基于混沌脉冲位置调制的实时超声测距系统串扰抑制  

Rejecting Crosstalk of Real-Time Ultrasonic Ranging System Based on Chaotic Pulse Position Modulation

作　　者：孟庆浩[1] 兰少莹[1] 姚振静[1] 李根旺[1] 

机构地区：[1]天津大学电气与自动化工程学院天津市过程检测与控制重点实验室,天津300072

出　　处：《电子学报》2008年第11期2268-2272,F0003,共6页Acta Electronica Sinica

基　　金：国家自然科学基金(No.60475028);新世纪优秀人才支持计划资助项目

摘　　要：超声测距系统中各换能器之间存在的干扰(即串扰)会严重制约测距的准确性;为消除串扰,采用混沌脉冲位置调制构造每个超声换能器的短发射序列;相关分析法被用于识别回声序列.分析了超声串扰产生原因,并给出了脉冲占空比与各次谐波能量的对应关系.为获得最佳的相关效果,采用遗传算法对Logistic混沌满映射调制的短序列脉冲间隔做了优化.所提方法在DC-DC(直流-直流)激励的静电型超声测距系统中获得了验证.结果表明,在合理配置脉冲间隔的情况下,混沌脉冲位置调制可用于消除实时超声测距系统的串扰.The crosstalk between transducers can seriously restrict the accuracy of ultrasonic ranging system. To eliminate ul- wasonic crosstalk, the Chaotic Pulse Position Modulation（ CPPM） is used to construct the short triggering sequence for each ultrasonic transducer. The correlation analysis is applied to identify the echo sequence. The cmsstalk sottrces are analyzed. The relation between pulse＇ s duty cycle and energy of harmonic components are deduced. To obtain the optimal correlation performance, the genetic algo- rithm is adopted to optimize the duration between pulses modulated by Logistic chaotic mapping. The proposed method is validated on a DC-DC fired electrostatic ultrasonic ranging system. The results demonstrate that the CPPM can be used to eliminate the crosstalk of the real-time ultrasonic ranging system provided that the duration between pulses is adjusted properly.

关 键 词：超声换能器 超声串扰 混沌脉冲位置调制 相关分析 

分 类 号：P225.6[天文地球—大地测量学与测量工程] TN918.66[天文地球—测绘科学与技术]