Quartz Resonance Based Torque Sensor Design

In this paper, a design method for torque sensor based on AT-cut quartz crystal resonators is proposed. The resonance frequency of AT-cut quartz crystal has the characteristic of changing with external force. In order to study the quartz resonant torque sensor, firstly, the quartz crystal resonators are designed by the requirement of resolution and measurement range. In order to obtain a sensor with high response characteristics, the quartz crystal is mounted on a unique spoke structure, and the finite element analysis software is employed to analyze the installation position of the quartz crystal sensitive unit and the stress of the quartz crystal are determined. The quartz crystal resonator with the fundamental frequency of 25 M is selected as the sensitive unit, and the force-frequency coefficient and the limit force of the quartz crystal resonators are determined. Moreover, the pierce circuit is selected as the quartz crystal oscillation circuit, and the frequency counting pre-processing circuit is designed to realize frequency counting. Finally, the sensor is placed in the calibration device for calibration, and the static indicators of sensor range, sensitivity, linearity, hysteresis, resolution and so on are obtained.