基于介电型EAP的柔性位移传感特性研究

发布时间：2018-11-10 21:40

【摘要】：介电型EAP(Electro-active Polymer)是一种超弹性绝缘材料,具有应变大、柔性好和质量轻等优点,可实现柔性传感,能适应被测对象的形状,不会阻碍被测对象的运动。论文基于介电型EAP的电容式传感原理,研究了介电型EAP的位移传感特性,在柔性机器人及康复训练等领域具有潜在的应用前景。分析了介电型EAP电容式位移传感器的工作原理,设计了传感单元的结构,通过单敏感单元与双敏感单元(面对面)的电容量分析,发现面对面单元的电容量差与位移之间的线性关系,由此确定采用差分测量法,以提高传感单元灵敏度和线性度。分析了传感单元的制造与安装误差对传感性能的影响,确定了传感单元的尺寸,完成了传感单元的制作。测试了用于电容量计算的相对介电常数,用于理论灵敏度计算。构建了传感单元的静态特性测试平台,利用最小二乘法拟合测试数据,进行了单自由度和二自由度位移传感标定。结果表明:敏感单元的电容量差与单自由度位移之间的线性度好,灵敏度分别为63.21 pF/mm(X向)和63.08 pF/mm(Y向);面对面敏感单元的电容量差只与该方向的位移呈线性关系,与另一方向位移基本无关,且标定结果与分析结果较吻合。在此基础上分析了安装误差对标定的影响,证明了差分测量法的可行性。在分析基础上,探究传感单元应用如下:将两个传感单元内框固连,采用差分法测量Z方向位移,其灵敏度为66.44pF/mm;基于该传感单元设计了二自由度角位移传感器,建立该传感器的电容量与绕X、Y轴角位移之间的关系,该传感器绕X和Y轴的灵敏度为111.28pF/(°)和114.76pF/(°);利用两个传感单元制作了一种四自由度位移传感器,用于检测导杆在X、Y方向位移和绕X、Y轴角位移,得到导杆末端误差在0.25%之内。
[Abstract]:Dielectric EAP (Electro-active Polymer) is a kind of superelastic insulating material, which has the advantages of large strain, good flexibility and light mass. It can realize flexible sensing and can adapt to the shape of the object under test, and will not hinder the movement of the object under test. Based on the capacitive sensing principle of dielectric EAP, the displacement sensing characteristics of dielectric EAP are studied in this paper. It has potential application prospect in flexible robot and rehabilitation training. The working principle of dielectric EAP capacitive displacement sensor is analyzed, and the structure of sensor unit is designed. The linear relationship between the capacitance difference and the displacement of the face to face unit is found, and the differential measurement method is adopted to improve the sensitivity and linearity of the sensor unit. The effect of the manufacturing and installation error of the sensor unit on the sensing performance is analyzed. The size of the sensor unit is determined and the fabrication of the sensor unit is completed. The relative dielectric constant used to calculate the capacitance and the theoretical sensitivity were measured. The static characteristic test platform of the sensor unit is constructed, and the measurement data are fitted by the least square method, and the displacement sensing calibration of single and two degrees of freedom is carried out. The results show that the sensitivity is 63.21 pF/mm (X) and 63.08 pF/mm (Y), respectively. The capacitance difference of the face to face sensitive cell is only linearly related to the displacement in this direction, but not to the displacement in the other direction, and the calibration results are in good agreement with the analytical results. On this basis, the effect of installation error on calibration is analyzed, and the feasibility of differential measurement method is proved. On the basis of the analysis, the application of the sensor unit is as follows: the sensitivity is 66.44pF / mm by using the difference method to measure the displacement of Z direction by fixing the inner frame of the two sensing units; Based on the sensor unit, a two-degree-of-freedom angular displacement sensor is designed, and the relationship between the capacitance of the sensor and the angular displacement around the X and Y axis is established. The sensitivity of the sensor is 111.28pF/ (掳) and 114.76pF/ (掳) around the X and Y axes. A four-degree-of-freedom displacement sensor is fabricated by using two sensing units, which is used to detect the displacement of the guide rod in the direction of XY and the angular displacement around the XY axis. The error of the end of the guide rod is within 0.25%.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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