There is no stone unturned by fuzzy logic controllers. There are certain terminologies in real time world, which cannot be defined with precision. E.g. When we say ‘the distance is more’, we fuzzify the distance ‘as more’ and soon in this paper we will apply fuzzy logic to reduce the engineering intricacies involved in designing the automobile brake systems, we will also see its superiority over other conventional solutions available. Here, Fuzzy Automobile Brake Systems intends to automate this process with the help of knowledge base acquired from the system experts. In addition, we will be discussing the simulation results of this system which we simulated in MATH WORK software MATLAB for Windows 98, with FUZZY TOOLBOX.
REQUIREMENTS FOR PRESENTATION:
OHP, Computer with color monitor and LCD Projector (for display of simulation results and power point presentation). We will bring the simulation CD-ROM alongwith.
INTRODUCTION:
FUZZY LOGIC is not a logic that is fuzzy, but is the logic that describes and tames fuzziness. Although it is based on a complex mathematics body, its practical use is easy to learn and apply. Fuzzy Logic is an innovative technology that enhances the conventional system design with engineering expertise. Using Fuzzy Logic, we can circumvent the need for rigorous mathematics modeling. In this paper we will be able to visualize the need for Fuzzy Logic and how it’s applications are in a better position than the conventional system in real-time world. And we will see how ill defined Conventional Automobile Brake Systems being handled by Fuzzy Controllers, and it’s superiority over other available methodologies.
CONVENTIONAL AUTOMOTIVE BRAKE SYSTEMS :
A brake is an appliance used to apply frictional resistance to a moving body to stop or retard it by absorbing kinetic energy i.e. controlling its motion. The Principle of brakes is that an external force is applied on the rotating drum incorporating a frictional resistance, which aids in retarding the vehicle. If the force applied is too large, the vehicle comes to rest instantly but the wear of the components is too high, this rules out this case under ordinary circumstances. On the other hand if the force applied is gradual, the vehicle covers some distance before ultimately coming to rest.
This distance covered is of vital importance as it is a factor which determines the amount of force to be applied and the instant at which it is to be applied so that safety of the vehicle is assured with little wear of the brake components, tyres etc.
We have a relation,
Work done against friction = Kinetic Energy of the vehicle
i.e. ( R n s = 0.5 m* v2 )
where,
where,
( = coefficient of friction at the rotating drum;
Rn = Pressure applied on the brake;
S = distance covered by the vehicle before coming to rest;
m = mass of the vehicle;
v = velocity (speed) of the vehicle.
From this relation we infer that:
Greater force is to be applied when the speed of the vehicle is high and the distance to be covered before coming to rest is small. In the same way, if the speed of the vehicle is less and the distance to be covered is more then lesser force is to be applied.
REASONS FOR SWITCHING TO FUZZY LOGIC CONTROLLERS
The potential advantages of Fuzzy Logic can be summarized as follows:
1. FUZZY LOGIC provides a more consistent way to deal with knowledge that imprecise and fuzzy, due to such factors as incompleteness of information and ambiguity of concepts. In particular, it relaxes the precision that presently dominates the “scientific” study of real-world situations. Where fuzziness increases in proportion to their complexity, can be more realistically modeled with Fuzzy Logic.
2. FUZZY LOGIC provides a more consistent way to deal with non-linearities. Many problems are heuristically solved, or dealt with in a satisfying way, without the need of analysing them in their elementary aspects.
3. FUZZY LOGIC provides a method to deal with linguistic expressions. This is a major step towards a more effective and friendly interaction between computer and people. Human language has a comprehensiveness that can only partially be reproduced by the conventional computer languages. Here again, the lack of precision may provide more Flexibility in matching reality.
4. Finally, as already highlighted in Fuzzy Expert systems, the flexibility of FUZZY LOGIC compared to the rigidity of conventional approaches, may result in more robust and less costly solutions.
Thereby, the Fuzzy Automobile Brake System (FABS) maintains a range of distances and corresponding range of forces to be applied on the brakes which are suitable for safe and comfortable travel with little human intervention. i.e. FABS adjust itself according to the changes in the distances between the obstacle and the vehicle and applies the necessary force on the brakes.
Next related FUZZY LOGIC: BIRTH, GROWTH AND MATHEMATICS BEHIND THE GIANT:
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