Closed-loop machining cell for turbine blades

This paper presents an innovative concept of a closed-loop machining cell for turbine blade finishing that integrates a robotic surface finishing device with an electro-optical, non-contact precision measuring system. We propose that a synergistic combination of these leading edge technologies allows us to close the loop between finishing and inspection. Instead of part measurement being a mere off-line verification operation, it can direct the robot to do the necessary work and provide feedback to achieve higher finishing precision. In this paper, we describe the challenges in closing the loop seamlessly and our approach to resolve them. We present the overall architecture in which the part is measured using a multiple cooperative sensor system, and the robot is directed until the desired finish is obtained. We present details on the use of multi-sensor inspection and corresponding integration of the various components (hardware and software). We validate by application to turbine blades that are used commercially. Utilizing the suggested concept, turbine blade manufacturers will benefit by realizing greatly increased product throughput and reduced cost. The potential for generating scrap is reduced, and two separate, time-consuming operations will be consolidated into a single setup. It will also reduce hardware, footprint, maintenance, and energy costs by their sharing of common components. This concept can be extended to similar closed-loop manufacturing cells with minor modifications.