FIRE EXTINGUISHING MONITOR AND METHOD

DESCRIPTION

The present invention relates to a monitor and a method for extinguishing fires.

Conventional remote-controlled monitors are generally composed of actuators (one for each individual operational action) connected by means of a power cable and one or more signal cables to a power board and remote control unit.

This board contains the protection devices and power controls (such as fuses or automatic switches and remote inverters) for each actuator as well as the control components (produced using techniques based on microprocessor/PLC technology or with relay logic circuits) to perform the functions requested from the monitor.

Therefore a bundle of cables is used to connect the monitor to the board, a bundle that must be suitably positioned and attached, and above all protected from possible damage caused by fire.

Furthermore, the board requires a certain amount of space, is rather costly, and in turn, must also be protected from the effects of a possible fire.

Therefore, the technical task proposed in the present invention is to provide a monitor for extinguishing fires which is able to eliminate the technical drawbacks present in prior art .

Within the context of this technical task, one aim of the invention is to provide a monitor for extinguishing fires that is highly efficient, reliable, and can be used for intervention in all environmental conditions .

Another aim of the invention is to provide a monitor for extinguishing fires able to provide far safer protection for its connection to a remote- control unit .

A further aim of the invention is to provide a monitor for extinguishing fires having a small - sized, compact connection to a remote-control unit.

By no means the last aim of the invention is to provide an extremely efficient and versatile method for extinguishing fires.

The technical task, as well as these and other aims, is achieved according to the present invention by providing a monitor for extinguishing fires according to claim 1.

The actuators of the mobile components of the monitor, mounted directly on the monitor in question, are already internally equipped with control and command devices, are powered at very low voltage, and possess a serial interface for connection to a bus .

These characteristics permit connection of all monitor actuators to a single cable that connects the monitor directly to the remote-control unit, which can consist of a simple local control box which can also be portable.

Other characteristics of the present invention are further defined in the successive claims.

Further characteristics and advantages of the invention will be made clearer from the description of a preferred but not exclusive embodiment of the monitor for extinguishing fires according to the invention, illustrated by means of a non- limiting example in the appended drawings, wherein: figure 1 shows a view in perspective of the monitor according to a preferred embodiment of the present invention; figure 2 shows a vertical side view of the monitor in figure 1;

figure 3 shows a block diagram illustrating the servomotor connections to the remote- control unit of the monitor in figure 1; and figure 4 shows a logical block diagram of the components of the monitor in figure 1.

In the above figures, the monitor is identified throughout by the reference number 1.

The monitor 1 has at least one, and preferably a plurality of mobile components among the various operating positions, such as, but not necessarily, four mobile components 2, 3, 4 and 5, for example.

Each mobile component 2, 3, 4, and 5 is associated with its own specific actuator 6, 7, 8 and 9 mounted directly on the monitor 1.

Each actuator 6, 7, 8 and 9 respectively comprises a servomotor having a motor 44, 45, 46 and 47 respectively, complete with a mechanical reducer box 48, 49, 50 and 51, respectively, presenting an exit axis 52, 53, 54 and 55, respectively, to which is connected the mobile component 2, 3, 4 and 5, respectively, and a position sensor 56, 57, 58 and 59, respectively, of the exit axis 52, 53, 54 and 55, respectively.

More precisely, the monitor 1 has a tubular trunk presenting a first and a second 180° curve 31 and 32, connected by means of a first rotation joint 33 having a rotation axis 29 which is preferably horizontal. The first curve 31 supports a nozzle 28 by means of a threaded nipple for the distribution of the extinguishing fluid, in particular, a water- based foam, and mounted with an internal fluid flow divider valve, while the second curve 32 is in turn connected by means of a second joint 34, having a preferably vertical rotation axis 30, to a fixed collector 35, mounted with an internal opening valve for the flow of the extinguishing fluid to the nozzle 28.

Therefore, in this specific embodiment, the first mobile component 2 is composed of the first curve 31 that is able to rotate in relation to the second curve 32 to regulate the increase of fluid jet power, the second mobile component 3 being composed of the second curve 32 that is able to rotate in relation to the collector 35 to regulate the direction of the fluid jet, the third mobile component 4 being composed of the extinguishing fluid jet divider valve obturator that can be

operated to regulate the flow and/or pressure of the jet, and the fourth mobile component 5 being composed of the opening valve for the extinguishing fluid flow to the nozzle 28, which can be operated to open and close the supply of the extinguishing fluid to the nozzle 28.

Furthermore, each actuator is provided with a corresponding power module 10, 11, 12 and 13, respectively, for direct current supply and localisation, and a corresponding command and control module 14, 15, 16 and 17, respectively, to perform its specific function.

Each control module 14, 15,16 and 17, respectively, presents corresponding interfacing means 18, 19, 20 and 21, respectively, with a bidirectional communication channel to a remote-control unit 22.

Advantageously the monitor 1 comprises a single power supply conductor 24 for serial connection to power modules 10, 11, 12 and 13.

The communication channel is a serial bus 23 having one or more signal conductors.

Preferably the interfacing means 18, 19, 20 and 21 include a standard ,,can open" system for communication with the serial bus 23.

Each position sensor 56, 57, 58 and 59, respectively, of the exit axis 52, 53, 54 and 55, respectively, of the actuator 6, 7, 8 and 9, respectively, is therefore able to continuously detect the current position of the corresponding exit axis 52, 53, 54 and 55 and consequently, of the corresponding mobile component 2, 3, 4 and 5. The information relative to the current position of the mobile components 2, 3, 4 and 5 is therefore made continuously available through the serial bus 23 to the remote- control unit 22.

Advantageously, the interfacing means 20 of the command and control module 16 of the actuator 8 of the third mobile component 4 comprise a printed circuit board inserted directly into the body of the nozzle 28 which is recognised as a network slave node by the control unit 22.

The power supply conductor 24 and the serial bus 23 are integrated in a single cable 25 that connects the actuators 6, 7, 8 and 9 with one another, and in turn connects them to the remote-control unit

22, to simultaneously provide the power supply as well as the command and bi-directional control of monitor 1.

A small duct 36 is included directly on the body of the monitor to position and fix a special cable 25 produced from a material with low smoke emission and resistant to flames for a minimum time span, more precisely, 180 minutes.

The conductors in the cable 25 are insulated with special materials, as well as being shielded and tape-wrapped in pairs for immediate use in industrial environments .

The remote-control unit 22 comprises a microprocessor logic unit for bus 23 coding and management as well as for interfacing with the means available to the operator for operating each mobile component 2, 3, 4 and 5.

The operating control means for the mobile components 2, 3, 4 and 5 comprise a manipulator device and preferably also a touch screen type display 26.

The manipulator device comprises a joy- stick 27 having four positions to control the first and

second actuators 6 and 7, a joy- stick 37 having two positions to control the third actuator 8, and two press-buttons 38 to control the fourth actuator 9.

The display 26 provides all the retroactive information on the status of the monitor 1, including the position of the mobile components 2, 3, 4 and 5, as well as their various limit positions and their operating conditions .

The touch- screen type display makes it possible to send all commands directly to the monitor 1 as an alternative to using the manipulator device described previously.

It is also possible to use a single control unit 22 for the independent control and command of the two monitors; in this case, a cable 25 for each monitor 1 is connected to the same control unit 22.

In the case where the remote-control unit is used to control the command of both monitors, the manipulator device also comprises two further press-buttons to select the specific monitor the operator wishes to use.

In a variant of the invention the remote-control unit 22 also presents a means for regulating the

speed of the operating motion of each mobile component 2 , 3 , 4 5.

In this case the four-position joy-stick 27 is replaced by a 2x4 position type version. Each movement is activated at normal operating speed by pressing the lever, while maximum operating speed is achieved by pressing the lever to its limit; when a further press-button next to the joy- stick is pressed, or maintained pressed down, all operating speeds are reduced to slow and normal speed respectively (this function is especially suited for micrometric adjustment of the monitor jet) .

One or more supplementary control units 50 can be connected to the control unit 22 by means of serial cable in order to localise the monitor command on several positions .

Since the serial connections to the control unit can also be achieved using optical fibres, the length of the projected distances can be designed according to necessity.

Naturally the control unit can be completed with an interface connection with other devices on more

complex installations for fire extinguishing purposes .

Moreover, a safety power supply module is able to guarantee emergency monitor function even in the case of main line power failure.

The method for extinguishing fires using the monitor 1 consists in detecting the position of the fire and activating the mobile components 2, 3, 4 and 5 of the monitor 1 in order to operate a jet directed exactly at the position of the fire.

As an alternative, the position of the fire is detected previously, and then the mobile components 2, 3, 4 and 5 of monitor 1 are activated successively in order to operate a jet not directly at the position of the fire, but to obtain a rainfall action by the extinguishing fluid jet on an area centred in the position of the fire.

In this case, the complete system comprises at least a first sensor means and a second sensor means based on different physical principles and connected to the remote-control unit 22. By way of example, the first sensor means comprise one or more infrared- sensitive flame sensors, while the

second sensor means comprise one or more video camera sensors using CMOS technology.

Therefore the fire is recognised and confirmed by the first and second sensor means that operate using different technologies to guarantee maximum safety and efficiency for both alarm detection as well as for eliminating false alarms through the automatic discrimination of inaccurate effects in environments not caused by fire.

Based on signals transmitted by sensor means, the remote-control unit 22 is able to determine the three-dimensional coordinates of the source of the fire .

The coordinates obtained in this manner are used to transmit a command signal through the serial bus 23 to the actuators of the first and second mobile components 2 and 3 for the automatic direction of the monitor 1 and to the actuator of the third command component 4 to regulate the flow as well as the pressure of the jet.

Therefore, in this way, it is possible to obtain maximum direct and indirect jets for the fire underway, while also automatically taking into consideration all the limits and architectural

barriers that may exist in the environment, in particular the maximum operating height that can be achieved by the jet according to any roofing present.

In this manner, it is possible to obtain an extinguishing system that combines the extinguishing efficiency provided by a monitor together with the selectivity and accuracy in intervention doses associated with precision in detecting the original fire zone.

The present invention provides an extremely precise method to determine the position of the fire by using an algorithm that calculates the space and time evolution of the image transmitted by two video cameras positioned parallel to each other, at the same height and on the same axis. The algorithm measures the size of the image by counting the number of pixels over a set threshold and, when the increase of the number of pixels over the set threshold continues, exceeding an established time span, an alarm signal is generated, transmitted from the position of the fire, calculated through triangulation of the image acquired from the two video cameras, after which the alarm signal in the

position of the fire calculated in this manner is transmitted to the program that controls at least one monitor conceived to extinguish the fire.

More precisely, the logic of the detection system of the position of the fire in a preferred case is described below.

The images from the two video cameras are pre- filtered through optical filters that allow only the infra red component of the light radiation to pass through, limiting the influence of the environmental light and normal light sources. The detection of a potential fire source is obtained by means of the algorithm which analyses the space and time evolution of the images. The first step of the algorithm consists in filtering a threshold of the image, which eliminates all those light sources which do not possess an optical power strong enough to be considered as the start of a fire, but which could trigger false alarms . The threshold is calculated, together with the adequate diaphragm opening, to obtain the visibility of fairly luminous sources close to infrared. The image processed in this way is composed of bright spots (the light sources) on a black ground. The size of

each light spot is measured by counting the number of pixels over the threshold, saving the variations compared to the previous image each time. An established number of images, such as three for example, are acquired per second. Staring with the principle that a fire source tends to increase its area over an established time span, and therefore to increase the number of pixels over the threshold inside the image captured by the video camera, it is possible to discriminate between the presence of a light source that can be a fire, from a light source such as a light bulb or a candle, whose size normally remains constant. The thresholds for the total number of pixels, for the variation percentage of the number of pixels, and for the variation speed of the number of pixels, are determined during the initial calibration stage of the system. When the first two thresholds are exceeded (total number of pixels, variation percentage of the number of pixels) a first alarm signal is transmitted to warn of the potential possibility of a fire. To determine whether the variations are caused by a starting point of the fire, the evolution of the image is analysed for a

longer time span: if the pixel increase over the threshold continues in time, then a second alarm is triggered (variation of the number of pixels time duration) . The time span linked with the processing of the second alarm concerns the evolution of the starting point of the fire. Once the alarm has been confirmed based on this time span, the system controls whether another type of fire sensor (such as the smoke or flame sensor for example) is signalling the presence of a fire. If this is the case, the system calculates the distance of the detected starting point and transmits the position of the centre of the fire to the program which controls the monitor conceived to extinguish the fire. The distance is calculated using the triangulation method: once a spot is detected that exceeds the pixel threshold, the images from the two video cameras that focus on the same viewpoint are processed in order to calculate the barycentres of the same spot on the two video cameras and, by using the triangulation process it is possible to calculate the three-dimensional coordinates of the object in question.

The monitor and the method for extinguishing fires conceived in this manner can be subject to numerous modifications and variants while remaining within the context of the inventive concept; furthermore, all elements can be replaced by others which are technically equivalent.

Practically speaking, all materials employed, as well as their size, can be of any type whatsoever according to needs and technical state of the art .