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The influence of wave motion can cause undesired motion in the spreader during the use of cranes for marine replenishment operations, potentially leading to significant impacts on the efficiency and safety of such operations. A novel rope-driven wave motion compensation device (R-WMCD) has been developed to achieve wave motion compensation for marine cranes in roll, pitch, and heave directions. Firstly, the attitude forward/inverse solution models of R-WMCD are established using Newton-Raphson iteration method, and the kinematic model is derived based on the vector closure method. Secondly, the dynamic model of R-WMCD is established using Newton-Euler method, considering the uneven loading condition. Furthermore, to enhance the precision of wave motion compensation, a robust proportional-derivative (R-PD) controller based on the nominal model is formulated, and the stability of the controller is demonstrated. The feasibility and validity of the scheme are ultimately confirmed through simulation and experimentation, demonstrating R-WMCD's capability to achieve wave motion compensation. The research presented in this paper offers a novel approach to the design of the structure and theoretical analysis of 3-degree-of-freedom (3-DOF) wave motion compensation device. • A novel 3-DOF wave motion compensation device is proposed for marine cranes. • The mathematical model of the R-WMCD is established in a non-inertial frame. • The danger area of the barycenter position of the spreader is analyzed. • A robust PD controller based on the nominal model is designed. [ABSTRACT FROM AUTHOR]

In this paper, the problem associated with active heave motion compensation during heavy-lift operations performed by ship-mounted offshore cranes beneath rough marine environment is investigated. To effectively decouple the correlated motion of the suspended payload from the support vessel via the secondary regulated active heave compensation (SRAHC) system, a novel hierarchical control strategy is proposed by integrating a cascade control structure with an adaptive robust control scheme that incorporates a vertical motion forecast algorithm based on autoregressive integrated moving average (ARIMA) model, a conventional proportional-integral-derivative (PID) framework, and a nonlinear model predictive control (NMPC) method. The introduction of the cascade structure is motivated by its prompt error response against control lag and efficient system order reduction for computational burden alleviation, which forms a crucial foundation for the NMPC-based real-time regulation of PID gains, ensuring optimal evolution of the SRAHC system while improving its practical feasibility. Furthermore, the enhancements in heave compensation and trajectory tracking performance, noise resistance, constraint satisfaction, and engineering application potential of the proposal are demonstrated through a thorough comparative analysis conducted in a practical co-simulation research system. • A novel hierarchical control strategy is proposed for the secondary regulated active heave compensation system. • A joint mechanical-electrical-hydraulic research system is employed for practical heave compensation analysis. • NMPC-PID is retained to ensure superior compensation accuracy, accounting for system nonlinearities and model constraints. • The response speed and computational efficiency of NMPC-PID are enhanced through the introduction of a cascade control structure. • The noise resistance performance of cascade PID controller is improved by the NMPC-based regulation mechanism, synthesized with an ARIMA-based heave motion prediction. [ABSTRACT FROM AUTHOR]

Container terminal operations are a core aspect of vessel operations in ports and necessitate an intelligent rescheduling approach to manage complex uncertainty scenarios. This paper investigates the problem of berth allocation and quay crane (QC) assignment with shifting strategies. A variable-length rolling mechanism (VLRM) is designed to identify uncertainty scenarios and determine the optimal rescheduling time point. Notably, we introduce a novel cross-wharf shifting movements strategy (CWSM) and develop a rescheduling model that accounts for constraints related to tidal time windows. The proposed Adaptive Large Neighborhood Search algorithm (ALNS) is tailored to solve this problem effectively. Computational results from various instance sizes validate the efficacy of both the model and the ALNS algorithm. These results demonstrate that the ALNS algorithm exhibits distinct advantages in solution quality and computational time for large-scale instances. Furthermore, the inclusion of tidal time window constraints significantly amplifies the complexity of uncertainty scenarios, emphasizing their importance and the impossibility of neglecting them. The cross-wharf shifting movements strategy, presented herein, effectively mitigates the impact of uncertainty scenarios within a defined scope while enhancing adjustment flexibility. • Investigated intricate scenarios emerging from the interplay between tidal constraints and uncertainty factors. • Proposed a cross-wharf shifting rescheduling strategy to enhance the terminal's emergency response capabilities. • Developed the ALNS algorithm, incorporating two types of operators—single-neighborhood and multi-neighborhood destruction and repair operators—to address the rescheduling problem. • Highlighted how tidal constraints markedly escalate the intricacy of uncertainty scenarios. • Demonstrated that the cross-wharf shifting movements strategy effectively limits the repercussions of uncertainty, thereby expanding the maneuverability within the baseline plan. [ABSTRACT FROM AUTHOR]

With the wide application of large cranes, what role does the crane play in the response of the pile-supported wharf needs to be carefully considered, but the effect of the crane is often ignored or considered by centralized mass simplification. Experimental and numerical investigation are effective ways to characterize the seismic performance of structures. To investigate the response characteristic of the crane-wharf structure located in liquefiable site, the study involves first conducting a centrifuge shaking table experiment to physically reproduce the behaviour of the crane-wharf structure from the experimental view, the response laws such as large deformation due to liquefaction of the crane-wharf structure are revealed. Furthermore, three-dimensional numerical simulation is carried out and the rationality is verified, and it lays a numerical foundation for further revealing the difference in structural response of crane wharf. Finally, the response characteristics of the pile-supported wharf with/without crane under different predominant frequencies earthquakes are discussed and compared, it is found that special attention should be paid to the predominant frequencies of earthquakes with crane. This study emphasizes the complexity of understanding different ground motion records in analysing the response characteristic and provides reference and guidance for the similar structures. • The centrifuge test is first performed to physically reproduce the behavior of the wharf with crane. • The response characteristic of the wharf with/without crane are analyzed by numerical simulation. • Special consideration should be given to the predominant frequencies of earthquakes with crane. [ABSTRACT FROM AUTHOR]

Ports are noisy areas that are often located near populated centers, leading to disturbances for citizens. Neglecting these issues can result in health problems and committees that can impede the natural development of port economic activity, which is growing rapidly. Attention to the sector has increased in recent years, but mainly with studies devoted to the general impact on the population. There is currently insufficient information available regarding the inputs required to conduct noise mapping and assess its effects. This is due to the high quantity and diversity of sources present in the port area. Basing on measurements conducted following established and standardized procedures, the present work reports a database of sound power levels, third-octave band spectra, average duration, and source height for various types of equipment, including reach stackers, dock tractors, front lifts, forklifts, transtainers on wheels, container cranes, mobile cranes, and dry load handling scrapers, during their movements and cargo handling activities. Acousticians are expected to benefit from this detailed input data for noise mapping and environmental acoustic impact assessments. • The study improves technical knowledge about noise from port sources. • Sound power level and spectrum for port equipment in different activities are provided. • Sources include reach stackers, tractors, front and fork lifts, transtainers, cranes and scrapers. • Data are collected through measurements in ports, following established methodologies. • The detailed dataset is useful for acousticians as input values especially for noise mapping. [ABSTRACT FROM AUTHOR]

This study presents a novel electric-hydraulic servo system with an active–passive lift compensation feature designed for a lifting crane used in offshore operations. Additionally, the study explores the control methodology of this system. Firstly, the principle of the combined active–passive lift-compensated system is explained, and the mathematical model of the response is established. To eliminate the strong nonlinearities inherent and mismatched term, the method of exact input-state linearization is employed. For observing the uncertain disturbance terms in the model, a new type of expanded state sliding mode observer(ESSMO) is designed. Subsequently, a control strategy of sliding mode with variable structure is designed using the method of hyperbolic convergence law. The stability of the controller is proved based on Lyapunov's stability theorem. Finally, the control method is simulated and analyzed under different working conditions and compared with traditional PID control and sliding mode control strategies directly designed by the nonlinear model. The simulation results demonstrate that the feedback linearized hyperbolic convergence law sliding mode control strategy not only reduces dependence on exact parameters of the original system but also exhibits strong robustness and suppression of model nonlinearities and parameter uncertainty. • A new principle of combined active and passive lift compensation system is proposed. • The hyperbolic sliding mode control reaching law is introduced to improve the sliding mode control of the linearized system. • A new type of extended state sliding mode observer designed for observing uncertain disturbances. • The compensation rate of the dynamic combined lift compensation system is above 99%. • Linearization eliminates the strong coupling and nonlinearity in the compensation system model. [ABSTRACT FROM AUTHOR]

Anti-sway control systems are valuable tools for cranes to prevent unexpected payload sway and undesired motion. However, for shipboard cranes, where the operator moves with the ship, anti-sway control systems can result in significant relative motion between the payload and operator, particularly in rough seas while attempting to align the payload with an ocean-frame target. Therefore, an important question to ask is, do operators actually find anti-sway systems intuitive, or do they feel they have to "fight" the system to achieve their desired performance? To address the question, this paper presents a human factors study designed to evaluate the effectiveness of a shipboard crane anti-sway system with an operator-in-the-loop. Participants completed a series of tests in a virtual-reality simulator, in which they attempted to align the payload of a nine degree-of-freedom shipboard knuckle boom crane with targets in both the ocean/world coordinate frame and ship deck coordinate frame, using an anti-sway system that provided complete motion compensation in both coordinate frames. The study found that there was a statistically significant improvement in the participant's ability to track a desired payload target with the use of the anti-sway system of up to 49.1%. In addition, as the participant had no knowledge of how the anti-sway system operated, or even if it was active, the results indicate anti-sway control systems can be intuitive for operators to use. [Display omitted] • Development of a virtual reality (VR) system that uses hardware-in-the-loop controls. • Real-time operator-in-the-loop use of a motion compensation crane while in VR. • Development and examination of the human performance for an intuitive crane interface. • Operators tested the system in world-frame, deck-frame, and transitional scenarios. • Proposed system shows a statistically significant improvement in performance. [ABSTRACT FROM AUTHOR]

The Revolving FloatingCrane (RFC) is a vital engineering vessel for offshore lifting operations, with its operational safety and stability being of utmost importance. Nevertheless, potential mismatches in the lifting trajectory and ballast water allocation during manual operations may result in low efficiency, instability, and energy dissipation. Thus, a novel collaborative matching design (CMD) method of the lifting trajectory and ballast water allocation is proposed for the RFC intelligence. By establishing one-to-one correspondences between the lifting trajectory and the ballast water allocation, the CMD method is first developed based on the point to point (PTP) theory. Then, the dynamics model of lifting operations and CMD optimization model are established. To explore the superiority, the proposed CMD method is compared with the conventional method, finding that the CMD method surpasses the conventional sequential design method in terms of lifting operation time (11.20% reduction), total energy consumption (16.50% reduction), ballast water allocation (17.84% reduction), and decision-making time (54.50% reduction). Finally, numerical and experimental validations regarding various lifting scenarios are conducted to certify the efficacy and feasibility of the proposed CMD method, underscoring its potential to realize the optimal matches between RFC's lifting trajectory and ballast water allocation. • A collaborative matching design method for RFC offshore operations is proposed. • The optimization model of the CMD method for the RFC is established. • Superiorities of the CMD method over others is verified by a case study. • Efficacy of the CMD method is validated by numerical and practical experiments. • The CMD method greatly improves the overall operating performance of the RFC. [ABSTRACT FROM AUTHOR]

To solve the difficult problem of swing suppression of slender-beam payloads under rough sea conditions, the Multi-Tagline Parallel Anti-swing System (MTPAS) is applied to the lifting of slender-beam payloads in the offshore environment. The lifting dynamic model of the slender-beam payload under ship-motion excitation is presented using Newton's classical mechanics with the MTPAS dynamics and double-pendulum dynamics, and the dynamic characteristics of the double-pendulum system when subjected to ship-motion excitation are studied. The accuracy of the double-pendulum dynamic model and control strategy is verified by hardware experiments. The results of the study present an original idea to establish a dynamic model of a double-pendulum for transporting slender-beam payloads under rough sea conditions. • The MTPAS is first applied to the lifting of slender-beam payload under rough sea conditions. • The swing reduction effect of the TTAS on the slender-beam payload is 13% higher than that of the DTAS. • The experimental results prove the effectiveness of the double-pendulum dynamic model and control strategy. [ABSTRACT FROM AUTHOR]

In this study, a novel fuzzy sliding mode anti-sway controller (FSMASC) is proposed by combining the in-plane angle and the out-plane angle with the fuzzy sliding mode technology, with the aim of addressing the existing problems facing simple control algorithms, low control accuracy of ship-mounted crane by the mechanical anti-sway method. Moreover, an improved reaching law adaptive sliding mode cooperative controller (ASMCC-IRL) is developed by integrating the cooperative motion between the anti-sway cables with the adaptive sliding mode technology, with the aim of addressing the ineffective cooperative motion between the anti-sway cable in the multi-cable system. First, a model of the ship-mounted crane and a dynamic model of the multi-cable system are built by employing the design prototype of the 45-ton ship-mounted crane on the 27,000-ton multi-purpose ship of COSCO Shipping Group. Subsequently, the FSMASC is proposed to suppress the swing of the load, and the ASMCC-IRL is developed to control the cooperative motion between anti-sway cables. Lastly, the control effectiveness of the FSMASC and the ASMCC-IRL is verified through simulation experiments. As indicated by the simulation results, compared with the scenario without the anti-sway control, the in-plane angle and out-plane angle of the FSMASC decrease by over 75%. Compared with the augmented PD controller (APDC), the error control performance of the ASMCC-IRL is enhanced by over 77.5%, and the convergence speed increases by over 50%. • A ship-mounted crane model and a multi-cable system dynamic model is built using the 45-ton ship-mounted crane on the 27,000-ton multi-purpose ship of COSCO Shipping Group as the design prototype. Multi-cable system complex dynamic characteristics are simulated and analysed. • A novel fuzzy sliding mode anti-sway controller (FSMASC) is proposed by integrating the in-plane and out-of-plane angles with the fuzzy sliding mode technology, Moreover, a novel improved reaching law adaptive sliding mode cooperative controller (ASMCC-IRL) is proposed by combining the cooperative motion between anti-sway cables with the adaptive sliding mode technology. • This study considers that when the swing angle of a ship-mounted crane is being suppressed, the cooperative motion between the anti-sway cables should be achieved. This study also suggests that when the ship-mounted crane is affected by ship excitation, lifting, slewing, and luff-ing operations should be performed simultaneously, which can more realistically indicate the working scenario of the ship-mounted crane. • The in-plane angle and out-plane angle of the FSMASC decline by over 75%, compared with the scenario without the anti-sway control, such that the swing of the load is effectively suppressed, and the control accuracy of mechanical anti-sway increases. • The ASMCC-IRL proposed in this study effectively achieves cooperative motion between anti-sway cables. Compared with the augmented PD controller (APDC), the error control performance of the ASMCC-IRL is enhanced by over 77.5%, and the convergence speed increases by over 50%. As a result, the occurrence of anti-sway cable that will be pulled to an inclined condition, or even snapped anti-sway will be prevented. [ABSTRACT FROM AUTHOR]

In this paper, an offshore crane driven by a secondary controlled unit (SCU) which offers advantages in terms of high dynamic behavior and energy efficiency is investigated. To counteract the negative impact of the support vessel's heave motion on the station-keeping and trajectory tracking performance of heavy payload, an adaptive robust control scheme for the secondary regulated active heave compensation (AHC) system is proposed based on the combination of a nonlinear model predictive control (NMPC) strategy, a conventional proportional-integral-derivative (PID) control scheme and a vessel heave motion prediction algorithm. The motivation of utilizing the PID-based control structure is given by the excellent resistance against irregular external disturbances and robust capability to eliminate the uncertainties, with real-time tuning gains provided by the NMPC synthesized with the autoregressive integrated moving average (ARIMA) model to ensure optimal evolution that satisfies state and input constraints while accounting for model nonlinearities. Comparative simulation studies in the practical Simulink-based mechanical-electrical-hydraulic research system demonstrate the superior tracking and heave compensation performance, strong robustness, constraint satisfaction, and energy efficiency of the proposal. • A new adaptive robust control scheme for the secondary regulated active heave compensation system is proposed. • A joint mechanical-electrical-hydraulic research system is utilized for practical heave compensation analysis. • NMPC is introduced to conventional PID controller for system nonlinearities and constraints satisfaction. • The tracking accuracy and robustness performance of NMPC is improved by the PID component. • The energy efficiency of secondary regulated hydraulic system is enhanced by NMPC combined with PID. [ABSTRACT FROM AUTHOR]

Numerical modeling of crane ship dynamics has become widely used with the development of computational fluid dynamics methods. However, the high number of components in the hydrodynamic forces calculation algorithm introduces a degree of uncertainty, so researchers face difficulties in assessing the influence of various force contributions and model parameters on the result. In this regard, the authors of this paper investigate the parametric sensitivity of a reduced-scale crane ship numerical model. The study should provide some insight for research engineers on how the dynamics of the vessel visually change when different approaches to force calculations, mesh sizes, and cable modeling are taken into account. It would also facilitate optimized model creation for marine engineers since it is not always possible to perform the determination of all the terms of a complex multiphysics model. The comparison of simulation results with the wave-basin experiments on the determination of ship wave-induced motions accompanies the authors' conclusions. • Numerical studies of the wave-induced motions of a crane ship were performed. • Numerical experiments indicated good convergence with laboratory tests in the wave basin. • Linear and nonlinear methods for determining the wave excitation force and restoring force are tested. • Additional viscous damping contributed greatly to the convergence of suspended load vibrations with experimental results. • The Roll-Sway-Yaw lock was observed. [ABSTRACT FROM AUTHOR]

Offshore cranes generally have low working efficiency, high operating risk, and low lifting accuracy under rough sea conditions. In this study, a Multi-Cable Anti-Swing System (MCAS) is proposed in terms of a 45-ton crane of a 27,000-ton multipurpose vessel of COSCO Shipping Group as a design prototype, and it is adopted to investigate the dynamic characteristics of the MCAS for cranes within an offshore environment. The MCAS is simplified as a restricted-pendulum with ship-motion excitations, and a wind load is incorporated into the dynamic model of the MCAS. Moreover, the dynamic characteristics of the MCAS are simulated and analyzed using Matlab/Simulink, and the experiments were performed on the laboratory prototype of the crane equipped with the MCAS. As indicated by the crane operation data, the payload swing amplitude was reduced by 85% with the MCAS, which notably increased the lifting efficiency of offshore cranes. The results of this study will contribute to the in-depth optimization and engineering application of the MCAS onboard ships. • A MCAS is proposed to enable safe lifting operations under rough sea conditions. • Hardware experiments were conducted to demonstrate the effectiveness of MCAS. • The payload swing amplitude was reduced by 85% with the MCAS. [ABSTRACT FROM AUTHOR]

Abstract During the water entry phase in heavy lift marine operations, the involved crane system must satisfy stringent safety requirements. A hydraulic crane driven by a secondary controlled unit that has the advantage of high dynamic behavior and energy efficiency is investigated in this paper. The detailed models of the crane system and the offshore operating conditions are established. To guarantee functionality of the crane system under harsh sea conditions, a cascade control structure is constructed. In the outer loop, an extended state observer is used to estimate the unmeasured payload states. Then, an impedance controller is designed to realize trajectory tracking and impedance regulation of the payload. In the inner loop, the reference trajectory is provided by the impedance controller. An indirect adaptive robust control approach is applied to maximize the achievable tracking performance and to obtain accurate parameter estimates of the secondary controlled unit in the presence of parametric uncertainties and unknown disturbances. The proposed controller can lower a payload to a desired position, and keep the values of the hydrodynamic forces and wire tension within acceptable bounds at the same time. Comparative simulation results verify the effectiveness of the proposed control method. Highlights • This paper investigates the heavy lift offshore operation in the water entry phase. • The secondary controlled unit is employed in the crane system. • Indirect adaptive robust control is developed to regulate the crane system. • A novel estimation law is proposed to estimate the system parameters. • Impedance control is constructed to lower the payload safely and accurately. [ABSTRACT FROM AUTHOR]

Effective prediction of ship arrivals should provide the estimated delay or advance of arrival ships with greater accuracy, and improve the performance of container terminal operations. Therefore, taking Gangji (Yining) Container Terminal (GYCT), China, as an example, this paper resorts to data mining approaches to predict ship arrivals and explore the value of such predicted ship arrivals on the container terminal operation. First, this study applies three data mining approaches, including Back-Propagation network (BP), Classification and Regression Tree (CART) and Random Forest (RF), to estimate the delay or advance of ship arrivals using the collected data of ship arrivals. Then the predictive performance of these three approaches is compared and discussed, it is concluded that RF performs better than BP and CART, and ETA month and ship length are the most important determinants of ship arrivals in GYCT terminal. Finally, series simulation experiments are conducted to assess the value of the ship arrivals predicted by RF model on the improvement on daily operation planning of berth allocation and quay crane assignment in the GYCT terminal. And the results show that incorporating the predicted ship arrivals by RF model is beneficial to improve the performance of operation planning of GYCT terminal. [ABSTRACT FROM AUTHOR]

This paper proposes an event-triggered global sliding mode based anti-sway control for offshore container cranes. Its main objective is to guarantee the robust tracking performance of containers transferred by cranes installed on cargo ships, while saving the transmission resources. To this end, a suitable sliding manifold is formulated with the desired motion properties. A global sliding mode control is then synthesized to maintain stability of the system and ensure robustness against disturbances such as sea waves and wind induced movements. Finally, the event-triggered strategy is considered in the implementation phase to generate the sampling instant at which the control signal is updated, thereby minimizing communication resources and execution time. Using the Lyapunov's stability theory, it is proven that the controlled system reaches the manifold and equilibrium point from any initial state. We also prove that the proposed approach is free from the Zeno solution, i.e., a phenomenon when the infinite triggering instants exist in a limited time range. Eliminating the reaching phase of traditional sliding mode control, overcoming the effect of the disturbances during the entire dynamics, optimizing resources at the implementation phase, and removing the Zeno phenomenon are among the main advantages of the proposed control approach. • Design of GSMC to maintain stability and ensure robustness against disturbances. • Proposition of event-triggered strategy in implementation phase, minimizing communication resources and execution time. • Combination of resource optimization capability of event-triggered technique with robustness of GSMC. [ABSTRACT FROM AUTHOR]

Ship-to-ship load transfer with offshore cranes is challenging in rough sea conditions because of the difficulty in compensating for the increased position-velocity-acceleration errors and the restriction of the unloading area. This study proposes an efficient solution by integrating the combined vertical, horizontal, and anti-swing control system, experimentally validated mathematical hydraulic system and ship motions on irregular waves, the dynamic model of the crane, and an innovative control strategy. Particle Swarm Optimization-Proportional-Integrative-Derivate (PSO-PID) Trajectory Route Control System ensures safe unloading by advancing in the desired vertical position and speed route. The operation's horizontal positioning is realized even for very rough sea conditions with the support of the PID-controlled main and elbow boom. An extra added telescopic boom is used for anti-swing control with Particle Swarm Optimization Proportional-Derivative-Second Derivative (PSO-PDD2) control system. Simulations with different sea conditions were made and analyzed to verify the study's system model's effectiveness. The simulation results revealed that the system model is a valid and successful solution. • Ship-to-Ship load transfer with offshore crane under rough sea conditions. • Particle swarm optimization (PSO)-PID vertical trajectory route control. • Roll effect suspension by the strategy of keeping elbow boom in the globally flat. • PSO depends on proportional-derivative-second derivative (PDD2) of feedback. • An innovatively added telescopic arm for anti-swing PDD2 control. [ABSTRACT FROM AUTHOR]

Revolving floating crane (RFC) is one of the core equipment applied to major offshore lifting operations due to its strong working ability. Its operation safety is directly determined by the collaborative matching between the lifting trajectory and the ballast water allocation. However, such matches are accomplished manually in the actual operations, leading to low efficiency, high energy consumption, etc. To address these problems, the unattended intelligent operation mode is an inevitable solution for the RFC. Therefore, a novel sequential matching optimization (SMO) method for the lifting trajectory and the ballast water allocation of the RFC is proposed in this study. The SMO method is proposed based on the point to point (PTP) method and the corresponding principles are firstly explained in great detail. Then, the SMO model is established for searching the optimal scheme with the lowest energy consumption of the lifting and ballast systems. Furthermore, to explore the corresponding superiority, the proposed SMO method is compared with the conventional method, finding that the proposed SMO method can perfectly achieve better lifting performances. Finally, numerical experiments regarding different lifting positions, crane loads, and quantities of the ballast tanks are performed to verify the feasibility of the SMO method. • SMO method for lifting trajectory and ballast water allocation of RFC is proposed. • SMO model of the RFC considering complex sea conditions is established. • Superiorities of the SMO method compared with the conventional method is certified. • The feasibility of the SMO method under different working conditions is verified. • SMO method can reliably achieve optimal matching schemes for various lifting tasks. [ABSTRACT FROM AUTHOR]

The effectiveness of six seismic retrofitting intervention schemes on an existing jumbo-size container crane is investigated. They include the use of conventional steel braces and buckling-restrained braces, fluid viscous dampers and friction dampers, lead rubber bearing isolators, and natural rubber bearing isolators with viscous dampers. The six schemes can be grouped under three main strategies, i.e., the use of different types of bracings, dampers, and isolation systems. Nonlinear response history analyses, using eight spectrally matched ground motions, were conducted on 3D models of the crane, with and without any upgrading, using SAP 2000. The results showed that with the exception of the conventionally braced crane, which produced inconclusive responses, the other two retrofitting strategies of using different types of dampers and isolation systems significantly reduced the critical seismic responses of the crane. At a target drift of one-third the original, the damping systems caused on average reduction of approximately 32%, 36%, and 98% in the base shear, stress, and uplift responses, respectively. Moreover, a significant reduction of about 65% in the stress and base shear responses and a condition of no uplift were recorded when the isolation systems were applied. The results of this study show that the isolation systems produce the best performance and therefore can be considered as the most effective seismic retrofitting technique. • Vulnerability issues regarding container cranes are addressed by proposing upgrade systems to improve their performance. • The behavior of a jumbo-size crane in all its working conditions is well simulated and comprehensively studied in this paper. • The proposed retrofit systems are effective in reducing the seismic demand on the crane. [ABSTRACT FROM AUTHOR]

The offshore crane system is a typical underactuated system which is installed on the ship and carried out the payload transportation in the offshore environment. The payload transportation for offshore cranes is extremely sensitive to the influence of the ship motion. High couplings also exist between the offshore crane state variables. These factors may lead to large payload swing, and the offshore crane control problem is very difficult. In addition, since some physical parameters of the offshore crane system are difficult to be measured, there usually exist parameter uncertainties, which may lead to positioning errors. In order to tackle the above problems, a new adaptive tracking control method for offshore crane system is proposed, which brings satisfactory tracking performance of the reference trajectories and realizes the control objectives of the payload accurate and fast transportation, the payload swing elimination, and the accurate gravity compensation. Unlike the traditional adaptive control method, an elaborately designed adaptive estimation update law is proposed, which is used to ensure the accurate online estimation for gravity-related parameters. By using Lyapunov stability theory, it is proved that the proposed adaptive tracking controller is effective. Simulations are included to further show the performance of the proposed method. • The payload swing in the earth-fixed frame is effectively suppressed. • The proper tracking performance is achieved with respect to ship roll motion. • The gravity related parameters can be accurately identified online. [ABSTRACT FROM AUTHOR]

This paper presents a novel self-tuning anti-sway control system for shipboard cranes that provides full, six degree-of-freedom (DOF) motion compensation with respect to both the world (ocean) coordinate frame and the ship deck coordinate frame. The system can either manually or automatically switch between compensation modes during operation, and is capable of providing anti-sway action while tracking a time-varying operator input. Rather than requiring the operator to provide individual joint control, the entire system can track a simple three-axes Cartesian input from the operator, while simultaneously providing full anti-sway compensation in either coordinate frame. High-fidelity simulation case studies were performed with a nine-DOF shipboard knuckle boom crane, which included double pendulum dynamics between the hook and payload, in the presence of full six-DOF ship motion at sea-state six. The self-tuning anti-sway system showed at least a 92.70% reduction in payload tracking error when the corresponding compensation mode (either deck or world-frame) was activated, a significant reduction in undesired payload motion. Wind disturbances were added to the simulation using the Dryden wind model, where the system showed a maximum decrease in performance of only 0.73%; additional tests were run with self-tuning disabled, which resulted in a decrease in performance of up to 101%, indicating self-tuning is highly effective at minimizing the effect of wind disturbances. • A self-tuning anti-sway control system for a 9-DOF knuckle boom crane is developed. • The anti-sway system can smoothly switch between deck and world-frame compensation. • Compensation can be provided while tracking a time-varying input from an operator. • The system is tested in a high-fidelity simulation with wind and a double pendulum. • Self-tuning control reduces the effect of wind disturbances. [ABSTRACT FROM AUTHOR]

In the present study, a novel three-bucket jacket foundation with air-cushion launching technology is proposed. Through the theoretical analysis and commercial hydrodynamic software Moses, a crane vessel-three-bucket jacket foundation coupling hoisting system is established, and time-domain calculations are performed accordingly. Moreover, based on statistical information of the actual sea conditions in a certain sea area throughout the year, the corresponding permissible sea conditions for the construction of the sea are calculated to provide technical guidance for practical engineering. Furthermore, the hydrodynamic characteristics of the crane vessel, the motion response of the coupling hoisting system and variations of the cable tension under different configurations and wave directions are obtained. It is found that the vibration frequencies of the crane vessel and the foundation are the same, and the phase is maintained at 180°. It is considered that when the foundation is located at the stern of the vessel and encounters transverse waves, resonance occurs between the crane vessel and the foundation, which should be avoided in actual construction. • A crane vessel-three-bucket jacket foundation coupling hoisting system during the process of lowering. • The initial air storage in the bucket foundation and air cushion effect. • The crane vessel has a low-frequency resonance with the foundation. [ABSTRACT FROM AUTHOR]

Abstract: As a primary device of the S-lay technique, the stinger is used to protect the overbend section in a pipeline. It is difficult to determine the design loads acting on the rollers during the dynamic pipelaying condition using numerical methods alone. Instead, a test model is used to analyze this complex problem. This paper introduces some similarity criteria based on the dynamic similarity of a stinger, a pipeline, and a vessel. Then, the stinger of the first pipelaying crane vessel in China, “HYSY201”, is modeled with these similarity criteria. The loads for the stinger׳s structural design and movement mechanism in the off-design conditions are simulated, producing some useful conclusions and suggesting that local reinforcement of this stinger be performed. The vessel recently began its first deep-sea pipelaying project in Liwan in the South China Sea. Thus, the model method proposed in this paper is effective and could be used to design and test other articulated stinger structures rather than relying on engineering heuristics. [Copyright &y& Elsevier]

Abstract: To increase the lifting capacity and minimize the cost and time for building a ship and offshore structure, block lifting with multi-cranes becomes more and more important. In this paper, therefore, dynamic response analysis of the multi-cranes is performed for block lifting operation. By this simulation, one can confirm the dynamic effects, such as dynamic motion and load, to prevent fatal accidents during the multi-crane operation. There are several types of crane and the crane systems consist of several rigid bodies. These rigid bodies are connected with various types of joints and wire rope, and the crane system is called as multibody system. To carry out the dynamic simulation of the crane system, therefore, the program for dynamic analysis of multibody system is developed. Among the several types of the cranes, the floating crane is operated on the sea water. Therefore, the developed program includes the function for calculating the hydrostatic and hydrodynamic forces. Using the dynamics simulation program developed in this paper, a dynamic response simulation of several cases of block lifting with multi-cranes are carried out, and the simulation results are validated by comparing them with the measured data from the shipyard. [Copyright &y& Elsevier]

Shipboard rotary cranes are widespread used in industrial fields to carry out large-scale cargoes under marine environment, which are a class of representative nonlinear systems. For crane systems, there exist unactuated state variables (e.g., payload swing angles), which hence make them typically underactuated systems, whose degrees of freedom (DOFs) are more than the number of control inputs. Besides, due to the complexity disturbances of the marine environment, there are always inaccuracies in the three-dimensional (3D) dynamics model of shipboard rotary cranes, such as ocean waves, wind waves, ocean currents and so on, which make the control methods hard to achieve the perfect control effect. Most of the existing methods are built on the basis of simplified linear model, which often require precise model parameters or velocity signals. In order to solve the control problems caused by the above uncertainties, this paper proposes two nonlinear anti-swing control methods. First, considering the uncertain parameters, an adaptive controller is designed, which can achieve the control effect of suppressing swing when the model has unknown parameters. Second, considering the unmeasurable velocity signals, an output feedback controller is designed, which can achieve the control effect to suppress the swing angle with no need of velocity signals. On the basis of the above two control methods, we design corresponding different energy storage functions including kinetic energy and potential energy, respectively. Specifically, this paper has achieved an excellent effect of restraining swing without any linear approximation of the dynamic model. Lyapunov theorem and LaSalle invariance principle are utilized to further prove the asymptotic stability of the closed-loop system. Finally, experiments are implemented to further demonstrate the effectiveness of the proposed control methods. • This paper fully considers the spherical pendulum in 3D shipboard rotary cranes. • Two novel anti-swing control methods regarding the ship roll motion are constructed. • Without velocity signals, asymptotic stability of the closed-loop are achieved. [ABSTRACT FROM AUTHOR]

Installation of offshore structures for harvesting energy or oil and gas industries is still burdensome because of the rough sea state. Unless a calm water condition prevailing, installing any substructure or floating structure at offshore sites is very difficult. Hence, there has been great potential for research to investigate offshore structures' installation for normal and more energetic wave conditions. To understand and develop the methodology for the installation, the hydrodynamic response of the structure and impact received by the offshore crane is vital. In this context, the present study focuses on installing a heavy concrete jacket foundation sub-structure (Equivalent steel jacket) of an offshore wind energy structure. Due to the heavyweight and the temporary buoyancy tanks, the structure's response during installation is different from the tubular steel structures predominantly used for jacket structures. In this work, the structure's response in regular waves at different positions of upending is analysed. Also, the peak force received by the crane at different sea states is measured for different positions of upending. Finally, the forces to be expected while upending the jacket in waves is quantified, and a suitable weather window is suggested. Furthermore, the critical positions in upending are established. • The upending of the heavy concrete jacket structure in regular waves is reported. • The responses for three upending positions 16, 45 and 90 deg are investigated. • The peak force experienced by crane at 16 deg is 1.5 to 2 times higher than the rest. • Max. peak force was found to be 3 times the weight of the jacket in initial position. • RAOs of all motions decreases by 2 to 2.5 times, when jacket is connected to crane. • Differences in free-floating and crane rope connected conditions are reported. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a dynamic model of a ship-mounted container crane (called the “mobile harbor”) subject to the motions of ship itself imparted by random sea waves is investigated. The condition of the sea is assumed to be State 3. The ship''s heaving, pitching and rolling motions are considered as the main motions in exciting the mounted crane. Equations of motion are derived using the Lagrange method. Simulation results reveal that the lateral sway angle of the load becomes the biggest in the beam sea, whereas the pitching motion of the ship in the heading sea is the biggest. As a conclusion, the operation of mobile harbors in the heading sea is recommended. The developed mathematical model has been validated by experiments. [Copyright &y& Elsevier]

This paper summarizes all detailed results obtained from a series of shake table testings of a 1/20 scale container crane with friction and pin boundary conditions at the Seismic Research and Test Center in South Korea and compared them with those from its finite element analysis (FEA). The tested 1/20 scale container crane was initially designed based on the similitude laws with scaling factors proportional to the sectional properties and dynamic characteristics of a commonly used full-scale crane. To determine experimental natural frequencies of the tested crane, a white noise test was conducted on the shake table. Then, three different ground motions, including Manjil Iran Abbar, Nahanni Canada, and Mineral Virginia, were individually applied in a trolley-boom direction to the crane placed on the shake table to secure its seismic responses, especially for derailment, uplift and drift. A finite element model of the tested crane was also created using multi-frame elements available in commercially used FEA software and simulated to replicate the testing results. Key findings revealed that the effect of the boundary conditions did not significantly affect the mode shapes and frequencies of the tested crane, but the drifts of the crane with the friction boundary condition resulting from each of the ground motions changed substantially as compared to those from the crane with the pin boundary condition. The derailment displacement at the landside legs of the tested crane was also found to be 12.5 mm for the Manjil Iran and Nahanni Canada earthquakes and 11.5 mm for the Mineral Virginia earthquake. The results from the testing were, largely, in good agreement with those from the FEA. • Seismic responses of a 1/20 scale container crane were investigated by shake table testing and simulation. • The container crane was designed based on the similitude laws. • The derailments, uplifts, and drifts of container crane were captured and analyzed. • The boundary condition had an influence on the drifts of the tested crane. • Most results from the testing were in good agreement with those from the simulation. [ABSTRACT FROM AUTHOR]

Abstract: A large bow wave forms when blunt-shaped vessels like self-propelled jack-up crane vessels (liftboats) operate at high speeds. Above a critical speed, this bow wave spills over the bow causing swamping. To investigate this phenomena, towing tank tests of a 1/25 scale model liftboat hull were done over a speed range of 3–8kn. The test showed above 4kn the bow wave formed and the vessel trimmed by the bow. At speeds above 8kn the bow wave spilled over the bow (swamping). To cancel this critical bow wave a vertical bow plate was fitted ahead of the liftboat bow. This bow plate reduced the bow wave formation and achieved a 10–15% reduction in the towing resistance. The wave cancellation bow plate can reduce the liftboat power or increase its liftboat speed and operating range. [Copyright &y& Elsevier]