MULTIPARAMETER MEASUREMENT FOR RACEWAY GROOVE OF BEARING BASED ON 3D RECONSTRUCTION WITH DIGITAL STRUCTURED LIGHT

A fast 3D reconstruction method based on structured light to measure various parameters of the raceway groove is presented. Digital parallel grating stripes distributed with sine density are projected onto the raceway groove by a DLP projector, and distorting of stripes is happened on the raceway. Simultaneously, aided by three-step phase-shifting approach, three images covered by different stripes are obtained by a high-resolution CCD camera at the same location, thus a more accuracy local topography can be obtained. And then the bearing is rotated on a high precision computer controlled rotational stage. Three images are also obtained as the former step at next planned location triggered by the motor. After one cycle, all images information is combined through the mosaics. As a result, the 3D information of raceway groove can be gained. Not only geometric properties but also surface flaws can be extracted by software. A preliminary hardware system has been built, with which some geometric parameters have been extracted from reconstructed local topography.

Phase unwrapping based on deep learning in light field fringe projection 3D measurement

Phase unwrapping is one of the key roles in fringe projection three-dimensional(3D)measurement technology.We propose a new method to achieve phase unwrapping in camera array light filed fringe projection 3D measurement based on deep learning.A multi-stream convolutional neural network(CNN)is proposed to learn the mapping relationship between camera array light filed wrapped phases and fringe orders of the expected central view,and is used to predict the fringe order to achieve the phase unwrapping.Experiments are performed on the light field fringe projection data generated by the simulated camera array fringe projection measurement system in Blender and by the experimental 3×3 camera array light field fringe projection system.The performance of the proposed network with light field wrapped phases using multiple directions as network input data is studied,and the advantages of phase unwrapping based on deep learning in light filed fringe projection are demonstrated.

3D scanning modelling of auto parts for intelligent driving

In order to improve the accuracy of auto parts production and processing,and reduce the error of parts manufacturing,a 3D scanning modelling of auto parts for intelligent driving is designed in this paper.With the help of the structured light projection method,the auto parts image is obtained,and its horizontal axis grey value and stripe pixel value are analysed.The contour parameters are determined by k-frame strategy,and the width,length and height parameters of the external contour of vehicle parts are obtained.The basic principle of 3D scanning technology is analysed,its scanning process is designed,and the modelling of auto parts is realised with the help of 3D scanning technology.The experimental results show that the modelling method can effectively improve the machining accuracy and reduce the manufacturing error of the auto parts.

An integrative review on the applications of 3D printing in the field of in vitro diagnostics

Biomedicine is one of the fastest growing areas of additive manufacturing.Especially,in the field of in vitro diagnostics(IVD),contributions of 3D printing include i)rapid prototyping and iterative IVD proof-of-concept designing ranging from materials,devices to system integration;ii)conceptual design simpli-fication and improved practicality of IVD products;iii)shifting the IVD applications from centralized labs to point-of-care testing(POCT).In this review,the latest developments of 3D printing and its advantages in IVD applications are summarized.A series of 3D-printed objects for IVD applications,including single-function modules,multi-function devices which integrate several single-function modules for specific an-alytical applications such as sample pre-treatment and chemo-/bio-sensing,and all-in-one systems which integrate multi-function devices and the instrument operating them,are analyzed from the perspective of functional integration.The current and potential commercial applications of 3D-printed objects in the IVD field are highlighted.The features of 3D printing,especially rapid prototyping and low start-up,en-able the easy fabrication of bespoke modules,devices and systems for a range of analytical applications,and broadens the commercial IVD prospects.