Abstract: A crankshaft shape inspection method includes: acquisition step that acquires three-dimensional point cloud data of a surface of a crankshaft S; generation step that generates, while using the three-dimensional point cloud data, first point cloud data based on point cloud data generated by performing isolated point removal processing that removes data points whose distance to the nearest neighbor data point is equal to or more than first threshold value Th1 and generates second point cloud data based on point cloud data generated by performing isolated point removal processing that removes data points whose distance to the nearest neighbor data point is equal to or more than second threshold value Th2 (>the first threshold value Th1); and a calculation step that calculates a side dimension of a counterweight SC using the first point cloud data and calculates a longitudinal position of the counterweight SC using the second point cloud data.

Abstract: A crankshaft shape inspection method includes: acquiring three-dimensional point cloud data of a surface of a crankshaft S; superposing the three-dimensional point cloud data on a surface shape model of the crankshaft S; moving the three-dimensional point cloud data superposed on the surface shape model to match with a coordinate system used when the crankshaft S is machined; generating an estimated machined surface, which is the surface after machining of a predetermined machining portion of the crankshaft S, in the coordinate system used when the crankshaft S is machined; and calculating a distance between machining portion point cloud data extracted from the three-dimensional point cloud data moved and the estimated machined surface generated and determining a machining stock of the crankshaft S to be insufficient based on the calculated distance.