Hydraulic test rig for simulation of flight conditions
Test stand Ratio-Drive^®, test actuator as hydraulic test cylinder

A test stand for many tasks

Modern test bench technology is capable of providing a testing environment for a wide range of research tasks: For example, new subsystems such as actuators (e.g., hydropulscylinder), sensors, or computer systems can be test stand into the test stand . With their help, new algorithms for control or condition monitoring and prediction are developed, among other things, to subsequently test their functionality—even under various fault conditions. Furthermore, research into new data bus systems such as “Fly-by-light” or “wireless flight control” is possible. Another area covered by the Ironbird is the exploration of new flight control concepts for the entire flight control system. This allows for the investigation of the influence of and interaction with subsystems such as sensors, actuators, and computers.

Condition monitoring

To investigate condition monitoring methods for monitoring and predicting the condition of electromechanical or electrohydraulic flight control actuators, the developed methods are to be tested and evaluated under conditions that are as close to real-world conditions as possible. The Hänchen test actuator hydraulic test cylinder here test actuator hydraulic test cylinder to precisely simulate the aerodynamic loads acting on the control surfaces during flight. The setpoint values for controlling the hydropulscylinder a flight dynamics simulation. The test system continuously calculates new setpoint values based on various parameters such as airspeed, altitude, and control surface deflection, and transmits these to the cylinder control system to simulate the aerodynamic loads.

Maximum flexibility: Linear drive system Ratio-Drive^® made by Hänchen

Hänchen Prüfstandsbau is supplying the entire linear drive system two elevators, one aileron, and one rudder. The complete^{Ratio-Drive®} system forms a closed-loop system that receives external setpoint signals. The test stand using pressure transducers integrated by Hänchen. This means that the complete actuator—including sensor technology control systems sensor technology software—was implemented by Hänchen as a turnkey solution, including engineering. The company was tasked with meeting the requirements for the hydraulic cylinder dynamic parameters, the maximum forces acting on the system, sensor accuracy, and the operating conditions of the existing hydraulic system—namely fluid, maximum flow rate pressure range and maximum pressure range This required extreme flexibility, even with regard to external setpoint specifications. In addition, hardware interfaces had to be resolved: For example, to bypass Hänchen’s control system and implement proprietary control concepts quickly and flexibly using a Rapid Control Prototyping system, it was necessary to couple external controllers with Hänchen’s electronics. Since lateral forces virtually nonexistent during testing, the DLR uses^{a Servofloat®-grade}test actuator for its test stand .

The Servofloat^® floating gap seal

Hänchen recommended these test actuator for test stand construction, as the patented floating gap seal is the first choice, especially for applications with limited lateral forces with maximum dynamics and quality. The hydraulic cylinders in Servofloat^®-quality are practically friction-free. With extremely slow and very fast movements, they offer non-contact pressure reduction to the outside, low leakage, highest positioning and repeat accuracy and are stick-slip-free.