过零点采样法在超声测距中的应用

Application of implicit sampling for ultrasonic distance measurement

针对超声测距中传统处理的相关法计算量大,实时处理困难的问题,选用混沌脉位调制的随机二元波形作为超声发射信号。对回波进行过零点采样以替代传统的等时间间隔采样,用隐平均法处理采样信号,以确定延时时间,进而测距。该算法只需要移位和加法运算,不需要相关的乘法运算。通过仿真计算结果表明,在保证精度的同时,能有效减少计算量。选用的混沌脉位调制的随机二元信号产生简便,并且能降低发射功率和提高隐蔽性。

t is very difficult to distance measurement in real time because of the conventional corre- lation. In this paper,chaotic pulse position modulated random binary waveform is applied as emitted signal to solve this problem. Zero-crossing sampling is used to instead of evenly intermittent sampling. Delay time is calculated by means of the implicit averaging algorithm. Shift and addition replace multiplication in conventional correlation. This method can reduce time consuming. Chaotic pulse position modulation is used as a novel modulation scheme. The pulse is designed to be a random binary waveform. This method could ensure low probability of intercept and low power consumption with higher range resolution.