Close-range photogrammetry for the modelling of mouldboard plough surfaces

摘要

There are the geometric heterogeneity in different shapes of mouldboard ploughs. In order to evaluate the accuracy in measuring the 3D coordinates, and to study the simple mathematical surface which best fits the actual surface of the mouldboard plough, low-cost close-range photogrammetry were used for calculation of the 3D coordinates by co-linearity equation and direct linear transformation, which shoot the two image of 193 targets point marked on the model surface, and carry out binocular stereo matching according to the parallax factor. The results obtained indicate that the surface of a mouldboard plough can be shaped with an accuracy of approximately 1.3 mm, the 3D coordinates of 193 points on the surface of a plough are measured with great accuracy (root mean square 0.66 mm), with the adjustment of a cubic polynomial surface to just 25 control points randomly distributed over the surface of the plough, this surface can be applied to the theoretical analysis of the working process and the manufacture of the mouldboard plough.