Research On Methods And Techniques Of High Frequency Angular Vibration Calibration

With the rapid development of navigation and guidance technology，it urgently needsto develop, test and evaluation the high-frequency response inertial devices. Angularvibration exciter is the necessary device for the dynamic performance evaluation of inertialdevices, such as gyro and angular accelerometer. In the industry, to achieve accuratemeasurement of angular vibration, it also needs to evaluate the metrological characteristicsof the angular vibration sensor. Before the support project of the dissertation is completed,China has not established a national angular vibration calibration device. Thereforetraceability and unity of the angular vibration magnitude has become an important problemto be solved. The main innovations of this paper are listed as follows:Based on the basic theories and methods of vibration calibration, this paper studies thebasic principles of angular vibration exciter and laser measurement system for the dynamicangle; establishes the model of system uncertainty component; analyzes the waveformdistortion of the angular vibration exciter and the main factors affecting the calibrationaccuracy of dynamic angle laser measurement system; systematically studies the goals andmethods of the quantitative indicators for the calibration device. Based on the above studies,this paper presents two key technologies needed to be done: one is angular vibrationexcitation technology with high-frequency, low distortion and large load; another ishigh-precision dynamic angle measurement technology by diffraction grating laserinterferometer.In order to achieve the high-frequency standard angular vibration excitationtechnology, it compares and analyses the advantages and disadvantages of the differentdriving mechanisms of angle vibrator based on the theoretical analysis of the frequencyresponse characteristics of the vibrator. The different driving mechanisms include the DCmotor, the disc-type electromagnetic structure, the cup-type electromagnetic structure andthe frame-type electromagnetic structure. And it analyzes the generation reasons of theexcitation waveform distortion, designs the prototype of the cup-type electromagneticstructure and the frame-type electromagnetic structure, and validates through experiments.Considering the frequency range, angle range, carrying capacity and the difficulty ofimplementation process, choose the frame-type electromagnetic structure as a standardangle vibrator driven structure now. Combining with integration design of the air bearing and moving coil, the electrical characteristics analysis of the moving coil, the magnetic andthermal finite element analysis, natural frequency finite element analysis of the movingstructural and the tripod restoration spring, it establishes the main design parameters ofhigh-frequency standard angular vibrator.In order to achieve the high-precision dynamic angle measurement technology, itcompares different laser dynamic angle measurement technology, combines with thediscussing of the laser interferometer signal processing method. It proposes a mirrorassembly diffraction grating heterodyne laser interferometer. Then it researches the stableand efficient detection algorithm of photoelectric signal transition point, and the acquisitionand nonlinear correction of the orthogonal optical signal. The proposed interferometer canachieve a dynamic angular displacement measurement accuracy of0.02”, which becomes akey factor in the high-frequency angle vibration standard device implementation.Experiments showed that: the high frequency standard frame-type angular vibrationcalibration device, which uses the methods and technologies expatiated above. It achieve afrequency range of10Hz~550Hz, an angular acceleration range of0.2rad/s2~1760rad/s2,an angular velocity waveform distortion less than2%, an angular accelerometeramplitude sensitivity uncertain less than2%and an phase lag less than2o(k=2).