Miner guidance using laser and image analysis

A method of controlling a mining machine comprising a vehicle body having forward and rearward ends, said vehicle body being movable along a mine floor, and a cutter head mounted on said forward end of said vehicle body, said method comprising the steps of:

• (a) providing first and second generally vertical, generally parallel opaque surfaces on said vehicle body;
• (b) emitting a light beam that strikes said surfaces;
• (c) imaging both of said plates in a single image;
• and
• (d) using the single image to determine at least one of the roll, yaw and lateral offset of said machine.

A mining machine comprising

• a vehicle body having forward and rearward ends, said vehicle body being movable along a mine floor,
• a cutter head mounted on said forward end for upward and downward movement relative to said vehicle body,
• a conveyor mounted on said vehicle body for conveying material cut by said cutter head toward said rearward end, and
• a position sensing and control apparatus including
• first and second generally vertical, generally parallel steel plates mounted on said vehicle body,
• an off-board laser emitting a beam in a generally vertical plane such that said beam strikes said plates,
• a camera mounted on said vehicle body, said camera having a filter so that said camera picks up only light having the wavelength of said laser, and said camera imaging both of said plates in a single image, and
• a computer having a framegrabber and receiving the single image from said camera, said computer using a Hough transform and thresholding to identify those pixels in the image that are illuminated by said laser, using the identified pixels to calculate a least-squares estimate of the plane containing the laser beam in the reference frame of said camera, transforming said estimated plane into the coordinate plane of said machine, and computing roll, yaw and lateral offset of said camera from said estimated plane.

A method of controlling a mining machine comprising a vehicle body having forward and rearward ends, said vehicle body being movable along a mine floor, a cutter head mounted on said forward end for upward and downward movement relative to said vehicle body, and a conveyor mounted on said vehicle body for conveying material cut by said cutter head toward said rearward end, said method comprising the steps of:

• (a) mounting first and second generally vertical, generally parallel steel plates on said vehicle body;
• (b) emitting a beam of light in a generally vertical plane such that said beam strikes said plates;
• (c) using an imaging device to image both of said plates in a single image having pixels;
• (d) using a Hough transform and thresholding to identify those pixels in the image that are illuminated by said beam of light;
• (e) using the identified pixels to calculate a least-squares estimate of the plane containing the beam in the reference frame of said imaging device;
• (f) transforming said estimated plane into the coordinate plane of said machine;
• and
• (g) computing roll, yaw and lateral offset of said imaging device from said estimated plane.