AU635761B2

AU635761B2 - Control process for open-cast mining conveying appliances

Info

Publication number: AU635761B2
Application number: AU60277/90A
Authority: AU
Inventors: Ralf Eckholdt; Franz-Arno Fassbaender; Franz-Josef Hartlief; Edmund Heimes; Dieter Dr. Henning; Hans-Joerg Nuesslin
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1989-08-08
Filing date: 1990-08-07
Publication date: 1993-04-01
Anticipated expiration: 2010-08-07
Also published as: EP0412402B1; AU6027790A; DE59001164D1; ES2040009T3; EP0412402A1; ATE87989T1

Abstract

The invention relates to a control method for earth-moving machines, such as bucket wheel excavators (5), gravel-bed receivers, etc., in which the morphology, determined in advance, of a deposit or the stratification of embedded material serves as command variables for the movements of the earth-moving machine. The profile of the material to be conveyed is continuously scanned by a light beam (14), and the values determined by the scanning are used as a control variable for the movements of the earth-moving machine. <IMAGE>

Description

FORM 10 0 5 S6F 137 52 4 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int Class Complete Specification Lodged: Accepted: Published: Priority: Related Art: Name and Address of Applicant: Siemens Aktiengesellschaft Nittelsbacherplatz 2 D-8000 Munich 2 FEDERAL REPUBLIC OF GERMANY G-B~ree h&n- Stat ev 4; -ahr-ek-r-een-4 24 D-1oOQ 1+1 D-2Q0-H&mbu-rg-7+I F@eeml Rq1AbttL O-em~ F[RALREPUbIC-,FERM NY Address for Service: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Males, 2000, Australia Complete Specification for the invention entitled: Control Process for Open-Cast Mining Conveying Appliances The following statement is a full description of this invention, including the best method of performing it known to me/us 5845/3 1 GR 89 P 8570 E/Foreign Abstract Control process for open-cast mining conveying appliances The invention relates to a control process for open-cast conveying appliances, such as bucket-wheel excavators, gravel-bed pick-ups, etc., in which the previously determined morphology of a deposit or the stratification of deposited material serve as command variables for the movements of the conveying appliance. The course of the material to be conveyed is sensed continuously by a light beam, and the values determined as a result of the sensing are used as a control variable for the movements oof the conveying appliance.

*ee Figure 1.

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S o o 1i- GR 89 P 8570 E/Foreign Siemens Aktiengesellschaft RHEINBRAUN Rheinische Braunkohlenwerke Aktiengesellschaft Control process for open-cast mining conveying appliances The invention relates to a control process for open-cast mining conveying appliances, such as bucket-wheel excavators, gravel-bed pick-ups, etc., in which the previously determined morphology of a deposit or the stratification of deposited material serves as a command variable for the movements of the conveying appliance.

10 Where open-cast mining conveying appliances, for example bucket-wheel excavators, gravel-bed pick-ups, etc., are concerned, the bucket wheel or skip of the conveying appliance has to be controlled according to the particular conveying task. With bucket-wheel excavators 15 which serve for the working of a deposit, for example coal, the task is either to strip away the overburden lying above or between the coal or to convey the coal, which occurs in seams. The coal seams usually do not extend horizontally and also do not have a straight *oo 20 surface. On the contrary, they are sometimes inclined, curved or even folded. To obtain as high a yield as possible with a low incidence of foreign material, the bucket wheel of a bucket-wheel excavator has to follow the course of the seam exactly. This has hitherto been attempted by an attendance crew who have used as guidelines the visual impression of the conveying location and the result of borings which have revealed the course of the seam.

The object of the invention is, in particular, to provide a control process for bucket-wheel conveying appliances, preferably for bucket-wheel excavators, which increases SHo/Th-13.07.1990 -2the yield of a coal deposit, without enlarging the fraction of foreign material conveyed. At the same time, an automation of the working of deposits, gravel beds or the like is to be obtained. The visual, subjective determination of the course of the seam is, at the same time, to be replaced by an objective measurement.

In accordance with the present invention there is disclosed a control process for an open-cast mining conveying appliance, in which the previously determined morphology of a deposit, or the stratification of deposited material, serve as command variables for the movements of the conveying appliance, and wherein the course of the material to be conveyed is scanned continuously by a laser beam which is generated in a measuring laser, and the layering or stratification of the materiai is determined from differences in the reflection properties of the material sensed by the laser beam and used as a control variable for the movements of the conveying appliance.

By means of the sensing by a light beam, it is advantageously possible to replace the visual, subjective determination of the course of the particular seam or stratum at the working location by an objective measurement. With laser sensing, there is at the same time an advantageous increase in the sensing reliability, since a laser beam, because of its high energy density, especially in the pulsed state, is influenced only slightly by air layers, dust, etc. A perfect sensing of the conveying location, even under difficult conditions, is possible by means of a pulsed laser.

Suitable lasers are known in principle, for example from the volume "Lasertechnik: e. Elnf.", HUthig Verlag, Heidelberg, 1982, page 368 ff.

However, a use of lasers for controlling the work of bucket-wheel appliances has not been provided hitherto.

S"In an advantageous embodiment of the invention, the sensing is carried out by scanning. A sensing by scanning with laser light advantageously makes it possible to track reliably the course of the changes in the reflection properties of the sensed material and, with the aid of calibration results, to draw a separating line between the workable and the non-workable material according to 8040 3 GR 89 P 8570 E/Foreign predetermined criteria. This is especially important for stratifications in which the reflection properties, particularly the reflection spectra, of the different materials differ from one another only slightly and merge smoothly into one another. Here, the invention affords the preconditions for an optimized and automated tracking of the course of the seams or other stratifications by the bucket wheel of the conveying appliance.

It is especially advantageous at the same time, if, when the conveying appliance starts work, the conveying starting line is first traversed manually. This traverse can serve, in the form of a stored learning step, as an actual value which is improved by means of the desired "o value determined by the sensing. Thus, the requisite .o 15 optimization and automation of the working of bucket- Se.* wheel conveying appliances is possible. To eliminate errors which are possible as a result of an oblique fee* position of the conveying appliance, at the same time there is advantageously a correction of the desired values by means of a vertical sensor which constantly feeds the vertical and therefore also the horizontal direction to the sensing instrument.

In the process according to the invention, an improvement of the stratum identification is possible by means of an averaging over a relatively large, especially horizontal range. This is especially important with regard to deposits in which a considerable proportion of clay constituents is present in the coal. Here, the reflection differences in relation to a clay covering layer are only slight; however, even in situations such as this, the mathematical determination of the course of the seam can be obtained with high accuracy by means of an averaging of the range located in front of the bucket wheel.

The stratification course values determined are advantageously monitored by means of a status check of the conveyed material, This is. conducted especially simply 4 GR 89 P 8570 E/Foreign if there is likewise used for this a laser instrument which, for example, checks the flow of conveyed material on the belt leading away from the bucket wheel. This check is insensitive to different temperatures, to dust swirled up and to the other environmental influences.

Particularly when there are especially sulphurous grades of coal or clayey covering layers, it is advantageous to use a UV sensing light beam. In UV light, the various stratifications can be identified especially clearly by means of a differing reflection. Identification can be carried out either via intensity differences or via a frequency analysis of the reflected light, for which .o.

stored standard reflection spectra are advantageously used.

is. In the control process according to the invention, it is S* advantageous if the instrument emitting the light beam or laser pulses is arranged on the conveying appliance, that is to say the excavator. An expedient design is one where it is possible to have a mounting which is steadier and .e 20 freer from vibration than the bucket-wheel jib and which also has the advantage of allowing sensing in an especially wide range.

0 00 The instrument carrying out the sensing can advantageously also be mounted on a movable, independent instru- 5 ment carrier. This makes it possible, in interaction with a storage device for the determined stratum course on the conveying appliance, to have the capacity to supply a plurality of conveying appliances with stratum course data from one sensing instrument. Such an instrument can also be equipped more easily with a gas laser, of which more stringent requirements regarding the elimination of vibrations, etc. are demanded than of a solid-state laser conventionally used.

Further advantages and details of the invention emerge from the description which follows of an exemplary 5 GR 89 P 8570 E/Foreign embodiment by reference to the drawing in conjunction with the subclaims.

In the drawing: Figure 1 shows the invention in principle, Figure 2 shows the sensing of a course of a stratum or deposit, and Figure 3 shows a block diagram of the sensing instrument.

In Figure 1, 1 denotes the diagrammatically indicated conveying appliance which in the exemplary embodiment is intended to represent a bucket-wheel excavator. In this exemplary embodiment, arranged on the conveying appliance a 1 is the sensing instrument 2 which is independently pivotable in relation to the conveying appliance 1. The 15 pivoting advantageously takes place according to a predetermined program which is governed by the intended operating tasks of the conveying appliance. The position of the sensing instrument 2 is advantageously selected so that a sensing of the working face which is as undis- 20 turbed as possible by the conveying appliance can be carried out.

The conveying appliance 1, a bucket-wheel excavator in the example shown here, is arranged on the undercarriage 3 which is movable via the travelling gear 4. The bucket 25 wheel 5 works onto a conveyor belt 6 which delivers the conveyed material onto the belt 8 which leads further on.

A skirt 7 which diverts material falling down is arranged under the conveyor belt 6 in the region of the excavator.

The conveying appliance stands on the ground 9 above which the material 10 to be removed is located. The material 10 to be removed is limited at the top by a covering layer 11. Light beams 14, by means of which the working face is sensed, are emitted by the sensing instrument 2. The light beams 14, preferably pulsed laser 6 GR 89 P 8570 E/Foreign beams, strike the working face at the points 13, a linear sensing preferably being chosen. However, it is likewise possible to select a sensing in a predetermined pattern, for example a zigzag pattern or a wave pattern.

It can be seen from the illustration in Figure 2 that, with linear sensing, both the covering layer designated here by 19 and the layer designated by 20 and lying under the seam 22, the coal stratum 22 and the intermediate strata 21 are detected multiply by the light beam of the sensing instrument 2. At the same time, position values can be obtained via the reflection properties, the fluorescence or the general spectrum analysis, for example by means of linear filters, for the individual strata from each individual line 23. By means of a spread 15 sensing, three sensing lines being shown as an example, the positions of the individual strata both in the region of the sensing lines and, by interpolation, also in the 9e e region between the sensing lines 23 can be calculated in a computer. Furthermore, a comparison of the values of the individual sensing lines 23 and a smoothing afford a possibility of correcting faulty measurements and for

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eliminating singularities, for example holes or included foreign materials.

As emerges from the block diagram in Figure 3, the values obtained from the sensing by the light beams 14 of the sensing instrument 2 are first supplied to an evaluation unit 15 which feeds them to a computer 16 with a display unit 17 which calculates the deposit course together with the positions and courses of the strata. The computer 16 preferably has a display unit which indicates both the positions of the strata and courses and the actual position of the jib. The control signals 18 are then transmitted to the conveying appliance or the excavator by the computer which is preferably designed as a microprocessor.

The mode of operation of the control process according 7 GR 89 P 8570 E/Foreign to the invention is such that the stratum position and course of a deposit or of a gravel bed etc. are determined by sensing with a light beam, preferably a pulsed laser beam. These values are used as command values for the movement of the conveying appliance which for the first time are executed under visual guidance within the framework of a learning step at the start of work. The learning step is stored and is used as a preset value for the further working steps. Correction values are now determined from the position and course of the deposit strata, and the work of the conveying appliance, here the excavator, is controlled by means of these. Incorrect measurement values and singularities are advantageously goo eliminated by means of a probability calculation, etc.

"Coo 15 In an especially advantageous utilization of the poso sibilitles afforded by the invention, the conveyance of the intermediate strata between the coal and overburden or a respective proportional conveyance of two strata can also be entered as a command variable, so that a hitherto unobtainable optimized working of a deposit is possible.

The control process according to the invention therefore *5@O not only allows a controlled guidance of the conveying S"appliance, but also leads to an optimized working, without the proportion of unutilizable materials .4 exceeding the permissable predetermined amount. By an appropriate programming, it is thus possible to optimize the quantity of conveyed coal by automatically admixing o*@ only a proportion of low-grade materials from the intermediate strata which is still just permissible.

The foregoing invention is described by means of an example. It is self-evident to an average person skilled in the art, however, that obvious changes are also covered by the invention. Rapid progress is to be seen, at the present time, in the sector of laser technology, scanning in general and computer technology, and the basic ideas of the invention can also be put into practice by other methods of evaluation.

Claims

1. A control process for an open-cast mining conveying appliance, in which the previously determined morphology of a deposit, or the stratification of deposited material, serve as command variables for the movements of the conveying appliance, and wherein the course of the material to be conveyed is scanned continuously by a laser beam which is generated in a measuring laser, and the layering or stratification of the material is determined from differences in the reflection properties of the material sensed by the laser beam and used as a control variable for the movements of the conveying appliance.

2. A control process according to claim 1, wherein the differences in the reflection properties of the material are determined by evaluating the reflection spectrum of the reflected laser beam.

3. A control process according to claim 1, wherein the differences in the reflection properties of the material are determined by evaluating differences in induced fluorescence.

4. A control process according to claim 1, 2 or 3, wherein the conveying appliance is first guided according to the deposit course under visual control and the sensing results serve as correction values for i repeat movements of the conveying appliance.

5. A control process according to any one of the preceding claims, wherein the scanning is carried out spread over a plurality of lines.

6. A control process according to any one of the preceding claims, wherein the scanning results are subjected to a course smoothing and to a relevance check, and the deposit course is then determined.

7. A control process according to any one of the preceding claims, wherein the operation of the conveying appliance is carried out according to the determined stratification and deposit course values is monitored by means of a status check of the conveyed material. :o iI

8. A control process according to any one of the preceding claims, wherein the measuring laser is designed as a UV laser.

9. A control process according to any one of the preceding claims, wherein the laser beam is emitted from the conveying appliance. 11 1 9 A control process according to any one of claims 1 to 8, wherein the laser beam is emitted from a position independent of the conveying appliance.

11. A control process according to any one of the preceding claims, wherein during the working of the deposit, a light beam is used for determining the material stratification course and for controlling the conveyance.

12. A control process according to claim 11, wherein the light beam is derived from a laser scanner.

13. A control process according to any one of the preceding claims, wherein said conveying appliance is a bucket-wheel excavator or a gravel-bed.

14. A control process for an open-cast mining appliance substantially as described herein with reference to the drawings. DATED this TWENTY-SEVENTH day of JANUARY 1993 Siemens Aktiengesellschaft Rheinbraun Aktiengesellschaft Patent Attorneys for the Applicants SPRUSON FERGUSON