Method for locating an impact on a surface and device for implementing such a method

Method for locating an impact on a surface belonging to an object provided with at least NSENS acoustic sensors, NSENS being a natural integer at least equal to 2, said method being implemented by a central processing unit linked to said acoustic sensors and in which method:

• the sensors are made to pick up respectively NSENS signals Ski(t) from acoustic waves generated in the object by said impact,
• i being an index between 1 and NSENS which denotes the corresponding sensor, where k is the area where the impact occurred
• there is calculated, for each reference point of index j, at least one validation parameter representative of at least one intercorrelation of complex phases representative of said picked up signals Ski(t) and of reference signals rji(t), each reference signal rji(t) corresponding to the signal that would be received by the sensor i in case of impact at a reference point j out of NREF reference points belonging to said surface, NREF being a natural integer at least equal to 1 and j being an index between 1 and NREF, and
• the impact is located by determining at least one reference point as close as possible to the point of impact, by applying at least one validation criterion to the validation parameter, characterized in that said validation parameter is representative of at least one intercorrelation:
• PRODkji1i2i2p(ω)=φSki1(ω)φRji1(ω)*φSki2(ω)*φRji2(ω) . . . φSki2p(ω)*φRji2p(ω)
• where:
• φSki(ω) is the complex phase of Ski(ω), for i=i1, i2, . . . , i2p
• φRji(ω) is the complex phase of Rji(ω), for i=i1, i2, . . . , i2p
• * denotes the conjugate operator, applied to φSki(ω) for i=i2m and to φRji(ω) for i=i2m-1, m being an integer between 1 and p;
• Ski(ω) is the Fourier transform of Ski(t),
• Rji(ω) is the Fourier transform of rji(t),
• p is a non-zero natural integer less than or equal to NSENS/2,
• i1, i2, . . . i2p are 2p indices denoting 2p sensors, each between 1 and NSENS.