Patent ID: 6434539
Filing Date: 2002-08-13
Classification: H01Q

Abstract:
A method for use in a non-homogenous/non-uniform acoustic imaging system for determining beamform factors for forming acoustic beams approximating an optimum acoustic beam for the directional transmission or reception of acoustic energy in a non-homogenous/non-uniform medium by an acoustic phased array system including a first plurality of elements connectable to a second plurality of signal channels wherein the first plurality is greater than the second plurality, comprising the steps of:(a) from a set of initial beamform factors, determining at least one dependent beamform factor of at least one optimum beam to be formed by the acoustic phased array system, (b) determining the maximum and minimum values of the dependent beamform factors, (c) generating a parent population of chromosomes wherein each chromosome includes a gene for and corresponding to each dependent beamform factor and represents a candidate beamformed by the acoustic phased array system for the initial beamform factors and the dependent beamform factors represented by the genes of the chromosome, by (1) generating a first parent population wherein the value of each gene corresponding to a dependent beamform factor has a value between the maximum and minimum values of the corresponding dependent beamform factor and (2) generating a subsequent parent population by cloning of the chromosomes of a surviving population, (d) generating a child population from the parent population by exchanging statistically selected pairs of genes of the chromosomes of the parent population, (e) generating a mutated population from the child population by mutating statistically selected genes of the child population, (f) selecting the surviving population from the mutated population by comparing the chromosomes of the mutated population with a fitness criteria based upon an optimum beamform factor and selecting for the surviving population the chromosomes of the mutated population meeting the fitness criteria, and (g) comparing the chromosomes of the surviving population with a solution criteria and when at least one chromosome of the surviving population meets the solution criteria providing the genes of the chromosome of the surviving population having the best match to the fitness criteria as the dependent factors for forming a beam approximating the optimum beam.