Inverted Rod Pendulum


Brief Description: The inverted rod pendulum is a challenging experimental setup that provides insight in control of highly nonlinear systems.


The Model 505 inverted pendulum apparatus is designed to provide insight to control system principles through hands-on  demonstration and experimentation. It is a unique mechanism which provides vivid demonstrations and challenging experiments for both undergraduate and graduate studies in control.

This novel design steers a horizontal sliding rod in the presence of gravity to balance and control the position of the vertical (pendulum) rod. The mechanism is open loop unstable (with a right half plane pole and two imaginary poles) and non-minimum phase (with a right half plane zero). As a result, feedback control is essential for stability and the structure of the controller must be selected carefully due to the non-minimum phase characteristics.

The stabilization of this inverted pendulum can be

accomplished through several methods like LQR/LQG optimal design. Note that a very important feature about this plant is that the system is tunable by changing the location of balancing weights and mass property which explores some interesting properties of the plant.