核电站核燃料运输起重机桥架驱动电机的同步控制

大亚湾核电站核燃料运输桥式吊车桥架采用两侧电机驱动方式。控制两侧同步方法是采用一个控制器同时拖动两台电机。为了保证桥吊两侧同步运行,桥架的运行速度不能太高,行程距离不能太长,这极大限制了换料大修的工作效率。改造后的桥式起重机驱动分别采用两个控制器拖动,并用可编程逻辑控制器（PLC）协调两台控制器工作,使得两台桥架驱动电机同步、同速,解决了桥架在高速、远程下的同步问题,达到满意效果。     

Response of sandhill crane (Grus canadensis) riverine roosting habitat to changes in stage and sandbar morphology

Over the past century, flow regulation and vegetation encroachment have reduced active channel widths along the central Platte River, Nebraska. During the last two decades, an annual program of in‐channel vegetation management has been implemented to stabilize or expand active channel widths. Vegetation management practices are intended to enhance riverine habitats which include nocturnal roosting habitat for sandhill cranes. Evaluating the success of other management treatments such as streamflow modification requires an understanding of how flow shapes the sandbars in the river and how sandbar morphology interacts with flow to create crane habitat. These linkages were investigated along a 1‐km managed river reach by comparing the spatial pattern of riverine roosts and emergent sandbars identified with aerial infrared imagery to variables computed with a two‐dimensional hydraulic model. Nocturnal observations made multiple years showed that the area and patterns of riverine roosts and emergent sandbars and the densities of cranes within roosts changed with stage. Despite sandbar vegetation management, low flows were concentrated into incised channels rather than spread out over broad sandbars. The flow model was used to compute hydraulic variables for identical streamflows through two sandbar morphologies; one following a period of relatively high flow and the other following the low‐flow period. Compared with the simulation using the morphology from the antecedent high flow, the simulation using the morphology from the antecedent low flow produced a smaller quantity of available wetted area. These remote‐sensing observations and hydraulic simulations illustrate the importance of considering flow history when designing streamflows to manage in‐channel habitat for cranes. Published in 2008 by John Wiley & Sons, Ltd.     

基于混合神经网络的门座起重机变幅机构参数优化设计

门座起重机变幅机构优化设计通常采用基于实例推理的方法确定优化设计初始参数,然后再对初始参数进行优化,得出最后的优化设计参数。这种基于实例优化方法的主要问题在于,难于确定相似实例和难于将相似实例应用于当前的实例中,并且由此确定的优化初始参数只偏向于某一个特定的实例,不具备某类实例的普遍特性。提出基于混合神经网络变幅机构优化设计方法,该方法采用一种混合神经网络,可用来确定优化设计的初始参数。这种方法计算上更为简单直观,对于训练好的混合神经网络,可直接由输入参数得到设计初始参数。这种初始参数并带有某类实例的一般特性,对其进行优化可得到较好的优化结果。     

超大型单体建筑群塔施工技术

新东安市场工程采用群塔施工，在大多数塔臂相互交叉，且有大臂甚至平衡臂已覆盖场区外围建筑的情况下，为确保塔吊安全运行，施工中采取对群塔进行严格的高差控制，合理安排塔位顶升顺序，设计塔间距离，同时加强运行管理安全防护措施，在解决垂直运输的同时，确保了整个工程同步施工。     

The NIST SPIDER,A Robot Crane

The Robot Systems Division of the National Institute of Standards and Technology has been experimenting for several years with new concepts for robot cranes. These concepts utilize the basic idea of the Stewart Platform parallel link manipulator. The unique feature of the NIST approach is to use cables as the parallel links and to use winches as the actuators. So long as the cables are all in tension, the load is kinematically constrained, and the cables resist perturbing forces and moments with equal stiffness to both positive and negative loads. The result is that the suspended load is constrained with a mechanical stiffness determined by the elasticity of the cables, the suspended weight, and the geometry of the mechanism. Based on these concepts, a revolutionary new type of robot crane, the NIST SPIDER (Stewart Platform Instrumented Drive Environmental Robot) has been developed that can control the position, velocity, and force of tools and heavy machinery in all six degrees of freedom (x, y, z, roll, pitch, and yaw). Depending on what is suspended from its work platform, the SPIDER can perform a variety of tasks. Examples are: cutting, excavating and grading, shaping and finishing, lifting and positioning. A 6 m version of the SPIDER has been built and critical performance characteristics analyzed.     

双桅杆式起重机的时变输入整形控制方法

为了满足实际生产需求, 在工业中常使用两台或者多台起重机协作完成大型运输任务. 双桅杆式起重机负载能力强, 工作姿态灵活, 在大型建筑工地上得到了广泛应用. 然而, 现有控制方法大多针对动力学特性相对简单的双桥式起重机, 而对耦合性更强、动力学特性更复杂的双桅杆式起重机关注不足. 为解决此类系统的控制难题,本文通过分析系统的几何约束与动力学模型, 得到状态变量及其高阶导数之间的关系, 从而实现双桅杆式起重机非线性动力学模型的合理变换. 随后, 本文准确分析了吊臂俯仰角与负载姿态角之间的关系, 通过计算得到双桅杆式起重机的时变振荡周期, 设计了一种极不灵敏型输入整形器. 最后, 实验结果验证了所提时变输入整形控制方法能够实现起重机的准确定位及良好的消摆效果     

三里坪地下电站厂房桥机安装方案优化

在三里坪地下电站厂房桥机安装过程中,针对厂房的特点,并参照其他工程的经验,拟定了汽车吊安装和厂房开挖时在顶拱布置相应锚索和起吊装置,配合地面卷扬机吊装两种方案。经综合比较两种方案的优缺点,决定采用汽车吊安装方案。针对拟定的汽车吊安装方案,详细设计了设备运输方式、安装时间、安装优化工艺。由于安装方案设计合理,保证了桥机的顺利安装。桥机安装后的荷载试验表明,安装质量满足设计要求,使用安全方便。     

欠驱动桥式吊车消摆跟踪控制

对于桥式吊车系统而言,其控制目标是将货物快速、精确、摆动尽可能小地运送到目标位置.为此,本文提出了一种新型的轨迹跟踪控制策略,可在保证负载快速平稳运送的同时,有效地抑制并消除整个过程中负载的摆动.具体而言,通过对吊车动力学模型进行一系列的变换,设计了一种新颖的跟踪控制器,并对闭环系统信号的有界性与收敛性进行了理论分析.与调节控制方法相比,本文方法可保证台车的平滑启动与运行;此外,本方法放宽了已有轨迹跟踪控制方法对参考轨迹的约束条件,更具实用性与一般性.实验结果表明,本文设计的控制器能取得优于已有方法的控制效果,并对外界干扰具有很强的鲁棒性.     

岸边集装箱起重机防摇及定位控制研究

研究了岸边集装箱起重机的防摇及定位控制.在对系统进行无源性分析的基础上,构造了控制Lya-punov函数,得到系统镇定控制律.理论分析和数值仿真算例表明,该控制方法对于岸桥防摇和定位控制有着较快的收敛速度和较强的鲁棒性.     

深圳平安金融中心多工序无缝衔接关键技术

深圳平安金融中心主塔楼建筑高度660m,结构形式为巨柱框架-核心筒-桁架抗侧力体系;采用核心筒先行,外框紧随其后的施工部署,4台大型动臂塔式起重机附着于核心筒外侧;核心筒采用多点小吨位液压爬升模架体系。施工期间如何做好塔式起重机爬升、钢结构安装、爬模爬升三者之间的施工衔接是制约施工总进度计划的重点及难点。