Crane Operation Research Articles

Optimization approach of berth-quay crane-truck allocation by the tide, environment and uncertainty factors based on chaos quantum adaptive seagull optimization algorithm

The post-epidemic era has led to the accumulation of cargo, which has brought greater pressure to container ports. Since traditional methods cannot simultaneously consider the effect of tidal, uncertain, and environmental factors on the allocation plan. To relieve this pressure, firstly, considering tidal factors, formulating time window rules, thinking out uncertain factors, and determining constraints from three perspectives of vessel berthing process, quay crane and container truck operation, a new berth-quay crane-truck joint scheduling model is constructed by minimizing three aspects of vessels turnaround time, the carbon emissions of quay cranes and trucks, namely TEU-BQCT model. Then, aiming at obtaining a relatively high-quality solution, combining chaotic mapping and quantum entanglement, a new chaotic quantum adaptive seagull optimization algorithm is proposed, namely CQASOA, exclusive coding rules suitable for the TEU-BQCT model is formulated, a feasible integer algorithm is developed, the external penalty function is constructed to limit constraints, and a novel joint scheduling solution method of berth-quay crane-truck is proposed, namely TEU-BQCT_CQASOA. Subsequently, two ports of different scales in South China are used to test the constructed solution method feasibility. The simulation results indicate that the constructed TEU-BQCT model can obtain a more suitable scheduling scheme. The proposed CQASOA has better performance than other comparison algorithms selected in this paper, which can obtain a better solution when solving the TEU-BQCT model.

Morbidity with temporal disability in workers engaged in refined copper production

Introduction. High ductility, electrical and thermal conductivity, and resistance to corrosion determine a high demand of the national economy for refined copper, thus necessitating a comprehensive study of the occupational environment and health status in workers employed in this branch of non-ferrous metallurgy. 
 The purpose of our study was to assess the morbidity with temporal disability in workers engaged in the fire and electrolytic refining of copper. 
 Materials and methods. Morbidity with temporal disability in both male and female workers was studied by means of its detailed personal record at one of the large copper refineries of the Middle Urals. 
 Results. Among those engaged in copper smelting, the highest morbidity with temporal disability rates per one hundred workers were registered among repairers and auxiliary personnel (95.3 sick leave episodes and 1,147.8 days) in men and among overhead crane operators (52.8 episodes and 657.6 days) in women. In the copper electrolysis shop, the highest rates were noted among both men (86.7 episodes and 954.0 days) and women (77.8 episodes and 841.2 days) constituting the core personnel. We established that in the study cohort lung diseases ranked first among the causes of the morbidity with temporal disability followed by musculoskeletal diseases.
 Limitations. Such a study is feasible only at the enterprises that record and measure morbidity with temporal disability due to work.
 Conclusions. Our findings may indicate work-relation of morbidity with temporal disability in male repairers and auxiliary personnel, as well as female crane operators engaged in fire refining of copper and in both male and female core personnel engaged in electrolytic refining.

Locating algorithm of steel stock area with asynchronous advantage actor-critic reinforcement learning

Abstract In the steel stockyard of the shipyard, the sorting work to relocate the steel plates already stacked to retrieve the target steel plate on the fabrication schedule is labor-consuming work requiring the operation of overhead cranes. To reduce the sorting work, there is a need for a method of stacking the steel plates in order of fabrication schedules when the steel plates arrive at the shipyard from the steel-making companies. However, the conventional optimization algorithm and heuristics have limitations in determining the optimal stacking location of steel plates because the real-world stacking problems in shipyards have vast solution space in addition to the uncertainty in the arrival order of steel plates. In this study, reinforcement learning is applied to the development of a real-time stacking algorithm for steel plates considering the fabrication schedule. Markov decision process suitable for the stacking problem is defined, and the optimal stacking policy is learned using an asynchronous advantage actor-critic algorithm. The learned policy is tested on several problems by varying the number of steel plates. The test results indicate that the proposed method is effective for minimizing the use of cranes compared with other metaheuristics and heuristics for stacking problems.

Fault‐tolerant controller design for tower cranes considering distributed payload beams

SummaryDue to the long‐term operation of the tower crane, various faults will inevitably occur, such as actuator faults, which further increases the difficulty of controller design. In this paper, a fault‐tolerant control method with adaptive gain is proposed for the double‐pendulum tower crane with distributed payload beam (DTCDPB) system in the existence of external disturbances and actuator failures. First, a nonlinear fault‐tolerant observer is designed for fault diagnosis. Second, an S‐shaped trajectory functions are coupled online and embedded into the system target trajectories for payload swing suppression. Then, feedforward compensation is applied in the controller for the observed faults. Moreover, the adaptive suppression term to be activated is also designed in the controller taking into account the errors existing in the observation. Finally, the effectiveness of the proposed observer and controller is experimentally verified.

Causes of safety risk during tower crane operations on construction sites in Vietnam

The construction industry holds significant importance for any nation; however, it remains a high-risk sectorcharacterized by a significant number of fatalities and grave injuries. Among these risks, tower crane operationsstand out as a leading contributor to the heightened risk rate. This research paper endeavors to assess the safety risks inherent in tower crane operations at construction sites in Vietnam. This assessment is conducted from the perspective of various stakeholders involved in tower crane activities, namely managers, operators, and workers. To achieve this, a meticulously structured questionnaire utilizing a five-point Likert scale was formulated and distributed to gather insights from 78 proficient individuals engaged in tower crane-related tasks. The outcomes from all participants collectively underscore 21 distinct causes that give rise to safety risks during tower crane operations in Vietnam. Nonetheless, noticeable differences in opinions appear when looking at answers from managers, operators, and workers. The operators and workers showed that “Winds (wind intensity seriously affects the lifted load and tower crane itself)” are the most common safety risk. On the other hand, the managers highlighted the issue of whether the “Tower crane operator is an in-house staff member or outsourced” as their main concern. The managers, operators and workers showed that “Experience and skills of the operator during operating tower crane”, “Maintenance management degree of the tower crane and lifting aids”, and “Overhead power lines in the tower crane’s work region” are the most severe cause of safety risk, respectively. Operators and workers pointed out that the "Degree of maintenance management for tower cranes and lifting aids"has the highest safety risk level. However, managers highlighted that “Winds (wind intensity seriously affects the lifted load and tower crane itself)” pose the highest safety risk level.

ANALYSIS OF DYNAMICS AND OPTIMISATION OF TRANSIENT MOTION MODES OF HOISTING MECHANISMS OF OVERHEAD URBAN CRANES

The research of operating modes of hoisting mechanisms and machines, in particular, overhead and city-building cranes is carried out. Based on dynamic analysis of operating modes of mechanisms of the mentioned machines the character of load occurrence in their elastic elements (ropes) is established. The synthesis of optimum transient modes of operation (start/braking) of city-building and overhead cranes is carried out. The models of L.D. Landau and N.A. Lobov for physical and mechanical analysis of motion of the specified machines are used, on the basis of which with attraction of methods of classical calculus of variations the laws of motion of a cargo and a cargo carriage of similar cranes which optimize (minimize) inevitably arising pendulum oscillations of a cargo on a rope (as in the period of start-up of the crane, and at its braking, up to full stop) are received analytically. The evaluation of motion modes in the work is carried out by using a criterion with sub-integral functions in the form of "energy" of accelerations of higher orders (third, fourth, etc.). Exactly such criteria are used in the selection of modes of motion of lifting mechanisms of cranes of bridge/bridge-building type, which have in their composition elastic elements (ropes). The above approach makes it possible to achieve continuity of functions of velocities and accelerations of various links of the system, which leads to a significant reduction in their oscillations. The analysis of modes of motion of the system, which is described by the main coordinate of motion and elastic coordinates, allowed one to establish the regularity of using the proposed criterion to minimize the elastic vibrations of individual links (ropes) of the crane hoisting mechanism. The results of this study can be further used to clarify and improve existing engineering methods for calculating loads in flexible/elastic elements (ropes) of bridge and city-building cranes both in the design of hoisting mechanisms and in the modes of their real operation when mechatronic control systems are used in controlling the movement of the load carriage.

Automatic non-destructive UAV-based structural health monitoring of steel container cranes

Container cranes are of key importance for maritime cargo transportation. The uninterrupted and all-day operation of these container cranes, which directly affects the efficiency of the port, necessitates the continuous inspection of these massive hoisting steel structures. Due to the large size of cranes, the current manual inspections performed by expert climbers are costly, risky, and time-consuming. This motivates further investigations on automated non-destructive approaches for the remote inspection of fatigue-prone parts of cranes. In this paper, we investigate the effectiveness of color space-based and deep learning-based approaches for separating the foreground crane parts from the whole image. Subsequently, three different ML-based algorithms (k-Nearest Neighbors, Random Forest, and Naive Bayes) are employed to detect the rust and repainting areas from detected foreground parts of the crane body. Qualitative and quantitative comparisons of the results of these approaches were conducted. While quantitative evaluation of pixel-based analysis reveals the superiority of the k-Nearest Neighbors algorithm in our experiments, the potential of Random Forest and Naive Bayes for region-based analysis of the defect is highlighted.

Evaluation of different feedback designs for target guidance in human controlled robotic cranes: A comparison between high and low performance groups

Labour shortages and costly operator training are driving the need for digital on-board robotic crane operator support in forestry and construction. This simulator study investigated the effects of sonification (auditory, pitch/loudness) and continuous visual (brightness/size) feedback on aiming movements with a robotic crane for low and high performers. The feedback was designed non-linear and linear. Thirty-six participants controlled a robotic crane bimanually using joysticks across 320 movements. Performance and skill indicators (movement time, accuracy, trajectory, smoothness) as well as satisfaction, and usefulness were assessed. Low-performing participants showed higher movement accuracy, particularly with non-linear pitch feedback compared to visual feedback. High performers exhibited no significant performance improvement in movement time, accuracy, or smoothness. There was no effect of linear or non-linear mapping of the feedback. Additionally, perceived satisfaction was lower with auditory than visual feedback. These results suggest that real-time auditory feedback can enhance operator accuracy whereas acceptance remains challenging.

Optimal Positioning of Mobile Cranes on Construction Sites Using Nonlinear Programming with Discontinuous Derivatives

Mobile cranes represent conventional construction machinery that is indispensable for the erection of most prefabricated buildings, especially those containing heavy components. However, it is also common knowledge that the engagement of these machines has a significant influence on the environment, various social aspects of the construction process, and its economic benefits. Optimal positioning of the mobile crane on the construction site, primarily driven by the contractor’s interest to perform assembly operations with expensive machinery as effectively as possible, considerably reduces not only the costs of engaging such a machine but indirectly also its negative impacts on construction sustainability. This paper discusses an exact nonlinear model for the optimization task. The optimization model consists of a cost objective function that is subject to various duration and positioning constraints for the mobile crane, including bounds on its degrees of freedom of movement and stop positions. Because the model formulation includes discontinuous and non-smooth expressions, nonlinear programming with discontinuous derivatives (DNLP) was employed to ensure the optimal solution was reached. The model provides the mobile crane operator with exact key information that enables the complete and optimal assembly of the building structure under consideration. Additionally, the information gained on the optimal distribution of the mobile crane rental period to assembly operations allows for a detailed duration analysis of the entire process of building structure erection, which can be used for its further improvement. An application example is given in this study to demonstrate the advantages of the proposed approach.

Research on Repair Welding Method for Ground Rail of Stacker in Automated Cigarette Products Warehouse

As the most important equipment in the automated storage of cigarette product warehouses, the stacker is a machine used for automated operation of high-rise shelves in cigarette product automated warehouses. In order to ensure the safe operation of the stacker crane, it is necessary to promptly repair the ground rail when the local rail cracks. After completing general welding operations such as surfacing, the track cracks again after three days of operation, and the stacker crane makes a huge noise during operation. In order to quickly eliminate abnormal noise in the stacking function and prevent the track from cracking again in a short period of time, this article provides a repair welding method based on the ground rail of the cigarette finished product automated warehouse stacking machine. This method is a new method aimed at the rapid cracking of the track after general repair welding and the significant abnormal noise caused by the operation of the stacker crane.

Predicting degraded lifting capacity of aging tower cranes: A digital twin-driven approach

Aging tower cranes face an elevated risk of failure, primarily due to structural fatigue and deterioration. Surprisingly, the degradation of aging-induced lifting capacity (LC) remains an unexplored domain. In response to this research gap, this paper introduces a digital twin-driven (DTD) framework and model to predict the degraded LC of aging tower cranes. This framework combines theoretical and numerical analysis of fatigue and degradation behavior in tower cranes with real-time vibration data obtained during cyclic load scenarios on the actual cranes. Machine learning (ML) techniques are employed to develop a model that accurately predicts the degraded LC caused by aging. A scaled-down tower crane prototype is adopted as a demonstrative case to illustrate the feasibility and effectiveness of the DTD framework. The DTD model predicts the degraded LC of the prototype with high accuracy, achieving a mean-square error (MSE) of 0.2253 and a coefficient of determination (R2) of 0.9973. The predicted degraded load charts of the tested tower crane for each decade of usage from 0 to 70 years are also presented to assist crane operators in applying safe loads, preventing unexpected failures and damages, and enhancing workplace monitoring and safety. This study helps monitor the safety conditions of tower cranes that are aging and susceptible to structural fatigue and deterioration, facilitates the prediction of the deterioration of complex machines and systems in the construction industry with real-time data, and highlights the potential of DTD approaches in improving efficiency, safety, and decision-making.

A study on crane accidents: investigating the role of hand signals in construction site communication

Construction industry is one of the largest industries in the global economy. In today's construction industry, where time and profit margins are crucial, modern construction equipments plays a crucial role. Hand signals are frequently used by construction workers on the job site to communicate, as they are easy and effective. However, there can be a risk of miscommunication or misinterpretation with hand signals, resulting in mistakes and potential hazards on the construction site. This paper presents a comprehensive study on crane accidents in construction sites, with a particular focus on the communication between crane operators and signal men through hand signals. The study begins with a literature review on the causes and effects of crane accidents, statistics and incidents on construction sites. The study then investigates the current practices of hand signals on construction sites and highlights the associated safety concerns. The study concludes that the misinterpretation of hand signals between the signal man and the crane operator is a significant contributor to crane accidents. To address this issue, the paper recommends the development of a real-time hand signal detection system for material handling using machine learning and computer vision. The proposed solution will reduce the strain on signal men and improve communication between the signal man and the crane operator, thereby enhancing safety in construction sites. Keywords: Safety Study, Crane Accidents, Construction Sites, Human Error, Hand Signals, Material Handling, Construction Safety, Signal Man

Key Factors in Crane-Related Occupational Accidents in the Spanish Construction Industry (2012-2021).

The construction industry is one of the riskiest sectors worldwide, with crane operations being one of the most dangerous activities. The aim of this study was to gain insight into the key factors involved in crane-related occupational accidents in the construction industry in Spain. To this end, 1314 accidents involving cranes were analyzed from a total of 241,937 accidents that occurred in the construction of buildings. The data were collected from the Spanish government's occupational accident statistics corresponding to the years 2012-2021. The results evidenced a statistically significant relationship between cranes as the material agent and the size of the company, with 95% of cases corresponding to small- or medium-sized companies (less than 250 employees). Additionally, it shows how the crane operator is identified as a material contributor to crane accidents in the construction industry, and may be considered a key component to these accidents. In conclusion, improving the knowledge gained about the key factors in crane-related accidents at work in the construction industry provides essential information that helps to design and implement appropriate preventive measures to avoid the recurrence of unwanted events with these machines.

Modeling of operational reliability of running wheels of overhead cranes of seaports

Overhead cranes are widely in operation in sea and river ports for cargo transshipment in open and closed storage areas. Since they are the main link in technological processes, the productivity of Port production lines depends on their reliable and continuous operation. It is known that during the operation of cranes, 90% of the running wheels fail and are replaced with new ones due to intensive wear of the edges, and 60-70% of crane rails due to wear of their side faces. Since the service life is the main indicator of the durability of parts and assemblies, therefore, increasing the installation of wheel life is an urgent task, which will reduce the cost of repair and operation of cranes. As the experience of operation shows, running wheels have the most worn elements of movement mechanisms. Thus, their service life ranges from several months to 2-3 years. This is due to the fact that replacing the wheels is cheaper compared to replacing the crane track. Since the service life is the main indicator of the durability of parts and assemblies, therefore, increasing the installation of wheel life is an urgent task, which will reduce the cost of repair and operation of cranes. Analysis of studies of complex technical systems shows that the reliability of overhead crane mechanisms operated for more than 30 years in the Seaport is not fully understood, the nature of wheel damage depends on the operating conditions. For research, 4 identical overhead cranes with a lifting capacity of 10 tons were selected, which operate in Hook mode in seaports. Crane wheels are made of 65g steel by casting. Crane mechanisms were visually examined and wheel wear was measured after 3 months during 4 years of operation. Based on the research results, the parameters of the Wear model from time to time in the form of a step function are calculated. The obtained values of the correlation coefficient indicate that there is a fairly tight relationship between wear and operating time. The average error value for the proposed model does not exceed 6.1%, which is quite acceptable for engineering calculations. It is established that the service life of Crane wheels does not exceed 3.3...3.4 years of operation, which is less than 4 years specified by the manufacturer.

Snake optimizer LSTM-based UWB positioning method for unmanned crane.

Position determination is a critical technical challenge to be addressed in the unmanned and intelligent advancement of crane systems. Traditional positioning techniques, such as those based on magnetic grating or encoders, are limited to measuring the positions of the main carriage and trolley. However, during crane operations, accurately determining the position of the load becomes problematic when it undergoes swinging motions. To overcome this limitation, this paper proposes a novel Ultra-Wide-Band (UWB) positioning method for unmanned crane systems, leveraging the Snake Optimizer Long Short-Term Memory (SO-LSTM) framework. The objective is to achieve real-time and precise localization of the crane hook. The proposed method establishes a multi-base station and multi-tag UWB positioning system using a Time Division Multiple Access (TDMA) combined with Two-Way Ranging (TWR) scheme. This system enables the acquisition of distance measurements between the mobile tag and UWB base stations. Furthermore, the hyperparameters of the LSTM network are optimized using the Snake Optimizer algorithm to enhance the accuracy and effectiveness of UWB positioning estimation. Experimental results demonstrate that the SO-LSTM-based positioning method yields a maximum positioning error of 0.1125 meters and a root mean square error of 0.0589 meters. In comparison to conventional approaches such as the least squares method (LS) and the Kalman filter method (KF), the proposed SO-LSTM-based positioning method significantly reduces the root mean square error (RMSE) by 63.39% and 58.01%, respectively, while also decreasing the maximum positioning error (MPE) by 60.77% and 52.65%.

Some points when designing tower crane foundations

With the current construction requirements of high-rise buildings, the demand for tower cranes is increasing. It is a construction support device, which helps to transport materials in large quantities quickly and save time. Currently, in the country, the documents on the design, manufacture and safe operation of tower cranes are quite complete. However, there are no guidelines/standards on specialized construction design for tower crane foundations. The majority of construction engineers do not determine the complete and correct tower crane foundation calculation procedure. The selection of references for calculation is also not simple. Therefore engineers often rely on experience, not much in fact, to design. This leads to difficulties in design practice and costs. From the above actual needs, a draft of the tower crane foundation calculation has been compiled. Here are some issues to keep in mind when designing tower crane foundations.

HIRADC Analysis for Rolling Stock Body Lifting Ngrombo Railway Maintenance Center

The Railway Maintenance Center as stated in the Regulation has the duty and function of carrying out the maintenance of state-owned railway facilities. The part of rolling stock heavy maintenance with high potential hazard is Lifting Body Activities Using OHTC in Maintenance of Hydraulic Diesel Locomotive Facilities activity. it so there is a need for a risk assessment which is a process to determine control priorities for the level of risk work accident or occupational disease. Part of OHSAS 18001:2007 Clouse 4.3.1. recommendation HIRADC methode for can support a safety system with 3 stage analisys (hazard identification, risk assessment, and control determination) The Hazard Identification results obtained 3 aspects of hazard risk in OHTC Rolling stock Body Lifting operations with the following analysis results Crane toppling, Equipment failure, Load falling with Death & asset / property damage impact factor. Risk Assessment analisys of Rolling stock Body Lifting using OHTC obtained results action taken when resources are available regarding handling which in general were Administrative Control. Determine Control relevant steps to minimize potential hazards immediately (1) Evaluating SOP Rolling stock Body Lifting and conduct outreach to all employees related to the work, (2) Making and or adding hazard signs and (3) Human development by conducting Training/Refreshment Crane Operator and Signal man. (4) Strictness of the rules for using PPE for all employees related to the work as the last step in minimizing the risk of occupational hazards.

Multi-sensor integrated monitoring equipment and its application to dynamic compaction quality in construction

Due to high labor costs, low monitoring efficiency, and susceptibility to subjective factors, manual monitoring methods are gradually difficult to meet the needs of dynamic compaction construction development. To this end, we innovatively developed a vision-based intelligent monitoring equipment and its supporting systems, focusing on key indicators during construction (tamping points layout, tamping times and tamping settlement). By integrating technologies such as GNSS-RTK, computer vision and photogrammetry, we monitor the operation of the Dynamic Compaction Crane (DCC), track the motion of the hammer, so as to achieve automatic monitoring of dynamic compaction construction process to provide feedback for construction control. The field experiment verified the monitoring accuracy and practical feasibility of the intelligent equipment. The non-contact monitoring method can reduce the interference of manual monitoring on construction, greatly improve the construction efficiency, and provide more objective and accurate monitoring results.

Don State Technical University Experience of Enhancing Vocational Training of the Specialists in Organisation of Construction

Introduction. Professional requirements set for the specialists in organisation of construction (job foremasters and foremen) grow from year to year along with the emergence of new building technologies, materials, machines and equipment. After implementation of the new professional standards in our country, such specialists are urged to acquire the additional knowledge, abilities and skills necessary for fulfilling their job functions and activities in compliance with their proficiency level. Therefore, searching the ways of enhancing the vocational training of the specialists in organisation of construction has become the objective of the authors’ research.Materials and Methods. To achieve this objective, the authors have developed a series of additional activities for teaching the specialists in organisation of construction, based on improving the competencies required in their profession. This series of activities includes the initial, intermediate and final stages of vocational training. The initial stage is implemented during the first three years of bachelor and long first degree (specialist) programmes within direction of study “Construction” and the remaining two stages – during the last years of university study or after graduation.Results. The article presents the Don State Technical University experience of enhancing vocational training of the specialists in organisation of construction. The article contains the information on integration into the educational process of the photo and video tests, construction machines simulators, business games (including the ones on erecting the building structures out of the crane operator’s field-of-view), thematic references on difficult (challenging) issues of construction production, glossary of construction slang, as well as the information on organisation of the student scientific circle “Student construction control”.Discussion and Conclusion. The experience of enhancing vocational training of the specialists in organisation of construction accumulated by the authors is successfully implemented at the Continuing Education Department and the Production Technology in Construction Chair of Don State Technical University. It can be recommended for implementation in other universities where students of the direction of study “Construction” are educated.

Object Detection and Distance Measurement Algorithm for Collision Avoidance of Precast Concrete Installation during Crane Lifting Process

In the construction industry, the process of carrying heavy loads from one location to another by means of a crane is inevitable. This reliance on cranes to carry heavy loads is more obvious when it comes to high-rise building construction. Depending on the conditions and requirements on-site, various types of construction lifting equipment (i.e., cranes) are being used. As off-site construction (OSC) is gaining more traction recently, cranes are becoming more important throughout the construction project as precast concrete (PC) members are major components of OSC calling for lifting work. As a result of the increased use of cranes on construction sites, concerns about construction safety as well as the effectiveness of existing load collision prevention systems are attracting more attention from various parties involved. Besides the inherent risks associated with heavy load lifting, the unpredictable movement of on-site workers around the crane operation area, along with the presence of blind spots that obstruct the crane operator’s field-of-view (FOV), further increase the accident probability during crane operation. As such, the need for a more reliable and improved collision avoidance system that prevents lifted loads from hitting other structures and workers is paramount. This study introduces the application of deep learning-based object detection and distance measurement sensors integrated in a complementary way to achieve the stated need. Specifically, the object detection technique was used with the application of an Internet Protocol (IP) camera to detect the workers within the crane operation radius, whereas ultrasonic sensors were used to measure the distance of surrounding obstacles. Both applications were designed to work concurrently so as to prevent potential collisions during crane lifting operations. The field testing and evaluation of the integrated system showed promising results.