机器表面喷漆常见缺陷及其消除法

拖拉机、挂车及其他农机具在表面喷漆时,漆膜常出现缺陷,影响承修单位声誉和成本。如何防止漆膜缺陷,结合我们多年的实践谈一谈,供同行参考。 1.漆膜常见的缺陷 (1)起泡 漆膜表面出现大小不同的圆形鼓泡。

船体表面清洗机器人磁吸附机构的优化设计

为提升永磁轮的磁吸附效率,以用于为船体表面清洗机器人提供吸附性能的永磁轮为研究对象,提出一种改进的径向充磁磁路。通过静力学分析获得永磁轮所需最小吸附力,分别针对3种磁路形式开展有限元仿真分析,结果表明,与传统的磁路相比,改进的磁路设计能明显地提高永磁轮的吸附力。在此基础上,开展永磁轮主要尺度的敏感性分析,确定该永磁轮模型结构尺寸,磁铁的厚度为20 mm,导磁铁的宽度为6mm,为船舶清洗机器人总体设计打下基础。研究成果对船舶爬壁清洗机器人、检测机器人、储罐检测机器人和核电站检测机器人等同类机器人的开发具有借鉴意义。

水下船体表面清刷机器人磁吸附系统的研究

介绍了船体表面清刷机器人磁路的设计,磁吸附力的计算和磁吸附系统的封装工艺及在水下磁吸附力的变化情况.研制了水下船体表面清刷机器人所用的磁吸附系统.经样机试验证明该吸附系统具有体积小、吸附性好、防护性能强的优点.

水下船体表面清刷作业机器人的控制系统

水下船体表面清刷作业机器人是一种新型的用于水下特种作业的机器人。作者从电机驱动、姿态检测、自主控制等几个方面进行了机器人控制系统的硬件及软件设计 。

一种能清洗机器内表面的树脂

一种能清洗模压机内表面的树脂,只需很少用量,以简单的操作方法,在短时间内,对模压机内表面上的热塑性树脂,能够很容易地完成颜色交换和树脂交换。这种树脂含有:(a)1～10重量百分数的聚苯乙烯树脂,1～20重量百分数的烷基苯磺酸中性盐,1～30重量百分数的无机填充剂和0.5～10重量百分数的抗水化合物;或(b)1～10重量百分数的聚乙烯蜡,1～20重量百分数的烷基苯磺酸中性盐和1～20重量百分数的无机填充剂,与熔融指数为1.0或小于1.0的高密度聚乙烯树脂混合物,而Q值表示分子量的分布为10或小于10。

1.3μm Si-Based MOEMS Optical Tunable Filter with a Tuning Range of 90nm

Optical filters capable of single control parameter based wide tuning are implemented and studied.A prototype surface micromachined 1 3μm Si based MOEMS (micro opto electro mechanical systems) tunable filter exhibits a continuous and large tuning range of 90nm at 50V tuning voltage.The filter can be integrated with Si based photodetector in a low cost component for coarse wavelength division multiplexing systems operating in the 1 3μm band.

HZ—1型自动幻灯机的维护保养

在电化教育中,幻灯教学是最常用的一种形式。我国目前的幻灯机尚未形成系列,也未标准化,但结构大致相同,一般由光学系统、电器控制系统与机身等构成。为了便于维护和保养幻灯机,下面以HZ—1型自动幻灯机为例,介绍有关维护和保养的知识。 1.幻灯机在使用前后,机器表面要保持清洁,清除灰尘、油垢,检查各部分螺钉有无松动,做到及时发现问题,及时处理。

Selectivity control in alkyne semihydrogenation:Recent experimental and theoretical progress

Researchers have been attempting to characterize heterogeneous catalysts in situ in addition to correlating their structures with their activity and selectivity in spite of many challenges.Here,we review recent experimental and theoretical advances regarding alkyne selective hydrogenation by Pd‐based catalysts,which are an important petrochemical reaction.The catalytic selectivity for the reaction of alkynes to alkenes is influenced by the composition and structure of the catalysts.Recent progress achieved through experimental studies and atomic simulations has provided useful insights into the origins of the selectivity.The important role of the subsurface species(H and C)was revealed by monitoring the catalyst surface and the related catalytic performance.The atomic structures of the Pd catalytic centers and their relationship with selectivity were established through atomic simulations.The combined knowledge gained from experimental and theoretical studies provides a fundamental understanding of catalytic mechanisms and reveals a path toward improved catalyst design.

Research on automatic inspection system for defects on precise optical surface based on machine vision

In manufacture of precise optical products, it is important to inspect and classify the potential defects existing on the products’ surfaces after precise machining in order to obtain high quality in both functionality and aesthetics. The existing methods for detecting and classifying defects all are low accuracy or efficiency or high cost in inspection process. In this paper, a new inspection system based on machine vision has been introduced, which uses automatic focusing and image mosaic technologies to rapidly acquire distinct surface image, and employs Case-Based Reasoning(CBR)method in defects classification. A modificatory fuzzy similarity algorithm in CBR has been adopted for more quick and robust need of pattern recognition in practice inspection. Experiments show that the system can inspect surface diameter of 500mm in half an hour with resolving power of 0.8μm diameter according to digs or 0.5μm transverse width according to scratches. The proposed inspection principles and methods not only have meet manufacturing requirements of precise optical products, but also have great potential applications in other fields of precise surface inspection.

Experimental Investigation of the Effect of Bow Profiles on Resistance of an Underwater Vehicle in Free Surface Motion

In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total resistances for different Froude numbers are considered experimentally. The towing tank is equipped with a trolley that can operate in through 0.05-6 m/s speed with ±0.02 m/s accuracy. Furthermore, the study is done on hydrodynamic coefficients i.e. total, residual and friction resistance coefficients, and the results are compared. Finally, the study on flow of wave fields around bows is done and wave filed around two bows are compared. The Froude number interval is between 0.099 and 0.349. Blockage fraction for the model is fixed to 0.005 3. The results showed that the residual resistance of the standard bow in 0.19 to 0.3 Froude number is more than the tango bow in surface motion which causes more total resistance for the submarine. Finally, details of wave generated by the bow are depicted and the effects of flow pattern on resistance drag are discussed.

Vector modeling of robotic helical milling hole movement and theoretical analysis on roughness of hole surface

To avoid the machine problems of excessive axial force, complex process flow and frequent tool changing during robotic drilling holes, a new hole-making technology (i.e., helical milling hole) was introduced for designing a new robotic helical milling hole system, which could further improve robotic hole-making ability in airplane digital assembly. After analysis on the characteristics of helical milling hole, advantages and limitations of two typical robotic helical milling hole systems were summarized. Then, vector model of helical milling hole movement was built on vector analysis method. Finally, surface roughness calculation formula was deduced according to the movement principle of helical milling hole, then the influence of main technological parameters on surface roughness was analyzed. Analysis shows that theoretical surface roughness of hole becomes poor with the increase of tool speed ratio and revolution radius. Meanwhile, the roughness decreases according to the increase of tool teeth number. The research contributes greatly to the construction of roughness prediction model in helical milling hole.

Facial Robot Expression Simulator(FRESi)——A Simulator to Implement Dynamic Facial Expression

Most of the robots are nowadays evolving and imitating huiron social skills to achieve sociable interaction with humanas. Socially interactive robots require different characteristics than conventional robots. Likewise human-human interaction, human-robot interaction is also accompanied with emotional interaction. Therefore, the robot＇s emotional expression is very important for human, especially facial expressions play an important role among the whole part of the human body. In this paper, we introduce a facial robot expression simulator FRESi.

Robotics and mechatronics for planetary surface exploration

The paper briefly addresses DLR' s ( German Aerospace Center) expertise in space robotics by handof corresponding milestone projects including systems on the International Space Station ISS. It then discussesthe key technologies needed for the development of an artificial "robonaut" generation with mechatronic ultra-light weight arms and multifingered hands. The third arm generation is nearly finished now, approaching thelimits of what is technologically achievable today with respect to light-weight and power losses. In a similar wayDLR' s second generation of artificial 4-fingered hands was a big step towards higher reliability, manipulabilityand overall performance.

Research on temperature rise of hoisting machine disk brake

A mathematical model and finite element model for analysis of temperature rise of the hoisting machine brake sys- tem was constructed, limit conditions were defined, and the law of temperature rise of brake shoes during emergent brake course was analyzed and calculated by using finite element software. By analyzing the calculation results, the law of tempera- ture change of surface of brake disk and shoes during the braking process was found. The law of brake shoes surface tempera- ture distribution and the law of temperature change along with thickness of brake shoes at brake time 0.5 s, 1.0 s and 1.5 s was analyzed. A hoisting machine emergent braking test was carried out. Finally, the author concluded that velocity rebound in the process of hoisting machine emergent brake is due to decreased friction coefficient caused by the temperature rise of the brake shoes surface.

Surface effects of liquid metal amoeba

Liquid metals(LM) such as eutectic gallium-indium and gallium-indium-tin are important functional liquid-state metal materials with many unique properties, which have attracted wide attentions especially from soft robot area. Recently the amoeba-like transformations of LM on the graphite surface are discovered, which present a promising future for the design and assemble of self-fueled actuators with dendritically deformable body. It appears that the surface tension of the LM can be significantly reduced when it contacts graphite surface in alkaline solution. Clearly, the specific surface should play a vital role in inducing these intriguing behaviors, which is valuable and inspiring in soft robot design. However, the information regarding varied materials functions underlying these behaviors remains unknown. To explore the generalized effects of surface materials in those intriguing behavior, several materials including glass, graphite, nickel and copper oxides(CuO) were comparatively investigated as substrate surfaces.Important results were obtained that only LM amoeba transformations were observed on graphite and CuO surfaces. In order to identify the proper surface condition for LM transformation, the intrinsic properties of substrate surfaces, such as the surface charge and roughness, as well as the specific interaction with LM like wetting behavior and mutual locomotion etc., were characterized. The integrated results revealed that LM droplet appears more likely to deform on surfaces with higher positive surface charge density, higher roughness and less bubble generation on them. In addition, another surface material,CuOx, is identified to own similar ability to graphite, which is valuable in achieving amoeba-like transformation. Moreover, this study offers a fundamental understanding of the surface properties in realizing LM amoeba transformations, which would shed light on packing and structure design of liquid metal-based soft device within multi-material system.

Building a dense surface map incrementally from semi-dense point cloud and RGB images

Building and using maps is a fundamental issue for bionic robots in field applications. A dense surface map, which offers rich visual and geometric information, is an ideal representation of the environment for indoor/outdoor localization, navigation, and recognition tasks of these robots. Since most bionic robots can use only small light-weight laser scanners and cameras to acquire semi-dense point cloud and RGB images, we propose a method to generate a consistent and dense surface map from this kind of semi-dense point cloud and RGB images. The method contains two main steps： （1） generate a dense surface for every single scan of point cloud and its corresponding image（s） and （2） incrementally fuse the dense surface of a new scan into the whole map. In step （1） edge-aware resampling is realized by segmenting the scan of a point cloud in advance and resampling each sub-cloud separately. Noine within the scan is reduced and a dense surface is generated. In step （2） the average surface is estimated probabilistically and the non-coincidence of different scans is eliminated. Experiments demonstrate that our method works well in both indoor and outdoor semi-structured environments where there are regularly shaped objects.

On-chip higher-order topological micromechanical metamaterials

Metamaterials with higher-order topological band gaps that exhibit topological physics beyond the bulkedge correspondence provide unique application values due to their ability of integrating topological boundary states at multiple dimensions in a single chip.On the other hand,in the past decade,micromechanical metamaterials are developing rapidly for various applications such as micro-piezoelectricgenerators,intelligent micro-systems,on-chip sensing and self-powered micro-systems.To empower these cutting-edge applications with topological manipulations of elastic waves,higher-order topological mechanical systems working at high frequencies(MHz)with high quality-factors are demanded.The current realizations of higher-order topological mechanical systems,however,are still limited to systems with large scales(centimetres)and low frequencies(k Hz).Here,we report the first experimental realization of an on-chip micromechanical metamaterial as the higher-order topological insulator for elastic waves at MHz.The higher-order topological phononic band gap is induced by the band inversion at the Brillouin zone corner which is achieved by configuring the orientations of the elliptic pillars etched on the silicon chip.With consistent experiments,theory and simulations,we demonstrate the emergence of coexisting topological edge and corner states in a single silicon chip as induced by the higher-order band topology.The experimental realization of on-chip micromechanical metamaterials with higherorder topology opens a new regime for materials and applications based on topological elastic waves.