US3846780A - Intrusion detection system - Google Patents

Intrusion detection system Download PDF

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Publication number
US3846780A
US3846780A US00382264A US38226473A US3846780A US 3846780 A US3846780 A US 3846780A US 00382264 A US00382264 A US 00382264A US 38226473 A US38226473 A US 38226473A US 3846780 A US3846780 A US 3846780A
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US
United States
Prior art keywords
electrically conductive
conductive member
wire
electrical
tubular member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00382264A
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English (en)
Inventor
H Gilcher
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Westinghouse Electric Corp
Original Assignee
Westinghouse Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US00382264A priority Critical patent/US3846780A/en
Priority to CA203,307A priority patent/CA1012225A/en
Priority to NL7408923A priority patent/NL7408923A/xx
Priority to GB3157574A priority patent/GB1456102A/en
Priority to TR18071A priority patent/TR18071A/xx
Priority to DE2435444A priority patent/DE2435444A1/de
Priority to BE1006088A priority patent/BE817967A/xx
Priority to ES428528A priority patent/ES428528A1/es
Priority to JP49084265A priority patent/JPS5248079B2/ja
Priority to FR7425749A priority patent/FR2238980B1/fr
Application granted granted Critical
Publication of US3846780A publication Critical patent/US3846780A/en
Priority to US05/719,500 priority patent/USRE29896E/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/22—Electrical actuation
    • G08B13/26—Electrical actuation by proximity of an intruder causing variation in capacitance or inductance of a circuit

Definitions

  • a signal developed by the combination in response to a mechanical disturbance includes a low frequency and a high frequency component.
  • the high frequency component code is comparable to a ringing condition much the same as is experienced by an accelerometer.
  • a novel detection system utilizing an insulated electrical wire loosely positioned within an electrically conductive tube member having an inside diameter substantially greater than the diameter ofthe wire.
  • the primary mechanism of operation is a change of capacity between the wire and the tube produced by mechanical disturbance of the wire within the tube.
  • the change in capacitance is transformed into a voltage signal which can be the result of an inherent electret characteristic of the wire developed during fabrication of the wire or can be provided or enhanced by the further application of a bias voltage to the wire.
  • a charge is developed by the electret characteristic of the insulation or the d-c bias voltage and a change in capacitance produced by a mechanical disturbance produces an electrical signal.
  • the loose positioning of the wire within the tube member causes the wire to contact the wall of the tube member at random and intermittent locations.
  • the wire will be displaced relative to the tube in response to surface disturbances and an output signal will be produced which includes both a low frequency and high frequency component. Due to the fact the wire is significantly closer to one wall of the tube than the opposite wall of the tube. the variation of capacitance produced by displacement of the wire relative to the near wall will be significantly greater than the variation in capacitance due to displacement of the wire relative to the far wall.
  • This wire-in-tube detection configuration provides advantages over prior art detection configurations for buried systems in that it does not require intimate contact with the soil to insure sensitivity.
  • FIG. 1 is a schematic illustration of an embodiment of the invention
  • FIG. 2 is a section on the line lIII of FIG. 1;
  • FIG. 3 is an electrical equivalent circuit of the embodiment of FIG. I.
  • FIG. 4 is an alternate embodiment of the invention disclosed in FIG. 1.
  • the electret characteristic found in dielectric insulation which covers some commercially available electrical wire is a characteristic produced during the fabrication of the wire which establishes an electrical charge condition in the dielectric material.
  • a common use of the electret characteristic is in the electret-foil capacitor microphone. In this microphone the electret is a MYLAR film that'is metalized on its outer side. The electret characteristic eliminates the need for a dc bias voltage.
  • the high and low frequency components capable of being developed by the combination of the loosely positioned wire relative to the electrically conductivemember in response to an intrusion disturbance, are both produced as a result in a change in capacitance developed in the vicinity of the intrusion.
  • the high frequency component attributable to an acceleration mode of operation, results from the vibration of the wire relative to the electrically conductive member while the low frequency component, which is attributable to a strain mode" of operation results from the deflection of the electrically conductive memtion of FIG. 5 that the invention concept is equally applicable to a flat electrically conductive member with a wire loosely positioned thereon.
  • a disturbance detector 10 in an embodiment for use in buried applications comprised of a wire 12 loosely positioned within a tubular member 14.
  • the wire 12 consists of an electrical conductor 16 and an insulating coating 18.
  • the selection of the wire for use in the disturbance detector can be such to take advantage of the electret characteristic of some commercially available wire.
  • Some insulating materials used in coating electrical wire exhibit an electret effect. Evaluation of numerous commercially available wire material indicates that the most significant electret signal is derived from a TEFLON coated electrical conductor.
  • the tubular member 14 is constructed from an electrically conductive material such as a metal or a metalized plastic.
  • the tube member 14 is connected to ground and the conductor 16 of the wire 12 is electrically connected to amplifier which in turn is connected to a signal processing circuit 30.
  • FIG. 3 An electrial equivalent circuit of the embodiment of FIG. 1 is illustrated in FIG. 3.
  • the signal source voltage source be it the electret characteristic or a d-c bias voltage, is represented as a generator G, and the tube 14 and wire 12 capacitances are represented as capacitors C1 and C2.
  • FIG. 1 Two types of wire movement are represented in FIG. 1 occurring as a result of a disturbance.
  • the wire movement represented by the dashed lines corresponds to displacement of the wire 12 from the tube contacting points P produced by deflection of the tube 14 in response to the pressure applied to the surface of the ground.
  • the second movement of the wire l2 in response to a disturbance is represented by the dotted lines of FIG. 1 wherein the portions of the wire 12 between the contacts points P undergoes an acceleration mode or vibratory mode of movement due to the mechanical shock introduced by the disturbance.
  • the inside diameter of the tube member 14 is selected to be significantly larger than the outside diameter of the wire 12 such as would be represented by a quarter-inch copper tube and a No. 22 gauge wire.
  • the positioning of the wire 12 within the tube 14 as illustrated in FIG. 1 locates the wire in a near wall relationship with one portion of the tube 14 such that a portion of the wire 12 adjacent to the contact point P establishes minimum distance Dl between the wire 12 and the near wall of the tube member 14. Since the minimum distance (air gap) provides a maximum capacitance. very small displacement of the wire relative to the near tube wall provides maximum capacitance modulation and in turn maximum signal voltages which are applied to the amplifier 20.
  • the same mechanical displacement of the wire 12 provides a much smaller capacitance change since the wire to the tube wall capacitance is much smaller and thus the proportional change in this capacitance is also much smaller. It is therefore obvious that for this detector configuration.
  • the capacitance between the wire 12 and the far wall of the tube wall 14 is negligible.
  • the distance between the wire 12 and the tube wall 14 as defined by Dl corresponds to the wire in a rest condition whereas the distance D2 corresponds to a typical displacement of the wire in response to a disturbance.
  • the signal produced as a result of a relative movement of the insulating material of the wire 12 relative to the conductive members corresponding to the tube 14 and electrical conductor 16 exhibits a low frequency and high frequency component.
  • the low frequency component is a function of the displacement of the wire as illustrated by the dashed lines while the high frequency component corresponds to the dotted portion of the illustration of FIG. 1.
  • the low frequency component is typically in the range of 0.1-10 hz. while a typical high frequency range corresponds to 10-100 hz.
  • the output of the amplifier 20 is applied to a filter circuit 22 which effectively isolates the low frequency and high frequency components and applies the respective components through signal attenuating circuit 24 and 26 to a monitoring device herein represented as recorder 30.
  • the high frequency component of the output signal of the detector circuit 10 is determined by the distance between the contact points P and the mass per unit length of the wire.
  • the isolation of the low frequency and high frequency component of the output signal permits independent monitoring of the components. It has been determined experimentally that the low frequency component provides characteristic information under certain operating conditions while the high frequency component provides information under other operating conditions.
  • the use of the attenuating circuits 24 and 26 provides control of the relative weight attributed to the low frequency and high frequency components depending on the operating conditions to which the detector 10 is subjected.
  • the circuits 24 and 26 would be adjusted such that recorder 30 would respond primarily to the low frequency component of the signal developed by the detector 10.
  • the circuits 24 and 26 would be adjusted such that recorder 30 would respond primarily to the low frequency component of the signal developed by the detector 10.
  • the circuits 24 and 26 would be adjusted such that recorder 30 would respond primarily to the low frequency component of the signal developed by the detector 10.
  • the circuits 24 and 26 would be adjusted such that recorder 30 would respond primarily to the low frequency component of the signal developed by the detector 10.
  • detector systems utilizing a low frequency output signal such as the system in the above-identified patent, are sensitive to wind pressure changes on the ground which adversely affect the accuracy of the detector signal.
  • signal processing circuit 30 has been shown to consist of basic components which clearly indicate a typical utilization of the detector 10, it is apparent that the signal processing circuit illustrated can be replaced with a far more sophisticated electronic system which could cause automatic adjustment of the sensitivity of a monitoring device to the low and high frequency components of the detector device in response to changing conditions.
  • the mechanism for developing the detector signal can be based solely on the electret characteristic of the wire or solely on the application of a remote d-c bias signal or on the combination of the electret characteristic and the d-c bias signal depending on the particular application of the detector device. For instance in a buried application requiring extensive length of the detector device it may be necessary to incally conductive member, electrical insulating material disposed between said first and second electrically conductive members to establish a capacitance therebetween, disturbance of said substantially rigid first elecclude an external d-c bias source to provide an ade- 5 trically conductive member resulting in mechanical disquate signal output.
  • FIG. 1 A typical application of a d-c bias placement of said second electrically conductive memvoltage source is illustrated in FIG. 1.
  • a voltage source her with respect to said first electrically conductive S is applied to the conductor 16 through a high impedmember, the displacement producing a change in said ance device 40. Isolation of the bias voltage from the capacitance.
  • amplifier 20 is provided by capacitor 42. 1O 2.
  • Apparatus as claimed in claim 1 further including cation of the detector device of FIG.
  • I is loosely positioned relative to the electriment of the second electrically conductive member cally conductive member 40 such that impact by an in- 2 with respect to the first electrically conductive member trudcr on the surface of the conductive member 40 will is manifested by the develoment of an electrical signal, cause displacement of the wire 42 relative to the plate said electrical signal consists of a low frequency com- 40 thus producing an electrical signal in accordance ponent corresponding to the capacitance change prowith the operation described above.
  • Amplifier 44 reduced' by separation of said first electrically conductive sponds to the electrical signal by activating alarm cirmember from said second electrically conductive memcuit 46.
  • Teflon do clear 18 330 MV No. 22 Teflon do. red 25.5 26 MV No. 30 Teflon do. I5 275 MV .IZS" O.D. No. 20 Teflon do. hlue 3
  • a disturbance second electrically conductive member disposed in a causing displacement of the loosely positioned flexible loose fitting, intermittent contacting relationship with said first electrically conductive member and being mechanically free to move with respect to said first electrielectrical conductor relative to said substantially rigid tubular member causing a change in said capacitance, said change in capacitance resulting in the development of an electrical signal indicative of the disturbance.
  • said electrical insulating material is a coating on said flexible electrical conductor, the effective diameter of the combination of said flexible electrical conductor and the coating of electrical insulating material being substantially less than the inside diameter of said tubular memher.
  • Apparatus claimed in claim 7 including a d-c voltage source operatively connected to said flexible electrical conductor and said tubular member to establish a charge condition in said insulating material.
  • said electrical signal is comprised of a low frequency and high frequency component, wherein said low frequency component corresponds to the change in capacitance produced by the displacement of said wire element relative to said tubular member in response to said disturbance and said high frequency component corresponds to the vibration of said wire element relative to said tubular member in response to said disturbance.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Switches That Are Operated By Magnetic Or Electric Fields (AREA)
US00382264A 1973-07-24 1973-07-24 Intrusion detection system Expired - Lifetime US3846780A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US00382264A US3846780A (en) 1973-07-24 1973-07-24 Intrusion detection system
CA203,307A CA1012225A (en) 1973-07-24 1974-06-25 Intrusion detection system
NL7408923A NL7408923A (nl) 1973-07-24 1974-07-02 Binnendringingsdetectie-inrichting.
GB3157574A GB1456102A (en) 1973-07-24 1974-07-17 Intrusion detection system
TR18071A TR18071A (tr) 1973-07-24 1974-07-22 Entruesiyon tespit sistemi
BE1006088A BE817967A (fr) 1973-07-24 1974-07-23 Systeme de detection d'intrusion
DE2435444A DE2435444A1 (de) 1973-07-24 1974-07-23 Anordnung zur ueberwachung von stoerungen infolge mechanischer stoesse etc
ES428528A ES428528A1 (es) 1973-07-24 1974-07-23 Aparato para vigilar perturbaciones provocadas por choques mecanicos, presion, impactos, etc.
JP49084265A JPS5248079B2 (ja) 1973-07-24 1974-07-24
FR7425749A FR2238980B1 (ja) 1973-07-24 1974-07-24
US05/719,500 USRE29896E (en) 1973-07-24 1976-09-01 Intrusion detection system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00382264A US3846780A (en) 1973-07-24 1973-07-24 Intrusion detection system

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US05/719,500 Reissue USRE29896E (en) 1973-07-24 1976-09-01 Intrusion detection system

Publications (1)

Publication Number Publication Date
US3846780A true US3846780A (en) 1974-11-05

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US00382264A Expired - Lifetime US3846780A (en) 1973-07-24 1973-07-24 Intrusion detection system
US05/719,500 Expired - Lifetime USRE29896E (en) 1973-07-24 1976-09-01 Intrusion detection system

Family Applications After (1)

Application Number Title Priority Date Filing Date
US05/719,500 Expired - Lifetime USRE29896E (en) 1973-07-24 1976-09-01 Intrusion detection system

Country Status (10)

Country Link
US (2) US3846780A (ja)
JP (1) JPS5248079B2 (ja)
BE (1) BE817967A (ja)
CA (1) CA1012225A (ja)
DE (1) DE2435444A1 (ja)
ES (1) ES428528A1 (ja)
FR (1) FR2238980B1 (ja)
GB (1) GB1456102A (ja)
NL (1) NL7408923A (ja)
TR (1) TR18071A (ja)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4047166A (en) * 1976-01-26 1977-09-06 Gte Sylvania Incorporated Electrostatically charged cable transducer
US4197529A (en) * 1978-02-17 1980-04-08 The United States Of America As Represented By The Secretary Of The Navy Intrusion detection apparatus
FR2439509A1 (fr) * 1978-10-19 1980-05-16 Gen Electric Capteur a effleurement de type capacitif a une seule electrode
US4236109A (en) * 1977-12-12 1980-11-25 Lockheed Corporation Dielectric monitored composite assembly
US4251849A (en) * 1977-09-27 1981-02-17 Alps Electric Co., Ltd. Trimmer capacitor
US4527150A (en) * 1982-06-11 1985-07-02 Beta Engineering & Industrial Development Intrusion detection system
DE4010774A1 (de) * 1989-04-07 1990-10-11 Hesa Spa Alarm- oder meldevorrichtung
US4994793A (en) * 1989-12-08 1991-02-19 Kevin Curtis Weight shift detector
US20050024210A1 (en) * 2003-07-28 2005-02-03 Maki Melvin C. Integrated sensor cable for ranging
FR2863395A1 (fr) * 2003-12-04 2005-06-10 Internat Pool Safety And Light Barriere pourvue d'un dispositif de detection de contraintes de franchissement
FR2876481A1 (fr) * 2004-10-13 2006-04-14 Atral Soc Par Actions Simplifi Systeme d'alarme equipe d'un detecteur de court-circuit
US20080024297A1 (en) * 2004-07-28 2008-01-31 Senstar-Stellar Corporation Triboelectric, Ranging, or Dual Use Security Sensor Cable and Method of Manufacturing Same
US20080077333A1 (en) * 2006-09-25 2008-03-27 Maxey Lonnie C Apparatus and method for detecting tampering in flexible structures
ITBA20090007A1 (it) * 2009-02-03 2009-05-05 Rocco Carone Sensore capacitivo di presenza per antintrusione e comando
US20130134828A1 (en) * 2010-01-08 2013-05-30 Omron Corporation Electrostatic induction power generator

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2391519A1 (fr) * 1977-05-16 1978-12-15 App Automatiques Ste Fse Dispositif de discrimination de presence
US5705984A (en) * 1996-05-10 1998-01-06 The United States Of America As Represented By The Secretary Of The Navy Passive intrusion detection system
US6025782A (en) 1996-09-04 2000-02-15 Newham; Paul Device for monitoring the presence of a person using proximity induced dielectric shift sensing
DE20301907U1 (de) 2003-02-07 2003-04-30 Wintjens, Rüdiger, 47533 Kleve Synthesizer gelenktes IR-Laser-Sicherheitssystem mit 4D-Barriere und Punkt-Matrix-Anzeige

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US2649579A (en) * 1950-02-01 1953-08-18 Standard Oil Dev Co Detector for seismic exploration
US2787784A (en) * 1954-04-30 1957-04-02 Harold T Meryman Triboelectric detecting system
US2837082A (en) * 1954-03-18 1958-06-03 Elliott Robert Vincent Accelerometer
US2965877A (en) * 1957-06-10 1960-12-20 James H Stein Capacitive-type line hydrophone
US3109165A (en) * 1958-09-05 1963-10-29 Specialties Dev Corp Intruder detecting system
US3750127A (en) * 1971-10-28 1973-07-31 Gen Dynamics Corp Method and means for sensing strain with a piezoelectric strain sensing element
US3763482A (en) * 1971-02-01 1973-10-02 Gte Sylvania Inc Coaxial cable transducer

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3889230A (en) * 1966-09-02 1975-06-10 Woods Hole Oceanographic Inst Capacitive transducer and method of using the same
GB1209506A (en) 1968-03-18 1970-10-21 Marconi Co Ltd Improvements in or relating to vibration detectors
GB1278249A (en) 1968-12-10 1972-06-21 Marconi Co Ltd Improvements in or relating to vibration detectors

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2649579A (en) * 1950-02-01 1953-08-18 Standard Oil Dev Co Detector for seismic exploration
US2837082A (en) * 1954-03-18 1958-06-03 Elliott Robert Vincent Accelerometer
US2787784A (en) * 1954-04-30 1957-04-02 Harold T Meryman Triboelectric detecting system
US2965877A (en) * 1957-06-10 1960-12-20 James H Stein Capacitive-type line hydrophone
US3109165A (en) * 1958-09-05 1963-10-29 Specialties Dev Corp Intruder detecting system
US3763482A (en) * 1971-02-01 1973-10-02 Gte Sylvania Inc Coaxial cable transducer
US3750127A (en) * 1971-10-28 1973-07-31 Gen Dynamics Corp Method and means for sensing strain with a piezoelectric strain sensing element

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4047166A (en) * 1976-01-26 1977-09-06 Gte Sylvania Incorporated Electrostatically charged cable transducer
US4251849A (en) * 1977-09-27 1981-02-17 Alps Electric Co., Ltd. Trimmer capacitor
US4236109A (en) * 1977-12-12 1980-11-25 Lockheed Corporation Dielectric monitored composite assembly
US4197529A (en) * 1978-02-17 1980-04-08 The United States Of America As Represented By The Secretary Of The Navy Intrusion detection apparatus
FR2439509A1 (fr) * 1978-10-19 1980-05-16 Gen Electric Capteur a effleurement de type capacitif a une seule electrode
US4237421A (en) * 1978-10-19 1980-12-02 General Electric Company Single-electrode capacitance touchpad sensor systems
US4527150A (en) * 1982-06-11 1985-07-02 Beta Engineering & Industrial Development Intrusion detection system
DE4010774A1 (de) * 1989-04-07 1990-10-11 Hesa Spa Alarm- oder meldevorrichtung
FR2645671A1 (fr) * 1989-04-07 1990-10-12 Hesa Spa Dispositif d'alarme ou de signalisation dans lequel l'element detecteur est constitue par un cable coaxial blinde polarise en courant continu
US4994793A (en) * 1989-12-08 1991-02-19 Kevin Curtis Weight shift detector
US20050024210A1 (en) * 2003-07-28 2005-02-03 Maki Melvin C. Integrated sensor cable for ranging
WO2005013225A1 (en) * 2003-07-28 2005-02-10 Senstar-Stellar Corporation Triboelectric, ranging, or dual use security sensor cable and method of manufacturing same
GB2420630A (en) * 2003-07-28 2006-05-31 Senstar Stellar Corp Triboelectric, ranging, or dual use security sensor cable and method of manufacturing same
US6967584B2 (en) 2003-07-28 2005-11-22 Senstar-Stellar Corporation Integrated sensor cable for ranging
GB2420630B (en) * 2003-07-28 2007-03-07 Senstar Stellar Corp Triboelectric, ranging, or dual use security sensor cable and method of manufacturing same
FR2863395A1 (fr) * 2003-12-04 2005-06-10 Internat Pool Safety And Light Barriere pourvue d'un dispositif de detection de contraintes de franchissement
US20080024297A1 (en) * 2004-07-28 2008-01-31 Senstar-Stellar Corporation Triboelectric, Ranging, or Dual Use Security Sensor Cable and Method of Manufacturing Same
US7479878B2 (en) 2004-07-28 2009-01-20 Senstar-Stellar Corporation Triboelectric, ranging, or dual use security sensor cable and method of manufacturing same
FR2876481A1 (fr) * 2004-10-13 2006-04-14 Atral Soc Par Actions Simplifi Systeme d'alarme equipe d'un detecteur de court-circuit
US20080077333A1 (en) * 2006-09-25 2008-03-27 Maxey Lonnie C Apparatus and method for detecting tampering in flexible structures
US7881882B2 (en) * 2006-09-25 2011-02-01 Ut-Battelle, Llc Apparatus and method for detecting tampering in flexible structures
ITBA20090007A1 (it) * 2009-02-03 2009-05-05 Rocco Carone Sensore capacitivo di presenza per antintrusione e comando
US20130134828A1 (en) * 2010-01-08 2013-05-30 Omron Corporation Electrostatic induction power generator
US9362849B2 (en) * 2010-01-08 2016-06-07 Omron Corporation Electrostatic induction power generator

Also Published As

Publication number Publication date
JPS5044794A (ja) 1975-04-22
TR18071A (tr) 1976-09-21
BE817967A (fr) 1975-01-23
CA1012225A (en) 1977-06-14
FR2238980A1 (ja) 1975-02-21
NL7408923A (nl) 1975-01-28
GB1456102A (en) 1976-11-17
DE2435444A1 (de) 1975-02-13
ES428528A1 (es) 1976-08-16
JPS5248079B2 (ja) 1977-12-07
USRE29896E (en) 1979-01-30
FR2238980B1 (ja) 1978-12-08

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