Research On Acquisition And Analytical Processing Of Helicopter Rotor Sensor Signal

In the field of aviation measurement and control,analog data acquisition technology has been widely used,especially in helicopter ground wind tunnel tests.When the helicopter rotor is rotating,the signal quality puts forward higher requirements on the performance and function of the data acquisition system.The comprehensive evaluation of the characteristics of the data acquisition system is particularly necessary for the acquisition,analysis and processing of rotor sensor signals,and simulation research of the rotor sensor signal will effectively grasp the blade motion state.Therefore,the thesis focuses on the acquisition analyzing and processing the helicopter rotor signals,and the following research is carried out:Firstly,the thesis proposes a data collector design scheme based on the application scenarios of the rotor blade wind pressure signal acquisition in the helicopter ground test.Combined with the performance index requirements of the data acquisition system,a data acquisition device suitable for parallel and synchronous acquisition and storage of 128 channels of rotor sensor signal analog data has been developed.The data collector is composed of two parts: the sensor signal acquisition daughter card and the core control card.The acquisition daughter card mainly includes the design of secondary gain amplification,signal low-pass filtering,ADC analog-to-digital conversion,master-slave data SPI communication.The core control card mainly includes external clock and external trigger acquisition,DC power management,data buffering and TCP ethernet communication.Secondly,according to the rotor sensor signal data acquisition system test,error analysis is performed,including clock jitter,gain error,and ADC channel phase matching error estimation and calibration to ensure acquisition accuracy.Next,on the basis of error estimation and calibration,the thesis studies the definition and evaluation methods of the performance index parameters of the rotor sensor signal data acquisition system,including the gain accuracy,spurious-free dynamic range,common mode rejection ratio,channel phase matching,channel crosstalk,dynamic effective bit,filter characteristics,error limit,linearity and intercept error of the data acquisition system.Then,under the premise that the wind tunnel test data must not be published,based on the COMSOL multi-body dynamics module to simulate the rotation of the rotor,the analysis and processing of the blade sensor signal is carried out,which is the dynamic displacement signal of the blade under the rotation of the rotor is simulated.To compare and analyze the sensor signals and motion state changes of rotor blades of different materials.Finally,the data acquisition system has designed in thesis,which is suitable for128-channel data acquisition and storage of rotor sensor signal analog quantity,completed the performance test of the data acquisition system in a laboratory test environment,and verified that the data acquisition system satisfies the rotor sensor signal acquisition index,passed the ground static test of the helicopter rotor,completed the acquisition and analysis of the rotor pulsation pressure signal.Compared with the traditional way that the sensor output signal is firstly amplified,and transmitted to the ground through the electric slip ring for data collection,the data collector design in the thesis achieves a high signal-to-noise ratio of77.27 d B for the sensor's collected signal and reduces the number of electric slip ring cable channels on the rotor test bench,improves the accuracy of test results.