Method for inspecting a workpiece in the process of being manufactured

A method for an inspection of a face of a workpiece that is held in a manufacturing fixture, between a first manufacturing operation and a second manufacturing operation of a manufacturing range, by means comprising:

• a measurement sensor adapted for acquiring points on the face of the workpiece, the measurement sensor having an acquisition distance, an acquisition volume and an acquisition direction cone from a fixed position;
• a robot configured for holding and moving the measurement sensor in positions;
• a computer comprising a memory, computation means and a display, comprising in the memory a three-dimensional digital model of the workpiece, and adapted for recording coordinates of points acquired by the measurement sensor;
• the method comprising steps, implemented by the computer, of:
• i) obtaining a digital model of the workpiece comprising the face and sampling this model in a point cloud by a tessellation of faces of the digital model;
• ii) obtaining the acquisition distance, the acquisition volume and the acquisition direction cone of the measurement sensor;
• iii) creating a visibility graph GV, of the workpiece by:
• iii.a) segmenting the digital model of the workpiece into nodes, each node being included in the acquisition volume of the measurement sensor and a normal to each of the nodes being inside the acquisition direction cone of the measurement sensor;
• iii.b) determining a visibility of each node from positions of the measurement sensor with respect to the node;
• iii.c) determining common visibilities, designated as edges, between the nodes, two nodes being connected by an edge when an acquisition carried out in a fixed position with respect to the workpiece by the measurement sensor makes it possible to simultaneously cover at least a portion of a surface of each of the two nodes;
• iv) from the visibility graph GV obtained in step iii) defining a sequence of acquisitions making it possible to cover the face in a reduced number of overlapping acquisitions by defining a path connecting all the nodes of the face through a minimum number of edges of the visibility graph GV;
• and
• implementing the sequence of acquisitions defined in step iv) by moving the measurement sensor with the robot, between the positions allowing the sequence of acquisitions to be carried out.