CONTROL STRATEGY FOR AN ELECTROMECHANICALTRANSMISSION VEHICLE BASED ON A DOUBLE MARKOV PROCESS

Liu, Hui; Xu, Riming; Han, Lijin; Xiong, Shanshan

doi:2021.22.3.761

International Journal of Automotive Technology > Volume 22(3); 2021 > Article

Chassis, Electric, Fuel Cell, and Hybrid Vehicle, Transmission and Driveline, Vehicle Dynamics and Control

International Journal of Automotive Technology 2021;22(3): 761-770.
doi: https://doi.org/10.1007/s12239-021-0069-4

CONTROL STRATEGY FOR AN ELECTROMECHANICALTRANSMISSION VEHICLE BASED ON A DOUBLE MARKOV PROCESS

Hui Liu^1,2, Riming Xu¹, Lijin Han^1,2, Shanshan Xiong¹

¹Beijing Institute of Technology
²National Key Laboratory of Vehicle Transmission

Corresponding Author. Lijin Han , Email. lj_han@bit.edu.cn

ABSTRACT

Based on an analysis of the driving demand and system dynamics of heavy-duty vehicles equipped with electromechanical transmission (EMT), a double Markov model is put forward to represent drivers’ power demand for driving and electricity. Transfer probability matrices are calculated by utilizing the maximum likelihood estimation method. A power distribution control strategy based on stochastic dynamic programming (SDP) is proposed. With economy being the optimization goal, the model for power allocation control based on SDP is established while regarding the engine torque, motor speeds, vehicle speed and state of charge (SOC) as state variables’ engine speed and motor torques as control variables’ and power demands as interference variables. The SDP problem is solved by an improved policy iteration algorithm based on value iteration and policy iteration algorithms.

Key Words: Electro-mechanical transmission, Control strategy, Stochastic dynamic programming, Double Markov model