Construction of sculptured surfaces from CMM measurement data

[[abstract]]Reverse engineering (RE) approach is widely applied in design and manufacturing of sculptured surfaces. The first step of RE process is collecting data lying on surfaces. When using a coordinate measuring machine (CMM) with a touch trigger probe for digitizing data points, probe radius must be compensated according to normal vectors. Previous works were addressed on iterative measurement procedure to reduce the error caused by the compensation. Major problem of iterative methods is time consuming in digitization. This paper proposes a new architecture based on look-up table that keeps the estimated normal vectors of the measurement data to refine the data points digitized by CMM. The digitized data are first fitted into several NURBS curves by interpolation. The skinning method is then applied to interpolate these curves. Thus a smooth NURBS surface can be constructed and more accurate normal vectors of the measurement points can be obtained to compensate for the probe radius. By using this technique, we need only one digitization procedure. Therefore much time can be saved and the efficiency of reverse engineering can be improved[[fileno]]2020408030003[[department]]工工