Feedback on a ball balancer

The open loop transfer function of a ball balancer shows it to be unstable. Application of a feedback loop is required to stabilize it. This paper provides a practical touch to the undergraduate linear control systems course, where compensation is commonly and theoretically applied in various control systems to achieve stability and in which no practical insight is provided as to what constitutes a feedback, nor how it can be physically realized. This paper shows the design of a feedback system. We hope that the paper will enlighten undergraduate linear control students.