Remaining Useful Life for Heavy-Duty Railway Cast Steel Knuckles Based on Crack Growth Behavior with Hypothetical Distributions

The current research on the integrity of critical structures of rail vehicles mainly focuses on the design stage,which needs an effective method for assessing the service state.This paper proposes a framework for predicting the remaining useful life(RUL)of in-service structures with and without visible cracks.The hypothetical distribution and delay time models were used to apply the equivalent crack growth life data of heavy-duty railway cast steel knuckles,which revealed the evolution characteristics of the crack length and life scores of the knuckle under different fracture failure modes.The results indicate that the method effectively predicts the RUL of service knuckles in different failure modes based on the cumulative failure probability curves for different locations and surface crack lengths.This study proposes an RUL prediction framework that supports the dynamic overhaul and state maintenance of knuckle fatigue cracks.

Method for Analyzing Articulated Torques of Heavy-duty Six-legged Robot

The accuracy of an articulated torque analysis influences the comprehensive performances of heavy-duty multi-legged robots. Currently, the extremal estimation method and some complex methods are employed to calculate the articulated torques, which results in a large safety margin or a large number of calculations. To quickly obtain accurate articulated torques, an analysis method for the articulated torque is presented for an electrically driven heavy-duty six-legged robot. First, the rearmost leg that experiences the maximum normal contact force is confirmed when the robot transits a slope. Based on the ant-type and crab-type tripod gaits, the formulas of classical mechanics and MATLAB software are employed to theoretically analyze the relevant static torques of the joints. With the changes in the joint angles for the abductor joint, hip joint, and knee joint, variable tendency charts and extreme curves are obtained for the static articulated torques. Meanwhile, the maximum static articulated torques and the corresponding poses of the robot are also obtained. According to the poses of the robot under the maximum static articulated torques, ADAMS software is used to carry out a static simulation analysis. Based on the relevant simulation curves of the articulated torques, the maximum static articulated torques are acquired. A comparative analysis of the maximum static articulated torques shows that the theoretical calculation values are higher than the static simulation values, and the maximum error value is approximately 10%. The proposed method lays a foundation for quickly determining accurate articulated torques to develop heavy-duty six-legged robots.

Static Force Analysis of Foot of Electrically Driven Heavy-Duty Six-Legged Robot under Tripod Gait

The electrically driven six-legged robot with high carrying capacity is an indispensable equipment for planetary exploration, but it hinders its practicability because of its low efficiency of carrying energy. Meanwhile, its load capacity also affects its application range. To reduce the power consumption, increase the load to mass ratio, and improve the stability of robot, the relationship between the walking modes and the forces of feet under the tripod gait are researched for an electrically driven heavy-duty six-legged robot. Based on the configuration characteristics of electrically driven heavy-duty six-legged, the typical walking modes of robot are analyzed. The mathematical models of the normal forces of feet are respectively established under the tripod gait of typical walking modes. According to the MATLAB software, the variable tendency charts are respectively gained for the normal forces of feet. The walking experiments under the typical tripod gaits are implemented for the prototype of electrically driven heavy-duty six-legged robot. The variable tendencies of maximum normal forces of feet are acquired. The comparison results show that the theoretical and experimental data are in the same trend. The walking modes which are most available to realize the average force of distribution of each foot are confirmed. The proposed method of analyzing the relationship between the walking modes and the forces of feet can quickly determine the optimal walking mode and gait parameters under the average distribution of foot force, which is propitious to develop the excellent heavy-duty multi-legged robots with the lower power consumption, larger load to mass ratio, and higher stability.

Shear performance analysis of a heavy-duty universal hinged cast steel support

This paper presents the shear performance analysis of a heavy-duty universal hinged cast steel support with the largest bearing capacity. The effect of 9 parameters ( 52 specimens) ,i. e. height of the upper support,depth of the ring of the upper support,depth of the top plate of the bottom support,height of the ribs of the bottom support,depth of the ribs of the bottom support,bolt hole diameter,number of the ribs of the bowl,depth of the ribs of the bowl,and yield strength of the material,were analyzed with a 3-dimensional elastic-plastic finite element model in which the nonlinearities of geometry,material and contact were all considered. Analysis shows that height of the upper support,depth of the ring of the upper support and yield strength of the material have a great effect on the mechanical performance of the support. Height of the upper support has the largest effect on performance price ratio of the support,and the maximum effect can be up to 160% . Depth of the top plate of the bottom support,height of the ribs of the bottom support and depth of the ribs of the bottom support have a medium effect on performance price ratio of the support,and the effect is within the limit of 15% 19% .

Grinding/Cutting Technology and Equipment of Multi-scale Casting Parts

Multi-scale casting parts are important components of high-end equipment used in the aerospace,automobile manufacturing,shipbuilding,and other industries.Residual features such as parting lines and pouring risers that inevitably appear during the casting process are random in size,morphology,and distribution.The traditional manual processing method has disadvantages such as low efficiency,high labor intensity,and harsh working environment.Existing machine tool and serial robot grinding/cutting equipment do not easily achieve high-quality and high-efficiency removal of residual features due to poor dexterity and low stiffness,respectively.To address these problems,a five-degree-of-freedom(5-DoF)hybrid grinding/cutting robot with high dexterity and high stiffness is proposed.Based on it,three types of grinding/cutting equipment combined with offline programming,master-slave control,and other technologies are developed to remove the residual features of small,medium,and large casting parts.Finally,the advantages of teleoperation processing and other solutions are elaborated,and the difficulties and challenges are discussed.This paper reviews the grinding/cutting technology and equipment of casting parts and provides a reference for the research on the processing of multi-scale casting parts.

基于ROS的铸件分拣机器人运动规划研究

为铸件分拣机器人在分拣铸件时能快速规划出一条稳定合理的路径、有效躲避障碍物、提高运动规划效率,文章通过ROS进行运动规划研究。利用ROS提供的C++接口完成笛卡尔指定轨迹规划验证。为进一步提高分拣效率和避障能力,文中改进算法在GB-RRT*算法基础上引入了局部迭代人工势场,加入了自适应目标偏置策略和直连策略。通过Matlab和ROS设计并完成了仿真实验和铸件分拣实验,实验结果表明采用改进算法后可有效减少无效点生成,缩短规划时间,减小路径长度,提高规划效率。同时,在规划运动时各关节运动平稳,轨迹平滑,极大地提高了铸件分拣效率,改善了分拣环境,保证了其安全性。

视觉引导与工业机器人驱动的钢包长水口装卸技术

为了解决连铸高温、高噪声环境下钢包水口人工装卸劳动强度大、安全风险高、连铸钢包对接水口准确率低与效率低等问题,设计了以3D高精度视觉引导技术为检测系统,PLC设备为控制平台,六轴工业机器人为柔性驱动源的连铸钢包长水口装卸控制方案。该方案通过以太网通信将视觉系统检测到的位置信息经PLC控制传送至机器人系统,并按工艺要求驱动机器人完成自动化动作流程,实现连铸钢包长水口装卸流程动作的精确智慧控制。经测试结果证明,该技术实现了从机器人取工装开始到放回工装,整个安装或拆卸长水口时间≤80 s,装卸命中率>99%,满足了工艺要求和指标。此系统不仅使操作人员从重体力劳动和恶劣工作环境中解放出来,而且提高了装卸水口的准确性和稳定性,极大地提升了生产效率,保证了铸坯质量。

自动化铸造生产线工艺特点分析

为推进机器人在铸造行业应用,深入分析了自动化铸造生产线各工艺工序的特点。介绍了自动化铸造生产线的整体工艺流程,详细讨论了砂芯浸涂和铸件打磨两个最为重要的工艺工序及其主要工艺参数。最后,对生产工序中出现频次最高的搬运操作进行了重点分析。

连铸大包自动浇钢技术开发与应用

介绍在中南股份炼钢厂应用的连铸大包自动浇钢技术,技术主要配设3台6轴铸造级工业机器人,自动完成机器人自动拆装滑动水口滑板油缸,机器人自动拔插介质管线,机器人自动套装拆卸大包长水口,机器人自动测温取样、长水口碗部自动清理及自动加大包长水口密封圈,机器人自动分拣及自动加覆盖剂等工作。技术的应用效果良好,具有广阔的应用前景。

缸体缸盖铸件机器人打磨的关键技术及其应用

简要介绍了缸体缸盖清理线工艺流程及人工打磨存在的问题,对机床打磨、机器人打磨两种主要的自动化打磨技术进行了对比,在此基础上,结合工厂实际情况,选择了机器人打磨方案。分析了铸铁缸体缸盖机器人打磨的主要难点和重点,阐述了机器人打磨工作站的整体方案、动作流程、系统组成,详细阐述了打磨工作站仿真、通过适应多品种缸体缸盖的浮动夹具、气浮式柔性电主轴、激光检测系统等关键技术手段来解决因铸件一致性差、待打磨部位一致性差对机器人打磨可靠性和打磨质量的难题。简要说明了应用情况,指出了机器人打磨辅以人工补清,是提高机器人打磨缸体缸盖类复杂铸件的可靠性、解决清理打磨用工问题突出的有效途径。

基于3D打印的机器人手臂无模快速铸造方法研究

随着制造技术的不断进步,传统的铸造方法非常繁琐且耗时,为此,提出了一种创新性的机器人手臂3D打印无模快速铸造方法。该方法将铸造与3D打印无模铸型制造工艺相结合,可获得精度高、质量高、轻巧的机器人手臂,有效提高机器人的负载能力和响应速度,同时,省去模具的制作环节,节约材料。

七轴浇铸机器人的运动学建模和仿真技术

为了使七轴浇铸机器人能够更好地在我国工业领域发挥技术优势,在分析机器人结构的基础上,利用SolidWorks软件建立三维模型,并根据七轴浇铸机器人的运动特点,在标准D-H方法下建立运动模型,通过解析法推导计算机器人的末端位置姿态。用MATLAB平台进行仿真分析,将仿真结果与运动模型计算结果进行比对发现基本一致,说明此次运动学建模准确性较高,也表明七轴浇铸机器人的结构参数能够达到期望位姿。通过此次研究,希望为工业机器人的推广应用提供参考。

基于PLC技术的连铸机坯火焰切割机器人自动化控制系统

探讨PLC技术在连铸机坯火焰切割机器人自动化控制系统设计中的应用,研究内容包括机械系统设计、自动化控制系统设计以及系统的试验验证。机械系统设计采用了YZX直角坐标式布局,系统软件设计方面则涵盖PLC程序设计、人机交互界面设计和数据通信处理。经模拟工业环境试验验证可知,系统拥有优异的切割精度、速度和质量。

Full-Degree-of-Freedom Space Robot Developed in China

Beijing Institute of Control Engineering(BICE),a subsidiary of CAST,has developed the nation’s first full-degree-of-freedom full-physical simulation test system for space operation recently.The system is used in space operation simulation like fueling in orbit.It is an important preparation to provide orbital service and maintenance for China’s spacecraft in the future.

A Lab for Intelligent Space Robot System Established

Beijing Municipal Science and Technology Commission certificated the Beijing Key Laboratory for Technology and Application of Intelligent Space Robot System(Lab for short)in December 2014.The Institute of Spacecraft System Engineering of CAST is the supporting institution of the Lab.Space intelligent robot is a cross-discipline high-tech area,which is an important trend in global science and tech-

基于RobotStudio的机器人轮毂铸件去毛刺工作站设计与仿真

针对轮毂行业现有毛坯毛刺去除方法,如使用刮刀、砂纸等工具均无法满足去毛刺要求的情况,提出了一种机器人自动化去毛刺的新方案。运用RobotStudio软件对工作站的设计进行仿真验证。仿真结果表明:机器人轮毂铸件去毛刺工作站的设计合理,能满足生产需求,为后续构建机器人轮毂铸件去毛刺工作站奠定了良好的基础。

库卡机器人在热轧连铸生产中的应用

随着工业信息化和智能化的快速发展,利用工业机器人代替人工作业,可确保标准化精准作业,减少危险岗位人工操作及重复性劳动,提升产线效率。本文针对河钢集团唐钢公司连铸中包区域6轴库卡机器人未能高效运行的现状,从其工作原理、开发程序入手,分析了制约中包区域机器人使用的因素。在提高设备安全性,考虑操作人员操作习惯的前提下,通过优化回转台速度控制、调整机器人位姿、优化运动轨迹、提高非干涉区域运行速度、缩短机器人运行环节等途径,统筹兼顾各设备动作时间,达到了连铸工艺要求。

一种基于视觉识别的机器人随动挂件系统

悬挂链输送作为发动机缸体铸件工序转运过程中的一个重要环节,针对现有工艺流程中人工挂件生产效率低、劳动强度大、存在安全隐患和造成铸件磕碰伤等问题,设计了一种基于视觉识别的机器人随动挂件系统,该系统采用视觉识别技术和机器人随动跟踪技术,实现悬挂链在运动状态下300 kg重载缸体自动抓取挂件。系统已投入使用,运行稳定可靠,机器人有效替代人工,生产效率提高10%,因铸件磕碰伤导致的废品率降至0.4%以下,具有良好的应用前景。

基于数字孪生的压铸机器人模型构建与演化

数字孪生作为新一代信息技术和制造产业集成的前提条件,利用闭环交互实现信息物理融合,构建物理实体的数字模型,促进系统的智能化和数字化升级。传统的基于单一对象的数字孪生压铸机器人模型,功能较为单一,忽略了不同层级间的相互影响,无法实时对故障进行预警决策且在进行离线分析时需要依赖实际系统,具有很大的不确定性,动态追踪效果差,应用于高精度压铸机器人时效果不理想。针对这一情况,设计了一种面向压铸机器人现场的数字孪生数据采集与处理系统为压铸机器人提供数据基础,在分析不同数字孪生平台建模效果的基础上,将外部数据与孪生模型进行映射构建动态模型,实现数字模型准确描述物理设备的功能。通过对压铸机器人状态检测以及数据分析,验证数字孪生的辅助决策和运行诊断能力,得到满足需求的压铸机器人数字孪生模型。

摇枕铸钢件机器人自动化打磨系统研究与应用

铁路货车用摇枕为砂型铸钢件,铸件表面的清理打磨以人工为主,存在安全隐患、劳动强度大、作业环境恶劣等问题。本文以铁路货车转K6摇枕为例,通过分析摇枕打磨部位,调研铸件清理打磨现状,针对自动化打磨难点提出了解决措施,设计了机器人自动化打磨方案,研制并应用了自动化打磨设备,实现了摇枕铸件打磨工序“机器换人”,提高了企业安全系数,减轻了工人劳动强度,改善了作业环境,提高了企业自动化水平。