基于静态电容补偿的压电换能器锁相环频率跟踪  

A PLL-dependent piezoelectric transducer frequency tracking technique based on static capacitance compensation

作　　者：武剑[1] 董惠娟[1] 张广玉[1] 

机构地区：[1]哈尔滨工业大学机电工程学院,哈尔滨150001

出　　处：《大连海事大学学报》2009年第1期57-61,共5页Journal of Dalian Maritime University

基　　金：国家自然科学基金资助项目(50674036);哈尔滨市科学研究基金资助项目(2003AFQXJ004)

摘　　要：为解决压电换能器锁相环频率跟踪中存在的跟踪范围狭小、易出现误跟踪和失锁等问题,提出一种基于静态电容补偿的锁相环(PLL)频率跟踪技术:根据电容元件伏安特性对由静态电容造成的不良影响进行补偿,使换能器对锁相环呈现理想的LCR串联谐振回路特性,并结合线性拟合法完成对机械臂电压电流相位差的测量,避免了误跟踪和失锁,实现了较以往更宽频带下的换能器准确跟踪.实验表明:对两个-3 dB带宽分别为120 Hz和663 Hz的换能器,跟踪误差分别为-9 Hz和+28 Hz,跟踪范围可达10 kHz.To eliminate the phase locked loop＇ s （PLL＇ s） perfor mance degradation of narrow tracking range, mistracking and losing lock in the piezoelectric transducer＇s frequency tracking, a PLLdependent transducer frequency tracking technique based on static capacitance compensation was developed. According to the general character of capacitance component, the negative ef fects from static capacitance were compensated, and thus the transducer could be equivalent to an ideal LCR serial resonance circuit. The mechanical branch＇s voltagecurrent phase differ ence was obtained by using the linear regression approach, which offered a .solution to the mistracking and losing lock. Comparing with prior PLL methods, the technique suggested here provides more precise frequency tracking in a wider frequency range. Experiments were carried out on two transducers whose 3 dB bandwidth value covered over 120 Hz and 663 Hz respectively, and the results show that the tracking errors for autoremnance were 9 Hz and ＋ 28 Hz, and the tracking range is up to 10 kHz.

关 键 词：压电换能器 锁相环 频率跟踪 静态电容 补偿 线性拟合 

分 类 号：TB553[理学—物理]