提高智能机器人性能的探索研究

以广茂达的能力风暴机器人为例从中小学信息课机器人教学活动中对机器人进行改装、提高及优化机器人的各项性能等方面介绍了改装机器人,提高机器人性能所应考虑的一些问题.     

轮腿可切换机器人步态切换动作设计及其机体位姿测量仿真

轮腿可切换机器人在不同的环境下具有不同的运动性能,研制一款新型轮腿可切换机器人。该机器人可实现轮式步态和腿式步态的切换以适应不同环境,最大限度提高机器人运动性能。本文研究了机器人进行步态切换时,机器人机体位姿变化及机器人机体质心在空间的位移及机器人腿各个关节的旋转角度的变化的测量方法,为机器人稳定性研究提供依据。通过对机器人步态切换动作进行仿真,测量机器人质心在空间的变化量及关节角度变换,分析测量结果表明机器人位姿变换平稳,证明机器人步态切换动作的合理性。     

抛光工业机器人主动恒力装置设计研究

研究了工业机器人抛光中的恒力控制,针对传统的机器人恒力控制中既要对机器人进行力控制又要对机器人进行位置控制,导致工业机器人整体控制复杂,响应较慢,精度较低的问题,采用机器人力和位置分离的方式,设计了独立于机器人本体的主动恒力控制装置来解决机器人作业的力控制,使机器人力控制作业中不用考虑机器人的运动控制,从而达到解耦的效果。实验验证结果表明,设计的主动恒力装置提高了工业机器人力控制精度,具有良好的恒力控制性能。     

基于S型曲线的包装堆垛机器人轨迹规划

目的为了保证包装堆直角坐标堆垛机器人系统能够平滑、稳定、高速运行,避免机器人出现速度、加速度的突变,并对机器人轨迹进行规划。方法首先分析直角坐标机器人的运动过程,在此基础上提出一种基于多项式的S型曲线包装堆垛机器人轨迹规划方法,并设计机器人控制系统,利用威纶TK6050ip触摸屏对机器人进行监控和参数设定,采用西门子S7-200 PLC和EM253位置控制模块实现对机器人速度和位置的控制,最后对机器人运动轨迹进行仿真实验分析。结果仿真实验结果表明,该轨迹规划方法能够保证机器人速度和加速度无突变,确保了机器人平滑稳定运行。结论该控制系统有效提高了包装堆垛机器人的运行效率,对于机器人稳定可靠运行具有重要意义。     

机器人定位精度标定技术的研究

机器人末端位姿的精度依赖于各连杆几何参数的精度。为了提高机器人的位姿精度,需要对机器人进行标定,为此必须研究机器人运动学模型的建立方法。基于MDH模型和微分运动学,识别出机器人的各个连杆几何参数误差对机器人位姿精度影响程度,并结合最小二乘算法,对机器人的定位精度进行修正。实验表明,该方法适合对机器人几何参数误差的标定,并且能够提高机器人的综合性能。     

轻工业包装物品搬运机器人路径跟踪控制

目的 为了提高直角坐标搬运机器人的定位精度,保证机器人能够按照预定路径运动。方法 介绍直角坐标机器人工作原理,并基于模糊控制理论,提出一种基于模糊PID的直角坐标机器人轨迹跟踪控制算法,并将其应用于机器人运动轨迹跟踪控制中。结果 仿真和实验结果表明,基于模糊PID的机器人控制器能够保证机器人沿预定路径运动,机器人轨迹跟踪误差能够很快收敛于0附近,该轨迹跟踪方法具有较好的抗干扰性和鲁棒性。结论 所提方法能够明显提高直角坐标机器人的路径跟踪能力,对于提升机器人运动精度具有参考价值。     

基于任务规划的机器人运动学分析与仿真研究

针对机器人在复杂任务场景中的运动学问题及工作可靠性的需求,提出一种基于任务规划的机器人运动学分析方法。首先,介绍了机器人的任务场景,阐述相应的机器人末端轨迹;其次,采用D-H参数法对机器人进行运动学建模,求解相应的正、逆运动学算法;最后,利用机器人操作系统(ROS)完成实体机器人任务规划工作。结果表明,该方法相较于用示教器控制机器人,更符合复杂任务需求,降低了机器人拖动示教的难度,具有较好的稳定性和准确性。     

新型模块化可重构机器人设计与运动学分析

采用模块化设计思想,设计了一种新型可重构工业机器人.通过对机器人进行结构优化设计,机器人的负载自重比达到1/4.5.机器人各关节模块的结构均相同,大幅减少了设计工作量;关节模块中传动部件均采用通用件,降低了机器人的成本.通过关节模块和手臂模块的组合,可形成多种机器人构型.针对其中一种机器人构型,利用DH法建立了机器人正运动学模型.该构型机器人不符合相邻的3根关节轴线交于一点的条件,利用传统方法很难求得全部逆解,因此提出一种代数法与几何法相结合的新方法,求得该构型机器人逆运动学的完整解析解.机器人运动学分析的正确性通过算例进行了验证,为机器人的运动控制奠定基础.     

浅析日本机器人产业的现状

素有"机器人王国"之称的日本,在2008年全球经济危机之后,其机器人产业的市场结构发生了重大转变。2014日本政府拟把机器人作为经济增长战略的重要支柱。扩大工业机器人的应用领域,研究开发、普及服务型机器人是日本机器人产业再发展的突破口。     

基于S曲线的包装码垛机器人轨迹优化

目的为了提高包装搬运机器人的码放效率,提升机器人运动轨迹的平滑性,降低机器人运动过程中因加速度突变出现的振动。方法针对包装码垛机器人的运动轨迹特点,在机器人最大运动速度恒定的前提下,提出一种以时间和冲击为优化指标的五阶S曲线优化方法,将可变化参数引入优化冲击力中,在保证冲击力最小的情况下大大缩短机器人加速时间。结果仿真结果表明,经过五阶S曲线优化的机器人加减速时间明显缩短,机器人的加速度曲线更加平滑。结论该优化方法大大降低了机器人因速度突变出现的振动,有效提升了包装码垛机器人的工作效率。     

太平洋牡蛎(Crassostrea gigas)鳃氯细胞的超微形态研究

利用透射电子显微镜研究了太平洋牡蛎鳃氯细胞的超微结构。氯细胞主要分布于鳃小叶的基部,呈口袋状,细胞个体较大,在鳃表面有一凹隐的分泌腔。细胞中,细胞核多位于基部,体积较小;具有发达的微细小管系统,但小管的分支程度低;线粒体数量较少且结构不够发达;可见少量的高尔基体,未见内质网。鳃氯细胞是太平洋牡蛎鳃渗透压调节的重要细胞系统。     

An inverse problem technique for detecting irregular cavities in circular cylinders by infrared scanning

An inverse problem technique has been developed for detecting irregular cavities in circular cylinders. In this method, the cavity is considered a part of the unknown geometry of the investigated system, and the evaluated temperature is used to locate this geometry. An auxiliary problem is introduced in the solution of this problem; and in the solution, the cavity wall is located by forcing the temperature to satisfy the condition imposed at the cavity. The new methodology is validated by an experiment presented in this paper, and the test results indicate that this method is highly successful in locating cavities. The accuracy of the method is closely related to the accuracy of the temperature that can be measured at the surface. A small error in the surface temperature results in a slight cavity error for deep cavities, while a shallow cavity is not severely affected by a surface temperature error. This method is particularly attractive in detecting shallow cavities in nondestructive evaluation.     

用ObjectARX实现设计图纸的管理

对制造业中设计人员最关心的设计图纸的计算机管理问题进行了研究和开发。对AutoCAD中的ObjectARX技术的功能和特点进行了概述，提出了对设计图纸的图形文件采用以设计号为基础的树型管理方式，并通过ObjectARX技术，以AutoCAD为背景，实现对设计图纸的自动化管理；同时介绍了图纸数据库的存储模式，并对于如何在数据库中定义存储过程和使用触发器给出了程序实现方法。     

Influence of vanadium on grain boundary segregation of phosphorus in iron and iron-carbon alloys

The influence of vanadium on grain boundary segregation of phosphorus has been studied in iron and iron-carbon alloys by means of fracture experiments in a scanning Auger microprobe. The emphasis here is to study the effects of vanadium on the interaction processes operative under circumstances when structure in the interior of the grain (in the present case carbide formation) and grain boundary segregation form simultaneously. It is emphasized that to predict and analyse the behaviour of an alloy, it is important to consider atomic interactions both at the grain boundaries and in the grain interior and that between the constituents and the grain boundaries. The study suggests that the principal determining factor in the scavenging or retardation of migration of phosphorus to the grain boundaries is whether vanadium is present in the combined form (say, carbide) or is available in solid solution form. When vanadium is present in solid solution form, grain boundary segregation of phosphorus is low because of the chemical interaction of vanadium and phosphorus. However, as carbon is increasingly introduced in the alloy, vanadium now preferentially reacts with carbon in view of higher interaction for carbon as compared to phosphorus. A consequence of this is the increase in the grain boundary concentration of phosphorus. In such a situation the presence of excess carbon in addition to what is stoichiometrically required to precipitate the entire vanadium as vanadium carbides, serves as a palliative with regard to the reduction in the intergranular concentration of phosphorus. This palliative behaviour is explained in terms of the sitecompetition model. An effort is also made to examine the behaviour of segregating elements in terms of whole range of probable interactions (both at the grain boundaries and in the grain interior) and chemical interaction energies.     

铝镁合金熔炼中气体保护法的动力学研究

在铝镁合金熔炼过程中,因为镁的化学性质活泼,导致合金的氧化、烧损现象十分严重,不仅降低了合金中镁的收得率,而且造成了巨大的经济损失.为了达到阻燃目的,国内经常采用熔剂法,而目前在国外用的较多的则是气体保护法.本实验对气体保护法进行了研究,建立了相应的动力学曲线规律,并对温度因素的影响进行了探讨,所得实验结论对生产实践具有一定的指导作用.     

'Arching' effect in elastic polycrystals: implications for the variability of fatigue lives

ABSTRACT The paper deals with a study of heterogeneous stress and strain distribution in polycrystals in relation with elastic anisotropy of grains. A similitude with the arching effect widely studied in granular materials is proposed and this concept is extended to heterogeneous polycrystals in which the load transfer is not binary in the way it is in granular media but may vary significantly and suddenly from one grain to another according to the crystal orientation to the load direction. Experiments and 3D finite element analyses show that though the individual orientation of grains is random, the strain and stress distribution is not. A network is formed inside the polycrystal whose scale is larger than the grain size. The load percolation network consists in heavily loaded links whose direction is coincident with the direction of the principal stresses. So, the typical scale for the variability of the local stresses is not the grain size but the size of the load percolation network. Since this scale is found to be rather large in particular for iron, zinc and copper, this effect should contribute significantly to the variability of the fatigue lives of notched vs. smooth components.     

基于并联机构及MR阻尼器的多维减振平台半主动控制研究

分析了磁流变阻尼器的力学特性,将其应用于多维减振系统中。采用经典的三平移并联机构作为多维减振平台的主体机构,推导出其位置逆解公式;建立了系统动力学状态方程模型,以运动学方程得到的支路加速度作为输入信号,控制器采用了基于线性二次型最优控制理论的半主动控制算法。考虑到动态过程中机构动力学方程的复杂性,采用稳态方法对并联机构处于某一运动姿态的支路移动副振动进行控制,从而控制了整个平台的振动。仿真结果表明,所采取的控制算法有较好的控制效果。     

Formation of conducting polymer nanostructures with the help of surfactant crystallite templates

An extremely simple approach is described here to synthesize bulk quantities of conducting polymer microspirals assembled from nanofibers by in situ chemical oxidative polymerization in the presence of a conventional surfactant. It is worth noting that the surfactant used in our approach is in crystalline state, which is quite different from micellar state in emulsional polymerization reported previously. The growth mecha-nism of the conducting polymer is proposed.     

Brain tumor detection and diagnosis using ANFIS classifier

In this article, the segmented brain tumor region is diagnosed into mild, moderate, and severe case based on the presence of tumor cells in the brain components such as Gray Matter (GM), White Matter (WM), and cerebrospinal fluid (CSF). The modified spatial fuzzy c mean algorithm is used to segment brain tissues. The feature Local binary pattern is extracted from segmented tissues, which is trained and classified by ANFIS Classifier. The performance of the proposed brain tissues segmentation system is analyzed in terms of sensitivity, specificity, and accuracy with respect to manually segmented ground truth images. The severity of brain tumor is diagnosed into mild case if the segmented brain tumor is present in the grey matter. The severity of brain tumor is diagnosed into moderate case if the segmented brain tumor is present in the WM. The severity of brain tumor is diagnosed into severe case if the segmented brain tumor is present in the CSF region. The immediate surgery is required for severe case and medical treatment is preferred for mild and moderate case.