DE10029918A1 - Method and device for detecting the presence of people in underground mining - Google Patents

Abstract

Method and device for detecting the presence of people in struts in underground mining that have been expanded with expansion racks, at least part of the expansion racks (10) being associated with detection sensors (25) which are coupled to control devices (27) for the expansion racks, the detection sensors detecting the Scan the work and operating area (24) of the assigned expansion frame and stop their movement sequences when the presence of a person is detected in the detection area (30) of the sensors. According to the invention, the detection sensors of the individual expansion racks can be switched on and off by the control devices and are only activated when the assigned expansion rack is to be moved and are deactivated again after the movement of the assigned expansion rack has ended. The monitoring of the strut therefore takes place only in the area at risk from the movement of a frame, so that any electrosmog which may be harmful to the miners is limited to a minimum by electromagnetic waves emitted by the detection sensors.

Description

The invention relates to a method for detecting the property of people in struts with expansion frames in the underground mining, with at least part of the expansion place detection sensors are assigned that with Steuereinrich lines for the expansion racks are coupled, the Erfas solution sensors at least the working and operating range of the orderly ordered expansion racks and scan them in their movement shutdown processes or a movement of the assigned expansion Do not allow frames if in the detection range of the sensors the presence of a person is determined. The invention is also on a device for detecting the presence of People in struts with subframes in the underground current mining directed, with at least part of the expansion Frame detection sensors are assigned, which with Steuerein directions for the expansion racks are coupled and the at least least the working and operating area of the assigned removal place.

With modern mining of coal or other minerals in the under day mining takes place using one in one Strive for two-way profit tion machine, for example a cutting machine or a Mining planer, the hanging in the longwall of a variety underpinned by side by side expansion racks and is supported, usually all at a conveyor to Removal of the coal or materials obtained are closed, on which the extraction machine also operates.  

After passing the extraction machine, conveyors and Extension frames advanced towards the dismantling front, for what after advancing the conveyor the individual removal place a piece in a row (stolen) then with the help of a screeching cylinder towards the fjord Pull forward (stride) and then the hanging end cap as which extend until the specified support pressure is reached and that Hanging is again safe to do. The working such a progressive expansion is from the state of the Technology well known.

In modern expansion, each expansion rack has its own provided electrical or electro-hydraulic control, wherein the controls with each other for the exchange of information with can be connected to each other, which also means dependent movements on several shields arranged side by side can be carried out. The different movements of a Extension frame can be automatically controlled by a higher-level tax expect to be triggered and carried out independently, it is but also possible to manually select a selected expansion frame to move the keyboard of a control unit, in this If not, the attached to the moving rack itself ordered control unit is operated by hand, but in the be neighboring expansion rack arranged control unit, which has a Control line with the control unit of the expansion to be moved frame is connected (neighborhood control).

A movement of a rack, that is, the retraction of the Hangendkappe (robbery), walking towards the Strebför and the extension of the hanging end cap (setting) may only then take place if there is in the working and operating area of the respective expansion rack, no person is present to deal with accidents To avoid personal injury. As a work and operating area of a rack here is that of the hanging cap, the Lying runners, the rear breaking plate of the expansion frame and the area in front of this face conveyor  be understood, that is, the section of a strut that is supported by an expansion frame. To move the Avoid expansion rack, as long as there are people in this Ge monitoring equipment and - procedures are used that involve robbery, striding and set Only allow the racks if no people are there are at risk.

From DE-OS 36 27 174 is a generic method and a device of the type mentioned is known, wherein the Detection sensors are arranged on the expansion racks, wherein each sensor sends out a continuous signal to the ever monitor the detection area. In the known Ver every individual in the longwall carries a transponder a small transmitter and receiver unit that works with the acquisition sensors at the individual expansion sites and from a sensor is located when the person in the he of the respective sensor. As soon as a sen sor receives a signal from the transponder, there is the tax setting up the expansion rack a control signal, as a result whose the control device of the expansion rack, in which the person is overriding the normal control functions sets and prevents the movement of the frame as long as the person in the work and operating area of the rack located.

The known device and the known method have the Disadvantage that all detection sensors in the face are permanently active are fourth, resulting in a relatively high power consumption result, which is covered by complex, intrinsically safe circuits must become. By permanently activating all sensors in the But the transpon worn by the individuals are also longing who are permanently active and have a large energy requirement, the through a portable energy supply (battery, accumulator) must be covered and at a required minimum operation duration of ten hours is comparatively large and difficult. Dar  in addition, the detection sensors send in the known Ver drive and the known device permanently electromagnetic cal signals, which when all sensors are permanently activated not cause negligible electrosmog in the face, the health effects on the people working in the longwall may have and possibly their ability to concentrate influences what threatens the safety of miners. About that It can also be done by permanently activating all sensors and the electromagnetic waves emitted by these too Malfunctions easily occur when coming from a sensor sent electromagnetic signals may be after more fold reflection or the like falsified and from one whose detection sensor mintered as a signal from a transponder be pretiert and lead to the shutdown of a rack in whose working and operating area there is no miner located and that could therefore be moved safely.

The object of the invention is a method and a device to create the type mentioned, in which electrosmog in Streb to be avoided as a result of the detection sensors and being the power requirement not only of the detection sensors, but also those possibly worn by the persons to be monitored Transponders is as low as possible.

This is achieved with the method according to the invention solved that the detection sensors from the control devices the assigned expansion points can be activated and in front of a planned movement of the expansion racks activated and after completion movement can be deactivated again. The fiction Accordingly, moderate equipment is characterized in that the detection sensors assigned by the control devices Neten expansion racks can be activated and deactivated.

According to the invention, the detection sensors are in the face from the control devices of the off assigned to the sensors Construction sites only activated when there is a movement in the expansion  frame is imminent. Usually a shield is used approximately five seconds before starting the motion sequence announced by a warning signal. At about the same time then also the detection assigned to the extension frame to be moved activated sensor, which after its activation the working and operating area of the affected rack to scan determine whether a person is in the danger zone. The sensor remains activated until the movement sequence (Robbery, striding, setting) of the expansion frame completely det is and is then like by the associated control device who switched off. According to the invention, they are on the removal put arranged detection sensors mostly deactivated and are only switched on when a rack is moved should. This selective control of the individual sensors the power requirement of the monitoring device is only low and Miner exposure to electrosmog is negligible small or not given at all.

Each expansion rack is expedient to have at least one of its own assigned sensor, but it is also conceivable to capture sensors sensors only to be provided on every second expansion frame, the The detection range of the sensors is then so large that it also the working and operating area of the two neighboring ones Expansion racks can be monitored.

The scanning of the working and operating areas of the removal position is preferably based on an active / passive mark development process, in which the people in the long term with a transponder device are equipped by a activated detection sensor itself is activated when the Person in the scanned area of coverage sors arrives or is in it and then to the Erfas solution sensor transmits a presence signal, as a result the detection sensor sends a stop signal to the associated control facility issues. Because in this embodiment of the invention that of a miner, for example, on a helmet or belt  carried transponder device is only activated when the Miner in the work and operating area of an expansion rack that is to be moved shortly, and accordingly only in this comparatively rare case outputs the signal, the transponder's power requirement is only low because it is in one most of the time "Stand-by" mode with low energy consumption. It is therefore out sufficient to power the transponder device comparatively small and therefore light battery or a Ak to be provided.

In a preferred embodiment of the method according to the invention the detection sensors scan their respective detection range cyclically with a cycle time of at most 0.2 seconds. The cycle time of the scanning is expediently in the range between between 10 and 100 milliseconds. This means that a person that in the detection range of a sensor and thus in the Ar working and operating area of the corresponding expansion rack comes, within the very short, in any case under 0.2 seconds the lying cycle time recorded and the presence of the person is indicated by output of the stop signal to the control, so that an expansion rack already in motion can be shut down in fractions of a second, to the in the Do not endanger the danger zone.

A particularly advantageous because simple design results itself when the signals generated by the detection sensors DC signals with different voltages are wherein the DC voltage signals from the control device in their different heights are easily recorded and evaluated the can and where by suitable logging devices logging not only that of the detection sensors stop and release signals, but also from set operating states or the like easily possible is.  

The detection area of each detection sensor pre-detects preferably the working and operating area of the assigned off construction frame and at least part of the work and operation areas of the neighboring expansion racks. A sensor can not only determine whether a person is in the arranged expansion rack that is to be moved or is already moving, but can also determine whether a person in the neighboring expansion frame close to the moving or too moving frame comes and possibly in the short term Work and operating area of this frame arrives, so that whose movement can already be prevented or stopped, be before a person enters the actual danger zone.

The detection sensors preferably lead one cyclically Self-test by, and only useful if after Akti vation of a detection sensor and scanning of its detection no person is detected by the sensor. The self-test of the sensors makes error conditions very bad quickly recognized and can control the expansion rack reported and using a display device, for example a light emitting diode.

The detection sensors can work at different sizes and operating areas of the expansion racks can be adjustable where can be reliably avoided by error messages from a sensor, which may otherwise result from the sensor not being adapted to the Height, width and depth of the expansion rack in the operating state may occur. The detection sensors in FIG Protective housings arranged where they face the harsh operating conditions underground mining are protected. To avoid If there is a risk of firedamp, the detection sensors can work in other areas, such as in the underground mountain construction is known and often required. The detection sensors can, for example, on the stamps of the expansion racks or on whose hanging caps are arranged.  

It is particularly advantageous if the detection sensors each because essentially of a transmitter unit and a receiver unit exist, the transmitter unit a signal for activation tion of a transponder device carried by a person in the Transmits detection area and the receiving unit one of the Transponder device activated in this way receives, which then passed on to a shield monitoring unit is conducted, which it evaluates and as a control signal to the sub the shield movement of the control electronics of the respective Extension rack feeds.

An exceptionally advantageous and particularly functional design of the invention results when the transmitting unit Magnetic field antenna arrangement with two parallel, has in-phase connected ferrite coil antennas, wherein the two ferrite coil antennas preferably each with one Capacitor are connected in series. Which then conveniently next each other approximately parallel to the cap of the respective rack on this arranged ferrite coil antennas generate a common same, complementary and magnetically amplifying field with one in the plane approximately elliptical extension, the larger one Semi-axis between the two antennas parallel to these and whose smaller semiaxis ver perpendicular to the longitudinal direction of the antenna running. The field can thus match the floor plan of each Extension rack to be adjusted so that it with one Sen deunit is possible, the longer than wide extension frame to be monitored completely, but without immediately being neighboring frames can also be recorded. The longitudinal direction of the fer Rit coil antennas are of course expediently about transverse to the longitudinal direction. For an optimal adjustment of the two antennas to the dimensions of the respective expansion rack it is useful if the antennas are spaced from each other which are adjustably attached to the extension frame.

The receiving unit preferably has three at an angle to one another arranged receiving coils, which are thereby able  one that is sent out by the transponder device, only dim sional generated presence signal reliably and independently of which direction the presence signal is received is actually emitted by the transponder device. For this purpose, the three receiving coils are in front of a receiving unit partially arranged at right angles to each other.

In a manner similar to that of the detection sensors, the Transponder devices are designed and each Emp catching device and have a transmitting element, the reception of the signal emitted by the transmitting unit by the Emp catching device is activated by this. The reception direction then has three individual ones arranged at an angle to each other l Receiver on, preferably at right angles to each other are aligned.

It has turned out to be particularly advantageous in practice installed when the ferrite coil antennas of the transmitter unit operating at a frequency between 7 and 11 kHz. tries with a frequency of 9 kHz have particularly good results shows.

To achieve the desired elliptical field shape the ferrite coil antennas are best spaced between 100 and 180 mm apart from each other on the rack, in the ge given floor plan dimensions of a rack of about 4 times 1.5-2 m, a distance between 120 and 150 mm made sense fully proven.

That of the activated transmission element of the transponder device generated presence signal is preferably at a frequency output between 1.5 and 2.5 MHz. In the experiment one has Frequency of 2 MHz proved to be particularly practical, the si is large enough to influence other electro exclude niche components underground, on the other hand  is low enough to generate the desired magnetic field gene.

Further features and advantages of the invention result from the following description and the drawing, wherein a before drafted embodiment of the invention closer to an example he is refined. It shows:

Figure 1 is a side view of one of several jigs arranged side by side in the longwall with a device according to the invention for performing the method according to the invention.

Fig. 2 is a highly schematic plan view of part of the strut with expansion racks according to Fig. 1 in a reduced dimension.

Fig. 3 is a block diagram of a preferred embodiment of the detection sensor used in the invention;

FIG. 4 shows the antenna arrangement of the transmission unit of the detection sensor according to FIG. 3; and

Fig. 5 is a block diagram of a preferred embodiment of the transponder device carried by the person.

For a better understanding of the invention, reference is made to FIG DE-OS 36 27 174 or the corresponding British Offen GB 85/21 813, which is hereby expressly open content of the present application is made.

In Fig. 1, 10 is an expansion frame, the stock is part of a progressive longwall construction underground, as is common when mining coal and other minerals in modern underground mining. A plurality of support frames 10 at the face 11 are arranged side by side, as interpreted in Fig. 2 in a schematic plan view of the expansion of the longwall.

The expansion racks consist in a known manner essentially of a lying on the lying 12 lying frame 13 , a ver articulated with this via a Lemniskaten gear 14 connected fracture plate 15 and with this in turn articulated hanging cap 16 , which is supported by two support cylinders 17 on the lying frame and which underpins the slope 18 . In the front region 20 of the lying frame, pointing towards the front 19 , this is coupled via a back cylinder 21, only indicated, to a face conveyor 22 , on which in turn a mining machine 23 can move, which is indicated in FIG. 2 as a roller cutter loader and which in in a known manner, the coal at the mining front wins when driving through the longwall, which is then transported away by the longwall conveyor 22 . After the passing of the extraction machine 23 at a removal position 10 is the known from individual Rinnenschüs sen and thus articulated in its longitudinal direction formed face conveyor 22 from the back cylinders 21 of the removal point forward in the direction of the mining front 19 , as this is indicated in Fig. 2 with the expansion frame designated 10d. Subsequently, a rack after the other by retracting the Stützzy cylinder 17 and thus lowering the hanging cap 16 from the hanging 18 robbed, moved by retracting the back cylinder 21 towards the front of the mining front 19 (stride) and then closing by extending the support cylinder 17 in the new position is set again. The operation of such a screaming expansion is well known and therefore does not require any detailed explanation.

In order to avoid accidents with personal injury which could occur if people are in the working and operating area 24 delimited by the hanging end cap 16 , the lying frame 13 and the rear break plate 15 , while the removal is one of its movements for robbery, When walking or sitting, the expansion racks 10 are provided with a device for detecting the presence of persons, which is the subject of the present invention. For this purpose, all removal place detection sensors 25 , which are arranged in protective housings 26 on the underside of the hanging end caps 16 . The acquisition sensors are connected via control lines 31 to individual control devices 27 , which are indicated schematically in the figures. The control devices of the individual expansion racks are in turn connected to one another via control cables, as is indicated by the dashed lines 28 in FIG. 2 and as is known in the case of face construction control systems.

The detection sensors 25 a) to f) assigned to the individual expansion racks 10 a) to f) consist of a transmitting and receiving unit which can be activated and deactivated by the associated individual control devices 27 . The method of operation is such that the detection sensors of the various expansion racks 10 arranged next to one another in the strut 11 are not permanently activated, but only the sensors of the expansion racks that are currently carrying out one of their movements (robbing, striding, setting) or shortly should execute. This fact is best seen in Fig. 2.

In the expansion racks 10 a) to f) shown in FIG. 2, the two racks 10 a) and b) shown on the left are already set in their new position advanced in the direction of the dismantling front 19 . Your detection sensors 25 a) and 25b) are not activated, so that they do not respond to the presence of a person in the work area 24 of these racks. In the next expansion frame 10 c), which is to advance as the next frame in the direction of the dismantling front 19 and is to be set again there, the detection sensor 25 c) has been activated by the associated control unit 27 c), which is caused by the signal waves emanating radially from the sensor 29 is indicated. The detection area of the sensor 25 c) is indicated in FIG. 2 by 30 in dash-dotted lines and not only covers the working and operating area 24 c) of the removal position 10 c), but also detects a part of the working and operating areas 24 b) and 24d) of the neighboring expansion racks.

The detection sensor 25 c) is activated by the associated control unit 27 approximately three to five seconds before the time at which the movement of the frame is to begin by retracting the hanging end cap. The detection sensor 25 c) therefore begins to scan the detection area 30 three to five seconds before the intended robbery in order to determine whether there is a person in the working and operating area 24 c) of the support frame to be moved or in the transition areas to the neighboring support racks, which could be endangered by the movement of the frame. If the detection sensor detects a person in the danger area 30 , it sends a stop signal to the individual controller which prevents movement of the frame or continues as long as the person is in the detection area 30 of the sensor.

The detection sensor 25 c) remains activated until the complete sequence of movements when robbing, striding and reinserting the expansion frame has ended. The sensor scans the working and operating area of the shield and partially the neighboring shields cyclically with a short cycle time of about 20 milliseconds and sends a new signal to the controller 27 after the end of each sampling cycle, which is either a release signal if none Person was detected in the hazardous area, or provides a stop signal for an immediate interruption of the movement process when a person gets into the detection area 30 of the sensor during the lifting, walking or setting.

As soon as the expansion frame has reached its new, front position and how the previously moved frames 10 a) and 10b) have been set in the new position, the detection sensor of this frame is deactivated and therefore no longer feels the working and operating range of the frame that has been newly set from.

In FIGS. 3 to 5, a particularly advantageous and before ferred embodiment of a detection sensor 25 and a transponder device 32 is shown (Fig. 5) schematically. As can be seen from FIG. 3, a detection sensor consists essentially of a transmitter unit 33 and a receiver unit 34 , where the transmitter unit begins to emit a signal from a transponder device about three to five seconds before the respective expansion frame (32 in FIG. 5) can be received by a person who is in the detection area. The signal emitted by the transmitter unit then activates the transponder device, which in turn then outputs a signal that is received by the receiver unit of the detection sensor.

As can be seen from FIGS. 3 and 4, the transmission unit has a magnetic field antenna arrangement 35 with two parallel aligned, in-phase connected ferrite coil antennas 36 , each of which is connected in series with a capacitor 37 . The ferrite coil antennas 36 which are arranged next to one another are arranged on the hanging end cap of the associated support frame 10 approximately horizontally, that is to say parallel to the cap, in such a way that their longitudinal direction points in the direction of the dismantling front. As shown in FIG. 4, 36 up to 150 mm from the two approximately at the distance of 120 from one another arrange th ferrite coil antennas a common, mutually complementary and magnetically reinforcing panel 38 generates, which has an approximately elliptical cross-sectional shape whose greater Hal B-axis in the longitudinal direction the coils 36 runs. The field gain resulting from superimposition of the field lines is achieved with essentially the same current requirement that also has a single ferrite coil antenna, which has an approximately circular scanning and detection area as indicated in FIG. 2 at 30. The preferred, elliptical shape of the field 38 has the particular advantage that the shape of the field with a greater length than the width is adjusted to the floor plan of the respective expansion position 10 , which is also longer in the walking direction than in its width, that in the longitudinal direction of the strut is running. It can thus be scanned the entire working and operating area 24 of the respective shield with only a slight overlap of the corresponding area of an immediate neighboring shield with only one detection sensor, which in turn has the part before that a person when stepping out of a position also immediately can stop the neighboring sign, for example to control the neighboring sign manually from there with the help of the neighborhood control or to monitor the automatic robbery, walking and setting process with your own eyes.

The field generated by the two ferrite coil antennas 36 is a one-dimensional call field, the frequency of which is determined by a frequency generator 39 and is 9 kHz in the preferred embodiment. In order to ensure that the transponder device is activated in any case by the one-dimensional call field 38 when it comes into the detection range of the detection sensor, regardless of its respective orientation relative to the field 38 , it is provided with a receiver 40 with three individual receivers 41 equipped, each because at right angles to each other in the ge carried by a person identification block and thus allow optimal reception in all directions of a three-dimensional coordinate system, which is indicated in Fig. 5 by the names of the coordinate axes X, Y and Z. should be. The field generated by the transmitting unit 33 of the sensor 25 is received by the receiving device of the transponder as soon as the transponder is in the detection area 30 in which the field signal is strong enough, and then activates the transmitting element 42 of the transponder device, which in turn is a one-dimensional Response field generated with a frequency of preferably about 2 MHz. The presence of this response field is determined by the receiving unit 34 of the detection sensor 25 , which then outputs a warning signal to a logic circuit 43 , which triggers an optical alarm on warning lamps (LEDs) 44 via control lines 31 and immediately stops the movement of the corresponding expansion frame. Since the response field generated by the transmitting element is also a one-dimensional field, the receiving unit of the sensor also has three receiving coils 45 , which are arranged at right angles to one another in the sensor and thus always reliably detect the response field, regardless of the spatial orientation the transponder device in the area of the mounting frame is occupying.

It can be seen that an over guarding the strut to avoid endangering people due to progressive expansion racks only in the area follows in which a danger to the miner actually occur can. Unlike the state of the art, there is always only one small section of the strut from electromagnetic waves selected sensors are scanned so that they work in the face Miners are not exposed to permanent electrosmog. Also by the miners when using a so-called active / Passive marking technology carried transponder devices, which in turn is activated by an activated detection sensor be and an Ant to the receiving part of the detection sensor word signal will only be out of their stand-by mode switched to transmit mode if the transponder carrying Person comes into the danger zone from the sensor of a currently in motion or soon to be in motion setting mounting frame is scanned.

In order to further improve the security of the process, detection sensors at the end of a scan cycle Self-test to make sure the sensor is working properly works properly. The self test of the detection sensor follows if after activating the sensor and scanning the No person was found in the detection area. Should However, when scanning the detection area, a person in the  Working and operating area of the expansion rack or in the over corridor to the neighboring expansion racks a self-test is not necessary and the detection sensor sends its stop signal without comparison with the result of a self-test directly to the tax authority advises.

The one from an activated detection sensor to the associated one Control unit transmitted results of the cyclically repeated Samples are taken in a suitable, not shown Storage device captured and logged and can later can be called up and analyzed by the operator of the system. There can also be used later in the event of a malfunction of the monitor Chungseinrichtung be determined, which led to the error and caused the malfunction.

The invention is not based on that shown and described Embodiment limited, but there are many Changes and additions without going beyond the scope of the invention leave. For example, it is conceivable to monitor the Work and operating area of a rack several To arrange individual sensors at different points on the frame, to optimally monitor this. When carrying out the invent In accordance with the method according to the invention, it is also entirely possible to acquire the data to activate not only one expansion frame, son possibly also the sensors of the two neighboring ones Frames so as to enlarge the prohibited area in which people are out of the way while moving a rack allowed to. It is crucial for the invention that not all Sensors of all expansion points in the longwall activated at the same time are, but only the sensors work in the area in which Danger to persons caused by the movement of the frames can actually occur.

Claims (36)

1. A method for detecting the presence of people in struts removed with expansion racks in underground mining, where at least part of the expansion racks are assigned detection sensors that are coupled to control devices for the expansion site, the detection sensors at least the working and operating area of the assigned Scanning the removal frame and stopping its movement sequences or not allowing the assigned removal frame to move if the presence of a person is detected in the detection area of the sensors, characterized in that the detection sensors ( 25 ) are controlled by the control devices ( 27 ) of the assigned removal frame ( 10 ) can be activated and activated before a planned movement of the expansion racks ( 10 ) and deactivated again after the movement has ended. 2. The method according to claim 1, characterized in that at least one separate detection sensor ( 25 a-f) is assigned to the expansion frame ( 10 a-f). 3. The method according to claim 1 or 2, characterized in that the detection sensor ( 25 ) of a moving rack ( 10 ) is activated a time before the planned rack movement and then the working and operating area ( 24 ) of at least the assigned rack ( 10 ) scans and the Steuereinrich device ( 27 ) transmits a stop signal when the presence of a person is detected during scanning, or a release signal is transmitted when no person is detected in the scanned area ( 30 ) during scanning. 4. The method according to any one of claims 1 to 3, characterized in that the scanning of the working and operating areas ( 24 ) of the extension frame ( 10 ) takes place according to an active / passive marking method, in which the in the face ( 11 ) located people are equipped with a transponder device which is activated by an activated detection sensor ( 25 c) itself when the person enters or is located in the scanned detection area ( 30 ) of the detection sensor ( 25 c) and which is then connected to the detection sensor ( 25 c) transmits a presence signal, as a result of which the detection sensor ( 25 c) outputs a stop signal to the assigned control device ( 27 ). 5. The method according to any one of claims 1 to 4, characterized in that the detection sensors ( 25 ) cyclically scan their respective detection area ( 30 ) with a cycle time between approximately 2 and 200 ms. 6. The method according to claim 5, characterized in that the Cycle time is preferably in the range of 10 to 100 ms. 7. The method according to any one of claims 1 to 6, characterized in that the Si signals generated by the detection sensors ( 25 ) signals are DC voltage signals of different magnitudes. 8. The method according to any one of claims 1 to 7, characterized records that the signals generated by the detection sensors are binary and the information to be transmitted through serial protocols are encoded. 9. The method according to any one of claims 1 to 8, characterized in that the detection area ( 30 ) of each detection sensor ( 25 c) the working and operating area ( 24 c) of the associated expansion rack ( 10 c) and at least part of Working and operating areas ( 24 b, 24 d) of the neighboring expansion racks ( 10 b, d) are recorded. 10. The method according to any one of claims 1 to 9, characterized in that the detection sensors ( 25 ) perform a self-test cyclically. 11. The method according to claim 10, characterized in that the self-test of a detection sensor ( 25 ) after its activation is only carried out when no person is detected by the sensor when scanning the detection area ( 30 ). 12. A device for detecting the presence of people in struts with underground racks in underground mining, where detection sensors are assigned to at least part of the racks, which are coupled to control devices for the racks and at least the working and operating area of the assigned racks Scan, characterized in that the detection sensors ( 25 ) can be activated and deactivated by the control devices ( 27 ) of the associated expansion frames ( 10 ). 13. The device according to claim 12, characterized in that the detection sensors ( 25 ) are adjustable to different sized work and operating areas of the expansion rack ( 10 ). 14. Device according to claim 12 or 13, characterized in that the detection sensors ( 25 ) monitor the detection area ( 30 ) cyclically with a cycle time of at most 0.2 s. 15. Device according to one of claims 12 to 14, characterized in that the detection sensors ( 25 ) in Schutzgehäu sen ( 26 ) are arranged. 16. Device according to one of claims 12 to 15, characterized by logging devices for detecting and logging the setting of the detection sensors ( 25 ). 17. Device according to one of claims 12 to 16, characterized in that the detection sensors ( 25 ) are connected to the control devices ( 27 ) via control signal lines. 18. Device according to one of claims 12 to 17, characterized in that the detection sensors ( 25 ) work in the intrinsically safe power range. 19. Device according to one of claims 12 to 18, characterized in that the detection sensors ( 25 ) are preferably arranged on the hanging end caps ( 16 ) of the extension frame ( 10 ). 20. Device according to one of claims 12 to 19, characterized in that the detection sensors ( 25 ) are associated with display devices. 21. The device according to claim 20, characterized in that the display device best of light emitting diodes or the like hen. 22. Device according to one of claims 12 to 21, characterized in that the detection sensors ( 25 ) each consist essentially of a transmitter unit ( 33 ) and a receiver unit ( 34 ), the transmitter unit ( 33 ) providing a signal for activation transmits a transponder device ( 32 ) carried by a person in the detection area ( 30 ) and the receiving unit ( 34 ) receives a signal transmitted by the activated transponder device ( 32 ). 23. Device according to one of claims 12 to 22, characterized in that the transmitting unit ( 33 ) has a magnetic field antenna arrangement ( 35 ) with two parallel, in-phase connected ferrite coil antennas ( 36 ). 24. The device according to claim 23, characterized in that the two ferrite coil antennas ( 36 ) are each connected in series with a capacitor ( 37 ). 25. Device according to one of claims 12 to 24, characterized in that the juxtaposed ferrite coils antennas ( 36 ) are arranged approximately parallel to the cap of the respective removal position ( 10 ) on this. 26. Device according to one of claims 12 to 25, characterized in that the longitudinal direction of the ferrite coil antennas ( 36 ) extends approximately transversely to the longitudinal direction. 27. Device according to one of claims 12 to 26, characterized in that the receiving unit ( 34 ) has three mutually angled receiving coils ( 45 ). 28. The device according to claim 27, characterized in that the three receiving coils ( 45 ) of a receiving unit ( 34 ) are arranged at right angles to each other. 29. Device according to one of claims 12 to 28, characterized in that the transponder device ( 32 ) comprises an receiving device ( 40 ) and a transmitting element ( 42 ) which, upon receipt of the signal ( 38 ) transmitted by the transmitting unit ( 33 ) is activated by the receiving device ( 40 ). 30. Device according to one of claims 12 to 29, characterized in that the receiving device ( 40 ) has three individual receivers ( 41 ) arranged at an angle to one another. 31. The device according to claim 31, characterized in that the individual receivers ( 41 ) are aligned at right angles to each other. 32. Device according to one of claims 12 to 31, characterized in that the ferrite coil antennas ( 36 ) of the transmitting unit ( 33 ) are operated at a frequency between 7 and 11 kHz. 33. Device according to claim 32, characterized in that the frequency is 9 kHz. 34. Device according to one of claims 12 to 33, characterized in that the ferrite coil antennas ( 36 ) were in an Ab between 100 and 180 mm from each other on the expansion frame ( 10 ) are arranged. 35. Device according to claim 34, characterized in that the distance is between 120 and 150 mm. 36. Device according to one of claims 12 to 34, characterized in that the presence signal generated by the activated transmitting element ( 33 ) of the transponder device ( 32 ) is preferably output at a frequency between 1.5 and 2.5 MHz.