基于多传感器的超高压输电线路巡检机器人越障控制

根据500 kV超高压架空输电线路的结构及障碍特点,设计多传感器、多驱动器巡检机器人越障控制方案,提出采用多传感器二次定位方法实现巡检机器人越障时的空间定位.阐述系统的结构和越障原理,通过线下模拟实验环境,不断测试生成合理的知识库,实际越障时根据实测信号自动调用知识库完成自主越障动作.实验结果表明:传感器工作可靠,知识库和空间定位方法设计合理,巡检机器人能高效、快速、高精度地完成巡检及越障任务.     

巡检机器人机械臂空间变形解析模型分析

根据高压输电线路检测环境,提出一种高压输电线路巡检机器人.以该输电线路巡检机器人为研究对象,采用Denavit-Hartenberg法建立巡检机器人的连杆坐标系,推导巡检机器人的变换矩阵.并应用微分变换法推导巡检机器人的雅可比矩阵,得到操作空间外力(速度)与关节空间内力(速度)的线性映射关系.机器人操作臂的刚度影响整个...     

基于多传感器信息融合的输电线路巡检机器人自主越障方法研究

针对550 kV架空输电线路巡检机器人在运行过程中对线上金具识别不稳定及自主越障效率低等问题,基于多传感器信息融合的方法,结合机器人在线越障过程的特点,提出了一种基于多传感器信息融合自主越障方法与策略,并进行了在线自主越障实验。结果表明:以巡线机器人为平台,基于多传感器信息融合的机器人自主越障策略是可行的,提高了机器人越障运动的准确性和灵活性,保证机器人安全可靠的运行。     

井下巡检机器人浮动式移动底盘设计与分析

为提高巡检机器人行走稳定性及越障性能,解决煤矿井下非结构化和复杂未知环境的安全巡检问题,提出一种浮动式巡检机器人移动底盘的设计方案。阐述巡检机器人浮动式移动底盘的结构设计及工作原理,分析巡检机器人越障过程,推导巡检机器人质心位置,得到越障高度与移动底盘位姿关系。运用ADAMS建立巡检机器人虚拟样机,模拟机器人在井下各种复杂路面行走及越障过程。结果表明：所设计的浮动式移动底盘提高了巡检机器人在井下复杂路面行走的稳定性,使巡检机器人具有平稳运行及良好的越障能力,进一步验证了井下巡检机器人浮动式移动底盘设计的可行性。     

基于有限状态机的输电线路巡检机器人自主越障运动控制方法

针对输电线路巡检机器人自主越障运动控制复杂、越障效率低等问题,以一款五臂式巡检机器人为例,通过规划与分析机器人越障动作序列,基于有限状态机理论,提出一种机器人自主越障运动控制方法。通过建立以传感器检测信息为迁移条件的越障运动控制模型,对机器人自主越障运动进行控制;将机器人置于线路环境进行巡检实验。结果表明：该机器人能自主识别并稳定、高效地跨越线路障碍,完成巡检任务,验证了机器人系统的合理性及自主越障运动控制方法的可行性。     

基于光电传感器的两轮自平衡机器人控制研究

针对两轮自平衡机器人的平衡控制问题,基于LEGO机器人构建两轮自平衡机器人本体,采用光电传感器作为倾角检测元件,替代传统的倾角传感器和陀螺仪,以降低成本且避免倾角传感器和陀螺仪的温度漂移。给出了该机器人的本体构成,根据Euler-Lagrange方法建立系统的数学模型,采用最优控制实现机器人的平衡控制。最后进行物理实验,实现了机器人的自平衡,效果比较好,具备一定的抗干扰能力,证明基于光电传感器的两轮自平衡机器人的控制是合理有效的。     

架空输电线路巡检机器人控制系统可靠性设计

针对550 k V架空输电线路巡检机器人在巡检作业中控制器死机、障碍误检以及抗干扰性能差问题,在介绍基于分布式的巡检机器人控制系统基础上,提出了主控制器双机冗余控制和传感器三模冗余容错的控制策略,并且在硬件上实行抗干扰设计。实验表明,该控制策略增强了巡检机器人控制系统可靠性,大大提高了机器人的巡检作业能力。     

高压输电线路巡检机器人机械结构研究现状及发展趋势

随着国家电网的发展,高压输电线路的人工巡检任务日趋繁重,因此利用智能机器人技术代替传统的巡检方法已经是国内外研究的热点。结合目前国内外巡检机器人的研究现状,对其机械结构研究现状进行了分析,并归纳了其类型以及行走机构、越障机构的结构特征,提出了电力巡检机器人的发展趋势。     

海底电缆巡检水下机器人建模及运动控制系统研究

海底电缆巡检水下机器人是为检测与维护海底电缆等管线的腐蚀、磨损等问题而设计的开架式水下机器人。结合海底电缆巡检机器人的实际应用需求,介绍了水下机器人四自由度运动建模方法,详细讨论了海底电缆巡检水下机器人的硬件体系结构组成,采用模块化的方法对海缆巡检水下机器人的软件体系进行了设计。     

基于UWB的智能巡检机器人定位系统研究

因城市地下管线综合管廊内环境恶劣,巡检距离长,固定式监测设备无法实现全覆盖监控,需要用智能巡检机器人代替传统管廊巡检方式,但是智能巡检机器人能够稳定、有序地运行,关键问题是实现智能巡检机器人的精准定位,即获得巡检机器人在管廊内的精确坐标。目前智能巡检机器人所采用的射频、WiFi、惯性里程计等定位技术易受管廊内环境干扰、累计误差干扰等,定位精度为5~50 m,难以满足管廊智能巡检机器人定位系统1 m以内的定位精度要求。为此,提出一种基于UWB的智能巡检机器人定位系统。采用分析UWB信号在管廊内的传输特性、构建巡检机器人在管廊内的运动模型、通过MATLAB建立巡检机器人定位跟踪仿真实验的手段,设计一种基于UWB管廊修正S-V信道模型的巡检机器人LS-PSO定位算法、一种基于巡检机器人运动模型的EKF跟踪算法,建立了巡检机器人LS-PSO/EKF融合定位跟踪模型。通过与KF算法进行MATLAB定位跟踪仿真对比验证,提出的巡检机器人LS-PSO/EKF融合定位跟踪模型在管廊复杂环境下能够有效去除管廊噪声干扰,定位精度相比KF算法明显提升。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.