Position control of two balls in two interconnected vertical tubes using controlled DC fans and sliding mode control

The aim of this paper is to control the position of two balls in interconnected vertical tubes using two dc fans, ultrasonic sensors and computerized controller. A comparison of different kinds of controllers is performed to find the best adjustment. Indeed, by controlling the speed of a fan that pumps the air toward a ball, the air pressure under the ball will be adjusted such that it suspends the ball in the desired position and hold it in that height. Firstly, required hardware that includes mechanical and electrical parts, is designed and implemented, then an appropriate controller is designed in MATLAB and connected to sensors and actuators via interfaces. The used controllers, are PID and sliding mode controller where sliding mode controller led to better results.