String Stability of Independent Autonomous Vehicles 

The purpose of this project is to study the instability that arises when there is a chain of independent autonomous vehicles following one another.The lead train accelerates and decelerates at random, while the tailing trains were programmed with a PID controller to follow the lead train at a safe distance. At the bend where the vehicles rapidly decelerate, the resulting instability propagates until the 4th and 5th vehicle collides with the vehicles directly ahead of them.

I used ultrasonic sensors to detect the train ahead, a Hall effect sensor on the wheels to measure the speed of the trains, and an Arduino microcontroller as a platform for the PID control system.