US 11,668,819 B1
System and method for rapid acoustic assessment of pipe obstructions
André Roman Taras, Montréal (CA); and Mathieu Soares, Montréal (CA)
Assigned to HYDRO-QUÉBEC, Montréal (CA)
Filed by HYDRO-QUÉBEC, Montréal (CA)
Filed on May 27, 2022, as Appl. No. 17/826,788.
Claims priority of application No. CA 3152895 (CA), filed on Mar. 22, 2022.
Int. Cl. G01S 15/89 (2006.01); G01S 7/539 (2006.01); G01S 15/10 (2006.01)
CPC G01S 15/89 (2013.01) [G01S 7/539 (2013.01); G01S 15/104 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for locating and quantifying obstructions in a pipe, the method comprising:
emitting, at an end of the pipe, through a loudspeaker, an emitted signal comprising a wave train, the waves being of an acoustic type;
receiving at the same end of the pipe, through a microphone, a reflected signal resulting from a reflection of the wave train on the obstructions in the pipe;
determining a position of each of the obstructions based on a time delay measured between the wave train of the emitted signal and the wave train of the reflected signal received by the microphone;
determining, for a most upstream obstruction, its degree of obstruction by performing the steps of:
a) extrapolating an energy of the emitted signal and an energy of the reflected signal at the position of the obstruction;
b) calculating a reflection coefficient CD=Er/Ei, where Ei is the extrapolated emitted signal energy and Er is the extrapolated reflected signal energy;
c) calculating a ratio a/A of a partly obstructed section and a complete section of the pipe, the ratio a/A being determined by a function of the reflection coefficient CD; and
determining, for subsequent obstructions, their respective degrees of obstruction by repeating steps a) through c) for each one, and by replacing the extrapolated emitted signal energy Ei with a transmitted energy Et once the upstream obstruction has been passed.