Electrohydraulic robotic leg: energy-efficient mobility on tough terrain

Inspired by animal muscles and skeletons, this electrohydraulic musculoskeletal leg offers an improvement in agility, adaptability, and energy efficiency compared to traditional robotic legs powered by electromagnetic motors.

Bio-inspired design

Most current robotic legs rely on rigid structures and electromagnetic motors, which can struggle to match the agility of animals when navigating rough, unpredictable terrains. In contrast, the newly developed leg is powered by pairs of artificial muscles that contract in a way similar to how biological muscles operate. This design enables the leg to move fluidly and with greater control over different surfaces, from grass and gravel to larger rocks.

One of the key innovations in the leg’s design is its use of electrohydraulic artificial muscles. These muscles use electrical signals to contract, similar to how biological muscles are controlled by electrical impulses in animals. The system also includes built-in self-sensing, allowing the leg to detect and respond to obstacles without the need for complex external sensors.

Efficient energy use for enhanced performance

Perhaps the most impressive feature of the electrohydraulic leg is its energy efficiency. When tested, the leg required only 1.2% of the energy needed by a conventional electromagnetic motor-driven leg during squatting motions. This dramatic reduction in energy consumption could open the door to more sustainable and longer-lasting robotic applications where conserving power is crucial.

The leg is also designed to perform highly dynamic tasks, including powerful jumps and high-frequency gait movements. It can leap to heights of up to 40% of its own leg length and can perform rapid gait motions exceeding 5Hz, demonstrating its potential for quick, reactive movements.

Future applications in robotics

While the design is still being refined, particularly in terms of making it fully untethered and self-powered, this technology could lead to the development of robots that can move more naturally and efficiently in environments like forests, mountains, and other unstructured terrains.

The electrohydraulic robotic leg is a leap forward in developing versatile, energy-efficient robots that can better adapt to the natural world, and these advances could lead the way for robots that capable of operating in diverse fields, from search and rescue missions in difficult terrains to agricultural work and exploration.

By drawing on principles from biology and advancing the use of electrohydraulic muscles, the new leg design gives a glimpse of a future where robots not only function more like animals but also conserve energy, improving their usability across various demanding environments.