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In order to solve the problems of complex processes, long cycle, high cost and high risk in traditional installation methods of large floating crane jibs, a novel prevent failure method using a gantry crane to install the floating crane jib is proposed and key technologies, such as reasonable solution for distributing force on the lifting point in the jib lifting through adopting balanced suspensory rigging, efficient shaft threading technology with guide and traction device and newly developed compliant support structure against ship rolling. In this article, we present the application cases of systematic installation method of the large floating crane jib to real production process. The engineering practice proves that the novel installation method proposed is simple in operation and low in cost and provides a new and reliable choice for the installation and maintenance of large floating crane. [ABSTRACT FROM AUTHOR]

The gantry crane, positioned atop the bridge pier cap for the installation of Super-T girders, is a specialized construction unit within the bridge construction industry. The article presents a summary of research results investigating dynamic parameters and their influence on the operation of gantry cranes with assembled structures on the cap of bridge piers, serving the installation of Super-T beams in two scenarios: lifting with pre-stressed cable and moving with load (Super-T beam). To examine the dynamic parameters affecting the operation of the gantry crane, the authors first constructed a dynamic model. Subsequently, the influential parameters were determined, and the Matlab Simulink software was employed to develop a survey model corresponding to different values of each parameter and under various working conditions of the gantry crane. This process aimed to identify patterns and unfavorable values of these parameters affecting the operation of the gantry crane. The research results revealed that in both scenarios of lifting with pre-stressed cable and moving with a load (loading), factors such as lifting speed (Vn), stiffness of the main steel structure (S3), conversion stiffness of the lifting cable (S1), oscillation mass of the main structure (m3), wind load acting on the beam (Pg2), wind load acting on the main steel structure (Pg1), and stiffness of the hanging cable (S1) significantly influence the operation of the gantry crane. The survey results also indicated reasonable values for these influential factors during the operation of the gantry crane. The obtained research results can serve as a basis for computational design problems and effective utilization of gantry cranes with assembled structures on the cap of bridge piers for the installation of Super-T beams. Through analysis and simulation using Matlab-Simulink software, specific data on cable tension, main structure acceleration, and structural deformation were collected. The results emphasize the importance of limiting the lifting speed to 2 m/min to ensure stability during cable tensioned lifting and restricting the crane's moving speed to 7.85 m/min to maintain safety and performance when moving loads with tensioned cables. [ABSTRACT FROM AUTHOR]

Building in the river: major maintenance of the Kachlet weir system after 100 years of operation The Kachlet weir system is one of the largest weir systems on the German Rhine‐Main‐Danube waterway and is reaching a 100‐year service life. In order to ensure the continued navigability of the Danube, a major overhaul will be carried out in which the weir base will be preserved, the piers upgraded and the weir superstructure and hydraulic steelwork as well as the technical equipment completely renewed. New approaches are being considered for this particular challenge, especially in terms of construction logistics. As a construction aid for the planned construction project, a portal crane system will be erected above the weir system, which will enable the project to be carried out with a high degree of prefabrication and, as a result, a comparatively short construction period. However, the portal crane system also brings new challenges with it, that need to be taken into account during planning. [ABSTRACT FROM AUTHOR]

In order to address stringent standards, energy efficiency objectives or also cost reduction imperatives, the optimal design of complex industrial structures is an important concern. In this context, parametric optimization offers a powerful tool for engineers. Taking into account nonlinear behavior in the models allows performing high-fidelity numerical simulations and thus reducing safety margins. However, in vibration dynamics, the use of classical global optimization methods on industrial-scale structures with nonlinearities is not affordable due to too many required solver calls to localize the optimum. This work proposes an approach to achieve global constrained optimization of structures with local nonlinearities in vibration. The strategy is based on a Bayesian Optimization process relying on two tools: (i) a Gaussian Process as a surrogate model and (ii) a dedicated nonlinear mechanical solver based on the Harmonic Balance Method. These two tools are presented in detail. Their performance and characteristics are presented and analyzed on academic and industrial-scale examples. The whole strategy is finally applied on a Duffing oscillator without optimization's constraint and a gantry crane to illustrate the efficiency on constrained optimization. In addition, many discussions are made relative to the number of initial sample points. The results show that the proposed approach is able to find the global optimum with a limited number of solver calls, demonstrating its ability to be integrated into an actual industrial design process. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a robust adaptive vibration control method for gantry crane system is proposed considering unknown parameters brought by unknown payload, cable length and tension. The control objective is to transport the cargo to the desired position while suppressing the vibration of the cable in the presence of unknown parameters. For this purpose, a boundary controller is designed with an adaptive law to compensate the parameter uncertainty of the system. The well‐posedness of the closed‐loop system is proved by means of operator semigroup theory and the asymptotic stability of the closed‐loop system is analyzed. Finally, the effectiveness of the proposed control approach is demonstrated through both numerical simulation comparisons and physical experiments. [ABSTRACT FROM AUTHOR]

Conventionally, researchers have favored the model-based control scheme for controlling gantry crane systems. However, this method necessitates a substantial investment of time and resources in order to develop an accurate mathematical model of the complex crane system. Recognizing this challenge, the current paper introduces a novel data-driven control scheme that relies exclusively on input and output data. Undertaking a couple of modifications to the conventional marine predators algorithm (MPA), random average marine predators algorithm (RAMPA) with tunable adaptive coefficient to control the step size (CF) has been proposed in this paper as an enhanced alternative towards fine-tuning data-driven multiple-node hormone regulation neuroendocrine-PID (MnHR-NEPID) controller parameters for the multi-input–multi-output (MIMO) gantry crane system. First modification involved a random average location calculation within the algorithm's updating mechanism to solve the local optima issue. The second modification then introduced tunable CF that enhanced search capacity by enabling users' resilience towards attaining an offsetting level of exploration and exploitation phases. Effectiveness of the proposed method is evaluated based on the convergence curve and statistical analysis of the fitness function, the total norms of error and input, Wilcoxon's rank test, time response analysis, and robustness analysis under the influence of external disturbance. Comparative findings alongside other existing metaheuristic-based algorithms confirmed excellence of the proposed method through its superior performance against the conventional MPA, particle swarm optimization (PSO), grey wolf optimizer (GWO), moth-flame optimization (MFO), multi-verse optimizer (MVO), sine-cosine algorithm (SCA), salp-swarm algorithm (SSA), slime mould algorithm (SMA), flow direction algorithm (FDA), and the formally published adaptive safe experimentation dynamics (ASED)-based methods. [ABSTRACT FROM AUTHOR]

The heavy congestion at the global ports and the impact of the pandemic spread make the automated container terminal competitive. With the operations of more and more automated container terminals, the optimization of yard space allocation becomes one of the most urgent issues for improving the handling efficiency for the automated container terminal. To figure out the optimal clustering strategy to allocate the containers in the automated container terminal, this study investigates the stacks allocation with different scenarios. A novel stack-based allocation model is built to balance both the transportation distance and the allocation dispersion among blocks. Based on the model we built, we talked about the impact of efficiency of automated rail-mounted gantry crane and the berthing time for each vessel on the stacks allocation. The results show that the stack-based allocation with multi-batches in the same bay is suitable for the automated container terminal, while both the efficiency of the automated rail-mounted gantry crane and the berthing time will directly affect the total transportation distance for allocating the containers. The research is very inspiring for the terminal manager to choose the suitable clustering strategy and improve the yard space management for the automated container terminal. [ABSTRACT FROM AUTHOR]

With the gradual improvement of market demand and the continuous improvement of equipment manufacturing, the demand for the use of large-section, large-scale, and large-scale structural wharf at home and abroad is increasing. Therefore, the difficulty of wharf construction has also increased accordingly, and the installation of prefabricated components requires construction equipment with more prominent lifting capacity and better construction techniques. This paper mainly introduces the key technologies for the installation and construction of prefabricated components for the ultra-wide wharf of the Wilmar Industrial Park Port Project in Banten Indonesia. The overall widest part of the hydraulic structure of this project reaches 70 m. This technology utilizes a 70 t special portal crane and a set of 250 t+5 000 t square barge crane unit for combined installation, and cooperates with the multi-functional hoisting frame to install the wharf beam and slab. The successful application of this technology in the water installation of prefabricated components similar to ultra -wide high -piled wharves has important reference significance for improving construction efficiency, ensuring structural safety, and reducing equipment costs. [ABSTRACT FROM AUTHOR]

Assessment of dynamic behavior of the gantry cranes by using mathematical modeling and shaking table tests is the subject of this study. In this context, the study was carried out in two stages through theoretical and experimental studies. In the theoretical study, a four degrees-of-freedom nonlinear mathematical model which represents the seismic behavior of gantry cranes was developed. In the experimental study, a 1/50 scaled crane model of a prototype crane with respect to dynamic equivalence principle was designed and constructed. Within the scope of theoretical and experimental study, the real earthquake and sine sweep motions were used as input data. To verify the mathematical model, the results of the experimental study were used. Comparison of the mathematical model with the experimental study for the gantry crane structure showed reasonable results. This study shows that dynamic analysis can be done with mathematical modeling of this kind of cranes theoretically. In this way, the dynamic analysis required for a crane which is still in the design phase will be made in a short time and it will be possible to apply the necessary changes and see their effects. [ABSTRACT FROM AUTHOR]

It is an important engineering safety problem to control the swing of the suspended objects of container gantry crane. As an important construction machinery for logistics transportation and handling, it is widely used in port container yards. However, due to the flexible characteristics of the wire rope and the heavy working level of the crane container, there will be a large swing during the transportation process, resulting in cargo collision and uncertain load, resulting in cargo damage and casualties. In this paper, a dynamic model of container gantry crane is established according to Lagrange dynamics equation and the controllability of the system is verified. A hierarchical sliding mode controller (HSMC) is designed, and its stability is proved by using Lyapunov theory and Barbalat's lemma. The simulation results show that the controller has high displacement tracking accuracy, can suppress the container swing Angle and attitude pitch Angle in a short time and has strong robustness and stability for the variable system with different parameters. In addition, a platform is built to verify the reliability of the method. [ABSTRACT FROM AUTHOR]

A timely damage state assessment of gantry cranes has a significant impact on the post-earthquake reconstruction and economic recovery in earthquake-stricken areas. This study aims to propose a methodology to rapidly predict the seismic damage states in light of nine classification-based machine learning methods. The 48 earthquake parameters is presented and of which relative importance and influence on the structural responses of the employed simple gantry crane are examined based on the data set matrix of 2760 (ground motions) ×48 (earthquake parameters). Meanwhile the innovative method is proposed to mitigate the class imbalance problem in the training data. Finally, the proposed method is applied to predict the fragility of a gantry crane subjected to ground motions and the efficiency and accuracy of nine machine learning methods are compared herein. The results demonstrate that the parameter of spectral acceleration Sa at the first self-vibration period of the examined structure is of great significance to predict the accurate damage states. Random Forest, Neural Networks, Logistic Regression, and Support Vector Machine are preferable in all selected machine learning methods hereon. And the predictive fragility curves and the fragility curves computed in FE model are consistent approximately in spite of maximum error of 7.5%. [ABSTRACT FROM AUTHOR]

• A new mathematical model for rubber–tyred gantry cranes is developed considering the elastic structure. • Two advanced sliding mode controls are proposed to validate dynamic model. • Experiment shows the sufficient accuracy and effective application of modeling and control to cranes. A gantry crane holds strict underactuation and elastic multibody structure, and thus faces challenges in control system design. For model–based control, we develop a three–dimensional dynamic model of rubber–tyred gantry cranes considering the distributed mass and bending deformation of gantry. Such modelling hybridises the lumped model of trolley–bridge–payload motions and continuous model of gantry vibration. We consider a complex operation in which three motors composed of travelling trolley, pushing bridge and hoisting container run simultaneously. We propose two versions of the robust controller, namely, dynamic sliding mode and fast terminal sliding mode for tracking the three motions, eliminating swings of container, and reducing the bending vibration of elastic gantry. Simulation and experiment reveal precision and effective application of our crane modelling to control approaches. The control system effectively tracks and stabilises all outputs and achieves robustness when a crane suffers from the structural and parametric uncertainties. [ABSTRACT FROM AUTHOR]

This paper presents the research results on the mechanical behavior of the low-carbon rolled steel of a sea portal crane after a 33-year operation depending on the operational stresses and rolling direction in order to assess its serviceability. The tensile properties of steels were investigated using rectangular cross-section specimens with different thicknesses and the same width. Strength indicators were slightly dependent on the considered factors (operational conditions, the cutting direction, and thickness of specimens). However, a clear trend of higher ultimate strength for thinner specimens was noticed, especially in the case of more brittle material due to its operational degradation. Plasticity of the tested steel specimens was more sensitive to the influence of the above-mentioned factors than strength but less sensitive than impact toughness. Uniform elongation was slightly less for thinner specimens regardless of the investigated steel state or the orientation of specimens relative to the rolling direction. The post-necking elongation was lower for transversal specimens compared with longitudinal ones, and the effect was more significant when testing steel with the lowest brittle fracture resistance. Among the tensile properties, non-uniform elongation was demonstrated to be the most effective for assessing the operational changes in the state of rolled steels. [ABSTRACT FROM AUTHOR]

The incidence of fishing boat accidents in Indonesia is very worrying, with 342 people dying during 2018-2020. Based on this, it is crucial to investigate the construction strength of fishing vessels against the possibility of a collision. In this study, the fishing boat due to the impact load was investigated in extreme weather conditions using Finite Element Method (FEM) analysis. Traditional fishing boat was constructed by measuring the thickness of the hull, deck, keel, frames, and longitudinal structure of the fishing boat. The collision model is carried out with an impactor in the form of a mooring pole during extreme weather with a wave height of 6 meters and wind speeds 30 knots. Variations in velocity and frame spacing as in actual conditions are modeled to obtain differences in deformation, absorption energy values, and plasticity of boat construction due to collisions. The collision speed of 30 and 20 knots are set on the extreme weather conditions, while the collision speed of 7 knots is set on operating speed. Frame spacing of 0.5 and 0.6 meters is built according to the boat's frame spacing in the field. Computer simulation is carried out using application software ANSYS Research License. The fishing boat material used is mahogany wood with tested by using impact test with a toughness value of 39.1 kJ/m². Based on the simulations results, the impact velocity has an effect deformation wider crash area and hull stress value. The speed of the ship collision was 7 knots, the collision did not damage the hull, but the construction failed at speeds of 20 and 30 knots. The closer of frame spacing, the higher collision performance of structure to withstand impact are indicated by the higher energy absorption. At a ship collision speed of 30 knots, the absorption energy of the construction at 0.5-meter frame spacing is 49.8 kJ, greater than 0.6-meter frame spacing with a value of 29.6 kJ. [ABSTRACT FROM AUTHOR]

The article deals with the issue concerning the working bodies of technological equipment designed for grinding pieces and particles of feed raw materials. The most profitable feed raw materials are by-products and waste materials of animal origin, which have a valuable high-protein content. An alternative way of mandatory waste disposal is their processing, including mechanical grinding to obtain feed products. In the process of grinding, particular importance is given to the working bodies, with the help of which the raw material is directly divided into parts. In this case, the destruction of the feed material often occurs by means of impact. Impact phenomena have proven to be highly effective in the process of intense cracking and chipping, which leads to the desired separation of the crushed particles into smaller ones. However, it is found that crushers have insufficient efficiency of impact elements. The work analyzes the processes of impact grinding from the standpoint of a number of scientific hypotheses, theories, modeling, simulation, experience and approbation, presented in various scientific publications. When studying and improving the theory of impact, attention is paid to nonlinear problems, cracking, modernization of the theory of brittle fracture, diagrams of force changes during impact force, impact equations, wave theory of impact, peridynamic theory. It should be noted that the main scientific results are directly reflected in the improvement of the design features of hammers. It has been revealed that the main improvement in the design of impact elements is in the direction of increasing the efficiency of working surfaces and developing the combination of impact with cutting, abrasion and crushing. [ABSTRACT FROM AUTHOR]

The article presents briefly findings in researching methods for determining dynamic stress of the bars in the main structure of gantry crane installed on the cap of bridge pier to install and launch SUPER-T girder. In order to study the dynamic stresses in the bars of the main truss structure of the gantry, the author first had to build a dynamic model, using Matlap software to solve the problem of dynamics with two cases cargo lowering combination combines braking and moving of gantry with cargo to find out the rules and values of dynamic cable tension, dynamic inertial force (time-varying force), then consider these forces is the external force acting on the main truss structure model of the gantry, from which the author calculates the value of internal force and stress of each bar corresponding to the value of dynamic cable tension and corresponding dynamic inertia force. with two adverse working cases of the gantry. Using Matlap software to calculate the author has obtained a graph of internal force, stress changes over time of each bar in the main truss steel structure of the gantry. The findings of the research provided methods for determining the dynamic stress of the bars in the main structure of gantry crane, pointed out values and rules of change of the dynamic stress of the bars in the main structure of gantry crane. The findings of the research may be used to calculate fatigue, life-span of the main steel structures as well as other parts of the gantry crane. [ABSTRACT FROM AUTHOR]

This paper presents a neural-network-based boundary control method for a gantry system with unknown friction and output constraint. Firstly, to tackle the unknown friction, a radial basis function neural network (RBFNN) is adopted to approximate it. Secondly, we employ a barrier Lyapunov function to handle the output constraint problem. Then, a neural-network-based boundary controller is proposed to deal with the aforementioned problems. Subsequently, based on the Lyapunov stability approach, the uniformly ultimately bounded stability of the state of the closed-loop system is guaranteed. Finally, the effectiveness of the developed control method is illustrated through both numerical simulations and physical experiments. [ABSTRACT FROM AUTHOR]

Green container terminals have gained much attention to satisfy the demand for sustainable and environmentally friendly transport. As one of the major polluters in container terminals, rubber-tyred gantry cranes have already been widely replaced by electric rubber-tyred gantry cranes (ERTGs). This article exploits the features of ERTGs and studies the ERTG scheduling problem in container terminal yards considering the carbon dioxide emissions and task delays simultaneously. The problem is converted into a selective vehicle routing problem with soft time windows (SVRPSTW) and formulated as a mixed integer linear programming model. A column generation algorithm embedded in a branch-and-bound framework is employed to solve the problem. A hybrid acceleration strategy combining the label-setting algorithm with a tabu search algorithm is proposed. Finally, the proposed method is validated via computational experiments. The proposed method provides an efficient tool for carbon-efficient scheduling of ERTGs and thus contributes to the development of green ports. [ABSTRACT FROM AUTHOR]

Linear municipal deep foundation pit tunnel project is generally characterized by long and narrow construction enclosed area, long curved section, large foundation pit span and depth, and many surrounding buildings. In order to achieve the efficient operation of foundation pit hoisting under such conditions, a long span gantry crane that can travel in the curved section was adopted. The optimization of long span gantry crane installation technology by using the foundation pit support structure, and the improvement of gantry crane traveling system to meet the requirements that the long span gantry crane can carry out hoisting operations in the curved section of deep foundation pit tunnel. The long span gantry crane for deep foundation pit hoisting has been successfully applied to the land project on the south bank of the Dalian Bay Subsea Tunnel, which has realized the gantry crane group operation, greatly improved the site space utilization, and accumulated valuable construction experience and parameters. It can provide reference for similar projects. [ABSTRACT FROM AUTHOR]

This paper proposes a combined planning and optimization method that enables a dual-arm robot to lift up and flip heavy plates using crane pulley blocks. The problem is motivated by the low payload of modern collaborative robots. Instead of directly manipulating heavy plates that collaborative robots cannot afford, the paper develops a planner for collaborative robots to operate crane pulley blocks. The planner assumes a target plate is pre-attached to the crane hook. It optimizes dual-arm action sequences and plans the robot’s dual-arm motion that pulls the rope of the crane pulley blocks to lift up the plate. The crane pulley blocks reduce the payload that each robotic arm needs to bear. When the plate is lifted up to a satisfying pose, the planner plans a sliding-pushing motion for one of the robot arms to tumble over the plate while considering force and moment constraints. The article presents the technical details of the planner and several experiments and analysis carried out using a dual-arm robot made by two Universal Robots UR3 arms. The influence of various parameters and optimization goals are investigated and compared in depth. The results show that the proposed planner is flexible and efficient. This paper is motivated by a cleaning process in a factory that produces sewage press machines. The pressboard of sewage press machines could be as heavy as 1000 kg. Human workers need to flip and clean both sides of the board before installing them to the main axis of a sewage machine. Their solution is using a gantry crane. They attach the board to the crane hook using bearing belts, activate the crane to lift up the board. When the board is raised to a satisfying pose, the workers turn the board over by pushing it. Motivated by human workers’ actions, we developed the planner presented in this paper. We assumed crane pulley blocks in the experiments and analysis, but in practice, they may be replaced with electronic ones to improve effort and efficiency. Using the electronic ones will be a sub-problem since there is no need for pulling ropes. The proposed method is expected to help a company’s technicians better judge if they need a heavy payload manipulator or keep their current crane equipment while employing several intelligent collaborative robots to operate them. As a result, it may help to accelerate the upgrade of manufacturing sites while reducing reforming budgets. Note to Practitioners—This paper is motivated by a cleaning process in a factory that produces sewage press machines. The pressboard of sewage press machines could be as heavy as 1000 kg. Human workers need to flip and clean both sides of the board before installing them to the main axis of a sewage machine. Their solution is using a gantry crane. They attach the board to the crane hook using bearing belts, activate the crane to lift up the board. When the board is raised to a satisfying pose, the workers turn the board over by pushing it. Motivated by human workers’ actions, we developed the planner presented in this paper. We assumed crane pulley blocks in the experiments and analysis, but in practice, they may be replaced with electronic ones to improve effort and efficiency. Using the electronic ones will be a sub-problem since there is no need for pulling ropes. The proposed method is expected to help a company’s technicians better judge if they need a heavy payload manipulator or keep their current crane equipment while employing several intelligent collaborative robots to operate them. As a result, it may help to accelerate the upgrade of manufacturing sites while reducing reforming budgets. [ABSTRACT FROM AUTHOR]

Depending on their dynamic properties, cranes can be classified as gantry cranes and rotary cranes. In this paper, we will focus on the so called 'knuckle boom' cranes which are among the most common types of rotary cranes. A first result of this paper is to present a complete mathematical model for this kind of crane where it is possible to control the three rotations of the crane and the cable length. On the basis of this model, we propose a nonlinear control law based on energy considerations which is able to perform position control of the crane while damping the oscillations of the load. The corresponding stability and convergence analysis is carefully proved using the LaSalle's invariance principle. The effectiveness of the proposed control approach has been tested in simulation with realistic physical parameters and in the presence of model mismatch. [ABSTRACT FROM AUTHOR]

With the growth of ocean transport and with increasing vessel sizes, managing congestion at the landside of container terminals has become a major challenge. The landside of a sea terminal handles containers that arrive or depart via train or truck. Large sea terminals have to handle thousands of trucks and dozens of trains per day. As trains run on fixed schedule, their containers are prioritized in stacking and internal transport handling. This has consequences for the service of external trucks, which might be subject to delays. We analyze the impact of prioritization on such delays using a stochastic stylized semi-open queuing network model with bulk arrivals (of containers on trains), shared stack crane resources, and multi-class containers. We use the theory of regenerative processes and Markov chain analysis to analyze the network. The proposed network solution algorithm works for large-scale systems and yields sufficiently accurate estimates for performance measurement. The model can capture priority service for containers at the shared stack cranes, while preserving strict handling priorities. The model is used to explore the choice of different internal transport vehicles (with coupled versus decoupled operations at the stack and train gantry cranes) to understand the effect on delays. Our results show that decoupled transport vehicles in comparison to coupled vehicles can mitigate the external truck container handling delays at shared stack cranes by a large extent (up to 12%). However, decoupled vehicles marginally increase the train container handling delays at shared stack cranes (up to 6%). When train arrival rates are low, prioritizing the handling of train containers at the stack cranes significantly reduces their delays. Further, such prioritization hardly delays external truck containers. • Model the interactions among train and external truck containers at shared cranes. • Model synchronization of train bulk arrival containers with transport vehicles. • Model the service priority of train container over external truck container. • Decoupled vehicles decrease external truck waiting time at shared cranes. • Decoupled vehicles slightly increase train container waiting time at shared cranes. [ABSTRACT FROM AUTHOR]

As a critical node of the global transportation network, ports have great potential in promoting transportation emission reduction. Promoting the low-carbon transition of ports by using clean energy is effective. Using hydrogen energy in automated container terminals (ACTs) has become popular in port emission-reduction research. The research object is the main port equipment—the automated rail-mounted container gantry crane (ARMG). This research designs a staged investment decision-making scheme for ARMGs' hydrogen energy transition. The Internet of Things (IoT) architecture in ACTs collects ARMG equipment operation and carbon emission data. It provides a basis for data acquisition in ARMGs' hydrogen energy transition. Furthermore, ports can adopt big data technology to analyze the correlation between equipment operation and carbon emissions. Finally, the digital twin platform will visualize the ARMG equipment operation and carbon emission behavior to remote operators. These advanced technologies can achieve status monitoring and simulation prediction, which will support ARMGs' hydrogen energy transition. However, the ARMGs' hydrogen energy transition has a long cycle, large investment, and strong variability. Ports should make staged investment decisions based on the digital twin platform's status monitoring and simulation prediction analysis results. Therefore, this research establishes an optimization model for ARMGs' low-carbon transition investment decision based on the real options method, and analyzes the staged investment scale and timing of ARMGs' hydrogen energy transition. The results provide a popularized decision-making scheme for the low-carbon transition of ports' equipment, which could facilitate the low-carbon transition of ports' equipment. [ABSTRACT FROM AUTHOR]

Introduction/purpose: To study the adequacy of applying numerical methods in the modal analysis of complex carrying structures of cranes. Methods: Comparative application of the analytical method and the numerical method - FEM. Results: Some comparative values of the modal parameters were obtained both analytically and numerically for the derived solution of a gantry crane carrying structure. Conclusion: It is shown that the numerical method can give a reliable general quality estimate of the structural behaviour of a complex carrying structure from the aspect of modal analysis. [ABSTRACT FROM AUTHOR]

Rubber tire container gantry cranes (RTG) are the most commonly used equipments to stack containers in ports. With four sets of ropes hoisting the cargo, the system dynamics become much more complicated and unpredictable when compared with traditional gantry cranes, which imposes higher requirements to the skills of operators. During the delivering process, large sway motion of the container is often excited by inappropriate manual operations, which badly impairs efficiency and safety. This issue is made even worse when considering the elasticity of rubber tire, wind disturbances, and many other practical disturbances. To improve the working efficiency of ports, an automatic antiswing trajectory planning method is proposed for RTG in this article. Specifically, reference trajectories are first generated to ensure that the trolley/rope accurately reach the desired position. After that, appropriate feedback terms are incorporated to online optimize the trajectories, so that the container swing motion is sufficiently suppressed even under unfavorable conditions. Lyapunov-based analysis is presented to guarantee the correctness of our conclusion. Furthermore, extensive hardware experiments on a practical RTG are performed to demonstrate the efficiency of the proposed method. To our best knowledge, with concise structure and superior antiswing ability, the proposed method is one of the very few methods which can be successfully applied to the practical RTG systems. [ABSTRACT FROM AUTHOR]

Crane hooks are used to ensure the safe transportation of loads to be lifted in load lifting and handling systems. In this study, special hooks for cranes designed to open and close the doors of warehouse zones used for ship cargo and cargo transport, and their responses under 60,000 N static loading conditions are numerically and experimentally analyzed. In the experimental study, ST37 structural steel and Weldox700 high-strength steel were used to manufacture the hook. Experimental data collected under static loading conditions of the component was measured via strain gauges sensors. It was concluded that the results of structural numerical analysis with the Finite Element Method (FEM) using ANSYS 2019 R3 analysis program with experimental data are in harmony with the results of experimental measurements. In addition, the maximum values of stress of the hook manufactured with Weldox700 and ST37 steels under the stress static loading conditions are obtained as 60 MPa and 57.3 MPa, respectively. In the numerical analysis results, stress value was obtained as 61.21 MPa. Compared to the analysis results based on experiments and FEM, numerical analysis results showed that fudge factors in ST37 and Weldox700 steels are 1.8% and 6%, respectively. This result confirms that experimental and mathematical data were in harmony with each other and reliable. [ABSTRACT FROM AUTHOR]

In order to realize the full-section pouring construction of the immersed tubeby dry dock method, the compatibility of the dry dock system suitable for full -section pouring was studied and designed. The dry dock system is equipped with a specific floor structure to ensure that the prefabrication of the immersed tube does not cause excessive settlement. The supporting formwork support system makes the formwork stably stressed and deformation controllable during the pouring construction process. A supporting complete transportation system is provided to ensure smooth traffic of construction equipment. The drainage system combining the bottom and top of the dock is set up to ensure that the accumulated water in the dock door can be discharged in time and quickly, which guarantees a good dry construction environment for the prefabrication of immersed tubes. The supporting tower cranes and gantry cranes are connected with each other to achieve full coverage of the construction scope of hoisting in the dock. The supporting the movable steel dock door to realize the repeated use of the dry dock. The dry dock system has been applied to the Chebei Road -Xinjiaodong Road Tunnel Project with good application effects. [ABSTRACT FROM AUTHOR]

To address the problems of the lack of an online data simulation test environment, the poor openness of data collection, and the low degree of data visualization in the online control process of port cranes, an operation state monitoring system framework for port cranes based on digital twins is proposed. In this framework, the digital twin port crane is used as the core, and the multi-sensor data acquisition method, OPC UA information model, and plug-in programming method are combined to realize multi-source heterogeneous virtual and real data fusion. The digital twin crane monitoring system based on this framework can fulfil the following functions: crane historical operation process reproduction, control program simulation testing, synchronous mapping simulation, and remote control. In order to verify the proposed method, a digital twin-based physical platform for monitoring a rail-mounted gantry crane (RMGC) was built, in which a virtual test of anti-swing control and a digital twin monitoring experiment were carried out. The results show that the virtual RMGC can test the control algorithm and map the movement process of the physical RMGC, and the crane operation monitoring system has high real-time performance and good visualization effect. In addition, the remote control of the software platform is accurate and effective. [ABSTRACT FROM AUTHOR]

While Unmanned Aerial Vehicles (UAVs) can be a valuable solution for the damage inspection of port machinery infrastructures, their trajectories are still prone to collision risks, trajectory non-smoothness, and large deviations. This research introduces a trajectory optimization method for inspecting vulnerable parts of a gantry crane by a UAV fitted with a high-definition (HD) camera. We first analyze the vulnerable parts of a gantry crane, then use the A* algorithm to plan a path for the UAV. The trajectory optimization process is divided into two steps, the first is a trajectory correction method and the second is an objective function that applies a minimum snap method while taking into consideration flight corridor constraints. The experimental simulation results show that, compared with previous methods, our approach can not only generate a collision-free and smooth trajectory but also shorten the trajectory length significantly while substantially reducing the maximum deviation average deviation distances. The simulation results show that this modelling approach provides a valuable solution for UAV trajectory planning for gantry crane inspection. [ABSTRACT FROM AUTHOR]

For antiswing control of underactuated cranes, how to guarantee the converging speed of cranes through control design is essential but still remains unsolved. In this article, the adaptive antiswing control for underactuated gantry cranes with guaranteed transient performance under unmodeled dynamics and external disturbances is investigated. To sovle this problem, a set of filters are proposed to make the backstepping technique applicable for the control of crane systems. Then through variable transformation the position error and swing angel could be guaranteed converging to the origin with a given exponential speed. Hardware experiments are conducted to show that the proposed scheme achieves better control performance over existing methods, and it is illustrated that the proposed control scheme possesses strong robustness to unmodeled uncertainties and external disturbances. [ABSTRACT FROM AUTHOR]

We analyze the specific features of evaluation of the in-service degradation of rolled steel sheets of the reloading equipment. It is shown that impact toughness, as an indicator of brittle-fracture resistance, is one of the determining mechanical characteristics for guaranteeing the serviceability of metal structures. Its catastrophic drop is caused by microdelaminations between the fibers of the structure and elongated nonmetallic inclusions. In order to increase the sensitivity of evaluation of the degree of degradation of steels, it is preferred to tests specimens transverse with respect to the direction of rolling. For the structures operating beyond their designed service life, it is recommended to use the limit value of impact toughness fixed on a level of 30 J/cm2 for which the hazard of uncontrolled fracture becomes high. [ABSTRACT FROM AUTHOR]

Dry bulk terminals at ports generate dust in the process of ore loading / unloading and transfer, and these particulate matters disperse to the atmospheric environment causing pollution and endangering human health. This study focuses on the funnel unloading point of a portal crane at a port terminal, and the variation characteristics of dust emission under different mass flow rates, ambient wind speeds, and moisture contents are investigated. The microscopic features of ore powders, i.e., wetting time, contact angle, particle size, specific surface area and pore structure, as well as microscopic morphology, are also determined to explore the intrinsic mechanism between wettability, moisture content, and dust emission. The impact of mass flow rate, ambient wind speed, and moisture content on dust emission is evaluated by employing the orthogonal test range method and response surface method. The experimental data reveals that the dust at the unloading point is dominated by coarse particles of total suspended particulate (TSP), and increasing the moisture content effectively reduced the dust emissions, with a suppression efficiency of TSP > PM 10 > PM 2.5. The experimental results on the microscopic features of the ore powders indicate that the above difference is attributed to wettability, which weakens with diminishing particle diameter. It is also concluded that the wettability of Australian ore 1 is determined to be superior to bauxite 394. Therefore, Australian ore 1 exhibits an excellent dust suppression effect at a moisture content of 4% ∼ 5%, whereas bauxite 394 requires a moisture content of approximately 5% ∼ 7% to achieve the same dust suppression. By conducting the orthogonal test range method, the three factors on the dust emission, in descending order, are moisture content > ambient wind speed > mass flow rate. According to the response surface method, the optimal parameter combination is determined and the dust emission is minimized as 4.149 μg/s, which corresponds to 0.386 mg TSP/ton, with the conditions of mass flow rate 10.356 kg/s, ambient wind speed 4.289 m/s, moisture content 6.983%. [Display omitted] • Dust emission patterns under varying conditions were experimented. • The microscopic feature of the wettability of experimented ore dust and particle size were measured. • The impact degree of the three factors on dust emission was assessed by orthogonal range analysis. • The optimal parameter combinations were determined with response surface method. [ABSTRACT FROM AUTHOR]

Assessing the seismic performance of the gantry crane is significant since the structure is more vulnerable to earthquakes with the increase in size and lifting weight capacity. This paper aims to investigate the seismic response of the gantry crane incorporating near-field ground motions using incremental dynamic and endurance time analysis (IDA and ETA) methods. To model the structure accurately, a nonlinear finite element model of the gantry crane considering the viscoelastic effect is developed in the OpenSees platform. Then, the IDA method is also carried out for a comparison with the ETA method. The results of the two methods are consistent with a correlation of 93.9% while the computational demand of the ETA method is much less than those of the IDA method. To study further, both the seismic incident angle and the application of viscous dampers using the Maxwell model are analyzed and discussed in detail. The results show that seismic incident angle has a distinct influence on the maximum seismic displacement and viscous dampers can significantly reduce the seismic demand of the gantry crane. These findings support the seismic design of gantry cranes and evaluate the structural seismic performance efficiently. [ABSTRACT FROM AUTHOR]

In this paper, the performance improvement of a payload angle deflection of a gantry crane has been studied and simulated using Matlab/Simulink toolbox successfully. H 2 optimal and observer based controllers has been used to minimize the payload angular deflection by controlling the trolley position. The gantry crane has been compared with the proposed controllers to track the reference trolley position using step and sine wave signals and a promising results have been achieved. [ABSTRACT FROM AUTHOR]

When the rail-mounted gantry crane (RMG) is transporting or transferring, it often meets the problem that the center lines of the rails which on the terminal are not same as the center lines of the RMG. In order to solve this problem, we introduced a new process scheme: the in -situ rotating transportation scheme of RMG. Combined with the successful case of Israel automatic rail -mounted crane project, the design principle of the scheme and the key factors affecting its safety and reliability were deeply analyzed. The research results can provide technical support for the transportation of large -scale equipment in the future. [ABSTRACT FROM AUTHOR]

During the process of steel casting, the task of worker is to identify the relative position of gantry hook and lifting lug of hot metal ladle so as to judge the appropriate time when gantry crane is to be lifted. Worker needs to stand near hot metal ladle, which does great damage to human's body if exposed to such a bad environment. For this reason, the author has designed a machine vision system to displace artificial recognition. The machine vision system consists of the vision recognition algorithm based on AlexNet Convolution Neural Network (CNN) and the improved Canny edge detection algorithm. AlexNet CNN completes the preliminary recognition of the image and provides the samples that meet the recognition conditions to the improved Canny algorithm. The improved Canny algorithm completes the extraction of parameters such as the relative distance between the gantry hook and lifting lug and the tilt Angle of gantry hook. The sample images are extracted from two environments: model simulation and field simulation. Experimental data shows that the recognition algorithm based on AlexNet CNN can achieve 100% image recognition rate, which is higher than other traditional machine learning algorithms; the improved Canny edge detection algorithm can improve edge quality of extracting images in harsh environments. [ABSTRACT FROM AUTHOR]

The gantry crane is an important and representative rotary rail loading and unloading crane. In order to ensure the safe and reliable operation of the gantry crane, it is particularly important to monitor its condition. Many ports still use the traditional after-sales maintenance system. And, the equipment and means for fault detection and repair are also backward. This paper proposes a design of a human-computer interaction system for gantry crane equipment on-line monitoring. The virtual reality technology is used to display the monitoring data and analysis results of the gantry crane in the three-dimensional space in real time. We sample the stress and temperature signals of the gantry crane using Fibre Bragg Grating sensors installed in some structural key points. The sensors are connected to the fibre grating demodulator of the monitoring room through a transmission fibre. Signals collected by the sensors are processed and analysed to diagnose the condition of the gantry crane. The system presents the crane's operating status to the user in a realistic 'virtual environment', so that the fault information can be quickly and accurately fed back. [ABSTRACT FROM AUTHOR]

Modern gantry cranes are an indispensable element of large industrial and transport enterprises. Port handling equipment is operated under conditions of complex spatial loading of varying intensity, as well as under conditions when the walls of structural elements are thinned in the crane carrier system. During the operation of handling equipment in ports, at construction sites, in machine-building industries, in addition to the external load, aggressive media act on the carrier system elements, which leads to various types of wear: corrosive, abrasive and mechanical. Monitoring of the state of handling equipment structures is a very important task of diagnosing the state of the material of elements of the carrier system of cranes and transporting machines. An important and urgent scientific and technical problem of taking into account the influence of aggressive environment on the stress-strain state of the metal structures of gantry cranes is considered. It is noted that during corrosion, a significant thinning of the walls of structural elements occurs. The safety of crane operation requires this factor to be taken into account. It is proposed to use modern numerical methods for this, i.e. the boundary element method (BEM) and the finite element method (FEM). The implementation of these methods is performed in the Matlab programming and modeling environment (BEM), and the FEM is used in the Ansys package. In accordance with the technologies of these methods, the design diagrams of the lower girders and the crane structure as a whole were formed. Exact models of strain of crane elements during transverse bending and constrained torsion are given. Calculations of the stressstrain state of the crane metal structures have been performed. On the basis of a preliminary field study, a numerical model is proposed for diagnosing the strength and stiffness characteristics of the carrier system of handling equipment using the BEM and FEM, which has never been used in the world. Conclusions are drawn about the influence of the thinning of the walls of metal structures on the values of normal and tangential stresses. [ABSTRACT FROM AUTHOR]

During the process of steel casting, the task of worker is to identify the relative position of gantry hook and lifting lug of hot metal ladle so as to judge the appropriate time when gantry crane is to be lifted. Worker needs to stand near hot metal ladle, which does great damage to human's body if exposed to such a bad environment. For this reason, the author has designed a machine vision system to displace artificial recognition. The machine vision system consists of the vision recognition algorithm based on AlexNet Convolution Neural Network (CNN) and the improved Canny edge detection algorithm. AlexNet CNN completes the preliminary recognition of the image and provides the samples that meet the recognition conditions to the improved Canny algorithm. The improved Canny algorithm completes the extraction of parameters such as the relative distance between the gantry hook and lifting lug and the tilt Angle of gantry hook. The sample images are extracted from two environments: model simulation and field simulation. Experimental data shows that the recognition algorithm based on AlexNet CNN can achieve 100% image recognition rate, which is higher than other traditional machine learning algorithms; the improved Canny edge detection algorithm can improve edge quality of extracting images in harsh environments. [ABSTRACT FROM AUTHOR]

This research aimed to study the effect of wind speed on the stability of a ship-to-shore gantry crane of 40 t analyzed using the finite element method (FEM). The main structure of the crane was made of SM 490 grade hot rolled steel. Analyses considered the crane's in-service state, the case when the crane was momentary out-off-service with wind load range of 16-35 m/s total of 7 working positions. With a constant axial force of 811,287 N (811.28 kN) and the crane in out-off-service state with a wind load of 48 m/s the results of the finite element of both states showed that the maximum stress that occurred in the boom pull set (Forestay) was 239.05 MPa. This is less than the yield strength of the material and in the linear elastic range it is safe from failure due to over yield strength. The maximum reaction force of the crane leg was 2,918.90 kN occurring in the left leg of the crane. Reaction force in the out-off-service state did not cause structure lifting. The maximum displacement was 157.02 mm occurring at the boom end with the maximum value being within the allowable values and the design conditions of the crane. [ABSTRACT FROM AUTHOR]