A Differential Entropy-Based Method for Reverse Engineering Quality Assessment

he present work proposes the use of point clouds differential entropy as a new method for reverse engineering quality assessment. This quality assessment can be used to measure the shape deviation of objects made with additive manufacturing or CNC techniques. The quality of the execution is intended as a measure of the deviation of the geometry of the obtained object compared to the original CAD model. The method exploits the quality index of the CorAl method. The advantages of CorAl are several, among them the use of a unique index of comparison, no problem of commutativity of the comparison, noise immunity, low influence of the presence of holes and of the point cloud densities. It is possible to plot quality maps showing the areas with the greatest deviation. In experiments, objects obtained by additive manufacturing with different print qualities are tested. The robustness of the method is also demonstrated. The quality index evaluated for each object, as defined in the CorAl method, turns out to be gradually closer to 0 as the quality of the piece’s construction increases.