Capital investment in equipment for measuring complex objects
Lead Research Organisation:
University of Huddersfield
Department Name: Sch of Computing and Engineering
Abstract
We propose to procure a high-end portable laser tracker for measuring surface geometry, profile and spatial coordinates. This equipment will be of vital importance in supporting the metrology of large aspherical telescope mirrors and provide a large dynamic range method in measuring complex shape objects. It will greatly enhance the speed of R&D in our two awarded STFC-IPS projects and enhance UK capability to meet the instrumentation requirements of the British and International Science Base. This equipment has a wide range of applications across astronomical optics, Infrared and X-ray optics, high-power laser system, head-up displays, synchrotron optics and medical instruments.
The first project that will be supported by this equipment addresses the challenge of polishing soft metal mirrors (aluminium) that can be used for ground-based and space astronomy. The second project deals with hard materials such as moulds and dies in tool steels, used for industrial mass production. The parts can also be additively manufactured. Our industrial partner Wayland Additive with NeuBeam technology can provide components of complex shape in a wide range of materials.
The key procedure in advanced manufacturing is metrology. Off the shelf products, such as interferometers, can measure optical surface at nano-meter level accuracy, but they require strict working environments and are of low dynamic range. We found the main challenges in measuring complex surfaces at manufacturing stages are the requirements for large dynamic range and a stabilised environment, especially for large aperture (diameter > 1 meter) optics where complicated support make it more challenging to measure. Deflectometry has previously been used as a quality control measure for low precision measurement until the introduction of phase-measuring technology. The College of Optical Science of Arizona University has demonstrated this technology on a large deformable mirror and achieved 0.2 microns accuracy. The primary function of the equipment will be to accurately calibrate the positions of multiple parts of the system (PC screen, camera, mirror) in a space. A laser tracker is the most direct and precise way of achieving such accurate calibration.
The second project is to process moulds and dies made of hard materials. Apart from refining rough surface conditions from the previous stage of manufacturing, there is an increasing demand for repairing worn moulds and dies through polishing. Since the working conditions vary, it is likely that these tools are not evenly worn. It is important that metrology can reflect the true surface geometries. A laser tracker with suitable probe and kinematic mount is well suited to this purpose.
The equipment we have identified has both of economic and versatility advantages. It has dynamic 6 degrees of freedom and an accuracy of 16 microns within 35m range. We will achieve a better than 50nm accuracy on deflectometry if we use this laser tracker to assist intrinsic and extrinsic calibration. Secondly, the quote we have obtained includes extensive accessories to enable us not only to cope with challenging coordinate measurement situations where many places are either not easy to reach or not able to touch, but also offer us fast and accurate real-time tracking. The latter function will enable us to record polishing robots or even high-end computer numerically controlled (CNC) polishing machine's coordinate information. These data will help us to develop a deeper understanding of the polishing process and analysis and maintain a leading edge in this area.
The first project that will be supported by this equipment addresses the challenge of polishing soft metal mirrors (aluminium) that can be used for ground-based and space astronomy. The second project deals with hard materials such as moulds and dies in tool steels, used for industrial mass production. The parts can also be additively manufactured. Our industrial partner Wayland Additive with NeuBeam technology can provide components of complex shape in a wide range of materials.
The key procedure in advanced manufacturing is metrology. Off the shelf products, such as interferometers, can measure optical surface at nano-meter level accuracy, but they require strict working environments and are of low dynamic range. We found the main challenges in measuring complex surfaces at manufacturing stages are the requirements for large dynamic range and a stabilised environment, especially for large aperture (diameter > 1 meter) optics where complicated support make it more challenging to measure. Deflectometry has previously been used as a quality control measure for low precision measurement until the introduction of phase-measuring technology. The College of Optical Science of Arizona University has demonstrated this technology on a large deformable mirror and achieved 0.2 microns accuracy. The primary function of the equipment will be to accurately calibrate the positions of multiple parts of the system (PC screen, camera, mirror) in a space. A laser tracker is the most direct and precise way of achieving such accurate calibration.
The second project is to process moulds and dies made of hard materials. Apart from refining rough surface conditions from the previous stage of manufacturing, there is an increasing demand for repairing worn moulds and dies through polishing. Since the working conditions vary, it is likely that these tools are not evenly worn. It is important that metrology can reflect the true surface geometries. A laser tracker with suitable probe and kinematic mount is well suited to this purpose.
The equipment we have identified has both of economic and versatility advantages. It has dynamic 6 degrees of freedom and an accuracy of 16 microns within 35m range. We will achieve a better than 50nm accuracy on deflectometry if we use this laser tracker to assist intrinsic and extrinsic calibration. Secondly, the quote we have obtained includes extensive accessories to enable us not only to cope with challenging coordinate measurement situations where many places are either not easy to reach or not able to touch, but also offer us fast and accurate real-time tracking. The latter function will enable us to record polishing robots or even high-end computer numerically controlled (CNC) polishing machine's coordinate information. These data will help us to develop a deeper understanding of the polishing process and analysis and maintain a leading edge in this area.
