This paper presents a novel stabilizing nonlinear PID controller with real time experimental validation on a gantry crane system. Our adaptive control technique describes the underactuated system as ...a nonlinear mapping of control signal with the hyperbolic tangent function. The proposed function is used to impose a constraint on the proportional, integral and derivative errors such that the system results an effective and robust performance. The main trait of the controller is to bound the high control error to result in a lesser correction value. An enhanced hybrid method based on the bioinspired meta-heuristic algorithm Particle Swarm Optimisation is utilised to tune the gain coefficients Kpδ, KIδ and KDδ. The Linear controller and the proposed controllers were compared based on the stabilizing action on the real time system. The real time results depict that the nonlinear PID performs better than the conventional PID.
The paper discusses determining crane block trajectories using the finite element method (FEM). The mathematical formulation for air resistance of hooks’ block is presented with kinematic analysis of ...the block. The three crane blocks are considered: without wind deflector, with a spherical deflector and a cylindrical fairing. The hook block was assumed as a physical pendulum. The FEM analysis is provided with the hook block movement consideration. Movement trajectories of hook blocks for different wind speeds is depicted and the results are. At the end of the paper, the conclusions are provided with the directions of future research.
Flexible structural vibrations of large gantry cranes are a well-known issue. Several control strategies were proposed for this problem, which require a detailed dynamical model. Since the modeling ...of large-scaled structures, as well as of significant nonlinear friction effects is complicated and time consuming, a direct data-driven dynamic reconstruction based on the Koopman operator theory is proposed. Such identification results in a higher order linear state-space model, which reflects the nonlinear behavior in the broad dynamical range of the system and does not depend on a specific operating point. In this paper, a data-driven linear model identification is investigated for a simulation model, as well as for an experimental laboratory crane. The damping and positioning control dynamics based on the identified model were studied and it was shown, that the resulting performance is comparable to model-based nonlinear approaches.
This paper focuses on the development of minimum time control profiles for point-to-point motion of a gantry crane system in the presence of uncertainties in modal parameters. Assuming that the ...velocity of the trolley of the crane can be commanded and is subject to limits, an optimal control problem is posed to determine the bang-off-bang control profile to transition the system from a point of rest to the terminal states with no residual vibrations. Both undamped and underdamped systems are considered and the variation of the structure of the optimal control profiles as a function of the final displacement is studied. As the magnitude of the rigid body displacement is increased, the collapse and birthing of switches in the optimal control profile are observed and explained. Robustness to uncertainties in modal parameters is accounted for by forcing the state sensitivities at the terminal time to zero. The observation that the time-optimal control profile merges with the robust time-optimal control is noted for specific terminal displacements and the migration of zeros of the time-delay filter parameterizing the optimal control profile are used to explain this counter intuitive result. As a comparison to the proposed controller, an acceleration constrained time-optimal control is analyzed which as expected demands a larger maneuver time. A two degree of freedom gantry crane system is used to experimentally validate the observations of the numerical studies and the tradeoff of increase in maneuver time to the reduction of residual vibrations is experimentally illustrated.
•A heuristic for the container retrieval problem is presented.•The method runs faster than earlier methods by several orders of magnitude.•Real-sized instances are solved in less than 1s.•The number ...of movements approaches a theoretical lower bound in most cases.•The tradeoff between the number of movements and working time is demonstrated.
The demand for container terminal yards is growing significantly faster than the supply of available land; therefore, containers are typically stacked high to better utilize the land space in container yards. However, in the process of container retrieval, non-productive reshuffling may be required to relocate the containers that are stacked on top of the target container. Container retrieval is directly related to the operational efficiency of terminals. Because the industry has become increasingly competitive, it has become critical to introduce a systematic approach to retrieving containers. In this study, we develop a heuristic that can generate feasible working plans for rail-mounted gantry cranes (RMGC) in container yards to minimize the number of container movements while taking the RMGC working time into consideration. The methodology takes into consideration the case that containers are grouped in terms of their retrieval order. Multi-lift RMGC models also are studied. Comprehensive numerical experiments reveal that the method runs faster than other methods published in the literature by several orders of magnitude; additionally, our method is able to solve instances larger than practical use. The number of movements approaches a theoretical lower bound, and the numerical results clearly demonstrate the tradeoff between the number of movements and the working time, and provide useful insights for yard planning.
With the support of gantry crane operators who load and unload containers between vessels and trailers, we visualized the gap in the line of sight between beginners and experienced operators. The aim ...was to explore training methods for skills transfer. Through an analysis of eye-movement data, we found that the working environment at 50 m above ground level was psychologically oppressive, so the beginners had an imbalanced gaze to the vital parts of the object. On the other hand, experienced operators made efforts to collect information by widening their gaze range.
When it comes to training, in a stressful environment, too much input may instead lead to panic for beginners. Gradually expanding the scope of the inputs becomes important. In addition, beginners also need to carefully imitate the experienced operators in focusing on objects, so that they may truly grasp the skills.
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.
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•Proposed a process handling scheme that connects two terminals.•Studied the different transportation modes in the underground logistics channel.•The scheduling problem concerns the ...connection of three equipment.•Proposed an optimization model to reduce the waiting time among the three types of equipment.
With an increase in the container volume, the problems of container terminal congestion and resource shortage may become increasingly critical. To enhance the service of a container terminal, this article investigates a novel loading and unloading scheme that optimizes the underground container logistic system and configuration and scheduling of underground logistics vehicles, gantry cranes at the handling shaft, and automatically guided vehicles on the ground. First, a mathematical model of the problem is established with the objective function of minimizing the maximum completion time. In addition, another objective function of minimizing the total waiting time of the underground logistics vehicles at the handling shafts is considered to form a multiobjective cooperative optimization model. Second, the genetic algorithm is adopted to solve the single model, and the nondominated sorting genetic algorithm-III derived from the genetic algorithm is applied to efficiently solve the multiobjective problem, and the corresponding performance is experimentally verified. To verify the correctness of the models and effectiveness of the algorithms, numerical experiments of different scales with the solutions of two transportation modes are illustrated. The sensitivity analysis proves that the underground logistics vehicle grouping transportation mode can significantly increase the operation efficiency of the underground container logistic system and container terminal. The “superiority” performance at different scales indicates that instance No. 6, which includes 96 containers, 3 gantry cranes and 8 automatic guided vehicles, has the maximum effect and highest performance in the underground logistics vehicle grouping mode. The experimental results and analysis demonstrate that the proposed method, which can select the configuration and scheduling scheme for an underground container logistic system, is rational and valid.
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.
Gantry crane merupakan salah satu jenis crane yang dapat digunakan di dalam dan di luar ruangan. Di kantor LAPAN Garut, gantry crane digunakan untuk proses perakitan roket sebelum dilaksanakan uji ...statik dan uji terbang. Penelitian ini mengkaji tentang prediksi umur fatik struktur crane menggunakan metode elemen hingga. Desain struktur gantry crane menggunakan Autodesk Inventor Professional 2017, sedangkan analisis elemen hingga menggunakan perangkat lunak Ansys Workbench 2019 R3. Struktur gantry crane dikenakan beban dengan variasi 7, 8, 9, dan 10 ton dengan jenis pembebanan fully-reserved. Prediksi umur fatik menggunakan teori tegangan rata-rata Gerber. Struktur gantry crane menggunakan material aluminium paduan. Hasil simulasi menunjukkan bahwa struktur gantry crane dengan 7, 8, 9, dan 10 ton memiliki umur kelelahan minimum berturut-turut 11,770 x 106, 2,307 x 106, 1,055 x 106, 0,494 x 106 siklus. Sedangkan faktor keamanan struktur gantry crane dengan 7, 8, 9, dan 10 ton memiliki faktor keamanan berturut-turut 1,296; 1,134; 1,008; dan 0.907. Pada pembebanan 10 ton, umur fatik minimum gantry crane kurang dari 1 juta siklus.
The gantry crane is one type of crane that can be used indoors and outdoors. In the LAPAN Garut office, the gantry crane is used for the rocket assembly process before static and flight tests are carried out. The study examines the fatigue life prediction of gantry crane structures using the finite element method. gantry crane structure design uses Autodesk Inventor Professional 2017, while finite element analysis uses Ansys Workbench 2019 R3 software. gantry crane structure is subjected to loads with variations of 7, 8, 9, and 10 tons with the fully-reserved type of loading. Fatigue life prediction using Gerber's mean stress theory. gantry crane structure uses aluminium alloy material. The simulation results show that the structure of the gantry crane with 7, 8, 9, and 10 tons have a minimum fatigue life of up to 11.770 x 106, 2.307 x 106, 1.055 x 106, 0.494 x 106 cycles, respectively. While the safety factor of the structure of the gantry crane with 7, 8, 9, and 10 tons have a safety factor of 1.296, 1.134, 1.008, and 0.907, respectively. At a loading of 10 tons, the minimum fatigue life of gantry crane less than 1 million cycles.
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