摘要：The visual inspection is an economical and effective method for welding. For measuring the feature sizes of grooves,a method based on line structured light is presented. Firstly,an adaptive algorithm to extract the subpixel centerline of structured light stripes is introduced to deal with the uneven width and grayscale distributions of laser stripes,which is based on the quadratic weighted grayscale centroid. By means of region-of-interest(ROI)division and image difference,an image preprocessing algorithm is developed for filtering noise and improving image quality. Furthermore,to acquire geometrical dimensions of various grooves and groove types precisely,the subpixel feature point extraction algorithm of grooves is designed. Finally, experimental results of feature size measuring show that the absolute error of measurement is 0.031—0.176 mm,and the relative error of measurement is 0.2%—3.6%.

摘要：Electron beam lithography(EBL) is a key technology in the fabrication of nanoscale silicon optical waveguide. The influence of exposure dose, the main process parameter of EBL, on the structure profile of poly-methyl methacrylate(PMMA) after development was studied using a silicon on insulator(SOI) wafer with 220 nm top silicon as the substrate. The relationship between exposure dose and structure pattern width after development was analyzed according to the measurement results. The optimum exposure dose of 220 μC/cm^(2) was found to obtain a final structure consistent with the designed mask value through subsequent processes. At the same time, according to the image segmentation curve tracking technology, the contour extraction process of the dose test results was carried out, and the relationship among mask design value, exposure dose and two-dimensional roughness of boundary contour was analyzed, which can provide reference for the subsequent electron beam lithography of the same substrate material.

摘要：Force closure and stability problems exist in heavy gripping *** on a typical gripping device for forging operations, the workpiece and the gripping device are innovatively considered as a single mechanism in this paper,and its global topological configuration is *** changing element method is used to establish the optimized topology geometry of the gripping device by decreasing the degrees of freedom of the gripping mechanism and improving the force closure performance. Therefore,a new idea for the innovative design of heavy-duty forging gripping devices is *** the effect of revolute joint friction on loading capacity of the gripping device cannot be ignored,a unified mechanical equation including friction in terms of the topological adjacency matrix is established to analyze the force closure performance and calculate the loading *** conclusions are provided by experiments.

摘要：The dynamic parameter identification of the robot is the basis for the design of the controller based on the dynamic ***,the primary method for solving angular velocity and angular acceleration is to filter and smooth the position sequence and then form a differential ***,if the noise and the original signal overlap in the frequency domain,filtering the noise will also filter out the valuable information in the frequency *** paper proposes an excitation trajectory based on Logistic function,which fully uses the information in the original signal and can accurately solve the angular velocity and angular acceleration without filtering and smoothing the position *** joint angle of the excitation trajectory is mapped to the joint angular velocity and angular acceleration one by one so that the joint angular velocity and joint angular acceleration can be obtained directly according to the *** genetic algorithm is used to optimize the excitation trajectory parameters to minimize the observation matrix’s condition number and further improve the identification *** using the strategy of iterative identification,the dynamic parameters identified in each iteration are substituted into the robot controller according to the previous position sequence until the tracking trajectory approaches the desired trajectory,and the actual joint angular velocity and angular acceleration converge to the expected *** simulation results show that using the step-by-step strategy,the joint angular velocity and joint angular acceleration of the tracking trajectory quickly converge to the expected value,and the identification error of inertia parameters is less than 0.01 in three *** the increase of the number of iterations,the identification error of inertial parameters can be further reduced.

摘要：With the continuous increase of social and economic competitiveness, the position of advertising becomes more and more important. For attracting people＇s attention to the advertising, merchants should not only rely on novel advertising creativity and also add some sentiment elements in advertising design under the background of today＇s advertising all over the world. Sentiments are the most capable of touching human nerves so as to leave a deep impression in the minds of people, so the quality of advertising can be well improved if appropriate sentiment elements are added in advertising design. In this paper, the application of emotional elements to advertising design is specifically discussed from emotional elements classification, main application methods, and matters needing attention.

摘要：Hydraulic valve block is an important part of the hydraulic *** traditional hydraulic valve block is made by turning and milling,drilling and boring,which leads to many right-angle bending and closed cavity structure of process holes in its internal flow channel,seriously affecting the flow performance of *** on the new design space provided by additive manufacturing technology,the internal hydraulic flow channel of valve block is optimized by using B-spline *** fluid dynamics analysis is carried out on the hydraulic flow channel to determine the optimal flow channel structure with the smallest pressure *** weight reduction of hydraulic valve block is carried out through topology *** to the results of topology optimization,using the method of selective laser melting(SLM),the printing of the hydraulic valve block is *** optimized hydraulic channel reduces the pressure loss by 31.4%compared with the traditional hydraulic *** with the traditional valve block,the hydraulic valve block manufactured by SLM with topology optimization reduces the weight by 33.9%.Therefore,the proposed flow channel optimization and valve block lightweight method provide a new reference for the performance improvement of the internal flow channel of hydraulic valve block and the overall lightweight design of valve block.

摘要：We introduce a novel strategy of designing a chaotic coverage path planner for the mobile robot based on the Che- byshev map for achieving special missions. The designed chaotic path planner consists of a two-dimensional Chebyshev map which is constructed by two one-dimensional Chebyshev maps. The performance of the time sequences which are generated by the planner is improved by arcsine transformation to enhance the chaotic characteristics and uniform distribution. Then the coverage rate and randomness for achieving the special missions of the robot are enhanced. The chaotic Chebyshev system is mapped into the feasible region of the robot workplace by affine transformation. Then a universal algorithm of coverage path planning is designed for environments with obstacles. Simulation results show that the constructed chaotic path planner can avoid detection of the obstacles and the workplace boundaries, and runs safely in the feasible areas. The designed strategy is able to satisfy the requirements of randomness, coverage, and high efficiency for special missions.

摘要：Based on the biological prototype characteristics of shark’s gill jet orifice,the flexible driving characteristics of ionic exchange polymer metal composites(IPMC)artificial muscle materials and the use of sleeve flexible connector,the IPMC linear driving unit simulation model is built and the IPMC material-driving dynamic control structure of bionic gill unit is ***,through the stress analysis of bionic gill plate and the motion simulation of bionic gill unit,it is verified that various dynamic control and active control of the jet orifice under the condition of different mainstream field velocities will be taken by using IPMC ***,the large-deflection deformation of bionic gill plate under dynamic pressure and the comparative analysis with that of a rigid gill plate is studied,leading to the achievement of approximate revised modifier from real value to theoretical value of the displacement control of IPMC.

摘要：可再生能源发电因其间歇性而具有多变性,对发展中国家来说,可再生能源发电的成本很高。由于电价定价和机制设计不合理,上网电价和净计量等支持性政策和方案对消费者也没有太大吸引力。屋顶太阳能光伏系统自用技术可以避免这些方案的缺点,因为这种技术比公用电网的发电成本更低。因此,产消者可以以最低价格使用大部分电力,更具吸引力。本文分析了并网工业太阳能光伏发电系统的成本和可行性。结果发现,基于储能并网的光伏系统成本为0.0086$/(kW·h),公用电网将以0.062$/(kW·h)的价格出售给产消者,与使用时间评级模型相比,年能源成本将降低35.23%。此外,所提出的方案可满足96%的年能源需求,保证了供应的安全性,所提出的模型可用于其他发展中国家。

摘要：Topological phases of matter have been extensively investigated in solid-state materials and classical wave systems with integer dimensions. However, topological states in non-integer dimensions remain almost unexplored. Fractals, being self-similar on different scales, are one of the intriguing complex geometries with non-integer dimensions. Here, we demonstrate fractal higher-order topological states with unprecedented emergent phenomena in a Sierpin? ski acoustic metamaterial. We uncover abundant topological edge and corner states in the acoustic metamaterial due to the fractal geometry. Interestingly,the numbers of the edge and corner states depend exponentially on the system size, and the leading exponent is the Hausdorff fractal dimension of the Sierpin? ski carpet. Furthermore, the results reveal the unconventional spectrum and rich wave patterns of the corner states with consistent simulations and experiments. This study thus unveils unconventional topological states in fractal geometry and may inspire future studies of topological phenomena in non-Euclidean geometries.