Acrobots 【PRO】

This joint is unpowered (passive). It hangs freely from a fixed pivot point, much like a gymnast's hands on a bar.

Modern robots like Boston Dynamics' Atlas use similar principles of momentum and balance to perform flips and navigate rough terrain. Acrobots

This joint is powered (active). By moving this single joint, the robot must generate enough momentum to swing its entire body upward. This joint is unpowered (passive)

Unlike a standard robotic arm where every joint has its own motor, the Acrobot has only one powered joint. It consists of two links and two joints: This joint is powered (active)

The robot must learn to oscillate back and forth, increasing its arc until it has enough speed to reach the top.

The lessons learned from Acrobots go far beyond the lab. By studying how these machines manage underactuated systems, engineers can improve:

Once at the peak, the Acrobot must perform a "handstand" on its passive joint. This requires constant, minute adjustments at the elbow to maintain a precarious equilibrium. Why Do We Build Them?