An Approach for Actuator Frequency Characteristic Test System Error Measurement

System error measurement is the essential step in actuator frequency characteristic testing and is studied to provide qualified results for system error compensation. We explored the approaches using swept sine and fast Fourier transform. We found that digital smoothing is introduced for improving accuracy of fast Fourier transform. The experiment numerical examples verified accuracy and robustness of swept sine and validity of FFT. These methods were applied to measure system error in actuator test system, the experiments showed that swept sine method could gain smooth and stable results and FFT method could achieve rather close results with swept sine.