Development of a Brake Control System for a Series Hybrid Electric City Bus Using Fuzzy Logic

In this paper, a fuzzy based controller is developed in order to control the braking action of the rear axle of a series hybrid city bus. The controller´s target is to recapture the kinetic energy of the bus as much as possible during braking, while still maintaining its stability. The bus under study is one of the Iran-Khodro Company´s productions called O457 which is currently undergoing a procedure of hybridization. The hybrid type used is a series hybrid configuration in which an internal combustion engine and a battery pack supply its electric traction motors in order to propel the bus. The implemented fuzzy controller takes the bus speed, batteries SOC level and the brake-pedal displacement as its three input variables. The developed controller is adopted to analyze the O457 energy regeneration performance on three different drive cycles, each repeated four times on three different ground grades. Simulation results show higher energy regeneration compared to the ADvanced Vehicle SimulatOR, ADVISOR results in all cases