Coordinated Control for Driving Mode Switching of Hybrid Electric Vehicles

Yanyan Zuo,Jiuyu Zang,Mingyin Zheng,Rui Sun

doi:10.1155/2020/7325456

Abstract

Taking a hybrid electric vehicle using double-row planetary gear power coupling mechanism as a research object, this study proposes a coordinated control algorithm of “torque distribution, engine torque monitoring, and motor torque compensation” in an attempt to realize coordinated control for driving mode switching. Characteristic analysis of the power coupling mechanism was carried out, and the control strategy model in MATLAB/Simulink was built. Subsequently, the analysis of mode switching from the electric mode into joint driving mode was simulated. In addition, a multibody dynamics model of the power coupling mechanism was established and the simulation analysis during mode switching process was carried out. The results show that the proposed coordinated control strategy serves to effectively reduce the torque fluctuation and the impact degree during the mode switching process and improve the ride comfort of the vehicle. In the meantime, the time-domain and frequency-domain characteristics of gear meshing force and bearing restraint force indicate that the mode switching process of the dynamic coupling mechanism is quite stable and this control strategy contributes to improving the characteristics such as vibration and noise.

Highlights

Hybrid electric vehicles have become a research focus due to their low emissions and outstanding advantages in energy conservation, which has made them the best choice for lowering vehicle energy consumption [1]. e hybrid electric vehicle using the double-row planetary gear power coupling mechanism simplifies the structure of power train and overcomes the shortcomings of the single-row and threerow coupling systems. is configuration includes engine and motors and the hybrid electric vehicle has several working modes. e mode is frequently switched during the driving process
Wang et al proposed a motor torque compensation method based on PID strategy to control the mode switching process of a parallel hybrid electric vehicle [5]
This paper proposed a dynamic coordinated control strategy of “torque distribution + engine torque monitoring + motor

Summary

Introduction

Hybrid electric vehicles have become a research focus due to their low emissions and outstanding advantages in energy conservation, which has made them the best choice for lowering vehicle energy consumption [1]. e hybrid electric vehicle using the double-row planetary gear power coupling mechanism simplifies the structure of power train and overcomes the shortcomings of the single-row and threerow coupling systems. is configuration includes engine and motors and the hybrid electric vehicle has several working modes. e mode is frequently switched during the driving process. Since the dynamic response between the engine and motors is different, it may give rise to output torque fluctuation during the mode switching process [2]. Wang et al proposed a motor torque compensation method based on PID strategy to control the mode switching process of a parallel hybrid electric vehicle [5]. Zhao et al proposed a strategy based on engine torque estimation and motor torque compensation to control the mode switching process of a hybrid electric vehicle [6]. In the mode switching process, the response difference between power sources will cause the fluctuation of the vehicle output torque, resulting in poor ride comfort. Erefore, it is necessary to develop a control strategy to compensate the engine to improve the vehicle ride comfort during mode switching process. We carried out the simulation analysis of the dynamics model during mode switching process in order to verify the proposed control strategy

System Structure

Dynamic Coordination Control Strategy

Findings

Conclusion