PRESENTATIONON

ANTI LOCK BRAKING SYSTEM USING FUZZY LOGIC

By

S.Akarsh(13stuhhec0073 ) Dheeraj Yadav(13stuhhec0077 )Srivastav Reddy(13stuhhme0105)

INTRODUCTION OF ABS SYSTEM Anti-lock braking system (ABS) is an automobile safety System that allows the wheels on a motor vehicle to maintain tractive contact with the road surface according to driver inputs while braking , preventing the wheels from locking up (ceasing rotation) and avoiding uncontrolled skidding

ABS generally offers improved vehicle control and decreases stopping distances on dry and slippery surfaces; however, on loose gravel or snow-covered surfaces, ABS can significantly increase braking distance, although still improving vehicle control

WORKING OF ABS SYSTEMABS CONSIST OF

Wheel speed sensors

Hydraulic Modulator unit

Electronic control unitBraking Device

FUZZY LOGIC Fuzzy logic is a form of many-valued logic in which the truth

values of variables may be any real number between 0 and 1. By contrast, in Boolean logic , the truth values of variables may only be 0 or 1. Fuzzy logic has been extended to handle the concept of partial truth, where the truth value may range between completely true and completely false.

For Intelligent control systems like fuzzy control can be used in ABS control to emulate the qualitative aspects of human knowledge by rule-based algorithms

Mathematical Modeling Vehicle Modeling

Wheel dynamics Model

Jw = ( 𝜇 * Fn *r ) - Tb 1

𝜆 = ( V – rw ) / v

𝜆 = [ V ( 1-

𝜆 ) - r w ] / V 2

rb = Ff

J s w(s) =[ Fn r ] – Tb(s)𝜇 T.F

𝜆(s) { s + ( 𝜇Fn/mv ) } = (𝜇Fn/mv ) – ( r s w(s) / v)

T.F

Slip ratio

V= 𝜇Fn/m

Brake Model

Tb = 𝜆d * rb * Fb 3

Tire Model

Tf = Ff * r Ff = Fn * 𝜆t Fn = Mg 𝜆 ( tire) = F(𝜆)

Tb(s) = 𝜆d * rb * Fb(s) T.F

Fb(s) rb 𝜆d + Js w(S) = Tf

Tb – Torque by brakeFb- Brake Force 𝜇d - 𝜆 for disc rb – disc radius

W= angular velocity𝜆t = 𝜆 = friction coefficient b/w tire & road Fn = Normal Force

W(s) = [ Fn 𝜆 r - 𝜆d rd Fb(s)] / Js

Block Diagram

1/ { s + Fn/mv }𝜇

+-

1/ Js 1/ r 𝜇 rb 𝜇d +-

Tf =𝜇 Fn r

𝜇Fn/mv

E2

E1 W(s)Fb(s)

𝜆 (s)

Torque of Tire o/p variable

Slip ratio o/p

Brake Force

Js ++E3

1/rmvrs /v

Tf(s)

Tf(s) Fn

Control system block diagram

Fuzzy controller