Drilling apparatus and drilling method

A drilling apparatus for drilling a pipe lining material from a main pipe side wherein illumination light from a lateral pipe passes through the pipe lining material that blocks a lateral pipe opening and an opening image corresponding to the lateral pipe opening is formed on the inner surface of the pipe lining material comprising:

• a rotatable drilling blade for drilling the pipe lining material;
• a work robot that moves in the longitudinal direction inside a main pipe with the drilling blade mounted thereon so as to be capable of turning in the circumferential direction about an axis extending in the longitudinal direction of the main pipe;
• a photodetector having a plurality of photodetector elements arranged in the circumferential direction of the main pipe to scan the opening image in the longitudinal direction and detect its contour points;
• an image generating means for generating a two-dimensional image indicating the contour of the opening image based on the contour points detected by the photodetector;
• and
• a calculation means for calculating a positional deviation in the longitudinal and circumferential directions between the center position of the generated two-dimensional image and the axial center position of the rotary shaft of the drilling blade;
• wherein the pipe lining material is drilled by moving the drilling blade in the longitudinal direction and turning it in the circumferential direction by the amount of positional deviation in a direction in which the positional deviation is eliminated.