Adjustable Gain Enhanced Fuzzy Logic Controller for Optimal Wheel Slip Ratio Tracking in Hard Braking Control System

Abstract

This paper has presented hard braking control system based on Adjustable Gain Enhanced Fuzzy Logic Controller (AGE-FLC) for optimal wheel slip ratio tracking performance. The purpose of the study was to improve slip ratio tracking and eliminate cycling while achieving very much shortened distance during emergency braking. The model of a braking vehicle at speed of 30 m.s^-1 subject to wheel locking was developed and implemented in MATLAB/Simulink environment. Simulation was conducted without a controller to study the slip ratio performance of the system on different road surfaces. The simulation results showed that stopping distance was 135.2 m in 5 seconds. A Fuzzy Logic Controller (FLC) whose control signal was enhanced by adding an adjustable gain mechanism to its output was designed. Simulation results showed that the AGE-FLC controller offered optimal tracking of desired wheel slip ratio of 0.1 as fast as possible on all road surface scenarios, while improving the stopping distance by 70.4% on dry road surface, 63.3% on wet road surface, 57.5% on cobblestone road surface and 48.8% on snow road surface in 2.651seconds.