title: Wireless Metal Detection and Surface Coverage Sensing for All-Surface Induction Heating.
abstract: All-surface induction heating systems, typically comprising small-area coils, face a major challenge in detecting the presence of a metallic vessel and identifying its partial surface coverage over the coils to determine which of the coils to power up. The difficulty arises due to the fact that the user can heat vessels made of a wide variety of metals (and their alloys). To address this problem, we propose and demonstrate a new wireless detection methodology that allows for detecting the presence of metallic vessels together with uniquely sensing their surface coverages while also identifying their effective material type in all-surface induction heating systems. The proposed method is based on telemetrically measuring simultaneously inductance and resistance of the induction coil coupled with the vessel in the heating system. Here, variations in the inductance and resistance values for an all-surface heating coil loaded by vessels (made of stainless steel and aluminum) at different positions were systematically investigated at different frequencies. Results show that, independent of the metal material type, unique identification of the surface coverage is possible at all freqeuncies. Additionally, using the magnitude and phase information extracted from the coupled coil impedance, unique identification of the vessel effective material is also achievable, this time independent of its surface coverage.
authors.affiliation: Department of Electrical and Electronics Engineering, Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey. vkilic@bilkent.edu.tr.
authors.forename: Veli Tayfun
authors.initials: VT
authors.lastname: Kilic
authors.affiliation: Department of Electrical and Electronics Engineering, Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey. unale@bilkent.edu.tr.
authors.forename: Emre
authors.initials: E
authors.lastname: Unal
authors.affiliation: Department of Electrical and Electronics Engineering, Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey. volkan@bilkent.edu.tr.|School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 639798, Singapore. volkan@bilkent.edu.tr.
authors.forename: Hilmi Volkan
authors.initials: HV
authors.lastname: Demir
keywords: all-surface heating; coils; electromagnetic induction; metal detection; wireless sensing