Automatic Car Braking System

This paper provides an efficient way to design an automatic car braking system using Fuzzy Logic. The system could avoid accidents caused by the delays in driver reaction times at critical situations. The proposed Fuzzy Logic Controller is able to brake a car when the car approaches for an obstacle in the very near range. Collision avoidance is achieved by steering the car if the obstacle is in the tolerable range and hence there is no necessity to apply the brakes. Another FLC (which is cascaded with the first FLC for collision avoidance) implements the Anti-lock Braking capability during heavy braking condition. Thus the system is made intelligent since it could take decisions automatically depending upon the inputs from ultrasonic sensors.

At the same time, traffic congestion has become a worldwide problem. This problem is mainly due to human driving which involves reaction time delays and judgment errors that may affect traffic flow and cause accidents. Engineers in the automotive industry put a lot of effort in devising systems which ensure safety in road vehicles. Even with all the advancements in vehicle safety technology, the number of people killed in auto accidents continues to rise. Close to 1.2 million people die each year on the world's roads and that number is expected to rise by 65 percent by the year 2020, says a report by World Health Organization (WHO) and the World Bank. Braking system is the most important system in a car. Generally, a car brake system is operated manually as the driver pushes the brake pedal. If the brake fails, the result can be disastrous. Countless rear-ending automobile accidents could have been prevented or at least reduced in damage cost if the rear-ending driver had applied a sufficient amount of brake pressure at the right time. Unfortunately, the time required by the driver to understand potential accident situations, compounded with driver’s delayed reaction times in applying the brakes, usually causes a lag between the identification of a potential accident situation and the execution of the corrective actions that will prevent the accident. Hence, in such emergency situations an efficient control mechanism

Our ultrasonic transducers have piezoelectric crystals which resonate to a required frequency and convert electric energy into acoustic energy and vice versa. The below illustration shows how sound waves, transmitted in a conical shape, are reflected from a target back to the transducer. Accordingly, an output signal is produced to perform some kind of indicating or control function. A certain minimum distance from the sensor is required to provide a time delay so that the "echoes" can be interpreted. Some variables which can affect the operation of ultrasonic sensing comprise, target surface angle, reflective surface roughness or changes in temperature or humidity. Targets can have any kind of reflective form. Even round objects can be