechanics and Maritime Sciences, Vehicle Engineering and Autonomous Systems

Mats Jonasson

Chalmers, Mechanics and Maritime Sciences, Vehicle Engineering and Autonomous Systems

Derong Yang

Chalmers, Mechanics and Maritime Sciences, Vehicle Engineering and Autonomous Systems

Volvo Cars

Bengt J H Jacobson

Chalmers, Mechanics and Maritime Sciences, Vehicle Engineering and Autonomous Systems

Vehicle System Dynamics

0042-3114 (ISSN)

Vol. In press

Next Generation of Algorithms to Enhance and Balance Energy Efficiency and Driving Dynamics for Electric Cars

Swedish Energy Agency, 2018-10-15 -- 2023-03-14.

Subject Categories

Vehicle Engineering

Control Engineering

DOI

10.1080/00423114.2020.1858121

More information

Latest update

1/14/2021