Actual Crane Research Articles

Computer-aided rotary crane stability assessment

This paper introduces a computer-aided approach for evaluating the stability of rotary cranes. Utilizing the Motion add-in within the SolidWorks package, a comprehensive numerical stability analysis was carried out. The interaction dynamics between the crane’s support system and the ground were modeled employing linear springs, while the rope system was characterized by a blend of linear spring and damper elements. The term “temporary loss of stability” was introduced to describe scenarios wherein one support loses contact with the ground. Furthermore, ramifications of overlapping control signals on crane operational safety were investigated. Validation of the numerical findings was accomplished through experimental tests conducted on an actual crane. This integrated methodology not only enhances the understanding of crane stability but also offers practical insights for optimizing crane operations in real-world settings.

Kinematic coupling‐based trajectory planning for rotary crane system with double‐pendulum effects and output constraints

AbstractWhen the payload is too large or the hook mass cannot be ignored, the double‐pendulum phenomenon may happen in rotary cranes practical applications. The increase in dynamic complexity makes it more difficult to fast and accurate positioning while suppressing swing during cargo transportation. Moreover, output constraints should be considered in actual crane systems. In this paper, a novel kinematic coupling‐based trajectory planning method is proposed for double‐pendulum rotary cranes with the constraints on angular acceleration and velocity of the boom. The proposed trajectory consists of two parts: a positioning reference component and a swing‐eliminating component. The positioning reference trajectory takes into account the physical constraints of the actuator. The swing‐eliminating trajectory is designed based on the kinematic coupling relationship among the boom luffing, the hook swing and the payload swing. Lyapunov techniques and Barbalat lemma are used for stability analysis. Numerical simulation and real experiments verify the superior control performance and robustness of the proposed control method.

Sensor-less and time-optimal control for load-sway and boom-twist suppression using boom horizontal motion of large cranes

Load-sway and boom-twist should both be considered in motion control given that a large crane typically has a long lattice boom. Hence, this study first analyzes the load-sway and boom-twist (vibration) of an actual crawler crane, and proposes a new dynamics model considering the above vibration. To ensure safety, sudden acceleration/deceleration is prohibited while controlling the motion of large crane. In addition, real time measurement and feedback of vibration is generally difficult. Hence, this study proposes a vibration sensor-less control based on a cycloidal motion trajectory with smooth acceleration/deceleration. Two-dimensional load-sway can be suppressed only by boom horizontal motion for simple implementation. Time optimality is also considered in the motion trajectory design in order to ensure operational efficiency. Experimental results demonstrate the effectiveness of the proposed approach.

Automatic parameter selection ZVD shaping algorithm for crane vibration suppression based on particle swarm optimisation

Abstract This work introduces the foundation of a new class of input shaping algorithm, designed based on the particle swarm optimisation. This algorithm is utilised to control the residual vibrations in the crane system. The motivation is the development of simple algorithms and architecture for controlling the motion in under-actuated nonlinear systems with minimal modelling effort. By recording the payload swing signal of the crane only once, the approach can automatically calculate the optimisation amplitude and time locations of the impulses required by a common zero-vibration-derivative (ZVD) technique. In this work, we use this algorithm to design a ZVD shaper for controlling the motion of an under-actuated nonlinear crane model system. We validate the approach using experiments. If this algorithm is implanted into the embedded system and applied to the actual crane, which will solve the problem of the traditional ZVD parameter adjustment and improve the vibration suppression effect of the ZVD Algorithm.

Hairpin RNA genetic algorithm based ANFIS for modeling overhead cranes

Obtaining an accurate mathematical model is an important subject to design an overhead crane control system. However, there are some deviations between an existing model and a physical system due to its nonlinearity and complexity characteristics. Motivated by this fact, an adaptive network-based fuzzy inference system (ANFIS) modeling method is proposed for obtaining high precision models. One of the challenges in ANFIS modeling is how to effectively optimize the premise and consequent parameters. To solve this problem, we propose the RNA genetic algorithm with hairpin genetic operators (hRNA-GA). In hRNA-GA, inspired by the hairpin structure in RNA molecules, we design the hairpin crossover operator and the hairpin mutation operator to maintain the population diversity and avoid the premature convergence. Numerical experiments have been conducted on some benchmark functions. The results indicate that hRNA-GA has better search ability with respect to quality and stability of solutions. Finally, hRNA-GA is applied to find the optimal parameters of ANFISs for modeling an actual overhead crane system and the satisfactory results are reached.

A study on DAA-based crane scheduling models for steel plant

Crane scheduling tasks in steelworks are a matter of uncertainty scheduling with certain probability distribution pattern. To better schedule tasks with this feature, this paper proposes a Dynamic Area Allocation (DAA)-based crane scheduling model according to the following steps. First, Bayesian network, according to the time sequence of crane transportation tasks, is constructed. Then, conditional probability for each network node on the basis of actual crane operating data is calculated for getting the corresponding time–space probability distribution, and then obtaining the spatial distribution by superposing of all crane transportation tasks in the space domain at certain time. At last, tasks are assigned to cranes based on their spatial distribution and the equal probability partition. Simulation testing on the scheduling model is carried out using practical crane transportation tasks in steelworks. Results show that the model based on the dynamic area allocation, with its scheduling period of 15 min, can greatly shorten transportation time and reduce times of collision resulted from crane interference, after compared with the current widely used crane scheduling programme based on the fixed area allocation (FAA).

Bayesian Policy Optimization for Waste Crane With Garbage Inhomogeneity

The objective of this study is to develop a framework that can optimize control policies of a waste crane at a waste incineration plant through an autonomous trial and error manner. Since a waste crane is a massive mechanical system that moves slowly and takes several minutes to execute a task, obtaining data samples by executing tasks is very costly. Moreover, no sensors are available that can observe the state of the grasped flammable waste composed of various materials with different degrees of hardness and wetness. Therefore, the inhomogeneity of waste causes unpredictable fluctuation in the crane's task performance. To cope with these problems, we propose a framework for optimizing the policy parameters of a parameterized control policy with Multi-Task Robust Bayesian Optimization (MTRBO). Our framework features the following two characteristics: (1) outlier robustness against garbage inhomogeneity and (2) sample reuse from previously solved tasks to enhance its sample efficiency. To investigate the effectiveness of our framework, we conducted experiments on garbage-scattering tasks with (i) a robot waste crane with pseudo-garbage and (ii) an actual waste crane at a waste incineration plant. Experimental results demonstrate that our framework robustly optimized the control policies of the garbage cranes, even with a much reduced amount of data under the influence of garbage inhomogeneity.

Energy-shaping-based nonlinear controller design for rotary cranes with double-pendulum effect considering actuator saturation

Dynamic performance analysis and controller design become more difficult when the load sway in rotary cranes exhibits double-pendulum characteristics. Furthermore, uncertain parameters and external disturbances in the crane system make it difficult for traditional methods to obtain satisfactory control performance. In addition, in an actual crane system, because of physical constraints, the output torque of the motors cannot be infinite. Therefore, the motor torque calculated by existing methods may exceed the maximum value, and actuator saturation will occur, which will affect the control performance. For this purpose, an energy-shaping-based nonlinear controller is presented after simplifying the original crane model. Stability analysis is carried out using the Lyapunov technique and LaSalle's invariance theorem. Numerical simulations validate that the proposed method can provide a robust control performance superior to that of traditional controllers.

INCREASING OPERATION EFFECTIVITY OF METAL PRODUCTS LOADING POINTS BY THE RATIONAL USE OF BRIDGE CRANES

Purpose. Taking into account research and improvement of transport and storage processes for loading railway cars with bridge cranes the purpose of the study is the analysis of actual crane operation zones, development of simulation models of their functioning and determination of the most effective load technology. The real object of the study — the finished goods warehouse of a metallurgical enterprise — is formalized as a linear load point. Methodology. To analyse various options for the crane operation zones of the investigated object, the simulation modelling method was used. It was taken into account that each bridge crane can load railway cars, which are located in different zones of the loading track. Situations when the cranes are on the same crane ways during cargo operations and the service area of cars partially coincides were considered. Under such conditions, cranes can interfere with each other; it makes it difficult to carry out the transport-technological process of loading. Findings. A simulation model in which the service elements, which are the individual cargo packages, move along certain routes has been developed. Freight traffic volumes are set according to certain laws of random value distribution, taking into account the stochastic nature of real transport processes. A model of the linear loading point of railway cars with bridge cranes has been developed. It allows us to analyse the performance indicators of various options for assigning service areas to loading facilities. The analysis of such indicators as an average transporting time of service elements, a time percentage of cranes work and idle, time for separate movement operations of freight traffic volume is performed. Based on the developed model, a procedure has been developed to determine the most effective strategy for managing the loading point operation. The methodology, which has been tested on the example of a finished product warehouse of a metallurgical enterprise, and allows reducing the total costs in the process of rolled metal products loading has been developed. Originality. Theoretical research and improvement of the operation models of the metallurgical enterprise`s transport and storage complex due to the rational assignment of vehicle loading areas to the cranes. Practical value. The results obtained make it possible to increase the efficiency of the transport and storage complex by reducing the time spent by railway cars in the system with the rational use of loading resources.

Fatigue behaviour of a welded I-section under a concentrated compression (wheel) load

This paper deals with the evaluation of fatigue cracks under a concentrated compression (wheel) load in an I-section with full penetration welds between the web and flange. The objective is to investigate whether cracks stop or nearly stop when they have grown through the residual tensile stress field.These experimental investigations are part of a review of a crane runway girder where after 20years of service fatigue cracks were observed in the flange at the toe of the full penetration weld. The fatigue analysis of the actual crane runway girder is described in (Wardenier et al., 2017).The fatigue tests under a concentrated wheel compression loading show that, for the specimens considered on a scale of about 1:2 with stiffeners at one side, the cracks only initiate and grow at the non-stiffened side to about 50 to 60% of the web thickness and then stop. Based only on the nominal stress range under the wheel, determined according to EN 1993-6 and neglecting the shear stress effect, an equivalent fatigue class of about 160N/mm2 was found for crack initiation in the web, whereas the minimum ratio in life between visually observed crack initiation and maximum crack length was about a factor 3.Comparison of the codes for a wheel loading in compression shows large discrepancies in effective width and fatigue classes to be used.

Design for a Crane Metallic Structure Based on Imperialist Competitive Algorithm and Inverse Reliability Strategy

Uncertainties in parameters such as materials, loading, and geometry are inevitable in designing metallic structures for cranes. When considering these uncertainty factors, reliability-based design optimization (RBDO) offers a more reasonable design approach. However, existing RBDO methods for crane metallic structures are prone to low convergence speed and high computational cost. A unilevel RBDO method, combining a discrete imperialist competitive algorithm with an inverse reliability strategy based on the performance measure approach, is developed. Application of the imperialist competitive algorithm at the optimization level significantly improves the convergence speed of this RBDO method. At the reliability analysis level, the inverse reliability strategy is used to determine the feasibility of each probabilistic constraint at each design point by calculating its α-percentile performance, thereby avoiding convergence failure, calculation error, and disproportionate computational effort encountered using conventional moment and simulation methods. Application of the RBDO method to an actual crane structure shows that the developed RBDO realizes a design with the best tradeoff between economy and safety together with about one-third of the convergence speed and the computational cost of the existing method. This paper provides a scientific and effective design approach for the design of metallic structures of cranes.

Development of simple operation crane system for the real application

In each industry, the weight of the transportation work and quantity of the load has increased. Thus, now the crane equipment is introduced than ever. For overhead crane used in factories and warehouses, efficient operation which suppresses the swaying of the suspended load during transport is strongly demanded. In particular, it is necessary to suppress the initial shaking or disturbance due to the shift of the center of gravity and the hanging point position at the time of raising the suspended load. Therefore, we need to develop the simple operation crane system that enables the operation of the same level as the person skilled in the crane operation in order to improve the safety and efficiency. The author have investigated the control using Dual Model Matching method based on characteristic transfer function matrix to a configuration of the controller. By implementing feedback control on an actual overhead crane in practical use, the efficacy and operability of the system and the method were discussed. The purpose of this study, by developing the simple operation crane system that allows the same operation as the skilled operator, is to improve the safety and efficiency of the crane operation.

Fatigue behaviour of a welded I-section under a line load in compression

This paper is part of an evaluation of fatigue cracks in a crane runway girder with full penetration welds between the web and flange. The fatigue analysis of this actual crane runway girder is described in [1].The investigation described in this paper deals with additional experimental tests on equivalent welded I sections on scale of approximately 1:2 subjected to a fluctuating line load in compression. The objective of these experimental investigations is to investigate whether cracks stop or nearly stop when they have grown through the residual tensile stress field.The test results show that, in some cases the cracks in the weld, at the weld toe with the web or with the flange initiate and grow from one side to about 50 to 60% of the web thickness and then stop. However, at the weld toe with the flange the cracks grow sometimes from both sides but with the cracks at one side having a small length and/or a small depth. The minimum ratio in life between crack initiation and maximum crack was a factor 1.2 for cracks occurring at one side only and 1.5 to 3.1 for cracks at both sides.

Anti-Sway Control of the Overhead Crane System using HOSM Observer

This paper proposes a sum of squares (SOS) method for anti-swing control of overhead crane system using HOSM (High-Order Sliding-Mode) observer. By representing the dynamic equations of overhead crane as the polynomial dynamic equations via Taylor series expansion, the control input is obtained from the converted polynomial dynamic equations by numerical tool SOSTOOL. Since the actual crane systems include disturbance such as wind and friction, we propose a method to compensate for the disturbance by estimating the disturbance using HOSM observer. Numerical simulations show the effectiveness and the applicability of the proposed method.

Construction Tower Crane SimMechanics-Visualized Modelling, Tower Vibration Impact on Payload Swing Analysis and LQR Swing Control

Fast and accurate positioning and swing minimization of payloads in tower crane operation are challenging as well as conflicting tasks. Minimizing the load swing is primarily limited by the existence of wind disturbance effect triggering higher tower vibration, especially in the high speed course and load is in the end of tower region. In this paper, the authors propose a new modeling scheme for 3D tower crane, analyze wind disturbance affected-tower vibration impact on the load swing and develop LQR swing control. Firstly, SimMechanics-visualized crane model has been developed using actual tower crane Morrow (Liebherr 71EC) datasheet. Secondly, wind disturbance model was designed based on Gawronski approach and applies different wind patterns on the model for vibration impact analysis. Thirdly, improved version of linear least square system identification algorithm using 7 past inputs-outputs data has been developed to create better fit model. And finally, propose a new control scheme for 3D tower crane that consists of a reference point tracking with full state feedback Linear Quadratic Regulator (LQR). The simulations results show the robust controller performs well in minimizing the load swing due to wind-affected tower vibration and high speed region.

The Dynamic Strength Calculation on the Reel Fulcrum of Crane Based on ADAMS and FEA

Based on the multi-body system dynamics in the ADAMS environment, a virtual prototype of the reel fulcrum of crane was developed. In this model, the whole system was disassembled lifting mechanism system with flexible body dynamics model of the wire rope. The virtual running environment was established according to the actual crane operation cases, which is designed the hanging & lifting working process. It is the key step to build the reel fulcrum dynamics model for performance analysis of system dynamics, which is the basis for the optimize design of the reel fulcrum of crane. Theoretical model analysis usually does not consider the coupling force status of the reel fulcrum of crane. It is a steady-state analysis to the reel fulcrum of crane models. These models have played an important role in the assessment of the reel fulcrum of crane performance and the system parameters, but do not reveal the interaction of the reel fulcrum of crane and the wire rope, which fail to be a comprehensive understanding practical system dynamics characteristic. Virtual prototype simulation results will be applied to prototype design and evaluation, and save a lot of manpower and material resources. At the same time,the method has an advantage for dynamics analysis to simulating some dangerous movement conditions, which is hard to be replayed or simulated at the test actual working condition site. In particular, some cases cannot be recurrence in the accident handling process. The simulation results show that the response value. Variable stiffness characteristics of wire rope of hoisting mechanism are implemented successfully through discrete multiple rigid body being applied to the wire rope in this paper. The establishment of the Reel fulcrum dynamic model is based on ADAMS, which realizes the reel fulcrum of crane system coupling modeling. These results show that the model reflects the actual dynamics of the reel fulcrum of crane, and also presents that some of the theoretical analysis results cannot be usually confirmed.

A Two-phase Heuristic for Crane Scheduling in Steel Slab Yards

In this paper, a two-phase heuristic algorithm is proposed for an expanded crane scheduling problem that combines a Resource Constraint Project Problem and a Block World Problem in order to develop a guidance system for minimizing crane handlings in slab yards of steel works. Due to its NP hardness, it is difficult to obtain the theoretically optimal solution of the problem. Therefore, a two-phase heuristic algorithm was developed to obtain an approximate solution in a practical calculation time. The first phase in this approach utilizes a genetic algorithm that is employed to solve a relaxed scheduling problem of rearranging steel slabs in an approximate manner. Next the partial solution is iterated upon by a rule-based algorithm to obtain a feasible solution. Computational experiments are conducted with operation data of JFE Steel, allowing a comparison to be made between actual and theoretical crane handling operations. The resulting data shows that this paper's proposal can reduce the number of handlings by 30%.

S151016 クレーンの制振搬送訓練シミュレータの開発

Expert skill is needed to operate a crane and transfer load without exciting the load sway. Typical teaching method such as explain verbally is difficult to be understood. Recently, a crane simulator is used to learn operator skill of crane. However, its time of training is no great distinction between a crane simulator and actual crane. In this paper, a simulator capable of shortening the training period of unskilled crane operators is newly built. First, referring to the sway suppression skill taught in crane driving school, sway suppressing control input is derived theoretically. Next, a learning support method that presents haptic and visual sensory information to facilitate acquisition of the sway suppression skill by the unskilled operators is proposed. An experiment was performed to validate the effectiveness of the proposed learning support method and the results indicate that proposed method can be beneficial in the training of crane operators.

2302 DMMによるクレーンの運動と振動の制御 : ヒューマン・インターフェースの実装実験(OS3-2 ビーグル制御,OS3 交通・物流システムの制御,オーガナイズド・セッション(OS))

The operation of overhead crane are required the vibration suppression of the suspended load and the accurate transport to the target position. In the previous study, we derive an analytical model of the overhead crane as a linear parameter varying (LPV) system, and good control results were obtained by combined control using Dual Model Matching (DMM) control method, but we have to input the target trajectory. Therefore, in this study, we realize of practical crane control system that reduces vibration suppression of suspended load from Crane operator by designed controller. In this paper, we implemented in the push button controller as an example of the typical human interface device of the crane to overhead crane to simulate the practical situations. Then, we verify the effectiveness of DMM controller to LPV system, by the experiments in the similar to actual crane operating environments.

The Dynamic Strength Calculation on the Reel Fulcrum Bearing and Gear Box Bed Plate of Crane Based on ADAMS and Mechanical Property

Based on the actual crane accident occurring in strange cases, the calculating process is that the reel bearing seat model based on ADAMS is established after hoisting wire rope is broken, which is used for the dynamic strength analysis on the damage of the gear box bed plate & reel fulcrum bearing of crane, and the calculating result of the dynamic model is used as the input item for the load calculation analysis. Metallographic analysis & mechanics service test are applied to material strength analysis. This is an effective method for the modeling analysis of complex crane accidents based on multi-body dynamics, which provides practical and theoretical support for the design and calculation of cranes.