Fast, accurate and reliable identification of hidden conductive objects with deterministic and stochastic methods

The identification of a conductive object known in shape but hidden by low- or non-conductive material is a special application of non-destructive eddy current testing. To find the positioning and orientation parameters of an object from the magnetic flux densities measured in a distance of several centimeters, a non-linear inverse problem has to be solved. This can be done by deterministic as well as stochastic optimization methods in principle. In order to fulfill all demands on the identification process, that are high accuracy, reliability and low computation time, a combination of a deterministic and a stochastic method is useful and was therefore applied to the problem at hand. It is shown that the computation time can be decreased enormously applying a hybrid method while the required accuracy and reliability hold.