In order to improve the anti-interference ability and measurement accuracy of the ultrasonic ranging system, an appropriately selected PN can be used.The code replaces the single pulse signal as the encoded information. The noise signal is uncorrelated with the encoded information can be filtered by

The ultrasonic receiver is composed of an ultrasonic transducer and a receiving circuit. In order to achieve a wide range of ultrasonic ranging, it is required not only that the ultrasonic receiving circuit can amplify the weak signal reflected from the distant target, but also that the strong signa

The basic ultrasonic transducer is commonly known as flat probe or straight probe, its structure includes many functions,like piezoelectric chip, the function of protective film and fast absorption