脉冲风洞一体化飞行器测力精度分析

为评估脉冲风洞一体化飞行器的测力精度，根据脉冲风洞测力系统特点，对其进行简化，建立其动力学方程，并获得其动态脉冲响应衰减函数；分析测力系统输出信号变化规律，对其进行傅里叶变换，获得系统振动主频，并运用神经网络、梯度下降法对天平信号进行准确拟合，预测了测力信号的趋势值；对多次试验结果进行了信号拟合和趋势预测，获得了天平测力的精度。结果表明:该方法能够准确预测天平稳定输出结果，且当天平输出信号达到4个周期时，测力精度能够达到97%以上。 

Analysis on the force measurement accuracy of the integrated vehicle in the impulse wind tunnel

To evaluate the force measurement accuracy of the integrated vehicle in the impulse combination wind tunnel, some actions were taken. Firstly, the force-measurement system was simplified and the dynamic equation was built according to its structural characteristics. Then, the impulse response attenuation function was deducted. Secondly, the time-dependent changing rule of the output signal of the force-measurement system was analyzed and the dominant frequency of was acquired through fast Fourier transformation (FFT) method. Next, the neural network algorithm and gradient descent algorithm were used to fit the signal of force balance and to predict the trend value of the force-measurement signal. Finally, the signal fitting and trend prediction of a number of tests data were conducted and the measurement accuracies were acquired. The result prove that this method can truly predict the stable output result, meanwhile, the measurement accuracy can reach over 97% when the output signal of force-measurement system includes 4 cycles.