Mathematical Modeling and Fuzzy Adaptive PID Control of Erection Mechanism

This paper describes an application of fuzzy adaptive PID controller to erection mechanism. Mathematical model of erection mechanism was derived. Erection mechanism is driven by electro-hydraulic actuator system which is difficult to control due to its nonlinearity and complexity. Therefore fuzzy adaptive PID controller was applied to control the system. Simulation was performed in Simulink software and experiment was accomplished on laboratory equipment. Simulation and experiment results of erection angle controlled by fuzzy logic, PID and fuzzy adaptive PID controllers were respectively obtained. The results show that fuzzy adaptive PID controller can effectively achieve the best performance for erection mechanism in comparison with fuzzy logic and PID controllers

SAR-NeRF: Neural Radiance Fields for Synthetic Aperture Radar Multi-View Representation

SAR images are highly sensitive to observation configurations, and they exhibit significant variations across different viewing angles, making it challenging to represent and learn their anisotropic features. As a result, deep learning methods often generalize poorly across different view angles. Inspired by the concept of neural radiance fields (NeRF), this study combines SAR imaging mechanisms with neural networks to propose a novel NeRF model for SAR image generation. Following the mapping and projection pinciples, a set of SAR images is modeled implicitly as a function of attenuation coefficients and scattering intensities in the 3D imaging space through a differentiable rendering equation. SAR-NeRF is then constructed to learn the distribution of attenuation coefficients and scattering intensities of voxels, where the vectorized form of 3D voxel SAR rendering equation and the sampling relationship between the 3D space voxels and the 2D view ray grids are analytically derived. Through quantitative experiments on various datasets, we thoroughly assess the multi-view representation and generalization capabilities of SAR-NeRF. Additionally, it is found that SAR-NeRF augumented dataset can significantly improve SAR target classification performance under few-shot learning setup, where a 10-type classification accuracy of 91.6\% can be achieved by using only 12 images per class

Matematičko modeliranje i neizrazito upravljanje mehanizmom za poravnavanje i podizanje

The moving process of a leveling and erecting mechanism is complicated, which involves six hydraulic cylinders. The research established mathematical model and optimized the moving process of the leveling and erecting mechanism. Kinematic analysis of the mechanism was accomplished. Mathematical model of the hydraulic system was established. Working scheme was designed consisting of workflow, trajectory planning, leveling strategy and control method. The mechanical, hydraulic and control models were respectively established in Pro/E, ADAMS, AMESim and Simulink software. Co-simulation was carried out to validate the designed scheme. Experiment was completed on a platform. The results of simulation and experiment indicate that the designed scheme is feasible. Fuzzy adaptive PID controller has an excellent effect in controlling the leveling and erecting mechanism.Gibanja mehanizma za poravnavanje i podizanje složeni je proces koji uključuje šest hidrauličkih cilindara. Istraživanje postavlja matematički model i optimizira proces gibanja mehanizma za poravnavanje i podizanje. Provedena je kinematička analiza mehanizma. Postavljen je matematički model hidrauličkog sustava. Radni program načinjen je uključujući tijek rada, planiranje trajektorije, strategiju poravnavanja i metodu upravljanja. Mehanički, hidraulički i upravljački modeli redom su izvedeni u Pro/E, ADAMS, AMESim i Simulink programskim paketima. Provedena je kosimulacija za validaciju načinjenog radnog programa. Eksperiment je proveden na stvarnoj platformi. Rezultati simulacije i eksperimenta ukazuju na izvedivost predloženog radnog programa. Neizraziti adaptivni PID regulator daje odličan efekt pri upravljanju mehanizma za poravnavanje i podizanje

Self-assembly of tetra(aniline) nanowires in acidic aqueous media with ultrasonic irradiation

An environmentally friendly method is developed to explore the self-assembly of Ph/NH2-capped tetra(aniline) nanowires in acidic aqueous medium with ultrasonic irradiation.</p

Research on Effects of Incidence to Turbine Guide Cascade Aerodynamic Performance

When steam turbine set runs, the changes of incidence angle could cause the change of the flow loss in the cascade passages. It was necessary to research the flow performance in steam turbine passages by changing incidence angle. With the help of hydrodynamic software CFX, we could conduct numerical simulations at three incidence angles of 20°, 0°, and -20°, respectively. The computation results indicated that the blades with aft-loading profile had a good adaptation to the incidence angle. After changing incidence angle, the incidence angle affected the distribution of static surface pressure less within most of the scope of pressure surface and suction surface than other location. However, incidence angle −20° would decrease pressure loss within a narrow range, and incidence angle 20° would increase pressure loss