Researchers have developed a light-weight optical system for 3D inspection of surfaces with micron-scale precision. The brand new measurement instrument may significantly improve high quality management inspection for high-tech merchandise together with semiconductor chips, photo voltaic panels and shopper electronics corresponding to flat panel televisions.
As a result of vibrations make it tough to seize precision 3D measurements on the manufacturing line, samples are periodically taken for evaluation in a lab. Nevertheless, any faulty merchandise made whereas ready for outcomes have to be discarded.
To create a system that might function within the vibration-prone surroundings of an industrial manufacturing plant, researchers headed by Georg Schitter from Technische Universität Wien in Austria mixed a compact 2D quick steering mirror with a excessive precision 1D confocal chromatic sensor.
“Robotic-based inline inspection and measurement methods corresponding to what we developed can allow 100% high quality management in industrial manufacturing, changing present sample-based strategies,” stated Ernst Csencsics, who co-led the analysis crew with Daniel Wertjanz. “This creates a manufacturing course of that’s extra environment friendly as a result of it saves vitality and assets.”
As described in The Optical Society (OSA) journal Utilized Optics, the brand new system is designed to be mounted on monitoring platform positioned on a robotic arm for contactless 3D measurements of arbitrary shapes and surfaces. It weighs simply 300 grams and measures 75 x 63 x 55 millimeters cubed, which is concerning the measurement of an espresso cup.
“Our system can measure 3D floor topographies with unprecedented mixture of flexibility, precision, and pace,” stated Wertjanz, who’s pursuing a PhD on this analysis matter. “This creates much less waste as a result of manufacturing issues will be recognized in real-time, and processes will be shortly tailored and optimized.”
From lab to fab
Precision measurements are often carried out with cumbersome devices within the lab. To deliver this functionality to the manufacturing flooring, the researchers developed a system primarily based on a 1D confocal chromatic distance sensor developed by Micro-Epsilon, a associate on this analysis challenge. Confocal chromatic sensors can exactly measure displacement, distance and thickness utilizing the identical ideas as confocal microscopes however in a a lot smaller package deal.
They mixed the confocal sensor with a extremely built-in quick steering mirror they beforehand developed that measured simply 32 millimeters in diameter. Additionally they developed a reconstruction course of that makes use of the measurement information to create a 3D picture of the pattern’s floor topography. The 3D measurement system is compact sufficient to suit on a metrology platform, which serves as connection to a robotic arm and compensates for vibrations between pattern and measurement system by way of lively suggestions management.
“By manipulating the optical path of the sensor with the fast-steering mirror, the measurement spot is scanned shortly and exactly throughout the floor space of curiosity,” stated Wertjanz. “As a result of solely the small mirror must be moved, the scan will be carried out at excessive speeds with out compromising precision.”
To check the brand new system, the researchers used varied calibration requirements that includes buildings with outlined lateral sizes and heights. These experiments demonstrated that the system can purchase measurements with a lateral of two.5 microns and axial decision of 76 nanometers.
“This method may finally deliver a wide range of advantages to high-tech manufacturing,” stated Wertjanz. “In-line measurements may allow zero-failure manufacturing processes, that are particularly helpful for low-volume fabrication. The knowledge may be used to optimize the manufacturing course of and machine instruments settings, which may improve general throughput.”
The researchers at the moment are working to implement the system on the metrology platform and incorporate it with a robotic arm. This can permit them to check the feasibility of robot-based precision 3D measurements on freeform surfaces in vibration-prone environments corresponding to an industrial manufacturing line.