Apparatus and method for removing noise of ultrasonic system

摘要

An apparatus and method for removing noise of an ultrasonic system to improve robustness against noise by removing external noise from a reception signal reflected from an object are provided. The method includes transmitting, by a sensor, a transmission signal to a medium and receiving a reception signal reflected from the medium. A controller is configured to remove noise from a frequency range recognized as a normal signal from the reception signal and calculate a correlation between the transmission signal and a signal in the frequency range recognized as the normal signal in the reception signal. In addition, the controller is configured to determine whether the signal in the frequency range recognized as the normal signal is the normal signal or noise based on the calculated correlation.

主权项

1. A method for removing noise of an ultrasonic system, the method comprising:
transmitting, by a sensor, a transmission signal to a medium and receiving a reception signal reflected from the medium; removing, by a controller, noise of the ultrasonic system beyond a frequency range recognized as a normal signal from the reception signal; calculating, by the controller, a correlation between the transmission signal and a signal in the frequency range recognized as the normal signal in the reception signal; and determining, by the controller, whether the signal in the frequency range recognized as the normal signal is the normal signal or noise based on the calculated correlation, wherein the calculating of the correlation includes:
calculating, by the controller, the correlation between the transmission signal and the signal in the frequency range recognized as the normal signal using:
R(τ)=∫−∞∞f(x)g(x+τ)dx, wherein f(x) denotes a function describing the transmission signal, and g(x+τ) denotes a function describing the reception signal over time, and wherein a frequency of the transmission signal changes over time, and a frequency of the reception signal is increased over time by the Doppler phenomenon by a correlation detector.