give me ppt on accident avoidance in train urgently. Thanx in advance.

sanjeet kuhad

Automotive vehicles are increasingly equipped with collision prevention and warning systems to predict possible collision with an external object such as another vehicle or a pedestrian. Upon detection of a potential collision, such systems typically initiate an action to avoid collision and / or provide a warning to the vehicle operator. 
This system consists of a distance measurement system based on ultrasonic sound that uses the micro-controller PIC 16f877A and transmits a burst of ultrasonic sound waves towards the target and then receives the corresponding echo. 
An ultrasonic sensor is used to detect the arrival of the echo to the system. The time required for the ultrasonic burst to travel the distance from the system to the subject and back to the system is measured accurately by the micro-controller. It also provides a warning signal to the driver if the distance between the vehicle and the obstacle crosses a particular limit. It also controls the speed of the vehicle and if the speed limit is exceeded the driver is informed. 
The speed limit for the different class of vehicles is set by the authorities in different.