A method includes receiving data characterizing a signal obtained by a plurality of magnetic field receivers, the signal formed of a combination of a first magnetic field, a second magnetic field resulting from interaction of the first magnetic field and a first object, and a third signal resulting from motion of receivers within the first magnetic field and/or an external magnetic field other than the first magnetic field. The method also includes determining a component of the signal characterizing a contribution of the second magnetic field to the signal by multiplying the received data by a mapping that characterizes the contributions of the third signal to the signal to cancel the contributions of the third signal. The method further includes providing the determined component of the signal characterizing the contribution of the second field to the signal. Related systems and computer program products are also provided.

The present disclosure relates to systems and methods for uniquely identifying buried utilities in a multi-utility region by sensing magnetic fields emitted from the buried utilities.

A metal detector apparatus having a balanced coil system, a receiver unit, a drive coil with at least one capacitor forming a series resonant circuit connected to a transmitter unit having a converter, and a drive controller. The metal detector apparatus configuration generates a first square wave signal set to a fixed/selectable operating frequency which is applied to a first drive switch connected on one side to a first voltage potential and on another side to a centre tap of a half-bridge circuit. A second square wave signal set is generated to the fixed/selectable operating frequency and is applied to a second drive switch connected on one side to a second voltage potential and on another side to the centre tap, via which a drive current is supplied to the drive coil.

A metal detecting system using search-coil type sensor includes sensor modules that detect respective objects which move around the corresponding sensor modules, each sensor module having one or more sensors that include respective housings having respective inner spaces, respective cores formed to be inserted into the inner spaces of the housings, and respective coils which are each wound around a portion of an outer circumferential surface of each of the housings, the portion corresponding to a position of each of the cores; imaging units that image the respective objects that move around the corresponding sensor modules and image respective persons possessing the respective objects; impedance matching units that are connected to a plurality of the sensor modules, respectively, and perform impedance matching; and amplifiers that are connected to the impedance matching units, respectively, and amplify a fine current and voltage generated during approach of the objects to the sensor modules.

A method includes compressing the dynamic range of the target detection signal so as to correspond to the desired dynamic range (60) of the audio signal (81) that is generated in order to acoustically render this detection signal to the user, so that the quietest signals are audible, the loudest signals do not cause hearing damage for the user, and that the sound volume is able to be perceived gradually for the intermediate-level signals. This avoids losing variations in the detection signal that are below the audibility threshold (63) and clipping them above a maximum hearing comfort threshold (64) in the corresponding audio signal (71) that would be generated according to the prior art.

A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat or other device with one or more wireless power transmitting coils for transmitting wireless power signals. The wireless power receiving device may be a portable electronic device with one or more wireless power receiving coils for receiving the transmitted wireless power signals. The wireless power transmitting device may have foreign object detection coils. Q-factor measurements may be made on the transmitting coil during wireless power transmission and/or voltage measurements may be made using the foreign object detection coils to detect whether a foreign object is present. The foreign object detection coils may include overlapping coils with different winding patterns to enhance foreign object detection coverage.

The disclosure discloses a detection coil structure based on interlayer coupling and a metal object detection system. The detection coil structure includes: a top sub-detection coil and a bottom sub-detection coil, wherein the top and bottom sub-detection coils are the same in structure and similar or same in size and are orthogonal to each other, and both the outer boundaries and geometric symmetry centers of the detection coils are completely coincident; the top sub-detection coil includes a first terminal, a second terminal, a third terminal and a fourth terminal, and the bottom sub-detection coil includes a fifth terminal, a sixth terminal, a seventh terminal and an eighth terminal; and the first terminal is connected to the second terminal, the seventh terminal is connected to the eighth terminal, and the third terminal and the fourth terminal are respectively connected to the fifth terminal and the sixth terminal. When there is no metal object near the coil, the top and bottom sub-detection coils are completely decoupled, and the mutual inductance is zero. When there is a metal object near the coil, the detection coil structure can significantly amplify the impedance variation of the metal object to the entire detection coil to improve the detection effect by means of the mutual inductance coupling effect between the top and bottom sub-detection coils, and at the same time, a staggered arrangement structure can further eliminate non-detection blind zones.

The present disclosure relates to a charging system, a foreign object detection method and component, and a charging control method and device, which belong to the wireless technical field. The foreign object detection method includes receiving a voltage value and a current value of the transmitting coil, and determining a mutual inductance value of the transmitting coil according to the voltage value and the current value of the transmitting coil; receiving a voltage value and a current value of the receiving coil, and determining a mutual inductance value of the receiving coil according to the voltage value and the current value of the receiving coil; and determining whether there is a conductor foreign object between the receiving coil and the transmitting coil according to the mutual inductance value of the transmitting coil and the mutual inductance value of the receiving coil.

A metal detector includes a balanced coil system with a transmitter coil connected to a transmitter unit, which provides a transmitter signal (s1) with at least one fixed/selectable transmitter frequency or a waveform having at least two different transmitter frequencies. First and a second receiver coils provide output signals to a receiver unit, which can include first and second phase detectors in which the output signals are compared with reference signals that correspond to the at least one transmitter frequency and are offset to each other in phase in order to produce in-phase components and quadrature components, which are forwarded to a signal processing unit to suppress signal components originating from goods or noise, and to process signal components originating from metal contaminants.

The invention concerns a combined detector comprising—an active metal detection system comprising at least two vertical posts together defining a transit channel and distributed in the two vertical posts configured to emit an alternating magnetic field and designed to generate signal representative of a perturbation of the magnetic field induced when an individual passes between the two vertical posts, at least one passive metal detection system comprising at least one static magnetostatic sensor configured to generate a signal indicative of an intensity of a static magnetic field, the passive detection system being housed in one of the vertical posts.