针对固冲发动机地面试验中点火过程推力测量信号失真的问题,对推力测量系统进行了动态建模。采用ARMAX模型为基础的试验建模方法,设计实施了辨识试验,得到了不同激励下的响应信号。依据试验结果辨识出了模型的结构与阶次,建立了推力测量系统的动态模型。通过分析模型适配率和评估残差白色性,验证了模型准确有效。时域和频域分析结果表明,该动态模型可真实反映推力测量系统的动态特性,为改善动态特性、增加推力补偿和恢复真实信号奠定了基础。

For ignition thrust measurement distortion of solid ramjet in ground test, a dynamic model for thrust measurement system was built.The responses at different excitation signals were obtained by designing and implementing identification test which based on ARMAX model.According to the test results, structure and order were identified and the dynamic model for thrust measurement system was built.Veracity and effectiveness of model were verified by fitting rate analysis and residual whiteness estimation.Time-frequency domain analysis results show that the dynamic model could be used to reflect actual dynamic characteristics of thrust measurement system, laying a foundation for improvement of dynamic characteristics, adding thrust compensation and real signals resume.