A study on surface finish of SiCp/Al composites machiningChen, Zhigao; Wang, Bo; Ding, Fei; Liao, Qiuyan; Xue, Jiadai; Wu, Kaiji; Fan, Yuxin; Zhang, Qinghui; Chen, Mingjun
doi: 10.1117/12.3008595pmid: N/A
SiCp/Al composites are suitable for manufacturing optical devices in various harsh environments such as mirrors, lenses, etc., and have broad application prospects in optics. The effective surface removal of the SiCp/Al composite is difficult due to irregular SiC-reinforced particles inside, resulting in the surface quality not being ideal. Therefore, it is necessary to study the removal mechanism of SiCp/Al composite materials. In this study, a statistical analysis based method was introduced to establish a particle random distribution model for SiCp/Al composite materials with a volume fraction of 30%. The removal mechanism of the composite material was revealed through a combination of simulation and experiments. In this study, the Sa20nm mirror was obtained by setting reasonable parameters. This study can provide a reference value for the removal mechanism and processing research of SiCp/Al composites.
Research on unattended vision inspection system for petrochemical industry based on 5GLu, Tielin; Yue, Lei; Liu, Xiaojing; Shang, Yujia; Feng, Xiawei; Gao, Jie
doi: 10.1117/12.3008807pmid: N/A
Nowadays, lots of vision devices have set in the industry process. The vision detect results from the devices have higher requirements for data storage and network transmission. Unattended vision detection technology has become the key research directions of multispectral optoelectronic devices. However, it has different needs about the architecture of the 5G network and how to design the system with unattended work for petrochemical industry. So it is quit necessary to find a root to study optoelectronic device using 5G network, in order to get the real-time transmission of results, and edge processing. This paper introduces the architecture unattended inspection system for petrochemical industry 5G network, composition system of multispectral optoelectronic devices. Finally, we have developed a use case of unattended vision inspection architecture based on 5G network structure. And also we have analysis the related applications in the petrochemical industry application scenario.
A white light interferometry stitching measurement method based on feature extractionChen, Junren; Chen, Shanyong; Chen, Weiwei; Liu, Junfeng
doi: 10.1117/12.3009483pmid: N/A
The white light interferometry technique can measure the three-dimensional topography of ultra-precise complex surface with sub-nanometer resolution and precision, and has been widely concerned by academia and industry since it was proposed. The measurement range of white light interferometry technology is usually limited by the size of the optical field of view of the system, and the surface of the measured object can only be measured within the limited range of the camera's single imaging. In order to obtain the microscopic surface topography with a larger field of view, it is usually necessary to conduct stitching measurement. In this paper, a measurement method of aperture stitching of white light interferometry based on feature extraction is presented. The first step is subaperture partitioning and data preprocessing. The second step is feature extraction. The feature points are extracted by the Speeded-Up Robust Features (SURF) algorithm. The third step is to identify and filter wrong match points in the feature extraction algorithm using the Random Sample Consensus (RANSAC) algorithm. The fourth step is to use the improved Iterative Closest Point (ICP) algorithm to accurately register the point cloud, and perform data fusion in the overlapping region to complete the reconstruction of the microscopic three-dimensional surface topography. This method is used to measure the microstructure of quartz vibratory beam accelerometer. The experimental results show that the proposed algorithm has a faster speed than the traditional algorithm while maintaining high precision.
Ultrafast laser induced surface instability for 3D nanoprinting wrinkled architecturesFan, Xuhao; Deng, Chunsan; Jiao, Binzhang; Liu, Yuncheng; Chen, Fayu; Gao, Hui; Xiong, Wei
doi: 10.1117/12.3008402pmid: N/A
The fabrication of three-dimensional (3D) wrinkle architectures has garnered extensive attention from both the academic and industrial sectors. Ultrafast laser 3D nanoprinting allows for the fabrication of intricate 3D wrinkle architectures, offering precise control over fine morphological characteristics. The temperature modulation induced by the ultrafast laser along the scanning path triggers a volume change in a thermal-responsive polymer, resulting in the surface instability of printed voxel lines. The printing process involves an external field coupling effect of photopolymerization, photothermal interaction, responsive deformation, and substrate adhesion. Based on recent theoretical studies on swell-induced surface instability, we simplified the layered polymerized structures as a plane film attached to an underlying substrate and focused on the essential physical features that determine the instability patterns, including mismatch strain, mechanical properties, and adhesion energy. Various modes of surface instability patterns in solid and hollow units are categorized, and an analysis model that accounts for diverse surface instability patterns in solid and hollow microgel units is constructed. The proposed analysis model not only improves the understanding of 3D nano-wrinkled structures but also paves the way for extending wrinkle applications.
Research on autonomous feeder chain building strategy for giant constellations based on maximum matching of bipartite graphLin, Xiaoxiong; Qi, Yu; Wang, Yufu; Li, Xiang; Hu, Weigang
doi: 10.1117/12.3008817pmid: N/A
The low orbit satellite network has features such as high-speed information transmission and on-planet routing exchange, in which the satellite-ground feeder link (the link between the satellite in the space segment and the gateway station in the ground segment) realising high-speed bidirectional communication between the satellite and the gateway station on the ground, and performing important functions such as user access to the terrestrial network and control and monitoring of the satellite by the ground management and control center. In fact, the satellites in the low orbit constellation move at high speed relative to the ground, and the feeder link from the low orbit satellites to the gateway station has a lot of mobile switching, so it is necessary to solve the routing addressing problem between the gateway station and the satellites under the conditions of dynamic switching of the feeder link in the low orbit satellite network, which is the need to design the link table between the satellites and the gateway station at the engineering level. However, the complex configuration of low-orbit giant communication constellations, the large number of satellites and the suddenness of working modes have brought great challenges to the generation of link strategies for the constellation satellites and the ground gateway stations at the system level. In order to solve the problem of efficiently generating link building strategies for giant constellations and many gateway stations, this paper proposes a dynamic and autonomous link table building algorithm based on maximum matching of bipartite graphs. First, a low-orbit constellation model and an access model of low-orbit constellations and gateway stations are established based on orbital dynamics, then a dynamic autonomous generation algorithm based on maximum matching of bipartite graphs is designed to balance the system load, and finally simulations a re performed to validate the algorithm in typical application scenarios. The simulation results show that the dynamic autonomous chain building strategy based on maximum matching of bipartite graph for giant constellation feeder catching and following proposed in this paper is universal, which can improve the autonomous operation capability of the system a nd reduce the operation cost of the system.
Dynamics of nanosecond laser-induced shock waves in water using multiple excitation beamsZhi, Yang; Bao, Hengzhu; Gao, Lou; Zhang, Hongchao; Lu, Jian
doi: 10.1117/12.3007697pmid: N/A
When a high-power laser beam is incident on water, the rapid heat transfer process triggers ionization of the water in theactive region, resulting in an explosion as well as outward propagating shock waves. Here, the formation, propagation, andinteraction of underwater shock waves induced by nanosecond laser pulses were experimentally investigated. By fittingthe theoretical model (Sedov-Taylor expansion model) to the experimental results, we quantified the effective energycarried by the shock wave during propagation. Numerical simulations with an analytic model using the distance betweenadjacent breakdown locations as input obtain the shock wave emission images at different time delays and provide insightsinto experimentally not accessible shock wave parameters. An empirical model is used to describe the pressure behind theshock wave. The results show the near-acoustic propagation behavior of the shock waves at longer time delays. On top ofthat, we compared the effect of the distance between adjacent excitation positions on the shock wave emission process.The shock wave parameters in the far field are more accurate and easier to perform. Furthermore, utilizing multipointexcitation offers a flexible approach to delve deeper into the physical mechanisms that cause optical tissue damage innanosecond laser surgery, leading to a better comprehension of the subject.
Starlink simulation and potential analysis for remote sensing applicationsYang, HaiTao; Wang, HaoYu; Lv, Bo; Wang, JinYu; Zhou, XiXuan; Zhang, HongGang
doi: 10.1117/12.3009125pmid: N/A
Starlink plans to provide faster Internet services in most parts of the world, as a space fast Internet communication plan of SpaceX in the United States. However, according to the overall design of the current Starlink system, Starlink satellites may adopt modular development ideas in the future, aiming at the feasibility and potential of Starlink satellite constellations carrying remote sensing payloads, this paper collects and sorts out the development of Starlink satellite constellations and the orbital parameters of some domestic remote sensing satellites and constellations, and proves the feasibility of Starlink satellites carrying remote sensing payloads through comparison between parameters. Secondly, this paper uses STK to simulate and model the Starlink satellite constellation, and at the same time adds available remote sensing sensors to the satellite, and concludes that at least 60 satellites are required for single-orbit Earth observation of the Starlink constellation to achieve the uninterrupted effect, and an imaging simulation is carried out on a building or object on land, and the visibility and sensor coverage effect of the satellite to the target are displayed in two-dimensional and three-dimensional forms. STK's display analysis function was used to visualize the detailed data report results, and finally the potential of Starlink satellite constellation to carry remote sensing payloads was analyzed.
Laser-induced freestanding graphene with porous nanostructure for antimicrobial devices and inhibition of microbial foulingLuo, Sida; Liang, Dejian; Wang, Dan; Wang, Guantao; Han, Mingguang; Yang, Weixiong; Liu, Zhixiao
doi: 10.1117/12.3009480pmid: N/A
Laser-induced graphene (LIG) is a novel strategy for preparing graphene by taking advantage of the sufficient photothermal and photochemical reactions to develop nanomaterials with good physical and chemical properties. Recently, considerable research is devoted to efficiently prepare graphene antimicrobial devices taking advantage of the size and shape customizability of laser processing. However, the relationship between quantification of reduction rate and graphene nanostructure porosity has not been systematically studied. Hence, in this paper we applied a simple and efficient method to prepare graphene antibacterial paper by in situ reduction of polyimide in one step by exploiting the absorption of laser photon energy by the chemical bonds in the precursor material. And we further clarified the antibacterial mechanism of laser-induced graphene paper (LIGP) with the aim of achieving better antimicrobial performance by microstructure modulation through laser processing parameters. Microscopic analyses and colony counting assay were employed to demonstrate the antibacterial effect of graphene. Notably, LIGP at 1.0W laser power (LIGP-1.0W) exhibits the most significant bactericidal rate (94.1% for E. coli and 97.5% for S. aureus) attributed to its extremely high specific surface area (SSA, 189.3 m2 /g), the unique tunable nonporous structure increases extensive contact area with bacteria to provide more sites for capturing bacteria, which was further verified by oxidative stress-related mechanism. The prepared LIGP device can be used to prevent aluminum biocorrosion on material surface and used as antibacterial devices which can be customized to match diverse application scenarios.
Decoupling and disturbance rejection for leveling and focusing stage of lithographic equipmentXue, Cheng; Gu, Lin; Zhou, Qinghua; Yang, Yong
doi: 10.1117/12.3008489pmid: N/A
As a key subsystem of step and scan projection lithographic machines, the three-degree-of-freedom leveling and focusing stage always fails to achieve ultra-precision motion because its control system cannot achieve complete decoupling. Taking up this challenge, in this paper we propose a complete decoupling control method containing static decoupling and dynamic decoupling based on nonlinear active disturbance rejection control (ADRC) for the stage. First, by setting virtual control variables, the three-input three-output coupled system is transformed into three nearly independent single-input singleoutput systems. Then, the nonlinear ADRC is utilized to solve the residual coupling caused by coupling model inaccuracies. Finally, the simulation results show that the proposed control method has better robustness and disturbance rejection ability than feedforward compensation PID control and linear ADRC.
Research on on-orbit calibration source technology for space infrared loadXu, Ziwei; Zhang, Xin; Wang, Jiapeng; Yang, Wanglin
doi: 10.1117/12.3009251pmid: N/A
In recent years, with the development of infrared technology, the radiation value of targets can be quantitatively detected through radiation parameter calibration, making it possible for infrared payloads to determine the type of target based on the radiation value, greatly improving the detection ability of infrared payloads. To ensure the quantitative detection accuracy, it is necessary to calibrate the radiation parameters of the infrared load, accurately grasp the inversion coefficient of the infrared load, and ensure the inversion accuracy of the detection data. This article focuses on the urgent need for on orbit radiation calibration of infrared payloads, and conducts research on on orbit calibration sources based on memes technology. Through experimental verification, the on orbit calibration source, as the standard source for on orbit calibration of loads, can provide a stable infrared radiation and has the characteristics of wide temperature range and multiple calibration points, meeting the calibration requirements during the operation of infrared loads. The on orbit calibration source can serve as a spatial quantity reference to provide high quantitative calibration for infrared remote sensing payloads, laying a solid technical foundation for the next step of space infrared payloads and future development of China's infrared satellites.