Automatic longwall mining system and method
First Claim
1. An improved method of controlling the operation of a longwall excavating machine which during a working trip works the face of a longwall excavation, particularly a power loader mounted for movement along the length of a face conveyor, or the like, the method being of the type wherein a coal-seam interface-shape program is stored in a programmable control arrangement operative for causing the excavating machine to excavate in accordance with the stored program during at least one working trip,the improvement comprising:
- using coal-seam interface sensor means to generate data indicative of true coal-seam interface-shape conditions;
feeding said data into the programmable control arrangement and causing the latter to compare said data against the stored coal-seam interface-shape program and ascertain the error in the stored coal-seam interface-shape program relative to the true coal-seam interface conditions detected by the sensor means;
and causing the programmable control arrangement to automatically and gradually modify the stored coal-seam interface-shape program in ongoing depedence upon the ascertained error to thereby automatically and continually update the stored coal-seam interface-shape program followed by the excavating machine.
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Accused Products
Abstract
A power loader having upper and lower cutting drums travels along the length of a face conveyor. Seam-top and seam-bottom sensors mounted on the power loader sense the heights of the true seam-top and seam-bottom. The data produced by these sensors during machine travel is not used to directly change the heights of the upper and lower cutters in the manner of an immediate-response automatic interface-follower system. Instead, to prevent the system from reacting and/or overreacting to changes in interface conditions, including changes which are physically insigificant and/or which, if fully reacted to, would exceed the floor and roof-negotiating abilities of the equipment, the system follows a preestablished interface-shape program. However, the true seam-top and seam-bottom height data from the sensors is fed into the process-control computer of the system, and used to modify and update the stored interface-shape program in a gradual ongoing manner. The computer ascertains, relative to predetermined criteria relating to the permissible rate of interface-shape program change in going from one power-loader working trip to the next, how much of the ascertained error in the interface-shape program can safely be eliminated per working trip for the successive working trips of the machine. And the erroneous intervals of the stored interface-shape program are then changed by such amounts during successive working trips, to gradually and stepwise dose out over a plurality of working trips the corrective reduction in the amount of the error exhibited by the stored interface-shape program.
38 Citations
12 Claims
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1. An improved method of controlling the operation of a longwall excavating machine which during a working trip works the face of a longwall excavation, particularly a power loader mounted for movement along the length of a face conveyor, or the like, the method being of the type wherein a coal-seam interface-shape program is stored in a programmable control arrangement operative for causing the excavating machine to excavate in accordance with the stored program during at least one working trip,
the improvement comprising: -
using coal-seam interface sensor means to generate data indicative of true coal-seam interface-shape conditions; feeding said data into the programmable control arrangement and causing the latter to compare said data against the stored coal-seam interface-shape program and ascertain the error in the stored coal-seam interface-shape program relative to the true coal-seam interface conditions detected by the sensor means; and causing the programmable control arrangement to automatically and gradually modify the stored coal-seam interface-shape program in ongoing depedence upon the ascertained error to thereby automatically and continually update the stored coal-seam interface-shape program followed by the excavating machine. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An improved longwall mining system, of the type comprising a longwall excavating machine which during a working trip works the face of a longwall excavation, particularly a power loader mounted for movement along the length of a face conveyor, the system furthermore being of the type including programmable control means operative for storing a coal-seam interface-shape program and causing the excavating machine to excavate in accordance with the program during at least one working trip,
the improvement comprising: -
coal-seam interface sensor means on the excavating machine operative for generating data indicative of true coal-seam interface-shape conditions as the excavating machine performs a working trip and feeding said data into the programmable control means, the programmable control means comprising means receiving said data, comparing said data against the stored interface-shape program, and ascertaining the error in the stored interface-shape program relative to the true coal-seam interface conditions detected by the sensor means, and means operative for automatically and gradually modifying the stored coal-seam interface-shape program in ongoing dependence upon the ascertained error to thereby automatically and continually update the stored coal-seam interface shape program followed by the excavating machine. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification