The Offline Program Profile Lining and Cutting Robot System

The paper introduces a new type of cutting system: the Offline Program Profile Lining and Cutting Robot System (OPPLCRS). The system adopts the offline program technology without teaching. The system can measure and compensate every profile’s deformation automatically, so it is suit to process any batch of profiles, and the order of processing different profiles can be arranged at will. The OPPLCRS, firstly appearing in China, will have wide application in profile cutting fields.

Prospects of Robot Laser Cutting in the Era of Industry 4.0

Laser cutting is a non-contact thermal cutting process and an integral part of manufacturing. In metal processing, laser cutting is at the forefront of the manufacturing chain followed by joining and manufacturing processes like welding. The future of metal manufacturing processes like laser cutting shall rely on intelligent systems such as automation and robotics based on the advancement of technology and digital transformation spearheaded by Industry 4.0. Moreover, the digital transition where robots and automated systems are key drivers creates a broader platform to utilize energy-efficiency materials. Such energy-efficient materials include high-strength steels (HSS) for structural applications (e.g. bio-energy structures, wind turbines, ice-going vessels) onshore, offshore and in the Arctic region. The aim of this paper is to elucidate the prospects of robot laser cutting systems in the framework of integrated metal manufacturing in future factories. Previous studies on laser cutting technologies are examined based on scientific and industrial perspectives. Robot laser cutting system is compared with the well-known flat-bed laser cutting CNC machine in several aspects including flexibility in manufacturing, ease for digitalization, off-line capabilities and investment analysis. The findings shall help to determine the competitiveness of robot laser cutting systems with flat-bed laser cutting CNC machines, especially when considering metal manufacturing in small and medium-sized enterprises (SMEs). The outcome of this study is to stir up experimental and computational research on robot laser cutting systems of metals, and help companies in their decision-making process when deciding which laser cutting system will best suit their manufacturing operations in the future.

Adaptive neural network control for coordinated motion of a dual-arm space robot system with uncertain parameters

Control of coordinated motion between the base attitude and the arm joints of a free-floating dual-arm space robot with uncertain parameters is discussed. By combining the relation of system linear momentum conversation with the Lagrangian approach, the dynamic equation of a robot is established. Based on the above results, the free-floating dual-arm space robot system is modeled with RBF neural networks, the GL matrix and its product operator. With all uncertain inertial system parameters, an adaptive RBF neural network control scheme is developed for coordinated motion between the base attitude and the arm joints. The proposed scheme does not need linear parameterization of the dynamic equation of the system and any accurate prior-knowledge of the actual inertial parameters. Also it does not need to train the neural network offline so that it would present real-time and online applications. A planar free-floating dual-arm space robot is simulated to show feasibility of the proposed scheme.

The Fuzzy Neural Network Control Scheme With H∞ Tracking Characteristic of Space Robot System With Dual-arm After Capturing a Spin Spacecraft

In this paper,the dynamic evolution for a dualarm space robot capturing a spacecraft is studied,the impact effect and the coordinated stabilization control problem for postimpact closed chain system are discussed.At first,the pre-impact dynamic equations of open chain dual-arm space robot are established by Lagrangian approach,and the dynamic equations of a spacecraft are obtained by Newton-Euler method.Based on the results,with the process of integral and simplify,the response of the dual-arm space robot impacted by the spacecraft is analyzed by momentum conservation law and force transfer law.The closed chain system is formed in the post-impact phase.Closed chain constraint equations are obtained by the constraints of closed-loop geometry and kinematics.With the closed chain constraint equations,the composite system dynamic equations are derived.Secondly,the recurrent fuzzy neural network control scheme is designed for calm motion of unstable closed chain system with uncertain system parameter.In order to overcome the effects of uncertain system inertial parameters,the recurrent fuzzy neural network is used to approximate the unknown part,the control method with H∞tracking characteristic.According to the Lyapunov theory,the global stability is demonstrated.Meanwhile,the weighted minimum-norm theory is introduced to distribute torques guarantee that cooperative operation between manipulators.At last,numerical examples simulate the response of the collision,and the efficiency of the control scheme is verified by the simulation results.

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.

Singular perturbation composite control of a free-floating flexible dual-arm space robot

The Free-floating Flexible Dual-arm Space Robot is a highly nonlinear and coupled dynamics system. In this paper, the dynamic model is derived of a Free-floating Flexible Dual-arm Space Robot holding a rigid payload. Furthermore, according to the singular perturbation method, the system is separated into a slow subsystem representing rigid body motion of the robot and a fast subsystem representing the flexible link dynamics. For the slow subsystem, based on the second method of Lyapunov, using simple quantitative bounds on the model uncertainties, a robust tracking controller design is used during the trajectory tracking phase. The optimal control method is designed in the fast subsystem to guarantee the exponential stability. With the combination of the two above, the system can track the expected trajectory accurately, even though with uncertainty in model parameters, and its flexible vibration gets suppressed, too. Finally, some simulation tests have been conducted to verify the effectiveness of the proposed methods.

Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

The automatic cutting of intersecting pipes is a challenging task in manufacturing.For improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single Y-groove.Firstly,it summarizes the intersection forms and introduces a dual-pipe intersection model.Based on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is defined.Secondly,a novel mathematical model for plasma radius and taper compensation is established.Then,the compensation model and groove model are integrated by establishing movable frames.Thirdly,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is proposed.Through the established models and moving frames,the planned path description of cutting robot is provided in this novel scheme.The accuracy of the proposed method is verified by simulations and robotic cutting experiments.

Stroke optimization of a novel multi-station rotary polishing robot based on workspace analysis

In order to meet the polishing requirement of faucets and other products,a novel multi-station rotary polishing robot is designed,which is a PPPR + RR type of degree of freedom( DOF) distribution structure,and is similar to dual-arm robot. Forward and inverse kinematic analysis is carried out by robot modeling. In order to make this robot structure more compact,first of all,X,Y and Z three moving degrees of freedom( DOF) limit stroke polishing need is calculated by using an artificial fish swarm algorithm,which analyzes dexterous workspace of this robot. Then,on the basis of the above analysis,the three DOF stroke is optimized. Simulation and polishing experimental results verify that this polishing robot with optimized stroke parameters can meet the polishing needs of faucets and other bathroom pieces.

智能采煤机器人关键技术

采煤机是综采工作面的核心装备,研发智能采煤机器人是实现综采工作面智能化的关键。综合分析当前采煤机机器人化研究进程中的传感检测、位姿控制、速度控制、截割轨迹规划与跟踪控制等技术的研究现状,提出研发智能采煤机器人必须破解的“智能感知、位姿控制、速度控制、截割轨迹规划与跟踪控制、位-姿-速协同控制”五大关键技术,并给出解决方案。针对智能感知问题,提出了构建智能感知系统思路,给出了智能采煤机器人智能感知系统的架构,实现对运行状态、位姿、环境等全面感知,为智能采煤机器人安全、可靠运行提供保障;针对位姿控制问题,提出了智能PID位姿控制思路,给出了改进遗传算法的PID位姿控制方法,实现了智能采煤机器人位姿精准控制;针对速度控制问题,提出了融合“力-电”异构数据的截割载荷测量思路,给出了基于神经网络算法的截割载荷测量方法,实现了截割载荷的精准测量;提出牵引与截割速度自适应控制思路,给出了人工智能算法牵引与截割速度决策方法和滑模自抗扰控制的牵引与截割速度控制方法,实现了智能采煤机器人速度精准自适应控制;针对截割轨迹规划与跟踪控制问题,提出了截割轨迹精准规划思路,给出了融合地质数据和历史截割数据的截割轨迹规划模型,实现了截割轨迹的精准规划;提出了截割轨迹精准跟踪控制思路,给出了智能插补算法的截割轨迹跟踪控制方法,实现了智能采煤机器人截割轨迹高精度规划与精准跟踪控制;针对“位-姿-速”协同控制问题,提出了“位-姿-速”协同控制参数智能优化思路,给出了基于多系统互约束的改进粒子群“位-姿-速”协同控制参数优化方法,实现了智能采煤机器人智能高效作业。深入研究五大关键技术破解思路,有利于加快推动研发高性能、高效率、高可靠的智能采煤机器人。

短横轴截割机器人直墙拱形巷道自动成形控制方法

针对掘进机在直墙拱形巷道掘进过程中存在定位难、截割效率低、成形质量差等问题,提出一种短横轴截割机器人及其自动成形控制方法。首先设计了串联式短横轴截割机器人结构,构建了短横轴截割机器人运动学模型,建立了截割臂升降油缸、滑移油缸及回转油缸伸缩量与截割头末端位姿的数学关系,提出了短横轴截割机器人直墙拱形巷道自动成形控制方法;其次研究分析了短横轴截割机器人截割头包络空间与直墙半圆拱形巷道空间耦合关系,确定了截割过程中截割轨迹关键点位置,提出了基于截割轨迹关键点的“弓”型截割轨迹规划方法;然后根据建立的短横轴截割机器人运动学模型,求解截割头在跟踪截割轨迹的过程中运动控制量和截割、修帮、扫底3个任务各个关节控制时序;最后以模糊PID为例,建立了短横轴截割机器人自动成形控制方法,利用Adams软件对短横轴截割机器人进行截割运动仿真试验。结果表明:利用“弓”型截割轨迹规划方法能够完成直墙拱形巷道的截割轨迹规划,控制截割头对截割轨道进行跟踪控制,实现了直墙拱形巷道断面的自动成形截割,截割成形的巷道最大欠挖量为48 mm,最大超挖量为21 mm,满足煤矿巷道成形质量要求。研究得出短横轴截割机器人可在沿巷道中线不左右移机的情况下,高效率、高质量地完成直墙拱形巷道断面自动成形截割任务。

双悬臂截割机器人相对动力学建模与力位混合控制研究

双悬臂截割机器人可解决传统单臂掘进机在截割大尺寸断面时效率低下的难题,但其与煤岩的动态交互影响控制性能。现有研究以双臂接触同一对象形成运动闭链为前提,无法满足双悬臂截割机器人双臂运动及末端截割头输出力的控制要求。针对该问题,设计了一种基于机器人相对动力学模型的力位混合控制系统。建立双悬臂截割机器人运动学和动力学模型,基于机器人的相对雅可比矩阵及虚位移与虚功原理推导出机器人的相对动力学模型,通过单一变量同时描述机器人双臂的运动状态,将机器人双臂独立的动力学模型整合为一个整体。基于机器人的相对动力学模型,设计了机器人双臂力位混合控制系统,通过李雅普诺夫函数验证了系统的稳定性和可行性。仿真结果表明:双悬臂截割工艺较单悬臂截割拥有更大的工作空间,具有一次性实现大断面截割的能力;双悬臂截割机器人力位混合控制系统能够完成对期望相对位置和期望相对力的同步跟踪,对截割头期望位置跟踪的绝对误差在0.3132 m以内,均方根误差为0.1447 m。

基于PLC和工业机器人的激光切割系统应用设计

洗衣机内胆质检过程中,需按照不同型号的产品切割内胆不同部位进行拉力强度试验。为解决人工切割试件质量不稳定,操作安全性低等问题,提出了基于PLC、工业机器人和调高器的激光切割系统,工业机器人夹持调高器与激光切割头,调高器快速跟随调节激光切割头的位置高度,保证了切割试件的质量。实践应用表明,该系统提升了试件的质量,操作安全性好,为质检的准确性提供了保障,具有较高的应用价值。

粮食收购智能扦样系统设计与研究

针对粮食收购扦样环节存在的劳动强度大、过度依赖人工、智能化程度低等问题,研发出一种能用于粮食行业车载散料或袋装的各类粮种的全自动、智能快速扦样系统。系统以机器人技术为载体,结合自动控制技术、图像识别技术、信息技术等,能够完成车辆信息识别、车厢尺寸及位置识别、自动扦样、智能缩分、自动输送、余粮回车、自动清理等。连续扦样时,粮食扦样分样时间约7 min/次。系统可对粮食入仓进行闭环控制,实现粮食入仓智能扦分无人化、标准化,消除人为因素干扰,杜绝扦样环节作弊现象。

薄煤层综采工作面智能化关键技术与应用

针对薄煤层工作面开采长期面临的装备配套性能低、智能化程度低、经济效益低、劳动强度高的“三低一高”问题,构建了工作面生产时地面工艺调度决策,井下设备依据决策自动执行的“地面规划采煤、装备自动执行、面内无人作业”的智能无人开采新模式。建立了以地面控制中心为核心,以井上下万兆网络通讯平台、采煤机规划截割、液压支架主从调度、机载音视频装置、巡检机器人、电缆拖拽、三岗合一为辅的成套化薄煤层智能化开采关键技术。通过工业实践表明,该模式可实现生产时将工作面内作业人员由原来3人减为无人,达到无人则安;生产效率由原来的每天12刀提升到14刀,最高达到16刀,平均提升17%以上。

Contact detumbling toward a nutating target through deformable effectors and prescribed performance controller

Detumbling operation toward a rotating target with nutation is meaningful for debris removal but challenging. In this study, a deformable end-effector is first designed based on the requirements for contacting the nutating target. A dual-arm robotic system installed with the deformable end-effectors is modeled and the movement of the end-tips is analyzed. The complex operation of the contact toward a nutating target places strict requirements on control accuracy and controller robustness. Thus, an improvement of the tracking error transformation is proposed and an adaptive sliding mode controller with prescribed performance is designed to guarantee the fast and precise motion of the effector during the contact detumbling.Finally, by employing the proposed effector and the controller,numerical simulations are carried out to verify the effectiveness and efficiency of the contact detumbling toward a nutating target.

Design and optimization on rootstock cutting mechanism of grafting robot for cucurbit

Cutting mechanisms in existing grafting machines are unable to completely cut through the rootstock growth point and can easily damage seedlings.During the mechanical operation of splice grafting,the cutting angle of the rootstock is an essential factor for ensuring the quality and survival rate of grafting seedlings and a stable process for grafting robots.Therefore,in this study,commonly used grafting rootstocks,e.g.,cucurbita moschata,and calabash gourd were used as research objects for studying and analyzing the cutting angle of a splice grafting method.The morphological and structural parameters of the rootstock and scion were measured,and a structural model of the internal cavity of the rootstock was constructed using an image analysis method.The critical cutting angles for the cucurbita moschata and calabash gourd seedlings were obtained.According to the analysis,the grafting cutting angles for cucumber seedlings matching with cucurbita moschata seedlings were 20°and 25°,respectively,and the fitting rate of the cutting surface of the rootstock and scion was 99.04%.A cutting mechanism for the rootstock growth point and geometric model of the cutting operation were established,and the structural parameters of the mechanism and cutting angle adjustment were optimized.A cutting performance test showed that the success rate of the pressing the cotyledons of cucurbita moschata seedlings was 96.67%,and the success rate of cutting was 98%.The cutting accuracy was 96.8%,and the cutting surface fitting rate of the rootstock and scion was 98.61%.The latter differed by 0.43%from the theoretical rate but met the requirements for the splice grafting method.Thus,this study can provide a reference for the design of a cutting mechanism for a grafting robot.

海上嵌岩钢管桩内卷边切割机器人的设计研究

海上风电桩在基础打桩过程中,容易造成钢管桩下端内卷边,这会增加下插的阻力,须将影响下钻的内卷边切除,提高风电桩插桩效率。现阶段内卷边的处理多是潜水员下水切割,处理过程较为繁琐,难以应对复杂的工况,且有一定的危险性。为解决以上问题,设计了一种用于海上嵌岩式钢管桩内卷边切除的切割机器人。通过对钢管桩内卷边切割现有的施工工艺和施工作业要求进行分析,总结了内卷边切割机器人所需满足的设计要求,提出了适用于切割钢管内卷边的多轴联动机器人系统;确定了总体方案,对内卷边切割机器人的力学性能进行分析,并进行具体结构设计。基于SPH-FEM耦合算法,对磨料水射流切割钢管壁过程进行研究,确定切割工艺参数,对射流反作用进行分析,并结合切割参数进行算例验证。理论分析以及仿真模拟验证表明,所设计的内卷边切割机器人符合施工要求,能改善海上嵌岩式钢管桩内卷边的精确切除问题,有助于完善海上风电桩基础施工工艺的完整性,可为后续内卷边处理技术的发展提供经验。

激光切割机器人视觉图像目标标注研究

在激光切割的工业环境下会存在大量干扰元素,例如电磁干扰、振动、烟尘和颗粒物、外部环境以及光源等,当前的结合类别学习方法,对目标抽象图形中凸显区域缺少单独目标对齐过程,导致目标特征关联性不强,标注结果不准。提出基于改进YOLOv5 s的激光切割机器人视觉图像目标标注方法。利用输入端、池化层、共享全连接层等搭建改进YOLOv5 s模型,该网络使用最大池化与平均池化生成两幅激光切割机器人视觉图像,根据通道维度连接图像特征实现激光视觉图像目标粗定位,结合调制因子和目标检测损失实现目标特征对齐。在目标特征对齐后确定激光切割机器人视觉图像关键凸显区域帧,通过对激光切割机器人历史标注图像实施半监督训练,确定图像空间区域关联,根据区域关联进行激光视觉图像目标标注。实验结果表明:所提方法的激光切割机器人视觉图像目标标注的交并比与准确率高、速度快,拥有极强的鲁棒性。

一种智能型砂箱自动化加工生产线

针对铸造装备砂箱的自动化加工,提出了一种智能、自动化砂箱生产线,包括桁架以及沿桁架直线方向上依次设有的可翻转伺服机械手、双向自对中机构及若干个切削机床。本生产线智能化及自动化程度高,通过伺服机械手,可实现对砂箱工件的抓取、旋转,可轻松应对多种不同尺寸的砂箱工件,且工件的对中精度高。切削机床还可满足立式及卧式的双面加工,大大提高了生产效率。

刀剪机器人开刃砂轮修整补偿系统

针对目前刀剪开刃生产效率低、质量不稳定等问题,根据机器人开刃工艺特点,设计刀剪机器人开刃砂轮修整补偿系统。介绍了这一系统的工作原理,分析了机械机构。通过数控系统进行砂轮磨损自动修整,利用数据传输与机器人控制实现数据同步,达到砂轮修整值与机械臂补偿值一致。试验结果表明,刀剪机器人开刃砂轮修整补偿系统以修整砂轮代替补偿砂轮,解决以往砂轮磨损补偿方法的不足,能够可靠保证机器人连续开刃精度的一致性,有效提高生产效率。