Torque Distribution Algorithm for an Independently Driven Electric Vehicle Using a Fuzzy Control Method

Jinhyun Park,Houn Jeong,Sung-Ho Hwang,In Jang

doi:10.3390/en8088537

Jinhyun Park, Houn Jeong + Show 2 more

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https://doi.org/10.3390/en8088537

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Journal: Energies	Publication Date: Aug 12, 2015
Citations: 50	License type: CC BY 4.0

Affiliation: Sungkyunkwan University, Mando Corporation (South Korea)

Abstract

The in-wheel electric vehicle is expected to be a popular next-generation vehicle because an in-wheel system can simplify the powertrain and improve driving performance. In addition, it also has an advantage in that it maximizes driving efficiency through independent torque control considering the motor efficiency. However, there is an instability problem if only the driving torque is controlled in consideration of only the motor efficiency. In this paper, integrated torque distribution strategies are proposed to overcome these problems. The control algorithm consists of various strategies for optimizing driving efficiency, satisfying driver demands, and considering tire slip and vehicle cornering. Fuzzy logic is used to determine the appropriate timing of intervention for each distribution strategy. A performance simulator for in-wheel electric vehicles was developed by using MATLAB/Simulink and CarSim to validate the control strategies. From simulation results under complex driving conditions, the proposed algorithm was verified to improve both the driving stability and fuel economy of the in-wheel vehicle.

Highlights

Eco-friendly vehicles are in the spotlight as a major research issue because of problems such as environmental pollution, energy, and resources
The vehicle that only applied the efficiency distribution strategy had its acceleration performance reduced by 11.3% to 12.3 s, whereas the performance of the vehicle that applied the integrated distribution strategy was only reduced by 0.45% to 11.1 s
A complex driving simulation used for the evaluation of fuel economy of internal combustion engine vehicles was performed to evaluate the validity of the algorithm

Summary

Introduction

Eco-friendly vehicles are in the spotlight as a major research issue because of problems such as environmental pollution, energy, and resources. Most existing commercial electric vehicles are similar in structure to vehicles with internal combustion engines, and they generate torque on the left and right wheels using a motor and differential gear. When a vehicle is formed with such a structure, the batteries are loaded on the fuel tank or trunk, and the motor is positioned in place of the engine. Since electric vehicles require an extremely large space for batteries and additional space for the attachment of electronic components like an inverter, unlike internal combustion engine vehicles, it is difficult to secure such space with the given structure [2,3]. The in-wheel system is at an advantage in terms of space because it simplifies the driving system, and the efficiency of the power system is increased as the power transmission components, such as the transmission and differential gear, are removed.

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