Research On Gas-film Rigidity Measurement Of Dynamic Pressure Motor With Dual-probe

As the most basic and important component of the gyroscope, dynamic pressure motor hasbeen widely used in aviation, aerospace and national defense, and also played a veryimportant role in a variety of inertial systems. The gas-film rigidity between axis and rotordetermines the load ability and performance of the motor, and directly affects the accuracyand stability of the gyroscope. So the gas-film rigidity is an important index of motor, and themeasurement of the gas-film rigidity is an important part of the quality evaluation of dynamicpressure motor. Currently existing measurement methods is wide variety, and theirmeasurement principles are different. But people are more focused on the search formeasurement methods of high efficiency and high accuracy with the development of high andnew technology.The specific content and work are as follows:Firstly, on the base of the gas-film rigidity measurement theory analysis of dynamicpressure motor, the advantages and disadvantages of the various measurement methods arecompared and the method of two position is selected. Against the lack of the currentSingle-probe measurements device, the dual-probe measurement method is proposed，whichuses capacitive sensor to measure motor radial rigidity and the triangular light sensor tomeasure motor axial rigidity. The four factors of causing deviation of system measurementresults are importantly analysed, including rigidity of measuring device, the turntable rotaryerrors, motor positioning error and relative positioning error of triangle light sensor and thethe motor. And design requirements of the corresponding parts are put forward on the basis oferror analysis result.Secondly, signal data processing algorithm and human-computer interface is designed,which achieve intelligent measurement functions of dynamic pressure motor gas-film rigidity.Through spectral analysis of the displacement signal data, low-pass filter is adopted toeliminate the high-frequency disturbance signal component in the signal. Compared thecharacteristics of a variety of analog filters, and a second-order butterworth low-pass filter isdesignend based on bilinear transformation. Besides, abnormal values of signal data areprocessed with Grubbs criteria. And it is used multi-thread mechanism to achieve loopmeasurement of displacement signal. Thirdly, the system platform of dynamic pressure motor gas-film rigidity measurement isconstructed. Many experiments are finished, which include verifying effect of butterworthfilter and analyzing the impact factors on the measurement results as well as measurementeffect of dynamic pressure motor gas-film rigidity. The experimental results indicate that themeasurement repeatability precision of radial and axial displacement of this system is betterthan0.04μm and the measurement uncertainty of radial and axial displacement is about0.004μm and0.015μm, which achieve high-precision measurement of dynamic pressuremotor gas-film rigidity.Finally, the whole paper is summarized and the futher studied aspects are explored in thefuture.