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1.
For a container terminal system, efficient berth and quay crane (QC) schedules have great impact on the improvement of both operation efficiency and customer satisfaction. In this paper we address berth and quay crane scheduling problems in a simultaneous way, with uncertainties of vessel arrival time and container handling time. The berths are of discrete type and vessels arrive dynamically with different service priorities. QCs are allowed to move to other berths before finishing processing on currently assigned vessels, adding more flexibility to the terminal system. A mixed integer programming model is proposed, and a simulation based Genetic Algorithm (GA) search procedure is applied to generate robust berth and QC schedule proactively. Computational experiment shows the satisfied performance of our developed algorithm under uncertainty. 相似文献
2.
In the paper the 3-D model of a telescopic mobile crane is presented. In the model flexibilities and damping have been taken into account and also the number of degrees of freedom can be chosen according to the complexity of an approach. The algorithm of optimisation of drive functions for the slewing upper structure is given. The main goal of optimisation was to ensure load positioning at the end point of a work cycle in the case when oscillations are minimal. In order to achieve appropriate numerical effectiveness, the optimisation problem was solved for the simple, fully rigid model of a mobile crane. The method of compensating neglected flexibilities of the base structure of the crane and inner disturbances connected with the feedback control system via digital PID controller is presented. 相似文献
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根据钢筋混凝土长桩(柱)吊装的实际工程需要,进行了双机三点吊吊装方案的研究分析,建立了双机三点吊吊装方案的数学模型,编制了微机软件,解决了双机三点吊中的难题。 相似文献
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Cargo Pendulation Reduction of Ship-Mounted Cranes 总被引:4,自引:0,他引:4
Ship-mounted cranes are used to transfer cargo from large container ships to smaller lighters when deep-water ports are not
available. The wave-induced motion of the crane ship can produce large pendulations of the cargo being hoisted and cause operations
to be suspended. In this work, we show that it is possible to reduce these pendulations significantly by controlling the slew
and luff angles of the boom. Such a control can be achieved with the heavy equipment that is already part of the crane so
that retrofitting existing cranes would require a small effort. Moreover, the control is superimposed on the commands of the
operator transparently. The successful control strategy is based on delayed feedback of the angles of the cargo-hoisting cable
in and out of the plane of the boom and crane tower. Its effectiveness is demonstrated in a fully nonlinear three-dimensional
computer simulation and in an experiment with a 1/24th-scale model of a T-ACS (The Auxiliary Crane Ship) crane mounted on
a platform moving with three degrees of freedom. The results demonstrate that the pendulations can be significantly reduced,
and therefore the range of sea conditions in which cargo-transfer operations can take place can be greatly expanded. 相似文献
5.
整立电杆三点吊最优吊点的研究分析 总被引:5,自引:1,他引:4
根据输电线路中杆塔施工的实际工程需要,主要研究分析了整立电杆三点吊最优吊点的确定方法,建立了整体电杆三点吊的数学模型,编制了微机软件,解决了整体电杆三点吊方案设计中的难题。 相似文献
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A technique is proposed to reduce payload pendulations using the reelingand unreeling of the hoisting cable. The payload is modeled as a pointmass, the cable is modeled as a rigid link, and the assembly, aspherical pendulum, is attached to the boom tip. An excitation isapplied to the assembly at the boom tip. The motion of the payload isdescribed using two-dimensional and three-dimensional models. Ourresults demonstrate that cable-length manipulation can be used to reducepayload pendulations due to near-resonance excitations. Significantreductions can be obtained via an appropriate choice of thereeling/unreeling speed. We also demonstrate the limitations inherent intwo-dimensional modelings of a crane. 相似文献
9.
针对浅矿井提升容器仅有速度和位置监测,无姿态、冲击和纵横振动等监测,不满足超深矿井在超深、高速、重载工况下的安全监测需求的问题,设计了一种捷联惯性导航系统(SINS)/旋转编码器/接近开关组合导航式提升容器状态监测系统。通过IMU(惯性测量单元)测量容器加速度和角速度,由SINS解算出容器的速度、位置、姿态和纵横振动等参数,利用信息融合反馈校正SINS,提高监测精度。完成了系统软件设计和硬件搭建,并进行模拟实验,结果表明:系统竖直位置、横移竖直位置和姿态的测量精度分别为30 mm、5 mm和0.4°,竖直位置精度不受提升钢丝绳影响,解决了井筒内GPS和地磁无法使用问题,是一种超深井提升容器状态监测的可行方案。 相似文献
10.
检测仪的研制,是从工程中数量甚大的桥式起重机的安全性检测中,国家规范要求甚高而实际检测手段简陋的矛盾提出的。装置充分利用激光束的直线性和传输过程中光斑中心不变、光强较高的特性;通过集光、机、电为一体的测尺直接读出数据。应用这套装置,已进行11台双梁桥式起重机箱形主梁的变形测定,结果表明:这套装置在现场使用方便,精度与检测要求匹配,装置价格不高,对工程单位比较实用。1995年获国家实用新型专利 相似文献