Method for Improving the Hit Accuracy of Fire-Fighting Systems Controlled by Infrared and Video Fire Detection

Abstract

A method for improving the hit accuracy of fire detection systems controlled by infrared and video fire detection by means of a first IR/video camera system for the first detection unit (D1) to ensure continuous fire detection and a second IR/video camera system for the second detection unit (D2) to ensure automatic target tracking with respect to the source of fire, as well as to an extinguisher launcher (A) rigidly connected to the second detection unit. The method is characterised by steps through which video/infrared-controlled extinguishing systems can be precisely hit with regard to the target precision, and fires can be combated as quickly as possible, even in the early phase, with as little extinguishing agent as possible.

Claims

1. A method for improving the hit accuracy of fire detection systems controlled by infrared and video fire detection by means of a first IR/video camera system for the first detection unit (D1) to ensure continuous fire detection and a second IR/video camera system for the second detection unit (D2) to ensure automatic target tracking with respect to the source of fire, as well as to an extinguisher launcher (A) rigidly connected to the second detection unit (D2), characterized by determination of the deviation (F1) of the centre point of the extinguishing agent jet (F) in the direction of rotation (C) of the extinguisher launcher (A) to the centre point (M) of the detection area (E) of the second detection unit 2 (D2) by a single test measurement with an extinguishing agent on the source of fire (G), coarse alignment of the extinguisher launcher (A) with the source of fire, by means of the position of the source of fire (G) as determined with detection unit 1 (D1), determination by means of detection unit 2 (D2) of the deviation (G1) of the centre point of the source of fire (G) to the centre point (M) of the detection area (E) of the detection unit 2 (D2), counterbalancing by means of the extinguisher launcher (A) in its rotation (C) towards zero, determination of the width of the horizontal angular range, namely the width of the detected source of fire (G), by means of detection unit 2 (D2), wherein the extinguisher launcher (A) is moved until it is displaced with the centre point (M) of the detection area (E) of the detection unit (2) from the side of the source of fire (G) to the other side of the source of fire (G), or the angular range from the horizontal number of the image points of the thermal image describing the width of the source of fire (G) is set in relation to the number of all heat images available in the horizontal direction, with the associated detection angle, detection of the coincidence of the centre point (M) of the detection area (E) of the detection unit 2 (D2) with the centre point of the extinguishing agent jet (F), wherein knowing the horizontal and vertical intervals (X) and (Y) of the exit of the extinguishing agent of the extinguisher launcher (A) towards the source of fire (G) enables to calculate the tilting of the extinguisher launcher (A) based on a trajectory determined empirically a single time, inasmuch as the extinguisher launcher (A) is set in such a way that said launcher is aligned to the maximal theoretically and necessary throwing width and the throwing width deviation between the actual value and the setpoint value from which the real throwing parabola is calculated, is determined by a single triggering of the extinguishing process, or when the horizontal (X) and vertical (Y) distance of the exit of the extinguishing agent of the extinguisher launcher (A) towards the source of fire (G) is not known, the distance is measured by triangulation and calculated by means of trigonometric functions based on alignment angles (α; β) of the detection unit 1 (D1) and detection unit 2 (D2) with respcet to the source of fire (G), adjustment by means of the movement of the extinguisher launcher (A) in its tilting towards the center of the source of fire (G).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The idea underlying the invention is illustrated in more detail in the following description of the method with reference to the drawings. The figures are as follows:

[0058] FIG. 1 shows a schematic arrangement of an IR/video camera controlled fire extinguishing system with an extinguisher launcher,

[0059] FIG. 2 shows an infrared image or panoramic thermography, for example, of a delivery hall for recycling material,

[0060] FIG. 3 is a schematic representation of the most frequently used motion control of an extinguisher launcher,

[0061] FIG. 4 shows a schematic representation of the components on the extinguisher launcher according to FIG. 3 for describing the method according to the invention for improving the hit accuracy,

[0062] FIG. 5 is a schematic representation of the fire extinguishing system by means of an extinguishing launcher for describing the method for improving the hit accuracy during the tilting movement and

[0063] FIG. 6 is a schematic representation of the use of two IR/video camera systems of the described method allows distance measurement by triangulation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0064] FIG. 1 represents a monitoring area U, in which a source of fire G could be produced, in a room with a lid R. Two IR/video camera systems (hereinafter, referred to as detection unit 1 and detection unit 2, respectively) are used to improve the hit accuracy. The detection unit 1 D1 is responsible for the continuous fire detection. In the case of a detection of a source of fire G, the coarse coordinates for the alignment of an extinguisher launcher A are calculated. However, these are very inaccurate because of the above-described conditions.

[0065] The detection unit 1 D1 and the extinguisher launcher A are attached to the lid R.

[0066] The detection unit 2 D2, which is rigidly connected to the movable part of the extinguisher launcher A, which is directly aimed at the source of fire G, can secure automatic target tracking now actively.

[0067] For improved hit accuracy with respect to the rotary motion of the extinguisher launcher A:

[0068] Usually, there might be a deviation of the centre point of the extinguishing agent jet F in the direction of rotation C of the extinguisher launcher A with the centre point M of the detection area E of the detection unit 2 without prior adjustment of both axes.

[0069] The horizontal deviation F1 of the extinguishing agent beam F with respect to the centre point M of the detection area E can be easily determined by means of a single test measurement with the extinguishing agent. Due to the rigid coupling between the extinguisher launcher A and the detection unit 2, a long-term drift is almost impossible. Therefore, a readjustment can be dispensed with.

[0070] If the deviation F1 is known, the procedure described below follows:

[0071] The extinguisher launcher A is roughly aligned with the source of fire, on the base of the position of the source of fire G determined with the detection unit 1. The deviation G1 or G2 of the centre point of the source of fire G with respect to the centre point M of the detection region E of the detection unit 2 is then determined by means of the detection using 2 and is adjusted to zero by the method of the extinguisher launcher in its rotational movement C. In this case, the deviation F1, which has been determined as described above, must be taken into account as an angle constant.

[0072] The width of the horizontal angular range, that is, the width of the detected source of fire G, through which the extinguisher launcher A must be moved in order to completely extinguish the source of fire G, can be determined via the detection unit 2, which is rigidly connected to the extinguisher launcher A.

[0073] This can be achieved by two methods:

[0074] 1. The extinguisher launcher A is moved until it is displaced with the centre point M of the detection area E of the detection unit 2 from the side of the firing point G to the other side of the source of fire G.

[0075] 2. The angle is calculated from the horizontal number of the image points of the thermal image, which describe the width of the source of fire G, by setting it in relation to the number of image points, i.e. the thermal image points available in the horizontal direction. The associated detected angular range of the IR or video camera can normally be taken from the data sheet of the camera used.

[0076] For improved hit accuracy with respect to the tilting movement N of the extinguisher launcher A:

[0077] Ideal for improving the hit accuracy in the tilting movement N of the extinguisher launcher A would be a coincidence of the centre point M of the detection area E of the detection unit 2 with the centre point of the extinguishing agent jet F according to FIG. 4.

[0078] Since the course of the extinguishing agent jet F, as soon as it is applied at an angle to the earth attraction, has a parabolic course which is related to the exit velocity of the extinguishing agent, the application angle to the attracting force and the material composition (eg water/foam ratio), it always deviates from this ideal line. This vertical deviation describes F2.

[0079] If the distances X and Y according to FIG. 6 and thus the distance J of the extinguishing agent exit of the extinguishing device A to the source of fire G are known, the tilting of the extinguishing launcher A can be calculated from a trajectory empirically determined a single time. To do so, the extinguisher launcher A is set in such a way that said launcher is aligned to the maximal theoretically and necessary throwing width. The throwing width deviation between the actual value and the setpoint value is determined by a single triggering of the extinguishing process. This enables to calculate the real throwing parabola. If a tilting range is steered instead of a calculated inclination angle, any pressure fluctuations and fluctuations of the extinguishing agent composition are compensated.

[0080] If the distance J of the extinguishing agent exit of the extinguishing launcher A from the source of fire G is not known, the distance J must be determined. Currently, no IR/video camera system provides useful distance information to the source of fire detected.

[0081] Especially when measuring the distance of recycled material, conventional, inexpensive distance measuring systems can be based on laser or radar, since said systems are not able to reflect clearly in the diffuse surface of the material P to be monitored and thus do not provide usable measuring data.

[0082] The use of two IR/video camera systems of the described method allows distance measurement by triangulation according to FIG. 6. Triangulation is a geometric method of optical distance measurement by precise measurement of angles a and 13 within triangles and reference lines Z. The calculation is based on trigonometric functions.

[0083] FIGS. 5 and 6 also show the optional possibility of using a marking laser L which linearly marks the centre of point of the detection area E of the detection unit 2 D2. With E1, only the vertical portion of the detection area of the detection unit 2 D2 is shown.

LIST OF REFERENCE NUMERALS

[0084] A Extinguisher launcher [0085] C Rotation; rotation direction; rotation movement of the extinguisher launcher A [0086] D1 Detection unit 1 [0087] D2 Detection unit 2 [0088] E Detection area of the detection unit 2 [0089] E1 Vertical portion of the detection area E [0090] F Extinguishing agent jet [0091] F1 Horizontal deviation of the extinguishing agent jet F [0092] F2 Vertical deviation of the extinguishing agent jet F [0093] G Source of fire [0094] G1, G2 Deviation of the centre point of the source of fire G from the centre point M of the detection area E of the detection unit 2 [0095] J Distance from the extinguishing agent exit of the extinguisher launcher A to the source of fire [0096] L Marking laser [0097] M Centre point of the detection area E [0098] N Tilting movement of the extinguisher launcher A [0099] P Monitored material [0100] R Lid [0101] U Monitoring area [0102] X Distance from the extinguishing agent exit of the extinguisher launcher A to the source of fire G [0103] Y Vertical distance from the extinguishing agent exit of the extinguisher launcher A to the source of fire G [0104] Z Triangles or reference lines [0105] α Alignment angle; angle for Z [0106] β Alignment angle; angle for Z