This paper presents and discusses a method to calibrate a specially built laser triangulation sensor to scan and map the surface of hydraulic turbine blades and to assign 3D coordinates to a dedicated robot to repair, by welding in layers, the damage on blades eroded by cavitation pitting and/or cracks produced by cyclic loading. Due to the large nonlinearities present in a camera and laser diodes, large range distances become difficult to measure with high precision. Aiming to improve the precision and accuracy of the range measurement sensor based on laser triangulation, a calibration model is proposed that involves the parameters of the camera, lens, laser positions, and sensor position on the robot arm related to the robot base to find the best accuracy in the distance range of the application. The developed sensor is composed of a CMOS camera and two laser diodes that project light lines onto the blade surface and needs image processing to find the 3D coordinates. The distances vary from 250 to 650 mm and the accuracy obtained within the distance range is below 1 mm. The calibration process needs a previous camera calibration and special calibration boards to calculate the correct distance between the laser diodes and the camera. The sensor position fixed on the robot arm is found by moving the robot to selected positions. The experimental procedures show the success of the calibration scheme.

Gas metal arc welding (GMAW) processes need to guarantee the quality of the parts produced from this stability in the manufacture of a single bead. In addition to the visual inspection and subsequent characterization with the cutting of the samples, which consists of destructive analysis, it is possible to monitor the entire process and the quality of the part in a non-destructive way. Therefore, this work aims to develop a methodology for the analysis of non-destructive and online weld beads using high-speed cameras, thermal cameras, profilometer and algorithms in MatLab for data processing. The high-speed cameras allow the capture of images of the electric arc and the metallic transfer mode. The thermal cameras, on the other hand, allow the visualization of the melt pool and the temperatures reached during the deposition. Finally, the laser profilometer allows you to make a point cloud of the part and measure its geometry (height, width, height-to-width ratio, wetting angle) online and more accurately than the caliper. With this, it is possible to use the data, both for geometric quality, preliminary parameterization of additive manufacturing, and later for feeding simulations of welding. Promising the monitoring process during manufacturing.

Anais do Congresso Internacional de Engenharia Mecânica e Industrial (2764-4294) - Desenvolvimento De Bancada De Ensaios Para Avaliar Degradação De Óleos Isolantes Utilizados Em Transformadores Elétricos