Analysis and Control of Vehicle Anti-lock Braking System using Fuzzy Logic

Abstract

Antilock Braking System (ABS) prevents a vehicle from ceasing to rotate when brakes are applied. The non-linear behaviour of different road conditions makes it difficult to predict the optimal brake forces to be applied to minimize the stopping distance and maintain steerability. A quarter car model has been used and a mathematical and MATLAB/Simulink model of components of an ABS has been developed. Two Fuzzy Logic Controllers (FLC) have been used to control different parameters like optimal slip and brake pedal force on the basis of input parameters which are slip, road condition, coefficient of friction and wheel acceleration. The nature of slip curve during whole braking period with and without FLCs has been analyzed. The nature of curve involving wheel velocity and vehicle velocity, and the time to reach the stopping distance with and without FLCs have been analyzed. Fuzzy logic control mechanism resembles human brain in the sense of decision making and hence provides a better real time control over parameters in comparison to a simple bang-bang controller. Fuzzy logic controllers provide better steerability, slip control and braking distance in comparison to a simple bang-bang controller.