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Unformatted text preview: nd identified sub-clouds. Virtual Inspection: the appropriated inspection method is selected on the basis of the specific GT category (orientation) and type (parallelism) to be inspected. First of all the virtual datum need to be defined. In our example the orientation tolerance to be inspected is a parallelism tolerance and the datum is a plane split into three different regions corresponding to a single disconnected sub-cloud. In this case the virtual datum plane is defined as follows: first, the cloud medium plane is taken as reference, then a set of points is selected as the outer points in the direction perpendicular to the medium plane. The number of selected points represents 20% of the total points belonging to the cloud. Finally, the datum plane is defined as the medium plane of the set of selected points. Once the virtual datum plane has been defined, the tolerance is controlled by comparing the required value with the computed distance between two parallel planes, A Reverse Engineering Approach 155 parallel to the datum plane, passing through the most external points belonging to the cloud. In...
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- Spring '10
- The Land