METHOD FOR OPERATING A METAL DETECTOR AND METAL DETECTOR

A metal detector includes a balanced coil system with a transmitter coil connected to a transmitter unit, which provides a transmitter signal (s) 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. 11. A method for operating a metal detector that includes a balanced coil system with a transmitter coil that is connected to a transmitter unit which provides a transmitter signal (s) with at least one fixed or selectable transmitter frequency (f) or a waveform having at least two different transmitter frequencies (f) , and with first and second receiver coils that provide output signals to a receiver unit which includes a first phase detector and a second phase detector in which the output signals are compared with related reference signals (S; S) that correspond to the at least one transmitter frequency (f) and are offset to each other in phase in order to produce in-phase components (S) and quadrature components (S) of the output signals , which in-phase and quadrature components are forwarded to a signal processing unit that suppresses signal components originating from goods or noise and that further processes signal components originating from metal contaminants , the method comprising:a) providing at least one test loop with a test coil that is inductively coupled with the coil system and with a controllable switch, with which the test loop is opened or closed ...

Walk Through Metal Detection System

The present application is a detection system for locating and characterizing an object placed in a detection area in a three dimensional space. The detection system includes a plurality of magnetic field generators and magnetic field detectors arranged on opposite sides of the detection area and a control system for enabling generation of a magnetic field in the detection area by the magnetic field generators and for measuring of the magnetic field modified by the object at each of the magnetic field detectors. The detection system also includes a processor for processing the measured magnetic field to obtain a data set characterizing the object and a location of the object. The processor applies a reconstruction process on a predefined number of measurements of the modified magnetic field.

Walk Through Metal Detection System

The present application is a detection system for locating and characterizing an object placed in a detection area in a three dimensional space. The detection system includes a plurality of magnetic field generators and magnetic field detectors arranged on opposite sides of the detection area and a control system for enabling generation of a magnetic field in the detection area by the magnetic field generators and for measuring of the magnetic field modified by the object at each of the magnetic field detectors. The detection system also includes a processor for processing the measured magnetic field to obtain a data set characterizing the object and a location of the object. The processor applies a reconstruction process on a predefined number of measurements of the modified magnetic field. 1. A detection system for locating and characterizing an object within a detection area in a three-dimensional space comprising:a. a plurality of magnetic field generators arranged on at least a first side of the detection area;b. a plurality of magnetic field detectors, arranged on at least a second side of the detection area, wherein the second side is opposite to the first side;c. a control system for generating a magnetic field in the detection area by the magnetic field generators and for measuring a modified magnetic field at each of the magnetic field detectors, wherein the generated magnetic field is modified by the object; andd. at least one processor configured to process the measured modified magnetic field to obtain a data set characterizing the object and a location of the object, wherein said at least one processor is configured to execute a plurality of instructions defining a reconstruction process on a predefined number of measurements of the modified magnetic field.2. The detection system of further comprising an alarm generation unit for generating an alarm corresponding to at least one predefined type of object based on one or more parameters in the ...

METHOD FOR OPERATING A MULTI-FREQUENCY METAL DETECTOR AND MULTI-FREQUENCY METAL DETECTOR

A metal detector () has a drive coil (L) and at least one detection coil (L, L) that detect fluctuations in a magnetic field generated by the drive coil, caused by metallic particles present in an inspected object. A multi-frequency transmitter unit () has a converter () with a plurality of drive switches (S, S; S, S) driven by a drive controller (). The drive switches alternately conduct a drive current through the drive coil to generate an electromagnetic field with two or more different frequency components. A waveform of the drive current is determined, as is at least one pulse-modulated (PXM) signal corresponding to the determined waveform. The determined PXM-signal is determined online or is stored in a memory module (). The determined PXM-signal is generated and applied to control the drive switches. The drive current can be applied to the drive coil through an admittance unit (). 1. A method for operating a metal detector which has a drive coil that produces an electromagnetic field in a product , at least one detection coil that is arranged to detect fluctuations in a magnetic field caused by the presence of metallic particles in the product , and a multi-frequency transmitter unit having a converter with a plurality of drive switches that are driven by a drive controller according to operating instructions , with the drive switches alternately conducting a drive current (i) through the drive coil so that the generated electromagnetic field exhibits two or more different frequency components (f , f); the method comprising the steps of:{'sub': D', 'D1', 'D2, 'determining a waveform of the drive current (i) for the at least two different frequency components (f, f);'}{'sub': PXM', 'D, 'determining at least one pulse modulated (“PXM”) signal (s) that is a modulated pulse sequence which corresponds to the determined waveform of the drive current (i), each of the PXM signals being either a pulse-width modulated signal or a pulse-density modulated signal; and'}{' ...

Method for operating a multi-frequency metal detector and multi-frequency metal detector

Method for operating a metal detector (1), which comprises a drive coil (L61) for producing an electromagnetic field in a product, and at least one detection coil (L62, L63) arranged to detect fluctuations in the magnetic field caused by metallic particles present in the product, and a multifrequency transmitter unit (10) comprising a converter (4) with a plurality of drive switches (S41, S42; S43, S44) driven by a drive controller (2) according to operating instructions such, that the drive switches (S41, S42; S43, S44) alternately conduct a drive current (i) through the drive coil (L61) so that the generated electromagnetic field exhibits two or more different frequency components (f, f); comprising the steps of:- determining a waveform of the drive current (i) for the at least two different frequency components (f, f);- determining at least one pulse-width modulated or pulse-density modulated PXM-signal (S) corresponding to the determined waveform of the drive current (i);- PXM-signalaccording to the operating instructions provided selecting the at least one determined PXM-signal (S) which is determined online or stored in a memory module (231; 232) ; and- generating and applying the determined PXM-signal (S) to control the drive switches (S41, S42; S43, S44).The inventive metal detector (1) therefore allows selecting at least one stored PXM-signal (S) stored in the drive controller (2) with which a drive current (i) can be generated with at least two different frequency components (f, f), which drive current (i) is applied directly or via an admittance unit (5) to the drive coil (L61).

Walk-through metal detection system

The present application is a detection system for locating and characterizing an object placed in a detection area in a three dimensional space. The detection system includes a plurality of magnetic field generators and magnetic field detectors arranged on opposite sides of the detection area and a control system for enabling generation of a magnetic field in the detection area by the magnetic field generators and for measuring of the magnetic field modified by the object at each of the magnetic field detectors. The detection system also includes a processor for processing the measured magnetic field to obtain a data set characterizing the object and a location of the object. The processor applies a reconstruction process on a predefined number of measurements of the modified magnetic field.

Walk-through metal detection system

The present application is a detection system for locating and characterizing an object placed in a detection area in a three dimensional space. The detection system includes a plurality of magnetic field generators and magnetic field detectors arranged on opposite sides of the detection area and a control system for enabling generation of a magnetic field in the detection area by the magnetic field generators and for measuring of the magnetic field modified by the object at each of the magnetic field detectors. The detection system also includes a processor for processing the measured magnetic field to obtain a data set characterizing the object and a location of the object. The processor applies a reconstruction process on a predefined number of measurements of the modified magnetic field.

Method for operating a metal detector and metal detector

The method serves for operating a metal detector that comprises a balanced coil system (2) with a transmitter coil (21) that is connected to a transmitter unit (1) and with a first and a second receiver coil (22A, 22B) that are connected to an input of a receiver unit (3), which transmitter unit (1) comprises a transmitter signal path (tp) for which a transmitter signal (tx) with at least one fixed or selectable operating frequency and a related quadrature signal (tx90°) are provided, which transmitter signal (tx) is applied to an input of a transmitter amplifier (12) that forwards the amplified transmitter signal (tx) directly or via a transmitter matching unit (13) to the transmitter coil (21); which receiver unit (3) comprises at least one receiver signal path (rp) in which the modulated receiver signal (rs) received from the balanced coil system (2) is applied directly or via a receiver matching unit (31) to a receiver amplifier (33), which applies the amplified modulated receiver signal (rs) directly or indirectly to a receiver phase sensitive detector (34; 4534), which receiver phase sensitive detector (34, 4534) compares the modulated receiver signal (rs) with reference signals, which correspond to the transmitter signal (tx) and the quadrature signal (tx90°), to produce a demodulated complex receiver signal (rsc) with in-phase receiver signal components (rs-I) and quadrature receiver signal components (rs-Q), which in-phase receiver signal components (rs-I) and quadrature receiver signal components (rs-Q) are processed in a signal processing unit (45) which comprises at least one signal processing path (sp), in which signal components of the complex receiver signal (rsc) that relate to goods or noise are suppressed and in which signal components originating from metal contaminants are further processed. According to the invention at least one transmitter measurement channel (8) is provided, which receives a measurement signal (ms) taken from the transmitter ...

Method for operating a metal detector and metal detector

多周波数金属検知器を動作させるための方法および多周波数金属検知器

【課題】多周波数金属検知器を動作させるための改善された方法、およびこの方法に従って動作する改善された多周波数金属検知器を提供すること。【解決手段】金属検知器（１）は、製品内に電磁場を生成するための駆動コイル（Ｌ６１）と、製品中に存在する金属粒子によって引き起こされる磁場の変動を検知するように配置された少なくとも１つの検知コイル（Ｌ６２、Ｌ６３）と、複数の駆動スイッチ（Ｓ４１、Ｓ４２；Ｓ４３、Ｓ４４）を有する変換器（４）を備える多周波数送信器装置（１０）とを備えており、複数の駆動スイッチ（Ｓ４１、Ｓ４２；Ｓ４３、Ｓ４４）は、駆動スイッチ（Ｓ４１、Ｓ４２；Ｓ４３、Ｓ４４）が駆動電流（ｉＤ）を駆動コイル（Ｌ６１）に交互に伝導し、その結果、生成された電磁場が２つ以上の異なる周波数成分（ｆＤ１、ｆＤ２）を呈するような動作命令に従って駆動制御装置（２）によって駆動される。【選択図】図１ａ

Método para operação de um detector de metal de multifrequência e dispositivo para detectar metal em um objeto sendo inspecionado

método para operação de um detector de metal de multifrequência e detector de metal de multifrequência. método para operação de um detector de metal (1), que compreende uma bobina de acionamento (l61) para produção de campo eletromagnético em um produto, e bobina de detecção (l62, l63) de flutuações no campo magnético causadas por partículas metálicas presentes no produto, e unidade transmissora de multifrequência (10) compreendendo um conversor (4) com uma pluralidade de inter-ruptores de acionamento (s41, s42; s43, s44) acionada por controlador de acionamento (2) com instruções de operação onde os interruptores de acionamento (s41, s42; s43, s44) conduzem corrente de acionamento (id) através da bobina de acionamento (l61), onde o campo eletromagnético gerado exibe dois ou mais componentes de frequência diferentes (fd1, fd2); compreendendo as etapas de: determinar forma de onda da corrente de acionamento (id) para dois componentes de frequência diferentes (fd1, fd2); determinar sinal pxm modulado de pulso-largura ou sinal pxm modulado de pulso-densidade (spxm) correspondente à forma de onda determinada da corrente de acionamento (id); sinal pxmpxm de acordo com as instruções de operação providos que seleciona um sinal pxm determinado (spxm) online ou armazenado em um módulo de memória (231; 232) ; e gerar e aplicar o sinal pxm determinado (spxm) para controlar os interruptores de acio-namento (s41, s42; s43, s44).

Method for operating a metal detector and metal detector

The method serves for operating a metal detector that comprises a balanced coil system (2) with a transmitter coil (21) that is connected to a transmitter unit (1) and with a first and a second receiver coil (22A, 22B) that are connected to an input of a receiver unit (3), which transmitter unit (1) comprises a transmitter signal path (tp) for which a transmitter signal (tx) with at least one fixed or selectable operating frequency and a related quadrature signal (tx90°) are provided, which transmitter signal (tx) is applied to an input of a transmitter amplifier (12) that forwards the amplified transmitter signal (tx) directly or via a transmitter matching unit (13) to the transmitter coil (21); which receiver unit (3) comprises at least one receiver signal path (rp) in which the modulated receiver signal (rs) received from the balanced coil system (2) is applied directly or via a receiver matching unit (31) to a receiver amplifier (33), which applies the amplified modulated receiver signal (rs) directly or indirectly to a receiver phase sensitive detector (34; 4534), which receiver phase sensitive detector (34, 4534) compares the modulated receiver signal (rs) with reference signals, which correspond to the transmitter signal (tx) and the quadrature signal (tx90°), to produce a demodulated complex receiver signal (rsc) with in-phase receiver signal components (rs-I) and quadrature receiver signal components (rs-Q), which in-phase receiver signal components (rs-I) and quadrature receiver signal components (rs-Q) are processed in a signal processing unit (45) which comprises at least one signal processing path (sp), in which signal components of the complex receiver signal (rsc) that relate to goods or noise are suppressed and in which signal components originating from metal contaminants are further processed. According to the invention at least one transmitter measurement channel (8) is provided, which receives a measurement signal (ms) taken from the transmitter ...

Method for operating a metal detector and metal detector

The method, which serves for operating a metal detector that comprises a balanced coil system (2) with a transmitter coil (21) that is connected to a transmitter unit (1), which provides a transmitter signal (s1) with at least one fixed or selectable transmitter frequency (f TX) or a waveform comprising at least two different transmitter frequencies (f TX), and with a first and a second receiver coil (22, 23) that provide output signals to a receiver unit (3), which comprises a first phase detector (341) and a second phase detector (34Q), in which the output signals are compared with reference signals (S RI; S RQ) that correspond to the at least one transmitter frequency (f TX) and are offset to each other in phase in order to produce in-phase components (S3I) and quadrature components (S3Q) of the output signals, which are forwarded to a signal processing unit (4) that suppresses signal components originating from goods or noise and that further processes signal components originating from metal contaminants, comprising the following steps a) providing at least one test loop (28) with a test coil (24) that is inductively coupled with the coil system (2) and with a controllable switch (25), with which the test loop (28) is opened or closed depending on a first control signal (c25) applied to the controllable switch (25); b) applying the first control signal (c25) for closing the controllable switch (25) during a first test interval or applying the first control signal (c25) for recursively closing and opening the controllable switch (25) according to a test frequency during the first test interval, measuring the test signal (S T.phi.) and determining the phase angle (.phi.) of the test signal (S T.phi.); c) applying the first control signal (c25) for closing the controllable switch (25) during a second test interval or applying the first control signal (c25) for recursively closing and opening the controllable switch (25) according to a test frequency during the ...

Method for operating a multi-frequency metal detector and multi-frequency metal detector

Method for operating a metal detector and metal detector

Methods for operating a metal detector that includes a balanced coil system with a transmitter coil connected to a transmitter unit and first and second receiver coils connected to an input of a receiver unit. The transmitter unit includes a transmitter signal path for which a transmitter signal with at least one fixed or selectable operating frequency and a related quadrature signal are provided. The transmitter signal is applied to an input of a transmitter amplifier that forwards the amplified transmitter signal directly or via a transmitter matching unit to the transmitter coil. The receiver unit includes at least one receiver signal path in which the modulated receiver signal received from the balanced coil system is applied directly or via a receiver matching unit to a receiver amplifier, which applies the amplified modulated receiver signal directly or indirectly to a receiver phase sensitive detector, which compares the modulated receiver signal with reference signals, which correspond to the transmitter signal and the quadrature signal, to produce a demodulated complex receiver signal with in-phase receiver signal components and quadrature receiver signal components, which are processed in a signal processing unit which comprises at least one signal processing path, in which signal components of the complex receiver signal that relate to goods or noise are suppressed and in which signal components originating from metal contaminants are further processed. At least one transmitter measurement channel is provided, which receives a measurement signal taken from the transmitter signal path and which includes a measurement amplifier, which amplifies and forwards the measurement signal directly or indirectly to a measurement phase sensitive detector, which compares the measurement signal with the reference signals, which correspond to the transmitter signal and the quadrature signal, to produce a complex measurement signal with in-phase measurement signal ...

Walk through metal detection system

The present application is a detection system for locating and characterizing an object placed in a detection area in a three dimensional space. The detection system includes a plurality of magnetic field generators and magnetic field detectors arranged on opposite sides of the detection area and a control system for enabling generation of a magnetic field in the detection area by the magnetic field generators and for measuring of the magnetic field modified by the object at each of the magnetic field detectors. The detection system also includes a processor for processing the measured magnetic field to obtain a data set characterizing the object and a location of the object. The processor applies a reconstruction process on a predefined number of measurements of the modified magnetic field.