METHOD AND APPARATUS FOR MEASURING DISTANCE BY USING FREQUENCY SEPARATION IN ULTRASONIC SIGNAL, CONCERNED WITH EXTRACTING RECEIVING SIGNAL OF ORIGINAL PULSE BY SEPARATING INTRINSIC SIGNAL FROM ULTRASONIC SIGNAL

摘要

PURPOSE: A method and an apparatus for measuring distance by using frequency separation in ultrasonic signals are provided to improve measuring accuracy by amplifying small signals to recover original signals. CONSTITUTION: An apparatus for measuring distance using frequency separation from ultrasonic signals includes an ultrasonic pulse transmitter, a sensor, an amplifier, an analog filter, the second amplifier, an analog-digital converter, a memory, a digital signal processor, an output member, and a numeric input member. The sensor responds to a pulse from the ultrasonic pulse transmitter. The amplifier receives signals from the sensor. The analog filter selectively attenuates signals having a specific frequency. The second amplifier amplifies the selected signals. The memory stores digital data converted in the analog-digital converter. The digital signal processor processes data stored in the memory. The output member displays processed result. The numeric input member sets processing conditions. A communicator exchanges information between the processor and outer components. A time delay between a transmission time of an initial pulse and an arrival time of the initial pulse is measured.