Cranfield University is a British postgraduate and research-based university specializing in science, engineering, technology and management. The EPSRC Centre for Innovative Manufacturing in Ultra Precision is a collaboration between the Precision Engineering Institute at Cranfield University and the Institute for Manufacturing at the University of Cambridge. It aims to create ultra high precision manufacturing processes and tools for making products with nanoscale precision which can be used by companies to improve product yield and quality, and maintain a competitive advantage.
Virtual metrology frame
The goal of the project was to improve the dynamic performance of a CNC machine developed at Cranfield University. The Meso Scale Research Platform is a 6-axis micro-machining center, capable of creating nanometer scale features, over centimetres of product area.
Inaccuracies in machining occur due to tiny distortions in the machine frame. To reduce these effects the team wanted to use a measurement system to determine the displacement of the frame in real-time, and to combine the data with measurements from a conventional encoder also fitted to the platform.
A ‘virtual metrology frame’ concept was devised, where accelerometers were used to measure dynamic displacement without the need for a second reference frame.