The Right Choice: How Domin Servo Valves Enable Agile Quadruped Robots

Max

Quadruped robots are gaining increasing popularity in applications such as package delivery, inspection, search and rescue, and entertainment. Thanks to their animal-like leg mobility, they can navigate uneven terrain nimbly—terrain where wheeled robots struggle to traverse.Hydraulic actuators are the key enabling technology for high-performance quadruped robots. Compared with electric actuators, hydraulic systems deliver higher power density and impact resistance in a compact, lightweight package. This allows each leg to lift heavy loads and absorb the impact forces generated during jumping and running. Precise control of these hydraulic joints is critical for the robot to walk, trot and jump; without responsive valves, its gait will become unstable. The Domin S4 Pro electro-hydraulic servo valve provides the speed and precision required for agile quadruped robots.Researchers from Zhejiang University and Nanchang University have built a hydraulic quadruped prototype to evaluate control algorithms. However, achieving smooth control of multiple hydraulic leg joints has proven to be a challenge. This case study explores how the Domin S4 Pro servo valve delivers the precision and speed needed for their agile quadruped robot.

How Domin Servo Valves Enable Agile Quadruped Robots

The Quadruped Robot Challenge

The quadruped robots developed by the university researchers mimic animal movements with four legs, offering superior mobility over wheeled systems on rocky, sloped or sandy terrain. Controlling multiple active joints, however, is highly complex. Each leg must cycle through precise configurations to walk, trot, gallop or jump—any error poses a risk of instability.The hydraulic leg actuators that enable quadruped mobility also present control challenges. Valves must coordinate multiple joints quickly and accurately to maintain stability during dynamic movements. Slow or imprecise valves result in a shaky, inefficient gait. This demands servo valves with high bandwidth, fast response and a compact footprint for integration into the legs.

Advantages of the Domin S4 Pro

🔹Ultra-LightweightWeighing just 250 grams, the Domin S4 Pro minimizes mass on the moving legs, enabling faster cycling and more dynamic movements.

🔹High BandwidthWith a bandwidth of over 120 Hz, the S4 Pro delivers incredibly responsive control, allowing the legs to react more quickly to maintain stability.

🔹High Power DensityA compact yet powerful valve, the S4 Pro delivers a flow rate of 12 L/min in a small package, enabling the legs to generate greater force for its size.

🔹Fast ResponseA 3 ms response time enables precise motion control, allowing the legs to make micro-adjustments to navigate uneven terrain.

🔹Precision ControlSuperior servo performance empowers the quadruped to execute complex, stable gaits. The S4 Pro precisely controls the legs to follow accurate movement trajectories.