Fast measurement of freeform parts at elevated temperature using laser-triangulation principle

The increasing quality expectations and the global competition push manufacturing industry to adopt strategies of lean manufacturing and precision engineering. In order to reach these aims it is necessary that the measuring process be integrated in the production chain to provide timely feedback for process control. Nowadays, however, forged products are typically measured after the cool-down process, which can take several hours. The advantages obtainable if forgings would be measured online are clear: deviations in the production process would be recognized earlier and the production process would be promptly adjusted. On-line measurement capabilities have the potential to reduce overall production costs and consequently are of interest to many forging industries, including those producing complex products such as turbine blades. Under these circumstances, the HOTGAUGE project was initiated: An international EUROSTARS project with the final goal to develop a measuring system, which is capable of measuring freeform shaped parts at elevated temperature (approx. 800 °C) directly after the forging step. The output of the measuring system is a 3D model of the hot part including temperature information. The 3D measuring apparatus is composed by two main subsystems: A 2D laser- Triangulation system capable to scan a complete section of the part, and a moving platform, which transfers the part through the measuring plane. The architecture and the components of the measurement system as well as preliminary measurement results are presented in this paper.