Programming of Robotic System for Non Contact Ultrasonic Reverse Engineering of Complex Shapes

In this paper, the development and implementation of a robotic system for non-contact ultrasonic (UT) reverse engineering of 3D complex shape parts is presented. UT reverse engineering involves the use of high frequency focused probes, pulse-echo testing methods, and time-of-flight signal measurements. It is applicable to environments where touch probe contact or laser impingement is undesirable or impractical and has the capability of detecting surface features on object zones that are unreachable by a contact probe or out of the line-of-sight of a laser beam, such as inaccessible surfaces or internal cavities in hollow components. The programming of the automatic movement of the robotic manipulator used for the 3D UT scanning of complex shape parts is obtained by iterative algorithms that, based on accurate UT distance measurements, allow for the achievement of the perpendicularity between the sensor and the part at each surface interrogation point and provide for a constant distance (focal distance) between sensor and surface interrogation point to achieve maximum resolution. By iteratively improving the UT sensor position and orientation, very precise measurements are achieved that allow for accurate non-contact 3D UT reverse engineering.