Project for my System Controls class at Cal Poly Pomona. The cart and balloon are pulled up the incline via a motor. The motor speed is controlled with pulse width modulation and decreases proportionally with its distance from the wall of nails through use of an ultrasonic sensor. Once the cart is within 2 centimeters of the spikes it reverses back down the ramp. The wall of nails is able to be manually moved anywhere along the Velcro rails without changing the system performance.