Arm Driven Inverted Pendulum

Brief Description: The Arm-Driven Inverted Pendulum (aka PENDUBOT for PENDulum roBOT) is a double pendulum configuration in which only the first link (the shoulder) is actuated. The goal is to balance the second link in the upright position.


Given its underactuated nature, control of this plant is challenging. It shares some of the features of the classical pendulum on a cart and rotary (furuta) pendulum but it has the unique property that, in contrast to these, it has an infinite number of distinct equilibrium configurations, namely the second link in upright position and the first link at any angle. The plant also becomes increasingly difficult to balance the more one approaches the uncontrollable position (first link at 90°).

 It is also well known that double pendulums exhibit chaotic behavior. This makes system identification difficult and requires more advanced techniques, such as closed-loop system identification.

 All of the above mentioned features make this a very interesting plant for testing both linear and non-linear control algorithms.



Related Publications:

  • Ali, Mukhtar, Werner, Herbert (2011): Discrete-Time LPV Controller Synthesis Using Dilated LMIs with Application to an Arm-Driven Inverted Pendulum. In Proc. 18th IFAC World Congr