基于石英谐振式力学传感器的电子秤模块应用

Electronic Weighing Application Based on Quartz Resonant Force Sensor

摘要: 该数字称重模块采用AT切型石英谐振器作为敏感单元，通过力频转换实现高稳定性与强抗干扰能力，有效避免了应变片传感器固有的热漂移问题，借助有限元仿真优化了单点剪切梁结构，并设计应力集中槽以确保力的高效传递，系统搭载定制化FFT-PLL电路与低噪声电源，可维持优异的信号质量，测试结果表明，在40~100 N·m载荷范围内，器件精度误差为3.51%，重复性误差为1.32%，满足行业标准，当载荷大于30 N·m时，重复性误差可控制在2%以内，在10~40 N·m区间内精度偏低，主要源于振动阻尼不足与低载荷灵敏度下降，后续通过增设阻尼结构并优化低力响应特性，可将其应用场景从工业领域拓展至精密测量领域。

Abstract: This digital weighing module adopts an AT-cut quartz resonator as the sensing unit. By utilizing force-to-frequency conversion, the proposed design exhibits high stability and strong noise immunity, which effectively eliminates the intrinsic thermal drift problem of conventional strain-gauge sensors. The single-point shear beam structure is optimized through finite element simulation, and a stress-concentrating groove is integrated to ensure efficient force transmission. To maintain superior signal quality, the system is equipped with a custom-designed FFT-PLL circuit and a low-noise power supply. Experimental results demonstrate that the module obtains an accuracy error of 3.51% and a repeatability error of 1.32% under an equivalent bending moment of 40~100 N·m., satisfying standard industrial requirements. The repeatability error is kept below 2% when the load exceeds 30 N·m. The degraded accuracy in the range of 10~40 N·m is mainly caused by insufficient vibration damping and reduced low-load sensitivity. With further improvements such as introducing damping structures and optimizing low-force response performance, the proposed weighing module can be extended from general industrial applications to high-precision measurement fields.