Ground whirl flutter test system and test method for rotorcraft

A ground whirl flutter test system for a rotorcraft, comprising a hardware part and a software part, wherein

• the hardware part comprises a rotor test article—, a support system—, force loading devices, vibration signal sensors—, load cells—, vibration signal acquisition cards—, an industrial control computer—, force signal output cards—, power amplifiers—and load cell signal acquisition cards—;
• the rotor test article—is fixed to the support system—;
• the force loading devices—are placed along an O-Y axis and an O-Z axis respectively, and applied excitation forces and torques act on a point O;
• the load cells—are located at the top ends of the force loading devices—and acquire load cell signals—, which are applied to the point O by the force loading devices—;
• the vibration signal sensors—are arranged along the O-Y axis and the O-Z axis and acquire vibration signals—at the point O along the O-Y axis direction and the O-Z axis direction;
• the vibration signals are acquired through the vibration signal acquisition cards—;
• force output signals—of each force loading device—are outputted through the force signal output cards—, and outputted force signals are amplificated by the power amplifier—;
• the load cell signals—are acquired through the load cell signal acquisition cards—;
• the software part comprises a rotor force and moment calculation program and a multi—input multi-output force control program running on the industrial control computer—;
• wherein the closed-loop signal transmission process of the ground whirl flutter test system for the rotorcraft is as follows:
• the vibration signals—acquired by the vibration signal acquisition cards—are recorded by the industrial control computer—, and the industrial control computer—calculates forces that act on the point O located in the center of a rotor hub—by using the input vibration signals—and a pre-programmed rotor force and moment calculation program;
• the industrial control computer outputs force control signals—to the power amplifiers—through the force signal output cards, the power amplifier outputs the force output signals—after power amplification to the force loading devices—, and the force loading devices—are driven to load the rotor test article—;
• meanwhile, the load cells—acquire the forces applied by the force loading devices—and feed back the forces to the industrial control computer—via the load cell signal acquisition cards—;
• and the industrial control computer—performs closed-loop feedback control on the forces applied by the force loading devices—according to force signals fed back and the pre-programmed multi-input multi-output force control program, so as to achieve the accurate loading of rotor aerodynamics and moment, ultimately, the phenomenon of whirl flutter of the rotor test article—is reproduced on the ground.