EP2247824B1 - Method for automatically creating a defined face opening in longwall coal mining operations - Google Patents

Description

The invention relates to a method for an automatic production of a defined Streböffnung in a longwall conveyor, at least one mining machine and a hydraulic shield removal having longwall mining operations in underground coal mining.

One problem with the automatic control of longwall mining operations both in the mining direction and in the spearheading direction of the mining machine is, on the one hand, to produce a sufficiently large face opening to ensure the passage of the longwall equipment, for example, without collisions between the mining machine and shingles as the mining machine passes, and, on the other hand To keep the mountain accumulation during the extraction work as low as possible, thus limiting the extraction work as far as possible to the seaming horizon, without cutting too much neighboring rock. The reservoir data on seam size, lying or hanging level and the presence of saddles and / or depressions in the dismantling direction as well as in the longitudinal direction of the longwall equipment, that is to say in the direction of dislocation of the mining machine, are substantially inaccurate to be able to support an automated control of the extraction and expansion work.

In the DE 196 36 389 A1 an initially mentioned method is described, in which a load control of the shield removal point is provided, in which the critical load cases "unilateral load" and / or "peak dance" detected during the setting process using appropriate sensors and by appropriate control of the hydraulic punch and / or a corner cylinder be rendered harmless in their effect. In order to carry out this method, sensors are arranged on the components of the shield-mounting frame whose electrical measured values are used by a control unit for evaluating the measuring signals and for controlling the hydraulic punches and / or the corner cylinder assigned to the shield-mounting frame.

The invention is therefore based on the object to provide a method of the type mentioned, by means of which an automation of the extraction and expansion work with regard to the production of a defined Streböffnung is possible due to the data to be obtained on the longwall equipment.

The solution to this problem arises, including advantageous refinements and developments of the invention from the content of the claims, which are adjusted to this description.

The invention provides in its basic idea a method, in particular for the cutting extraction with a roller cutter as extraction machine, in which by means of at least three of the four main components of each shield frame such as Skid, breaker plate, support arms and fractured area of the Hangendkappe mounted inclination sensors, the inclination of the shield components against the Horizontal determined and calculated from the measured data in a computer unit by comparison with the stored therein, the geometric orientation of the components and their movement during walking defining basic data, the respective banking shield height of the Schildausbaugestells, and wherein further by means of attached to the mining machine sensors Cutting height of the mining machine is detected as a longwall opening, wherein the corresponding data records for each of an associated shield frame traversed portion of the Strebbetriebs stored rt and in terms of a spatially synchronous evaluation at a portion of the longwall operation, the cutting height of the mining machine is compared with the shield height of the shield support frame when the lagging behind with a delay sign extension frame reaches the point on which the comparison with the height of the sign underlying cutting height of the mining machine refers.

The invention has the advantage that initially due to be determined with a comparatively low effort shield height a parameter for the long-distance control in sufficient accuracy and reliability is available. The other parameter used in accordance with the invention consists in detecting the cutting guide of the mining machine by determining its absolute cutting height. Since the hang-end cap of the respective shielding rack reaches the area cleared by the mining machine as it passes by the relevant shield rack frame only after a time delay, that is to say with a so-called expansion delay of one to two expansion steps, the invention provides that the corresponding data records are assigned for each one by one Schildausbaugestell passed section of Strebbetriebs be stored and compared in terms of a local synchronous evaluation. Due to this measure, it is possible to make a statement as to whether the cutting height cut free by the mining machine also corresponds to the later height of the shield at this location, or if any accretion or incidence of convergence will lead to deviations of the height of the shield up or down from the cutting height, those at the next Passing the mining machine by a change or adjustment of their cutting height is taken into account. The same applies to the passage of troughs and / or saddles. In this respect, the method according to the invention essentially uses the determined height of the shield in order to set up, with the inclusion of the cutting height of the mining machine, a control loop for controlling the extraction and finishing work, which in its application leads to automatic maintenance of a defined longwall opening. It can be used as an indicator of the gutter height determined at the front edge of the Hangendkappe bank rights plate height between the upper edge of the cap and lower edge skid appropriately. As a control variable for the height control of the respective shield support frame, the shield height in the field of the shield temple, because otherwise the relative angle between the Hangendkappe and the Bodenkufe in individual Höhenanpassungsphasen leads to strong changes in height relative to the cap tip. insofar It may be expedient to determine the height of the shield between Hangendkappe and Bodenkufe at any point and to use the most appropriate for the respective method point for the height control.

According to an exemplary embodiment of the invention, it can be provided that the stored data sets for cutting heights and blade heights are matched with one another in the sense of a time-synchronous evaluation for a selected section of the longwall operation at the same time. Although at the time of reconciliation the shield construction rack concerned has not yet reached the cleared area, a time-synchronous evaluation of the available data sets can contribute to making forecasts regarding the development of the longwall and inclination changes to the shingles during the upcoming mining progress, so that by appropriate tendencies in the behavior of the stalk opening the extraction and expansion work can be adapted at an early stage with regard to the observance of a predetermined stalk opening.

The invention further provides, in one exemplary embodiment, for an individual longwall operation on the basis of the storage site data and the machine data applicable for the used longwall equipment, a desired height corresponding to the required longwall for the shield height of the shield building site and, in the case of deviations of the determined actual shield height, from the target Shield height automatic control of the cutting height of the mining machine to achieve the target plate height on the expansion takes place. The applicable for the longwall target shield height results on the one hand from the structure of the seam to be collected, the extraction should regularly capture the pending between a competent hanging wall and a competent footing material. This includes, where appropriate, the capture of a pending between coal and competent Hangenden lubricating pack as well as pending between coal and competent Lying Panas layer on. On the other hand, the data, in particular the shield removal point to pay attention to, especially their work area between getting up on the competent footing and a support of the competent hanging ends, so that the cutting height should not be designed to be larger than the work area of shield extension. In this case, the nominal cutting height is to be interpreted so that a passage of the mining machine with the predetermined cutting height within the working area of the shielding expansion station is possible without a collision. Since in operation the competent hanging end should not be attacked by the mining machine, if necessary, a planned lying incision should be provided in the definition of the cutting height in order to provide the required face opening even at lower seam widths.

Due to the inventively provided continuous monitoring of the actual shield height can be checked from section to section of the mining machine, whether the Streböffnung made by the mining machine is maintained according to the desired shield height, or whether it comes to deviations up or down. In accordance with these deviations, it is possible to perform automatic control of the mining machine, either by changing the top section on the leading roller, but leaving the competent hanging end unaddressed, or by changing the undercut on the trailing roller. In this case, the choice of the undercut size or, where appropriate, the overcut size is set for different deviations of the actual shield height from the desired shield height.

Thus, sudden changes in the inclination of the wall end caps of each shield replacement location in limited portions of the longwall operation towards a larger face opening may indicate the presence of localized bursts, and this may thus be differentiated are from an optionally incorrect cutting height of the mining machine.

The comparison of the desired shield height with the actual shield height can be superimposed by the occurrence of convergence, which reduces the cut-free end opening against the supporting effect of the shield construction used. Thus, according to one embodiment of the invention, it is provided that, when the value for the cutting height is undershot by the blade height, the convergence that has occurred has been determined and the convergence compensated, for example, by increasing the undercut. Hereby the influence of the convergence on the reach height can be compensated. In a special embodiment of the invention, it is provided that, in the case of planned shutdowns, the longwall opening is increased by the amount of convergence to be expected over the duration of the operational standstill.

Since the development of the longwall over the mining progress also depends on the relative inclination position the mining machine stands with its rollers to the shield extension points, according to an embodiment of the invention is provided that on the longwall conveyor and / or on the mining machine in each case a tilt sensor is arranged and the angle of inclination of longwall conveyor and mining machine is determined in the degradation direction. Here, the arrangement of an inclination sensor on the mining machine is sufficient. Although the extraction machine traveling on and guided on the longwall conveyor unit effectively forms a unit with the longwall conveyor, to improve the accuracy of the control, it may also be useful to detect the inclination of the longwall conveyor via a tilt sensor disposed thereon. Optionally, the arrangement of a tilt sensor is sufficient only on the longwall conveyor for the purpose of control.

The detection of the inclination behavior of the mining machine in relation to the position of the shield support frame makes it possible, with relative angular positions of shield extension and mining machine to each other on the one hand, a differential angle between the Bodenkufe of the shield support frame and the mining machine or the Strebförderer and on the other hand a differential angle between the hanging wall of the shield frame and the mining machine or to determine the longwall conveyor and to include the respective differential angle in the calculation of the Streböffnung to be produced by the mining machine during the swelling. Thus, it may be appropriate to detect the existing in the degradation direction runner angle against the horizontal and used as a control variable over the existing on the floor of the platform skid slope sensor, as the floor skid usually does not drive on the natural footwall, but along a cut-free step contour of rolling cut marks. When setting the shield support frame, it is therefore due to the high surface pressure of the floor skid with a pressure peak occurring near the top of the tuft often sinking into the artificially produced lying. The sinking of the floor skid is not parallel position, but because of the pressure distribution at the bottom skimmer reinforced at the top of the skiff, so that the bottom skid performs a kind of rotational movement. This effect can be counteracted by using a so-called "Baseliftes", by means of which the skid of a single shield support frame can be raised in the context of the walking process in comparison to the hanging end cap. In particular, when using the Baselifts the floor skids of the relevant shield support frame are raised before the walking process, so that the runners can slide on the lying or lying thereon heap. Thus it can be achieved that the bottom skids do not dig more and more. Also, the baselift is suitable to align a shield support frame when preferring advantageous. In cases where the floor skid without major problems on the footwall drives, a control of the shield support frame is sufficient, taking into account the determined Kufenneigung; insofar as it does not require the determination of a skid angle. On the other hand, in the case of the hang-end cap, such a case occurs less frequently, as long as there is no falling down on the hanging wall, since the hanging-end cap usually runs along the natural hanging slope. This usually does not occur a sinking of the Hangendkappe in the hanging wall. In the case of convergence, however, there is a loss of height at the shield support frame with associated angular movement of the hanging end cap, so that as already stated relative positions between mining machine and Hangendkappe also allow conclusions about the expected face opening.

Furthermore, climbing the mining machine to be detected via the tilt control on the mining machine leads to a reduction in the face opening with the danger of collisions of the mining machine with the shield building sites while a descent of the mining machine in the mining direction leads to an enlargement of the face opening, which may be the maximum Work area of shield extension exceeds. This must then be taken into account by adjusting the cutting height on the mining machine.

Such climbing or diving of the mining machine inevitably occurs when driving through depressions and / or saddles that are pronounced in the direction of dismantling. Thus, for example, the approach of a saddle is detected by the detected change in inclination of the adjacent hanging wall end cap of the Schildausbaugestells. From the measure of the change in inclination between two advancing steps of the shield construction, the change in height in the sense of a reduction in the height can be calculated for each further walking process of the respective shielding structure. To keep the face opening at the set target level and to counteract the reduction of the longwall opening, a control movement to perform an undercut is to be initiated at the mining machine. Subsequently, before a saddle high point is exceeded, a change in inclination of the hanging end cap to the horizontal can be recognized. This is to be used to timely control the cutting work with a return of the driven undercut, so that even when driving over the saddle, the target height of the longwall is maintained. Corresponding control operations, but with the opposite sign, are to be set when driving through a depression, in which the same directional processes prevail in principle.

The inclination sensors arranged on the shield extension points also give a measure of the inclination of the shield extension point transversely to the direction of dismantling, since saddles and depressions can also be pronounced in the direction of the dislocation of the mining machine in the course of the longwall. Since the course of the hanging and lying in the longitudinal direction of the pillar can be derived from the bank of the shield extension, it is possible to control the leading roller and the trailing roller of the mining machine by means of a continuous cut so that no unwanted Hangendanschnitt or no possibly over the set level outgoing lying incision is made so that an unnecessary mountain record or growing coal or the occurrence of bottlenecks between mining machine and shield removal are avoided.

According to one embodiment of the invention, it is provided that acceleration sensors are used as inclination sensors, which detect the angular position of the acceleration sensor in space via the deviation from the gravitational acceleration. In that regard, the angle to the vertical is determined physically, which is to be converted into the angle of inclination for the inclination of the shield components to the horizontal. In this case, to eliminate errors caused by the vibrations of the components used, it may be provided that the measured values ascertained by the acceleration sensors are checked and corrected by means of a suitable damping method.

Fig. 1

ein Schildausbaugestell mit daran angeordneten Neigungssensoren in Verbindung mit einem Strebförderer und einem als Gewinnungsmaschine eingesetzten Walzenschrämlader in einer schematischen Seitenansicht,

Fig. 2

die Strebausrüstung gemäß Figur 1 in der Zuordnung bei einer ortssynchronen Auswertung,

Fig. 3

die Strebausrüstung gemäß Figur 1 im Betriebseinsatz in einer schematischen Darstellung,

Fig. 4a

die Strebausrüstung gemäß Figur 1 bei Kletterneigung der Gewinnungsmaschine,

Fig. 4b

die Strebausrüstung gemäß Figur 1 bei einer Abtauchneigung der Gewinnungsmaschine,

Fig. 5a - c

in einer schematischen Darstellung die zeitversetzte Nachfolge eines Schildausbaugestells zum Verhieb der Gewinnungsmaschine,

Fig. 6a - h

in einer schematischen Darstellung eine Regelung zur Erreichung einer vorgegebenen Streböffnung ausgehend von einer anfangs zu großen Schildhöhe.

In the drawings, embodiments of the invention are shown, which are described below. Show it:

Fig. 1

a shield support frame with inclination sensors arranged thereon in conjunction with a longwall conveyor and a roller skid loader used as mining machine in a schematic side view,

Fig. 2

the longwall equipment according to FIG. 1 in the assignment in a location-synchronous evaluation,

Fig. 3

the longwall equipment according to FIG. 1 in operation in a schematic representation,

Fig. 4a

the longwall equipment according to FIG. 1 when climbing the mining machine,

Fig. 4b

the longwall equipment according to FIG. 1 at a Abtabtneigung the mining machine,

Fig. 5a - c

in a schematic representation of the time-shifted succession of a shielding expansion rack for the removal of the mining machine,

Fig. 6a - h

in a schematic representation of a regulation to achieve a predetermined Streböffnung starting from an initially too large height sign.

The principles of the method according to the invention will be explained in more detail with reference to the figures explained below.

In the FIG. 1 shown longwall equipment comprises first a shield support frame 10 with a bottom skid 11 on which two punches 12 are attached in a parallel arrangement, of which in FIG. 1 only one stamp is recognizable and carry a hanging end cap 13 at its upper end. While the Hangendkappe 13 protrudes at its front (left) end in the direction of the still to be described extraction machine, at the rear (right) end of the Hangendkappe 13 a crash plate 14 is articulated by means of a hinge 15, wherein the broken shield of the two in the side view on the Bodenkufe 1 resting support arms 16 is supported. In the illustrated embodiment, three inclination sensors 17 are attached to the shield support 10, namely, a tilt sensor 17 on the bottom skid 11, a tilt sensor 17 in the rear of the hanging end cap 13 near the joint 15, and a tilt sensor 17 on the fracture shield 14. As not further can be provided on the fourth movable member of the shield support frame 10, the support arms 16, also an inclination sensor, of the four possible inclination sensors 17 three inclination sensors must be installed in order to determine the position of the shield support frame in a working space with the determined inclination values , In this respect, the invention is not limited to the concrete in FIG. 1 illustrated arrangement of the inclination sensors limited, but includes all possible combinations of three inclination sensors to the four moving parts of the shield support frame.

This in FIG. 1 illustrated shield support frame 10 is struck on a longwall conveyor 20, which also has a tilt sensor 21, so that in terms of the control of the longwall equipment in general also here data regarding the conveyor position can be obtained. On the conveyor 20 is a mining machine in the form of a Walzenschrämladers 22 with an upper roller 23 and a lower roller 24, wherein also in the region of the Walzenschrämladers 22, a tilt sensor 25 is disposed, also a sensor 26 for detecting the respective location of the Walzenschrämladers 22 in the longwall and reed rods 27 for measuring the cutting height of the Walzenschrämladers 22. The metrological equipment of the longwall equipment is supplemented by the arrangement of sensors 18 on the punches 12, by means of which the change in the altitude of the hanging wall 13 by detecting the extension height of the punch 12 is possible. Furthermore, a Wegmesssystem 19 is integrated in the Bodenkufe 11, by means of which the respective Schreithub the shield support frame 10 in relation to the longwall conveyor 20 can be determined. As already stated, the arrangement of the inclination sensor 21 on the longwall conveyor 20 is not absolutely necessary as long as the inclination sensor 25 is set up on the drum skid loader 22. In such a case, the inclination sensor 21 may be additionally provided to improve the measurement accuracy.

As it turned out FIG. 2 results, the shield height 31 as well as the cutting height 32 of the mining machine 22 is used for the control of the extraction and expansion work. The shield height 31 is thereby determined between the upper edge 35 of the hang-end cap 13 and the lower edge 36 of the bottom skid 11 on the basis of the values supplied by the inclination sensors 17. As an indicator of the reach height while the determined at the top of the Hangendkappe 13 height is used. As a control variable for the height control of the shield support frame, the shield height in the area of the shield temple is particularly suitable, because otherwise the relative angle between the hanging wall and the floor skid in height adjustment phases leads to strong changes in height relative to the hanging wall. Therefore, it is proposed to determine the height of the shield at any point between the Hangendkappe and the Bodenkufe in the field of Schildausbaugestells and to use the most appropriate for the respective method position for the height control.

The cutting height 32 is determined with the aid of the reed rods 27 between the upper edge 37 of the upper roller 23 and the lower edge 38 of the lower roller 24. As is apparent from FIG. 2 results, the determination of the cutting height 32 takes place at the first coordinate 33, while the plate height 31 is carried out at the opposite of the coordinate 33 reset coordinate 34. This is due to the fact that the shield support frame 10 is moved to the coordinate 33 only after a time delay after the passage of the mining machine 22, so that the first edge of the hanging end cap 13, which is initially at the determination of the cutting height 32 at the coordinate 34, the coordinate 33 only reached at a later date. Thus, a spatially synchronous evaluation of the data obtained means that an adjustment of the cutting height 32 and the shield height 31 only takes place when the lagging with the time lag Shielding frame 10 has reached the coordinate 33, on which the comparison with the blade height 31 underlying cutting height 32nd the mining machine 22 refers. A time-synchronized evaluation is based on the values for the shield height 31 and the cutting height 32 that are currently determined at the coordinate 33 or the coordinate 34 at the same time.

In the operation of a longwall equipment results in an operating situation, as in FIG. 3 is shown by way of example. A seaming horizon 43 projecting between a hanging wall 40 and a footing 41 is recovered by the mining machine 22, with the cutting height 32 of the recovery machine 22 advancing in the plowing direction 44 adjusted so that a lying recess 42 is cut by the lower roll 24. The front upper roller 23 is adjusted so that it can stand under the hanging wall 40 a narrow coal pack, which automatically dissolves due to the cutting work from the hanging wall. In this respect, the set cutting height 32 in FIG. 3 entered. It turns out that in this case the shield height 31 is set larger than the cutting height 32, so that from a collision-free passage of the recovery machine 22 is to go out at the shielding development points 10.

In the FIGS. 4a and 4b FIG. 2 shows the conditions which result when the mining machine 22 has a climbing inclination with respect to the shield support frame 10 (FIG. FIG. 4a ), which manifests itself in the formation of a differential angle 45 between the bottom skid 11 and the lower roll 24 of the mining machine 22. It will be appreciated that in such a case, the risk of collision between the mining machine 22 and the shingles 10 increases, and this risk can be accommodated by changing the cutting height. The same applies to the in FIG. 4b illustrated situation in which the extraction machine 22 has a Abtabtneigung. Here, too, a corresponding differential angle 45 is established, which can be determined on the basis of the positions of mining machine 22 and shielding assembly 10 detected by inclination sensors 17 and 25 and 21, and the respectively entering differential angle 45 must be taken into account accordingly in the longwall control.

In the FIGS. 5a to 5c is shown schematically that the effect of a at the mining machine with a change of the cutting height or cutting position, for example in the form of an undercut set control movement only with a delay of several Nachrückschritten a shield support frame on the shield frame is effective.

So first off FIG. 5a it can be seen that the mining machine 22 is intended to make a directed downward movement over the two horizontal ridges 41, 50a and 50b, with respect to the horizontal leg 41 on which the shield support frame 10 is located, by making two planned lying incisions. It is off FIG. 5b it can be seen that the shield support frame 10 is still standing on the foot 41 when the Extraction machine 22 has already reached the new cutting horizon 50b as the new recumbent. In this respect, during the two recovery runs of the mining machine 22, only the mining machine 22 and the longwall conveyor 20 initially reacted to the predetermined control pulses. Only in the in FIG. 5c reproduced phase of operation follows the Schildausbaugestell 10 of Abtauchbewegung the mining machine 22 according to, with the FIGS. 5b and 5c It should be indicated that already during the deep substitution of mining machine 22 and longwall conveyor 20 with respect to the original footing 41, the cutting height of the mining machine 22 is to be controlled so that at the in FIG. 5c shown operation phase subsequent expansion steps does not oversteer with a high blade height sets. It is so far out FIG. 5c recognizable that there the cutting height of the mining machine 22 in comparison with FIGS. 5a and 5b has been withdrawn in order to avoid a too large stalk opening. As long as the shield support 10 in the in FIG. 5c shown tilt position with transition to the new prone horizon 50b is to take a corresponding elevation of the longwall in purchasing.

Basically, the controller should be freely parameterizable. The adjustment speed of the height control must be set via a freely configurable maximum step height. It is important not to choose the individual steps to be too large in upward movements, so that the longwall conveyor does not get caught on a step at the back and the longwall conveyor must be raised or an existing delivery control must tilt the longwall conveyor.

Based on Figures 6a to 6h Now, the flow control will be described in more detail at a Streböffnungsregulierung emanating from a first too high Streböffnung. The individual cutting fields of the mining machine 22 are in the direction of degradation consecutive Arabic numerals 1 ... 8. The upper section line of the upper roller is indicated by the solid line 37, corresponding to the lower section line of the lower roller with the solid line 38. The hangover cap 13 and the Bodenkufe 11 of the associated shield support frame 10 are also indicated in the form of solid lines and with the associated Reference numeral.

As it turned out first FIG. 6a shows, the previous course of the cutting work is shown in the indicated without numerical fields to the left of the first cutting field 1, in which the section line 38 of the lower roller determines the plane for the sliding of the bottom skid 11. It can be seen that the upper cut line 37 varies slightly from one field of cut to the next, but that the hangover cap 13 is clearly above the upper cut line 37, so that the height of the shield is greater than the cutting height. It can be assumed that the starting height for the shield height 31 is 3.0 m, while a target height for the longwall of only 2.30 m is to be maintained. In the out FIG. 6a apparent sectional field 1 it can be seen that in order to achieve the control target an upper section for the lower roller has been driven and executed, so that the lower section line 38 is raised relative to the initial state. The upper cut line 37 is unchanged. In the in FIG. 6b shown section 2, the system has caused the implementation of another upper section on the lower roller (section line 38). At the same time, it can be seen that the floor skid 11 has not yet changed its position because the floor skid 11 is still traveling on the originally produced lying level.

At the for FIG. 6c relevant cutting field 3, the system has recognized that the now obtained cutting height of the desired height corresponds to the longwall, so that in the cutting field 3, a neutral section is performed with an unchanged cutting height. This then applies accordingly also for those in the FIGS. 6d to 6h With regard to the reaction of the shield support frame 10, it should be noted that the bottom skid 11 only reaches the step cut free in the cutting field 1 when the cutting field 5 is interrupted and thus begins a climbing movement which continues up to the cutting field 8. In the section 8, the front tip of the Bodenkufe 11 has reached the new prone level and pivots with when passing through the nearest cutting fields only to the desired height. The above process can be observed and controlled by monitoring the inclination position of the mining machine and its cutting height and the inclination position of the components of the shielding structure 10.

A comparable sequence of movements takes place when starting from an initially low shield height, the longwall is to be increased. Again, the control begins with an increase in the cutting height of the mining machine by adding an undercut at the lower roller, so that the Bodenkufe of Schildausbaugestells inserted at the same level held Hangendkappe a plunge motion in the pruning pruned by the mining machine until the new cutting level for the Schreitbewegungen the shield construction is reached.

The features disclosed in the foregoing description, the claims, the abstract and the drawings of the subject matter of these documents may be essential individually or in any combination with each other for the realization of the invention in its various embodiments.

Claims (14)

1. A method for controlling a longwall mining operation, comprising a face conveyor (20), at least one extraction machine (22), and a hydraulic shield support, in underground coal mining, wherein, using inclination sensors (17) attached to at least three of the four main components of each shield support frame (10), such as floor skid (11), gob shield (14), support connection rods (16), and gob-side area of the top canopy (13), the inclination of the shield components to the horizontal is ascertained and, from the measured data in a computer unit by comparison with the base data stored therein, which defines the geometric orientation of the components and their movement during the stepping, the particular shield height (31) perpendicular to the bed of the shield support frame (10) is calculated, and, furthermore, using sensors (27) attached to the extraction machine (22), the cutting height (32) of the extraction machine (22) is acquired as the face opening, the corresponding data sets for each section of the longwall operation which an assigned shield support frame (10) passes through being stored and, in terms of a location-synchronous analysis on a section of the longwall operation, the cutting height (32) of the extraction machine (22) being compared to the shield height (31) of the shield support frame (10), when the shield support frame (10), which trails with a time delay, has reached the position to which the cutting height (32) of the extraction machine (22) relates, on which the comparison to the shield height (31) is based.
2. The method according to claim 1, wherein the stored data sets for cutting heights (32) and shield height (31) are compared to one another in terms of a time-synchronous analysis for a section of the longwall operation at the same moment.
3. The method according to Claim 1 or 2, wherein a target height for the shield height (31) of the shield support frames (10) is specified for an individual longwall operation on the basis of the mineral deposit data and the machine data of the employed longwall equipment, and in the event of deviations of the ascertained actual shield height from the target shield height, an automatic control of the cutting height (32) of the extraction machine (22) is performed to set the target shield height.
4. The method according to Claim 3, wherein the cutting height (32) of the extraction machine (22) is established by changing the top cut on one of the discs (23, 24).
5. The method according to Claim 3, wherein the cutting height (32) of the extraction machine (22) is set by changing the bottom cut of one of the discs (23, 24).
6. The method according to one of Claims 1 through 5, wherein, if the shield height (31) falls below the value for the cutting height (32), the occurring convergence is ascertained and the convergence is compensated for by increasing the bottom cut.
7. The method according to Claim 6, wherein, in case of planned operating shutdowns, the face opening is enlarged by the amount of a convergence to be expected over the duration of the operating shutdown.
8. The method according to one of claims 1 through 7, wherein an inclination sensor is situated in each case on the face conveyor and/or on the extraction machine, and the angle of inclination of face conveyor and extraction machine in the mining direction is ascertained.
9. The method according to Claim 8, wherein a differential angle between the floor skid of the shield support frame and face conveyor or extraction machine, which is calculated on the basis of the angle of inclination of face longwall conveyor and extraction machine measured in the mining direction, is incorporated in the calculation of the face opening to be cut by the extraction machine.
10. The method according to Claim 8, wherein a differential angle (45) between the top canopy (13) of the shield support frame (10) and face conveyor (20) or extraction machine (22), which is calculated on the basis of the angle of inclination of face conveyor (20) and/or extraction machine (22) measured in the mining direction, is incorporated in the calculation of the face opening to be cut by the extraction machine (22).
11. The method according to one of Claims 1 through 10, wherein the course of troughs and/or saddles in the mining direction is established via the ascertainment of inclination of the top canopy (13) of the shield support frames (10) in the mining direction and the change of the face opening is predicted via the established changes of the inclination of the top canopy (13) over a predefined period of time and the control of the cutting work of the extraction machine (22) is set accordingly.
12. The method according to one of Claims 1 through 11, wherein the course of troughs and/or saddles in the extraction direction of the extraction machine (22) is established via the ascertainment of inclination of the individual shield support frames (10) transversely to the mining direction, and the extraction machine (22) is controlled in its cutting behavior so that the discs 123, 24) follow the established course of the troughs and/or saddles.
13. The method according to one of Claims 1 through 12, wherein acceleration sensors are used as the inclination sensors (17), which detect the angle of the acceleration sensor in space via the deviation from the Earth's gravity.
14. The method according to Claim 14, wherein the measured values ascertained by the acceleration sensor are checked and corrected using a suitable damping method to eliminate errors caused by the vibrations of the components used.

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