在某带飞行控制系统的特种风洞试验中,试验模型在闭环大增益情况下出现了振动发散现象。为分析故障原因,对试验数据进行了频谱分析并检验了无风情况下伺服稳定性;同时,将风洞试验动力学系统简化为数学模型,并建立相应的运动微分方程进行分析,得到以下结论:加入支持结构后整个系统的弹性影响较大,并与控制及气动力发生耦合出现气动伺服弹性失稳。进一步针对以上简化模型,进行数值仿真,其结果验证了以上机理。为解决此失稳问题,对控制系统提出了2种改进方案:增加结构陷波器或更改操纵面偏转比例参数,2种方案亦得到仿真验证。最后,将增加结构陷波器的改进方案应用到试验中,达到了预期的效果。 In a special wind tunnel test with a flight control system, the experimental model shows vibration divergence under the condition of large closed-loop gain. In order to analyze the cause of the failure, the spectrum of the test data was analyzed and the servo stability under windless condition was tested. At the same time, the wind tunnel test dynamical system was simplified as the mathematical model and the corresponding differential equation of motion was established. The following conclusions were obtained : The flexibility of the whole system after adding the support structure is great, and the pneumatic servo instability is caused by the coupling with the control and aerodynamic forces. Further for the above simplified model, the numerical simulation, the results verify the above mechanism. In order to solve the problem of instability, two kinds of improvement programs are proposed for the control system: adding structural notch filters or changing the deflection ratio of control surfaces, and the two schemes have also been verified by simulation. Finally, the improved scheme of adding structure notch filter is applied to the experiment, and the expected result is achieved.