Patent ID: 8376467

Claim:
A method for automatically producing a defined face opening in a longwall mining operation in underground coal mining, including the steps of: providing a face conveyor; providing at least one plow, as an extraction machine, wherein said plow is guided on said face conveyor; providing respective hydraulic shield support frames that include, as main components, a floor skid arrangement, a gob shield, a top canopy, and support connection rods; disposing inclination sensors on at least three of the group consisting of said floor skid arrangement, said gob shield, said support connection rods and a gob-side region of said top canopy; ascertaining from said inclination sensors an inclination of those components of said shield support frames that are provided with said inclination sensors relative to a horizontal; in a computer, calculating from the ascertained inclination data, by a comparison with base data stored in the computer and which base data defines a geometrical orientation of the shield support frame components as well as a movement thereof during a stepping process, a respective shield height of said shield support frames perpendicular to a bed of said shield support frames; comparing the calculated shield height of a respective shield support frame with a machine-dependent fixed cutting height of said plow to establish if deviations exist; disposing a boom controller between said shield support frame and said face conveyor; initiating a height control of said plow, via said boom controller, to correct established deviations; and maintaining the initiated height control of said plow, in the sense of a location-synchronized evaluation, until said shield support frame, which trails said plow with a time delay, has reached the position at which said plow was located at the point in time when said height control of said plow was initiated.