High-precision hydraulic testing with high dynamics

Domin servo valves in custom-developed hydraulic test systems (S4 Pro, S6 Pro)

In hydraulic testing, it is increasingly common to require systems that operate with high dynamics (rapid load and direction changes, high-frequency cycles) while maintaining the accuracy, stability and repeatability necessary for reliable measurement. Whether testing components, actuators or complete systems, the quality of test results is fundamentally determined by the capabilities of the hydraulic control loop (valve + control + feedback).

In this short case study, we demonstrate how high-precision, high-dynamic hydraulic testing can be achieved using Domin S4 Pro and Domin S6 Pro servo valves in custom-developed test rigs.

Video: High-precision hydraulic testing with Domin servo valves

MCT Counterforce Actuator Test Bench on Vimeo

Challenges in hydraulic testing: when standard servo/proportional valves are not sufficient

The typical challenges of dynamic test rigs often go beyond what a “general-purpose” servo or proportional valve can deliver in a stable and repeatable manner:

• precise tracking of high-frequency loads
• stable control during rapid load changes
• requirement for low hysteresis and minimal backlash
• long-term reproducibility of measurement results

The problem usually arises when high dynamics and precise position/force control are required simultaneously. In such cases, valve dynamic limits, internal friction, hysteresis or control-loop stability directly manifest themselves in the measured curves.

Servo valve selection for hydraulic test systems: key technical focus areas

Based on these requirements, the following parameters typically become decisive when selecting a servo valve for a test rig:

• direct drive operation for fast response and good dynamic transmission
• extremely low internal friction for stable control of fine movements
• stable control at high frequencies (good tracking capability, controlled phase shift)
• compact design and easy integration, avoiding unnecessary constraints in system design

These considerations led to the use of Domin servo valves in the specific applications.

High-frequency test rig with the Domin S4 Pro servo valve

One of the developed solutions was a high-frequency hydraulic test rig, where fast and precise motion control with small strokes and sensitive mechanical elements was required.

With the Domin S4 Pro servo valve, the system became capable of:

• achieving an operating range of approximately 200 Hz within test cycles
• highly accurate position and force control
• stable, “vibration-free” control of small-stroke, fine mechanical movements
  

This setup is particularly advantageous for tests where measurement quality depends on the system’s ability to generate a “clean” load or displacement signal – for example in the testing of sensitive mechanical components or precision hydraulic applications.

High-force test system with the Domin S6 Pro solution

In another application, the focus was on high forces, long strokes and the stable handling of dynamic load changes. Here, the challenge is typically not just to move the system, but to operate it in a controlled, repeatable and stable manner across the entire operating range.

In this configuration, the Domin S6 Pro servo valve enabled:

• precise and reproducible control of high loads
• stable operation even under extreme operating conditions
• reliable measurement results under high loads across repeated test cycles

This setup is particularly suitable for validation testing of actuators, drives and industrial hydraulic systems, where control quality directly affects the evaluability of test results.

What does Domin technology add to hydraulic testing?

The use of Domin servo valves in test systems resulted in tangible benefits:

• high dynamics and fast response times
• outstanding control accuracy in both position and force
• low hysteresis and stable operation with fewer control-related side effects
• simpler system design with fewer compromises between dynamics and accuracy
  

These advantages are especially important where measurement accuracy has a direct impact on development and validation processes.

Custom hydraulic systems and test solutions from BIBUS Kft.

BIBUS Kft. does not only supply components, but provides system-oriented solutions. We support our customers in:

• designing custom hydraulic systems
• servo valve selection and integration
• development of complete hydraulic test systems

Our experts will help you find the solution best suited to your application.