Photo Credit: Cal McIntyre
This joint is unpowered (passive). It hangs freely from a fixed pivot point, much like a gymnast's hands on a bar.
Underactuated systems are often more energy-efficient because they utilize natural physics (like gravity and inertia) rather than fighting against them with heavy motors.
The lessons learned from Acrobots go far beyond the lab. By studying how these machines manage underactuated systems, engineers can improve: