Method and apparatus for monitoring a load condition of a dragline
A dragline includes a boom, a bucket, a hoist rope from which the bucket is suspended from the boom, and a drag rope for dragging the bucket. Data is produced on the alignment, with respect to a vertical plane containing the boom axis, of at least one of the following dragline components: i) the hoist rope; ii) the drag rope; iii) the boom; iv) the bucket. This data can be used for controlling the load condition on the basis of the dragline. The data can be inputted to a man-machine interface, e.g. a display device, controlled by a human operator, and/or it can be inputted to control the drive of the hoist rope and/or of the drag rope, so as to decrease or cease drive in response to detected misalignment of dragline component(s).
1. Method of monitoring a load condition of a dragline ( 1 ) or an electric shovel, the dragline comprising a boom ( 4 ), a bucket ( 8 ), a hoist rope ( 10 ) from which the bucket is suspended from the boom, and a drag rope ( 18 ) for dragging the bucket, the boom extending substantially along a boom axis (BA) in its normal, unstressed state,
characterised in that it comprises the steps of:
using technical means ( 26 , 28 ; 42 ; 46 ; 48 ; 60 - 70 ; 76 , 80 ; 82 ; GPS 1 -GPS 3 ; 96 , 98 ) to produce alignment data indicative of lateral alignment, with respect to a plane containing the boom axis (BA), of at least one of the following dragline components:
i) the hoist rope ( 10 ),
ii) the drag rope ( 18 ),
iii) the boom ( 4 ),
iv) the bucket ( 8 ), and
determining the lateral alignment.
2. Method according to claim 1 , further comprising a step of controlling ( 32 ; 34 , 72 , OP) said load condition of the dragline ( 1 ) or electric shovel on the basis of said alignment data.
3. Method according to claim 2 , wherein said alignment data is inputted to a man-machine interface ( 34 , 72 ), e.g. a display device ( 72 ), whereby said controlling step is performed via a human operator (OP).
4. Method according to claim 2 , wherein said alignment data is inputted to automated control means ( 32 ) for controlling at least one of:
i) the drive ( 106 ) of the hoist rope ( 10 ),
ii) the drive ( 108 ) of the drag rope ( 18 ),
iii) the drive ( 110 ) of the boom ( 4 ), for swinging the boom, to perform said controlling step.
5. Method according to claim 2 , wherein the controlling step is performed substantially in real time using a feedback of said alignment data.
6. Method according to claim 2 , wherein said controlling step is performed in a combined manner by a human operator (OP) via a man-machine interface ( 34 , 72 ) and by automated control means ( 32 ).
7. Method according to claim 2 , wherein said controlling step comprises authorizing a controlled overload of said dragline ( 1 ) or electric shovel, notably when controlling a maximum structure stress thereon, as a function of said alignment data.
8. Method according to claim 2 , wherein said boom ( 4 ) has a specified maximum load limit, and wherein said controlling step comprises authorizing a controlled overload of the boom above said specified load limit as a function of said alignment data.
9. Method according to claim 1 , wherein said technical means produce said alignment data as quantitative data indicative of an amount of misalignment in at least one said dragline component ( 4 , 10 , 18 , 8 ).
10. Method according to claim 1 , wherein said alignment data is obtained by measurement on a pulley ( 6 ) along which the hoist rope ( 10 ) passes to hang from a distal end ( 4 b ) of the boom ( 4 ).
11. Method according to claim 10 , wherein said pulley ( 6 ) is configured to sway in response to a lateral stress from the hoist rope ( 10 ), and wherein said alignment data is obtained by determining ( 100 a , 26 b , 28 ; 38 - 36 , 42 , 28 ) the amount of sway of said pulley.
12. Method according to claim 10 , wherein said alignment data is obtained by measuring ( 46 ) a lateral stress exerted on said pulley ( 6 ).
13. Method according to claim 1 , wherein said alignment data is obtained by physical contact ( 46 , 48 ) with at least one said dragline component ( 4 , 8 , 10 , 18 ).
14. Method according to claim 13 , comprising physically engaging ( 50 ) the hoist rope ( 10 ) with an angular or linear displacement sensor device ( 56 - 36 ).
15. Method according to claim 1 , wherein said alignment data is obtained by detecting a lateral deflection of the boom ( 4 ) from said boom axis (BA).
16. Method according to claim 15 , wherein said lateral deflection is detected by producing an optical beam ( 62 ) from a source ( 60 ) attached to the boom ( 4 ), preferably at or near a distal end ( 4 b ), and detecting a displacement (SD) of the beam spot ( 65 ′) where it impinges a target ( 64 ).
17. Method according to claim 1 , wherein said alignment data is obtained by imaging ( 42 ; 48 ; 50 ) at least one said dragline component ( 4 , 8 , 10 , 18 ).
18. Method according to claim 17 , comprising imaging the hoist rope ( 10 ) using camera means ( 76 , 80 ; 82 ).
19. Method according to claim 1 , wherein said alignment data is obtained by analysing coordinate data from GPS receiver means (GPS 1 -GPS 3 ), at least one GPS receiver (GPS 3 ) being positioned on said boom ( 4 ).
20. Method according to claim 1 , wherein said alignment data is obtained by surveying techniques ( 96 , 98 ), to determine coordinate evolutions of a portion of the boom ( 4 ) susceptible of deflecting laterally with respect to its boom axis (BA).
21. Method according to claim 20 , comprising surveying a target ( 98 ) substantially at the distal end ( 4 b ) of the boom using a surveying device, preferably a self-tracking total station ( 96 ) placed at a known reference point on the dragline.
22. Apparatus for monitoring a load condition of a dragline ( 1 ) or an electric shovel, the dragline comprising a boom ( 4 ), a bucket ( 8 ), a hoist rope ( 10 ) from which the bucket is suspended from the boom, and a drag rope ( 18 ) for dragging the bucket, the boom extending substantially along a boom axis (BA) in its normal, unstressed state,
characterised in that it comprises means ( 26 , 28 ; 42 ; 46 ; 48 ; 60 - 70 ; 76 , 80 ; 82 ; GPS 1 -GPS 3 ; 96 , 98 ) for producing alignment data indicative of a lateral alignment, with respect to a plane containing said boom axis (BA), of at least one of the following dragline components:
i) the hoist rope ( 10 ),
ii) the drag rope ( 18 ),
iii) the boom ( 4 ),
iv) the bucket ( 8 ), and
means for determining said lateral alignment.
23. Apparatus according to claim 22 , further comprising control means ( 32 ; 34 , 72 , OP) for controlling said load condition of the dragline ( 1 ) or electric shovel on the basis of said alignment data.
24. Apparatus according to claim 22 , comprising a man-machine interface ( 34 , 72 ), e.g. a display device ( 72 ), for receiving said alignment data.
25. Apparatus according to claim 23 , comprising automated control means ( 32 ) for controlling at least one of:
i) the drive ( 106 ) of the hoist rope ( 10 ),
ii) the drive ( 108 ) of the drag rope ( 18 ),
iii) the drive ( 110 ) of the boom ( 4 ), for swinging the boom, in response to said alignment data.
26. Apparatus according to claim 23 , wherein said controlling means ( 32 ; 34 , 72 , OP) are arranged to operate substantially in real time using a feedback of said alignment data.
27. Apparatus according to claim 23 , comprising means for commanding a controlled overload of said dragline ( 1 ) or electric shovel, notably when controlling a maximum structure stress thereon, as a function of said alignment data.
28. Apparatus according to claim 23 , wherein said boom ( 4 ) has a specified maximum load limit, and wherein said controlling means ( 32 ; 34 , 72 , OP) comprise means for commanding a controlled overload of the boom above said specified load limit as a function of said alignment data.
29. Apparatus according to claim 22 , wherein said means ( 26 , 28 ; 42 ; 46 ; 48 ; 60 - 70 , 80 ; 82 ; GP 1 -GPS 3 ; 96 , 98 ) for producing said alignment data comprise means for producing quantitative data indicative of an amount of misalignment in at least one said dragline component ( 4 , 10 , 18 , 8 ).
30. Apparatus according to claim 22 , wherein said means for producing said alignment data comprise means ( 26 , 28 ) for effecting a measurement on a pulley ( 6 ) along which the hoist rope ( 10 ) passes to hang from a distal end ( 4 b ) of the boom ( 4 ).
31. Apparatus according to claim 30 , wherein said pulley ( 6 ) is configured to sway in response to a lateral stress from the hoist rope ( 10 ), and wherein said means for producing said alignment data comprise means ( 100 a , 26 b , 28 ; 38 - 36 , 42 , 28 ) for determining the amount of sway of said pulley.
32. Apparatus according to claim 30 , wherein said means for producing said alignment data comprise means ( 46 ) for measuring a lateral stress exerted on said pulley ( 6 ).
33. Apparatus according to claim 22 , wherein said means for producing said alignment data comprise means for acquiring said alignment data by physical contact ( 46 , 48 ) with at least one said dragline component ( 4 , 8 , 10 , 18 ).
34. Apparatus according to claim 33 , comprising means ( 50 ) physically engaging the hoist rope ( 10 ) with an angular or linear displacement sensor device ( 56 - 36 ).
35. Apparatus according to claim 22 , wherein said means for producing said alignment data comprise means for detecting a lateral deflection of the boom ( 4 ) from said boom axis (BA).
36. Apparatus according to claim 35 , comprising a source ( 60 ) for generating an optical beam ( 62 ), said being attached to the boom ( 4 ), preferably at or near a distal end ( 4 b ), and means ( 66 - 70 ) for detecting a displacement (SD) of the beam spot ( 65 ′) where it impinges a target ( 64 ).
37. Apparatus according to claim 22 , wherein said means for producing said alignment data comprise means ( 42 ; 48 ; 50 ) for imaging at least one said dragline component ( 4 , 8 , 10 , 18 ).
38. Apparatus according to claim 37 , comprising camera means ( 76 , 80 ; 82 ) for imaging the hoist rope ( 10 ).
39. Apparatus according to claim 22 , wherein said means for producing said alignment data comprise GPS receiver means (GPS 1 -GPS 3 ), at least one GPS receiver (GPS 3 ) being positioned on said boom ( 4 ).
40. Apparatus according to claim 22 , wherein said means for producing said alignment data comprise surveying means ( 96 , 98 ) for determining coordinate evolutions of a portion of the boom ( 4 ) susceptible of deflecting laterally with respect to its boom axis (BA).
41. Apparatus according to claim 40 , comprising a target ( 98 ) substantially at the distal end ( 4 b ) of the boom, and a surveying device, preferably a self-tracking total station ( 96 ) placed at a known reference point on the dragline and aimed at said target.