Classifications

• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B13/00—Burglar, theft or intruder alarms
  • G08B13/18—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
  • G08B13/189—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems
  • G08B13/19—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using infrared-radiation detection systems
  • G08B13/193—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using infrared-radiation detection systems using focusing means

Definitions

• the invention relates to an angle-resolving passive infrared motion detector for room monitoring with at least one infrared sensor arranged in the focal point area of an optical means, which emits a signal as a function of a heat source, which signal is processed in a downstream evaluation device.
• the ultrasonic detector is an active detector, which in principle is a real motion detector because it detects objects that are actually moving in the room.
• the infrared motion detector is generally a passive detector that reacts to changes in the infrared structure of its surroundings.
• this property also makes it disadvantageously sensitive to changes in temperature which are not due to actual movement.
• radiators, buried heating pipes, incandescent lamps, etc. can erroneously trigger the infrared motion detector due to their change in heat.
• Conventional infrared motion detectors act almost exclusively in the form of a radiation into the room to be monitored.
• any stationary heat sources that act as interferers can be suppressed by aligning the insensitive areas with these interferers.
• a pyrodetector preferably suitable for motion and direction selective detection, is known.
• an angle-selective infrared detector is described which has a PVDF film with a number of IR sensor elements which are attached in the focal plane of a spherical or a spherical-parabolic mirror. Through this mirror optics, a corresponding lobe (radiation finger) or radiation “curtain” is assigned to each individual infrared sensor element in the detection area, so that an angle-selective detection of an infrared radiation source (heat source) is possible.
• the object of the invention is to provide an infrared motion detector which can detect a large number of narrowly defined, ie narrow, solid angles and one for each of these solid angles It can emit a signal if there is a heat source in this solid angle.
• an infrared motion detector described in the introduction in that only one infrared sensor is arranged, that the optical means is a parabolic mirror which is rotatably mounted about the focal point axis which is perpendicular to the optical axis, whereby for the infrared sensor a plurality of narrow-angle room segments are formed and the respective angular position can be determined, and that the evaluation device emits an alarm signal when a heat source moving through several room segments is detected.
• the infrared motion detector With the infrared motion detector according to the invention, a large number of room segments which have a very narrow angle are monitored for a moving heat source. In this way, a large number of horizontal pixels can be obtained, which enable a fine resolution of the space to be monitored and thus ensure reliable detection of a moving heat source or an intruder.
• the mirror can be mounted with tensioning straps and excited to the natural resonance oscillation.
• the respective angular position can be determined with a microcomputer for a predetermined number of spatial segments, so that the respective signal emitted by the infrared sensor is assigned to a specific spatial segment.
• several infrared sensors can advantageously be arranged next to one another in the focal point area, which are made of are directed that an infrared sensor receives the reflected infrared radiation optimally for certain angular ranges of the mirror.
• the infrared sensors are electrically connected.
• the infrared motion detector can be designed with a parabolic mirror and an infrared transmitter arranged in the focal point of the same such that the infrared sensor and the mirror oscillate and together about an axis that is perpendicular to the optical axis monitors a predetermined total solid angle.
• the respective angular position of the total angle and of the oscillation frequency and of the predefined number of room segments is likewise determined by a microcomputer, the evaluation device emitting an alarm signal in the case of a heat source moving through several room segments.
• the passive infrared motion detector is designed with its optical means so that the spatial representation of the focal point area is formed by a focal line, and that a plurality of infrared receivers are arranged on the focal line, each of which has a respective room segment assigned.
• the infrared receivers are formed by the CCD image converter, the signals of which are processed in the evaluation device with the aid of a microcomputer, the movement of a heat source through several room segments causing the alarm to be triggered.
• the optical means can be formed by a parabolic mirror or by a corresponding lens.
• two angle-resolving infrared motion detectors according to the invention are arranged at a certain distance from one another and are aligned with a common monitoring area. This is done by Triangulation of the location and the direction of movement of the heat source or intruder is calculated and an alarm is given depending on the course of movement.
• the distance between the two angle-resolving infrared motion detectors can be relatively small, it does not have to be the distance of a room width of, for example, 3 or 4 m, it can also be in the range from 30 cm to 1 m, because the very detailed high angular resolution in this Arrangement allows an exact location of the heat source.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Burglar Alarm Systems (AREA)
• Geophysics And Detection Of Objects (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6385215

Family Applications (1)

Country Status (1)

Cited By (4)

Family Cites Families (9)

• 1990
  • 1990-07-03 EP EP19900112705 patent/EP0408980A3/de not_active Withdrawn

Also Published As

Similar Documents

Legal Events