Advanced Metal Detector modelling

Abstract

This thesis describes an investigation of the effects of coil placement errors in very low frequency metal detector heads. An intended application of the metal detector is in finding metallic tripwires in minefields. Tripwires are considered to be some of the most difficult types of target to detect in humanitarian demining. Previous studies show the very low frequency metal detector is one of the most suitable tools to detect metal tripwire targets. However, coil placement errors in the detector head may affect the performance of such detectors. The effects of lateral displacement errors in concentric co-planar coil structures and orthogonality errors in orthogonal coil structures were investigated using an electromagnetic simulation tool. The simulation results suggested that the orthogonal-coil head can detect tripwire targets within 25 cm in ideal conditions. When the orthogonality error is 0.01 degree, the detectable range falls to 18 cm; and is 5 cm for 0.1 degree orthogonality error.