Research On The Key Technology Of Displacement Sensor Calibration Platform With High Resolution And Frequency Response

With the fast development and widely application of displacement sensor,the requirements of the displacement sensor has become higher and higher. In the practical application and scientific research, the reliability of the sensor performance, the accuracy of the measurement results and the real-time dynamic must be guaranteed with higher standard, and the accurate calibration of the sensor is an important factor to support the requirements. Nowadays, the sensor calibration is usually limited to the static or low frequency measurement, lack of the calibration platform which could satisfy the high precision, high frequency response and relatively large stroke at the same time. Therefore it is difficult to meet the demand of displacement sensor calibration with high speed and high precision, the development of dynamic measurement applications by displacement sensor in the high-speed has been limited.According to the above problem, this paper based on the existing calibration method of displacement sensor, designed the calibration platform compose of the flexure hinge mechanism and double measurement system as benchmark. The single frequency laser interferometer and the capacitance sensor applied in platform at the same time, due to the reason of the interferometer has higher measurement accuracy, while the capacitance sensor has higher frequency response and do not need to install the reflector on the displacement output. Have two sets of measuring devices respectively provides high accuracy and high frequency calibration reference. The flexible hinge mechanism have been designed to provide high resloution movement, the mathematical model of flexure hinge have been build, cooperate with Ansys simulation result to analysis the structural characteristics, design and build the overall calibration system. At last, processing the flexible hinge mechanism and setup the experiment to test the system performance.The paper will be based on the following several aspects to introduce:1. The principle of existing sensor calibration have been analysed, then proposed a calibration system composed of flexure hinge mechanism as the movement driver, and the single frequency laser interferometer plus capacitance sensor to povide calibration reference. The design objective of calibration system is high natural frequency, high resolution and the large stroke.2. Design and optimization the flexible hinge mechanism. Using the geometrical relationship and pseudo-rigid-body method to established the mathematical model of motion mechanism, combined with the finite element simulation analysis, study the influence relation of structure and parameters of hinge platform between the natural frequency, storke magnification and the stiffness. Balance all comprehensive performance requirements to select the appropriate structure parameters used for processing hinge.3. Processing the flexible hinge and affiliated fittings which have designed by previous work, building the integrated experiment system to measure various parameters of the flexible hinge mechanism platform. The displacement resolution is 4 nm and the maximum range is 52.08 ?m by interferometer measurement, stroke magnification is about 3.75 times. Capacitance sensors measured the resonance frequency of flexible hinge platform is 1000 Hz, meet the design requirements.