Three-dimensional shape measurement method based on composite cyclic phase coding.

Phase coding is widely used in 3D measurement due to its good anti-interference and robustness. However, the measurement accuracy is affected by the limitation of the number of codewords. To solve this problem, we propose a 3D shape measurement method based on composite cyclic phase coding. The traditional phase coding is quantized cyclic without adding extra patterns, further adopting composite coding, using the composite cyclic phase coding grayscale values to distinguish the same cyclic codewords, and finally integrating them into a new fringe order sequentially for phase unwrapping to achieve effective expansion of codewords. The related experimental results show that the proposed method stably achieves high accuracy 3D reconstruction, which overcomes the misjudgment of codewords caused by traditional phase coding under high-frequency fringes due to system nonlinearity and noise. Meanwhile, compared with the improved phase coding method of temporal domain combined with spatial domain information, such as the method of quantized phase coding and connected region labeling, it can effectively avoid the phenomenon of error propagation, with high robustness and low algorithm complexity.

Directional Migration and Distribution of Magnetic Microparticles in Polypropylene-Matrix Magnetic Composites Molded by an Injection Molding Assisted by External Magnetic Field.

Surface-functionalized polymer composites with spherical particles as fillers offer great qualities and have been widely employed in applications of sensors, pharmaceutical industries, anti-icing, and flexible electromagnetic interference shielding. The directional migration and dispersion theory of magnetic microparticles in polypropylene (PP)-matrix magnetic composites must be studied to better acquire the functional surface with remarkable features. In this work, a novel simulation model based on multi-physical field coupling was suggested to analyze the directed migration and distribution of magnetic ferroferric oxide (Fe3O4) particles in injection molding assisted by an external magnetic field using COMSOL Multiphysics® software. To accurately introduce rheological phenomena of polymer melt into the simulation model, the Carreau model was used. Particle size, magnetic field intensity, melt viscosity, and other parameters impacting particle directional motion were discussed in depth. The directional distribution of particles in the simulation model was properly assessed and confirmed by experiment results. This model provides theoretical support for the control, optimization, and investigation of the injection-molding process control of surface-functionalized polymer composites.

Dynamic Target Tracking Method Based on Medical Imaging.

The cross fusion of rehabilitation medicine and computer graphics is becoming a research hotspot. Due to the problems of low definition and unobvious features of the initial video data of medical images, the initial data is filtered and enhanced by adding image preprocessing, including image rotation and contrast enhancement, in order to improve the performance of the tracking algorithm. For the moving barium meal, the discrete point tracking and improved inter frame difference method are proposed; for the position calibration of tissues and organs, the Kernel Correlation Filter (KCF) and Discriminative Scale Space Tracker (DSST) correlation filtering method and the corresponding multi-target tracking method are proposed, and the experimental results show that the tracking effect is better. The two algorithms modify each other to further improve the accuracy of calibration and tracking barium meal flow and soft tissue organ motion, and optimize the whole swallowing process of moving target tracking model.

Long-Lived T-Shaped Micropillars with Submicron-Villi on PP/POE Surfaces with Grinding-Enhanced Water Repellency Fabricated via Hot Compression Molding.

Superhydrophobic properties are derived from the roughness of the surface of micro/nanostructures and low-surface-energy materials. However, they are both easy to damage on superhydrophobic surfaces after mechanical abrasion in practical applications, resulting in the transition from the Cassie-Baxter state to the Wenzel state and even the loss of water repellency. In this work, the mechanical properties of polypropylene (PP) toughened with poly(ethylene-co-octene) (POE) were improved for the fabrication of long-lived T-shaped micropillars with submicron-villi on top by a combined method of compression molding and grinding. A universal testing machine was modified as equipment for the precise control of the traveling distance of specimens on sandpaper in precise. The PP/POE blend possessed high tensile strength of up to ∼23.84 MPa as well as elongation at break of ∼533.60%. The abrasive grains on sandpaper reshaped their surface morphologies from micropillars to T-shaped microstructures, on which the submicron-villi as secondary structures formed. The abraded microstructured PP/POE surface exhibited the highest contact angle of 154.4° and the most stable wetting state with a bouncing height of 7.68 mm (3.2 times the diameter of the 7-µL droplet) after a traveling distance of 1000 mm on 3000-grit sandpaper among the abraded and unabraded PP/POE surfaces.