Automated in-line object inspection

A method for performing in-line inspection of objects comprising:

• positioning an object to be inspected on a transport;
• moving the object along a transport path using the transport;
• capturing an optical image of the object with an optical acquisition unit;
• capturing point cloud data representing the object with a laser module;
• selecting a CAD model for an object matching the object being inspected based on the captured optical image;
• and
• comparing the CAD model to the captured point cloud data.

A computer-implemented method for inspecting an object, the method comprising:

• receiving a target three dimensional point cloud representing a rigid object obtained from a scan of an object with a laser module;
• loading a projection library and a characteristic vector set of a reference 3D mesh model of the rigid object;
• calculating a two dimensional projection of the target point cloud and generating a corresponding characteristic vector;
• performing a coarse two dimensional registration of the target point cloud by identifying a rest position and rotation angle of the rigid object matching the target point cloud;
• generating a corresponding initial geometric transformation between the target point cloud and a reference mesh model based on the two dimensional registration;
• applying the initial geometric transformation to the target point cloud;
• performing a fine three dimensional registration of the transformed target point cloud with the same reference mesh model;
• generating a final geometric transformation between the target point cloud and the reference mesh model resulting from the three dimensional registration;
• applying the final geometric transformation to the target point cloud;
• measuring differences between the transformed target point cloud and the same reference mesh model, and recording the measured differences.