Rehabilitation of Overhead Crane in HPP

This paper presents a case study on the repair of a mechanical component of an overhead crane.The problem was initially identified through on-site inspection and analysis of the crane’s performance.The mechanical part was found damaged,leading to safety concerns and operational inefficiencies.The paper details the process of diagnosing the issue,developing a repair plan,and executing the repair work.The repair plan involved replacing the damaged component with a new one and conducting additional maintenance work to ensure optimal performance.The paper also discusses the outcomes of the repair work,which led to improved safety and increased efficiency of the overhead crane.The case study provides insights into the importance of regular maintenance and on-site inspections in ensuring the safe and efficient operation of mechanical systems.

Adaptive Proportional-Derivative Sliding Mode Control Law With Improved Transient Performance for Underactuated Overhead Crane Systems

In this paper, an adaptive proportional-derivative sliding mode control(APD-SMC) law, is proposed for 2D underactuated overhead crane systems. The proposed controller has the advantages of simple structure, easy to implement of PD control, strong robustness of SMC with respect to external disturbances and uncertain system parameters, and adaptation for unknown system dynamics associated with the feedforward parts. In the proposed APD-SMC law, the PD control part is used to stabilize the controlled system, the SMC part is used to compensate the external disturbances and system uncertainties,and the adaptive control part is utilized to estimate the unknown system parameters. The coupling behavior between the trolley movement and the payload swing is enhanced and, therefore, the transient performance of the proposed controller is improved.The Lyapunov techniques and the La Salle's invariance theorem are employed in to support the theoretical derivations. Experimental results are provided to validate the superior performance of the proposed control law.

A practical fuzzy controllers scheme of overhead crane

This paper presents fuzzy-based design for the control of overhead crane. Instead of analyzing the complex nonlinear crane system, the proposed approach uses simple but effective way to control the crane. There are twin fuzzy controllers which deal with the feedback information, the position of trolley crane and the swing angle of load, to suppress the sway and accelerate the speed when the crane transports the heavy load. This approach simplifies the designing procedure of crane controller; besides, the twin controller method reduces the rule number when fulfilling the fuzzy system. Finally, experimental results through the crane model demonstrate the effectiveness of the scheme.

The Application of PLC in the Overhead Crane

This paper is about the application of PLC (Model S5 135U made by Siemens) in the overhead crane.It is mainly about the working principles and application of PLC Model S5 135U.

Comparative analysis on the performance of different types of input-and command-shaping controllers in minimizing payload residual vibration of an overhead crane with an inclined supporting track

Reducing the effects of external disturbance on overhead crane systems is crucial,as they can impair the controller performance and cause excessive vibrations or oscillations of the payloads.One such external disturbance is the inclination of the supporting track of the crane trolley,which causes the system dynamics model to change.An open-loop control strategy is widely utilized to control the payload sway motion and generally does not require any alterations in the physical structure of a system or the installation of sensors and/or actuators.Input and command shaping are two common open-loop control techniques applied to control overhead cranes.In this paper,the effect of moving an overhead crane system along an inclined supporting track is investigated.In addition,the ability of different types of input-and command-shaping control schemes to suppress the residual vibrations due to trolley track inclination is demonstrated.Two types of input-shaping controllers,which are double-step,zero vibration,and one command waveform(WF)shaper based on a trigonometric function,are used and tested.A linear equation of motion of the overhead crane resting on an inclined surface is developed to simulate the overhead crane and payload motion.The effectiveness of the different types of open-loop controllers to suppress residual vibrations is verified by both simulation and experimental results.In addition,a new WF command shaper is proposed and designed to overcome track inclination while eliminating payload residual vibration.A comprehensive comparative analysis,both numerically and experimentally,is performed on the new proposed shaper to measure its effectiveness in handling inclination when compared to other types of open-loop controllers.The new shaper outperforms other controllers in eliminating payload residual vibration for a wider range of inclination angles.

An Efficient Adaptive Hierarchical Sliding Mode Control Strategy Using Neural Networks for 3D Overhead Cranes

In this paper, a new adaptive hierarchical sliding mode control scheme for a 3D overhead crane system is proposed. A controller is first designed by the use of a hierarchical structure of two first-order sliding surfaces represented by two actuated and un-actuated subsystems in the bridge crane. Parameters of the controller are then intelligently estimated, where uncertain parameters due to disturbances in the 3D overhead crane dynamic model are proposed to be represented by radial basis function networks whose weights are derived from a Lyapunov function. The proposed approach allows the crane system to be robust under uncertainty conditions in which some uncertain and unknown parameters are highly difficult to determine. Moreover, stability of the sliding surfaces is proved to be guaranteed. Effectiveness of the proposed approach is then demonstrated by implementing the algorithm in both synthetic and reallife systems, where the results obtained by our method are highly promising.

Damage Identification of General Overhead Travelling Crane Structure Based on Model Updating by Sensitivity

A model based damage identification was proposed by facilitating parameter sensitivity analysis and applied to a general overhead travelling crane.As updating reference data,experimental modal frequency was obtained by operational modal analysis(OMA)under ambient excitation.One dimensional damage function was defined to identify the damage by bending stiffness.The results showed that the model updating method could locate the damage and quantitatively describe the structure.The average error of eigenvalues between updated model analysis and the experimental results was less than 4% which proved the accuracy reliable.The comparison of finite element analysis and the test results of the deflection under the capacity load further verified the feasibility of this method.

桥式起重机分布式质量吊重系统双摆滑模控制

随着吊装作业的多元化发展,起重机吊装对象也从传统的质点式吊重向分布式质量吊重方向发展。针对桥式起重机在吊装分布式质量吊重时吊重的大摆角抑制和小车定位控制问题,提出了两种基于滑模控制理论的、用于吊重消摆和小车快速定位的方法。首先,综合考虑了桥式起重机吊装对象的结构特征、小车电机的驱动特性、摩擦阻力以及环境中的随机扰动对吊装作业的影响,建立了桥式起重机分布式质量吊重系统的非线性双摆动力学模型;然后,设计了桥式起重机分布式质量吊重系统的非线性双摆动力学普通滑模控制器(OSMC)和分层滑模控制器(HSMC),采用Lyapunov函数和Barbalat引理证明了闭环系统的稳定性;最后,利用数值仿真研究了OSMC和HSMC在分布式质量吊重减摆控制方面的性能差异。仿真及研究结果表明:与OSMC相比,采用HSMC不仅可以在12 s内实现小车精确定位目的,而且可以实现对分布式质量吊重在5°~9°摆动范围下的快速抑制目的,完成了对系统状态变量的有效控制;同时,对比结果表明HSMC对起重机系统内部和外部扰动变化有很强的鲁棒性和抗干扰性。

桥式起重机神经网络自适应滑模定位防摆控制

针对桥式起重机非线性、存在外界干扰的特点,提出了一种神经网络自适应滑模控制器。首先采用拉格朗日法建立桥式起重机动力学模型;然后在分层滑模控制器的基础上,设计了径向基函数神经网络权值自适应更新率,利用径向基函数神经网络补偿系统的非线性与外界干扰引起的不确定上界,并利用粒子群算法对控制器参数寻优,通过构造Lyapunov函数证明了系统的稳定性;最后设计了1组仿真实验和1组在搭建的实验平台上的验证实验,仿真结果表明:在非线性及外界干扰作用下,神经网络自适应滑模控制器可以快速实现小车定位和负载消摆,控制器可以消除不确定上界对系统的影响。实验结果也表明,所设计的控制器可以使桥式起重机达到控制目标,具有一定的抗干扰能力。

基于单目视觉实时测量桥式起重机负载摆角

针对目前基于视觉的桥式起重机负载摆角测量方法实时性较低,且没有考虑由运动模糊导致的测量精度下降问题,将一个对旋转和倾斜不敏感的球形标识物安装在负载上,设计一种计算灰度概率分布特征余弦相似度的方法,结合卡尔曼滤波器实时跟踪标识物。提出一种基于背景灰度值的局部自适应分割算法,使模糊边缘变清晰。从感兴趣区域(region of interest,ROI)的中心向周围8个方向寻找灰度梯度最大的点作为模糊图像的边缘点,对这些点采用最小二乘法进行拟合确定标识物位置。通过几何关系模型计算负载摆角。实验结果表明,本文方法在图像模糊情况下的测量精度和实时性能更优。

GZ350型自走式果园高架机的设计与试验

为提高果园管理中果树修剪与采摘的效率,设计了一款内燃机驱动、具有侧倾角调节和升降控制功能的自走式果园高架机。在确定果园高架机总体技术要求基础上,对其工作原理、结构特点进行分析,通过理论计算,对高架机的关键部件进行设计与选型,采用三维软件对高架机进行建模,且加工生产样机进行测试试验。试验结果表明:整机最大行驶速度为3.7km/h,最小离地间隙高度为85mm,升降高度调节范围为650~3000mm,最大运载负载为350kg,最大举升负载为210kg,能够满足一般果园采摘与管理等作业,可提高农业作业安全性,降低人员劳动强度。

基于改进双闭环模糊PID控制算法的桥式起重机控制系统

针对起重机在吊装作业时产生的负载摇摆以及行车定位的问题,提出了一种改进双闭环模糊PID控制算法,利用拉格朗日方程建立工业起重机防摇摆及行车定位控制系统数学模型。将该算法运用在建立的模型中,并在Simulink仿真平台上分别设计了PID控制系统、模糊PID控制系统和改进双闭环模糊PID控制系统进行对比实验。仿真实验的结果表明,与PID控制系统以及模糊PID控制系统相比,改进双闭环模糊PID控制系统对摆角的抑制能力分别提高了32.6%、16.5%,对小车的位置调节时间分别减少了5.442、2.743 s,且无超调量。改进双闭环模糊PID控制系统的精确性更好、稳定性更强,可以更好地满足桥式起重机系统的控制要求。

天车技术故障及钢丝绳脱槽优化措施探析

冷轧厂天车使用频繁、吊运重物多,经常因磨损而出现多种故障问题,特别是在镀锌线维修时,更换冷却塔顶辊包布作业对天车的使用需求较为特别,时常会导致钢丝绳滑出轮槽脱离导向轮的现象发生,造成生产事故。基于冷轧厂天车使用现状,分析天车钢丝绳的日常保养和维护要点,以及时消除一些故障和隐患,并针对不同的技术问题采取相应的优化措施,以确保天车的长期稳定运行,保证安全生产。

铜冶炼企业中原料库智能天车的功能需求及关键技术探析

铜冶炼行业中原料的搬运大多依靠人工驾驶天车进行,员工劳动强度大,天车运行效率不高,信息及现场管理原始粗放,急需借助智能化手段优化原有作业模式,以减轻员工劳动强度,提高生产效率,改善工作环境,实现无人化管理。针对以上问题及优化目标,对多品种物料原料库智能天车的软硬件功能需求以及精准定位技术、吊具防摇摆等关键技术进行探析,为后续深入设计和实施提供技术支撑。

Detection of mechanical stress in the steel structure of a bridge crane

A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track,which causes crane skewing.The main causes of crane skewing include unevenness of the crane track,unequal loading of the traction drives depending on the position of the crane trolley,slips and different sizes of travel wheels and combinations of these causes.Firstly,this paper presents a design solution that can be used to detect the magnitude of mechanical stress and deformation of the steel structure of the crane,caused by the effects of skewing.The mechanical stress generated by the transverse forces of the deformed geometric shape of the crane bridge structure is recorded by mechanical stress detectors installed in the inner corners of the crane bridge.The resulting electrical signal from element mechanical voltage detectors,loaded by axial forces,can be used for feedback control of separate crane travel drives controlled by frequency converters.Secondly,this paper presents the calculation of the lateral transverse forces according to CSN 270103 and the determination of the values of mechanical stresses of the deformed steel structure of the crane bridge of a two-girder bridge crane using the finite element method in the program MSC.MARC 2019.Finally,this paper presents the structural and strength design of mechanical stress detectors and the conclusions of laboratory tests of axial force loading of mechanical stress detectors on the test equipment.At the same time,it presents records of the measured axial forces acting in the mechanical stress detectors,arising from the deformation and warping of the crane bridge by the known magnitude of the axial force acting on the crossbeam and from the deformation of the crane bridge caused by the crane operating modes.

浅谈井下架空人车的各种保护设计

基于井下环境的愈发复杂,当前架空人车的实际运行仍存在较多的安全问题,如何有效结合常见故障进行保护设计,也成为很多矿企需要考虑的问题。基于此,分析了井下架空人车的常见故障类型,然后进行具体的保护设计,讨论架空人车保护的运行效果,表明能满足矿企的安全开采需要。

基于Unity Pro的安全智能大吨位桥机控制系统的研发

为解决水电站厂房桥式起重机起吊水轮机组的定转子时,电控系统的自动化和智能化问题,基于Unity Pro研究开发安全智能大吨位双小车桥式起重机控制系统,解决了长期以来困扰桥机安全运行的起吊溜钩、双小车抬吊同步性差以及定位困难等问题。该系统已成功应用于秘鲁圣加旺Ⅲ水电站桥式起重机项目(起重量125t+125t,桥机跨距18m),相比传统的桥机控制系统具有显著优势。

ACS880变频器在通用桥式起重机上的应用研究

通用桥式起重机采用西门子1513系列PLC和ACS880系列变频调速装置,PLC系统与变频装置之间采用Profinet总线通信连接。对ACS880变频器在通用桥式起重机上的应用进行了研究,充分利用ACS880直接转矩控制(DTC)的可靠启动和快速反应,可以实现通用桥式起重机的上升和下降,满足现场的使用要求。

一种用于焊接生产线大型工件上下料的智能天车

大型工件焊接生产线采用人工上下料方式,劳动强度大,且存在安全隐患。随着时代的发展、当前市场需求和技术水平的变革,传统制造业面临越来越多的困难,亟需智能化转型升级。因此,介绍了焊接生产线大型工件采用智能天车上下料的解决方案。该方案能满足现场的使用需求,取得了较好的效果。