两步相关法高抗干扰超声波距离测量技术的研究  

Research on the Robust Ultrasonic Distance Measurements based on Two Step Correlation Approaches

作　　者：葛万成[1] 吴凤萍[1] 

机构地区：[1]同济大学,上海200092

出　　处：《仪器仪表学报》2002年第3期253-256,共4页Chinese Journal of Scientific Instrument

基　　金：中国教育部留学人员科研基金;德国罗德与施瓦茨公司资助项目

摘　　要：本文采用相关方法确定超声波的传播运行时间。借助于一个经过适当选择的伪随机二进制序列信号作为超声波的发送信号 ,可通过相关方法把外部干扰信号的影响消除或减小到最小限度 ,这是因为这些外部干扰信号与所发送的伪随机二进制序列信号是不相关的。本文采用特征多项式通过软件方法生成伪随机二进制序列信号 ,十分简单而又灵活。由于省去了费时的乘法运算 ,所以在计算互相关函数时放弃了快速傅立叶变换 (FFT)算法。取而代之的是相关函数的两步计算法。它显著地减少了数据处理时间。合理应用微电子技术和有效的程序设计 ,使得一台具有高抗干扰能力的低成本便携式距离测量仪器得以实现。This paper uses correlation approaches to find the run time of the ultrasonic. With the help of an adequately chosen pseudo random binary sequence (PRBS) as transmitting signal of the ultrasonic sensor, the disturbs can be eliminated by using the correlation approaches. This is because the disturbs are not correlated with the transmitted PRBS. The PRBS are easily and flexibly realized by using the character polynomial. The cross correlation functions are computed without using of FFT algorithm because of omitting of multiplication. The two step correlation method shortens the processing time considerably. By the reasonable using of microelectronics and efficient software design the portable distance measurement instrument with the low costs and high robustness was realized.

关 键 词：超声波距离测量 抗干扰 两步相关法 伪随机二进制序列 

分 类 号：TH822[机械工程—仪器科学与技术] TP274.53[机械工程—精密仪器及机械]