Design of Control System for Dynamic Derivative Test System in Low-Speed Wind Tunnel

The dynamic derivative is a necessary parameter in the process of analyzing the stability of the aircraft and designing the control law. In view of the urgent need of the high-precision dynamic derivative wind tunnel test data for the development of large-scale military and civil aircraft and advanced layout aircraft in China, a new wind tunnel dynamic test system is developed driven by the coupling of electro-hydraulic motor and servo motor and whose oscillating mechanism is decoupled from the static angle-changing mechanism based on FL-51 wind tunnel of AVIC Aerodynamics Research Institute, which can conduct dynamic derivative test of pitch/yaw/roll oscillation modes with test model at the scale of 1–2.5 m under the wind speed range of 20–50 m/s. This test system uses electro-hydraulic motor to drive the oscillation mechanism and servo motor to drive the static angle-changing mechanism. We design the drive control scheme and introduce key technologies involved in the system design in detail. According to the Test index, we debug the motion index of the test system, and carry out the wind tunnel verification test with the standard dynamic model at the scale of 1 m and the wing-body fusion layout model at the scale of 2.4 m. The debugging results show that the test system has good static/dynamic control precision, and the performance index and function can achieve the design requirements. The wind tunnel test results indicate that the test system can obtain dynamic derivatives data with high accuracy and reasonable regularity, which can provide test platform support for the demand of dynamic derivative test data for the development of large wingspan military and civilian aircraft in China.