用于生物力学测量的新型电容式三维力传感器

针对生物力学测量的应用需求,考虑到电容型传感器温度特性好、功耗低等特点,研制了一种新型电容式三维力传感器。该传感器基于一种新颖的弹性体结构,以聚氨酯泡沫作为介质构成了3组电容,使得传感器能够同时感知3个维度的输入力分量并转化为3个通道的电容变化,利用ANSYS有限元分析确定了传感器的尺寸,使其各维度的量程达到±200N,安全过载大于150%。设计了由电容采集模块和信号处理模块组成的测量系统,嵌入传感器内部,一体化的设计实现了测量数据的实时解算和输出。此外,针对电容式传感器存在的迟滞效应和维间耦合干扰问题,建立了迟滞补偿与解耦模型。通过实验验证,该传感器的Ⅰ类误差低于2.8%,Ⅱ类误差低于4.6%。

Three Dimensional Force Sensor for Biomechanical Measurement Based on Capacitance Principle

To realize biomechanical measurement, a capacitive three dimensional force sensor was developed with low temperature drift and low power consumption. A novel structure of the elastomer was designed, and the polyurethane foam was used as the medium. The sensor can perceive the force components of three dimensions and convert them into capacitance changes of three channels simultaneously. After finite element simulation used ANSYS, the size of the sensor was determined, and the measuring range of each dimension reached ±200N with safety overload more than 150%. A measurement system composed of capacitor acquisition module and signal processing module was designed. The integration design made the calculation and output of measurement data real-time. In addition, to decrease the impact of the hysteresis effect and the inter-dimensional coupling, the hysteresis compensating and decoupling model was established. The experiment results show that the Class I Error is below 2.8% while the Class II Error is below 4.6%.