Research On High Precision Ultrasonic Ranging Method And Device

Ultrasonic ranging has been widely used as a kind of non-contact measurement technology which is real-time, easy to use in some high-risk, strong magnetic interference or dark environments. Ultrasound has a very strong directivity, and has a low frequency, energy consumption is slow in the air, compared with the laser, its transmission speed is very slow and easy to real-time control survey, considered it is not sensitive to the color, so it can be used in the environment with smoke. Traditional transit time method, however, the oscillator will not immediately start up at the instant of the transducer with bias voltage, it will produce a delay inequality, while at the receive end as well. This led to a decline in the accuracy of ultrasonic ranging. At the same time amplifying signals with clutter preamplifier, may lead to a loss of signal or deletion, reduced the precision of traditional transit time method measurement.In order to improve the accuracy of ultrasonic distance measurement, dual frequency phase in this paper is applicable to the high precision of ultrasonic ranging method. The method uses two columns of different frequencies of continuous ultrasonic wave, while wave velocity, frequency is known, can through the phase difference to determine the distance between the probe and the obstacles. This method of using continuous ultrasonic wave, solves the oscillator’s delay inequality problem, reducing the transit time method’s range error to a great degree. The measuring distance of the two frequency continuous wave is limited by characteristic of ultrasound wave.Therefore, further research was carried out based on the dual frequency continuous wave phase method, we design a set of ultrasonic ranging system which is based on the two frequency continuous wave ultrasonic ranging, comprehensive transit time method is extended to the range.