Calibration Verification of a Mining Machine using Image Processing

摘要

Recently developed mining machines are capable of cutting different profiles. Cutting desired profiles opens new fields of application for these machines. The precision of the profile, which is cut, depends on the kinematics of the machine and its calibration. The dimensions of the profiles up to 10 m wide and 5 m high make it difficult to calibrate and even measure. This paper presents an image processing system, which was developed to solve this problem. An ultra-bright infrared LED was mounted on the primary calibration point of the machine. The 2-R manipulator (i.e. the cutting arm) is moved so as to generate the desired outer profile. The 2-R kinematics of the machine result in the calibration point moving along the surface of a torus. The imaging system acquires a sequence of images, each of them captures the machine in one point along the profile. This delivers a 2-D central projection of the 3-D motion. The inverse projection is determined using projective geometry. The true position of the calibration points is determined by applying the inverse projection, which is then compared to the desired position. Measurements of a mining machine and a comparison with the desired profile are presented.