Piezoelectric ceramic micro displacement measuring device

Piezoelectric ceramic is a functional ceramic material that can convert mechanical energy and electrical energy. It belongs to inorganic non-metallic materials. Piezoelectric ceramics have sensitive characteristics and can convert extremely weak mechanical vibration into electrical signals, which can be used in sonar systems and meteorology. Detection, telemetry, environmental protection, household appliances, etc. Piezoelectric ceramics undergo small displacement after voltage driving. In order to detect the performance of piezoelectric ceramics, it is usually necessary to detect the micro-displacement generated by piezoelectric ceramics under different voltage conditions. There are two traditional piezoelectric ceramic displacement measurement methods. The mechanical measurement method and the eddy current displacement meter method are respectively, wherein the mechanical measurement method has relatively large relative error and complicated operation when measuring displacement, and the eddy current displacement meter measurement method is relatively affected by electromagnetic interference.

In order to solve the above technical problems, the piezoelectric ceramic displacement measurement is more precise, and after a large number of experiments are accumulated and tested, further improved, a device for measuring the micro-displacement of the piezoelectric ceramic with convenient operation and small error is obtained.

This device for measuring the micro-displacement of piezoelectric ceramics includes computers, data acquisition cards, voltage amplifiers, piezoelectric ceramics, and phase-shifting interference devices. The computer controls the data acquisition card to output a linear voltage ranging from 0V to 5V. Obviously, it can also be a non-linear voltage, and then the voltage is amplified by a voltage amplifier to drive the movement of the piezoelectric ceramic. The preferred voltage amplifier is a 40-times voltage amplifier. The displacement of the piezoelectric ceramic causes phase shift of the optical path in the phase shifting interference device, and the CCD image sensor collects the phase shift interference image and transmits it to the computer for processing. The phase shift amount between the interferograms in the phase shift interferogram is extracted, and the data of the center circle region of the phase shift interference fringe pattern is less than one stripe, and the data includes T pixels and T pixels. The light intensity data is summed.

The following figure shows a schematic diagram of this device for measuring the micro-displacement of piezoelectric ceramics:

Figure 1 is a schematic view of the structure of the device for measuring the micro-displacement of piezoelectric ceramics.

Figure 2 is a schematic view showing the structure of a phase shifting interference device for measuring the micro-displacement of a piezoelectric ceramic

Figure 3 is a phase shift interference fringe pattern acquired by a CCD image sensor

Figure 4 (a) is the distribution of the center circle light intensity data of the phase shift interference fringe pattern

Figure 4(b) is a motion trace diagram of the displacement of the piezoelectric ceramic

The device for measuring the micro-displacement of the piezoelectric ceramic uses the phase-shifting interference principle to design the optical path system, and the phase-shifting interferogram data is collected by the phase-shifting interference device to be transmitted to the computer to obtain a micro-displacement of the piezoelectric ceramic, and the structure is simple, the installation and the Easy to use, high measurement accuracy, improved measurement accuracy and work efficiency.