Method and a system for determining the geometry and/or the localization of an object

Abstract

A method for determining the geometry and/or the localisation of an object comprising the steps of:

• • sending one or more signals by using one transmitter;
  • receiving by one or more receivers the transmitted signals and the echoes of the transmitted signals as reflected by one or more reflective surfaces
  • building by a computing module a first Euclidean Distance Matrix (EDM) comprising the mutual positions of the receivers;
  • adding to the EDM matrix a new row and a new column, the new row and a new column comprising time of arrivals of said echoes and computing its rank or distance to an EDM matrix
  • determining the geometry and/or the position of the object based on said rank or distance.

Description

RELATED APPLICATION[0001]The present application claims the priority of the Swiss patent application CH2935 / 12 of Dec. 22, 2012, the content of which is hereby incorporated by reference.FIELD OF THE INVENTION[0002]The present invention concerns a method and a system for determining the geometry and / or the localisation of an object, e.g. of a wall, a room, a microphone, a loudspeaker or a person. The invention concerns in particular the estimation of the geometry of a room from its acoustic room impulse responses (RIR).DESCRIPTION OF RELATED ART[0003]The problem of estimating the geometry of a room from its acoustic room impulse responses (RIR) can be resumed by a question: can a person blindfolded inside a room hear the shape of the room after having snapped his fingers? In other words can the person reconstruct the 2-D or 3-D geometry of the room from the acoustic room impulse response (RIR)?[0004]Beyond the question of uniqueness, meaning that the RIR is a unique signature of a ro...

AI Technical Summary

Benefits of technology

[0039]The advantage of use the EDM approach is that it is exact, not approximate (like e.g. the discrete Hough transform). It is then a clear-cut criterion for good combinations of echoes.

[0040]It can be applied for many signals (acoustic signals, radio signals, UWB signals, etc.). It is very general and can be extended to multiple sources, multiple microphones very easily (as will be discussed here below, it can be applied to MIMO applications).

Problems solved by technology

However the described algorithm does not propose to find the source location immediately as there is a huge number of intermediated steps and hypothesis.

Moreover since many impulse responses have to be measured by putting a fake wall at different positions with respect to the microphone array and the loudspeaker, the resulting matrix of shifted impulse responses is also quite huge and then computing expensive.

The described algorithm is based on the complete knowledge of first and second generation echo Times of Arrivals (TOAs): however the second generation is often difficult to obtain for practical reasons (e.g. attenuation of the signal).

Then the proposed algorithm is not applicable in practice since without using second-order echoes a single RIR does not suffice for reconstructing the shape of the room.

The known solutions are then not often applicable in practice.

They require also a huge number of receivers and / or transmitters.

Images