Considerations for process to part inspection for flexible manufacturing NDT

Process to part inspection refers to the concept of having a flexible approach to NDT inspection, whereby the NDT process is brought to a component as a flexible scheduling process rather than having NDT in a fixed cell, where parts are fixtured and brought to the NDT process. The advantages for process to part are in higher flexibility, and ability to schedule NDT inspections as part of wider factory manufacturing processes. The increased pressures on energy costs and factory floor space constraints (to drive net zero manufacturing) are factors to be considered along with demands on rate in production schedules. Moving towards digital factory concepts, with flexible and reconfigurable spaces is now a possibility with the emergence of commercial mobile, collaborative and hybrid robot platforms. However these new robotic systems bring new challenges in terms of programming, path planning, accuracy and repeatability. This paper considers these factors, and reviews the state of the art in the supply chain, and recent technical advancements conducted by the Strathclyde University team. We report on our studies of the positional accuracy and repeatability of a hybrid robot system (KUKA KMR) using precision 3D volumetric metrology to show the opportunities and limitations of the current hybrid robotic technology for such “process to part” NDT inspections. Overall accuracy of the KMR platform was measured to 6mm, with repeatability measurement errors of 0.12% observed. Additionally, we discuss different strategies for the control of such platforms (e.g. coupled and decoupled kinematics). Finally, the challenges of making these sophisticated robotics technologies accessible for wider uptake are discussed in terms of software, programming and control.