Comparative Research On The Performance Of Piezoelectric LGS Sensor And Piezoelectric Quartz Sensor

With the advantages of excellent static stiffness, high sensitivity, high resolution, high inherent frequency, good frequency response and transient response, and good stability, piezoelectric quartz sensor has played an irreplaceable role in many engineering fields and force tests since 40’s in last century.In order to obtain the higher-quality and higher-performance functional material, more kinds of novel piezoelectric crystals are developed. As the novel piezoelectric material, LGS shows a good performance and attracts an extensive attention. LGS’s electromechanical coupling coefficient at normal temperature is about twice or three times that of quartz, the melting point is 1300-1500℃ and no phase change happens. Besides, LGS has a higher resistance and larger dielectric constant than quartz. With so many merits, the LGS crystal has been widely applied in resonator, optoelectronic switch and filter, but no reports about its application in force measurement can be found.The paper conducts a comparative research on the performance between the LGS sensor and quartz sensor. By studying LGS wafer’s processing technic, the sensitivity factor of specific-cut LGS wafer and the development of LGS chipset, a three-component LGS sensor is developed. Then, the static and dynamic calibration experiments for the sensor are done, acquiring the relevant performance parameters. The main research work is as follows:Research on processing technic of LGS wafer. The first step of developing the LGS sensor is to make xy-cut and yx-cut piezoelectric wafer with definite sensitivity factor. Based the cutting test of piezoelectric crystal, the optimized technological parameter of spindle speed and feeding speed is analysed, getting the LGS wafer whose design size and surface parameter meet the requirements. The three directions of crystal axis are calibrated, providing the reference for orientation of wafer’direction in the process of making chipset unit.Research on the piezoelectric effect of LGS crystal. Compared with piezoelectric quartz, the piezoelectric effect of LGS crystal is researched from the microstruction. By autonomously designing the calibration equipment and conducting the calibration experiment, the piezoelectric coefficient is obtained. The result shows that the piezoelectric coefficients of xy-cut and yx-cut LGS wafer are 5.5pC/N and 11.0pC/N respectively. Comparative research on the performance of LGS sensor and quartz sensor. In the research, two kinds of sensor which are LGS sensor and quartz sensor separately are developed and both of them have the same structure. Then the static and dynamic calibration experiment platform are built, the static and dynamic calibration experiments for two kinds of sensors are completed with the linearity, repeatability, transverse interference, stiffness and inherent frequency acquired. The maximum values of linearity, repeatability and first natural frequency of LGS sensor are 0.21%,0.53% and 5106.56 respectively, while that of quartz sensor are 0.74%,1.16% and 4907.18 respectively.The research results in the paper and the high-performance force sensor whose force-sensitive element is based on the novel piezoelectric material can serve the measurement of hypersonic-speed aerodynamic force in the field of aerospace and aviation, also can be applied in the real-time measurement of cutting force in the high-precision CNC and the dynamic thrust vector measurement of rocket engine, providing a firm technical support for the development of major industries in our country.