【摘要】 为了将电阻抗谱应用于复合材料构件的异常检测,针对被测对象电阻抗谱的测量,提出一种不同于传统扫频方式的脉冲式方法。采用软/硬件协同设计方法设计并实现基于现场可编程门阵列(Field programmable gate array,FPGA)的脉冲式检测系统。该系统能产生频率和脉宽可调的方波脉冲作为敏感电极的激励信号,基于FPGA芯片实现了一种能对瞬态响应电流曲线进行高速采集的步进采样方法,对采集到的电流曲线作进一步的处理以获得被测对象的电阻抗谱。为了验证脉冲式检测系统用于电阻抗谱测量的可行性和有效性,对Randles单元模型及双弛豫时间等效电路模型电阻抗谱的测量进行试验研究,并与理论计算得到的电阻抗谱进行了对比分析。初步的试验结果表明,脉冲式检测系统能有效地提取被测对象的电阻抗谱信息,所提出的方法用于测量被测对象的电阻抗谱是可行的和有效的。更多还原

【Abstract】 For the application of electrical impedance spectroscopy to the anomaly detection of composite material component, a pulsed method for impedance spectroscopy measurement, different from the traditional swept frequency methods, is presented. A string of square-wave pulses is digitally generated as the exciting signal to the sensing electrodes. A step sampling method for collecting the instantaneous response current curves is realized on the basis of a field programmable gate array (FPGA) chip. The collected curves are further processed to obtain the impedance spectroscopy. Experiments are carried out for the measurement of electrical impedance spectroscopy of the demo electric circuits in order to verify the feasibility and practicability validity of the pulsed measurement system. The preliminary experimental results indicate that the pulsed measurement system can effectively extract the electrical impedance spectroscopy information of the detected object. The proposed approach is feasible and practicable for evaluating the electrical impedance spectroscopy of the detected object.更多还原