Crane Operation Research Articles

Experimental studies of the motion modes of the main boom and jib of loader crane

In order to increase the productivity and reliability of a hydraulic-powered loader crane, according to the normative-technical documentation regulating the safe operation of multi-link cranes, it is allowed to combine movements with the simultaneous movement of several links of the boom system. As a result, the paper considers a technique for conducting experimental studies in the plane of changing the boom system of a loader crane with a load. Experimental studies were carried out under the condition of simultaneous angular movement of the main boom and jib. To carry out experimental studies, an experimental installation of a hydraulic-driven loader crane was designed and manufactured. Measuring and recording equipment has been selected and adjusted. In the framework of experimental studies of the dynamics of movement of the boom system of a loader crane with a load, a control system for drive mechanisms has been developed, which makes it possible to realize the optimal modes of movement of the links of the boom system. As a result, experimental studies were carried out under the condition of simultaneous movement of the main boom and jib with a load at the end of the boom system. A package of data on real and optimal modes of movement of the links of the boom system of the loader crane was received. The processed data are presented in graphical form and a comparative analysis with real and optimal modes of movement is carried out. The developed method of experimental research has made it possible to determine the effect of the simultaneous movement of the boom and jib on the oscillations of the load, and the effect of the oscillations of the load on the dynamic loads arising in the boom system and the drive mechanisms of the loader crane.

Research on the application of target detection based on deep learning technology in power grid operation inspection

-External damage to power facilities caused by crane, excavator and other construction operations increases year by year, which will seriously threaten the safe operation of power system. It is an important measure to ensure the safe and reliable operation of power system to implement intelligent monitoring and early warning of power external breakdown through video and other non-contact observation means. The video data of power mainly comes from the fixed monitoring of helicopters, uavs and transformation poles and towers, which is characterized by large amount of data, complex scenes and serious environmental interference. The traditional target detection method usually selects the candidate area first, and then makes judgment based on the characteristics of human construction. The detection speed is slow and the accuracy is low, which makes it impossible to monitor the video data in real time, so as to make timely and accurate early warning and intervention fbr external damage. The target detection method based on deep learning optimizes or even eliminates the selection of candidate regions, which greatly speeds up the detection speed. By learning a lot of target samples through the deep neural network, the characteristics of high robustness are gradually fitted to make the target judgment more accurate. There are three key problems in introducing the target detection method based on deep learning into the power video detection: Firstly, the target detection method based on deep learning has a large amount of calculation and many parameters. In order to realize in-place operation on terminals with limited computing and storage capacity, it is necessary to find a practical method to simplify the network and reduce the amount of operational data in the detection process, which is the key to realize in-place operation and terminal operation of deep neural network. Secondly, for specific application scenarios, the effect of different target detection algorithms varies greatly, and there is a strong particularity of power video. Finding an effective target detection method is the key to improve the detection speed and accuracy. Finally, with the continuous development of deep learning, the structure of deep neural network changes with each passing day, and each has its own characteristics, which network structure is used as the feature extraction layer of target detection algorithm is the focus of research.

Assessment of Musculoskeletal discomfort for mobile crane operators

Workers seated in mobile cranes and operating for a prolonged period with an awkward posture are facing various ergonomic problems in the different body parts and particularly in the lower back. The research study purpose is to find an association of discomfort with the mobile crane operations. A discomfort study was carried out in a heavy equipment manufacturing industry where most of the mobile crane operators are continuously suffering from musculoskeletal discomfort in different body parts. Discomfort information was obtained with the help of a body part discomfort questionnaire during the various shift intervals from the start to the end of the shift. A total of 30 mobile crane operators of age from 21 to 59 years were made to participate. The study results reveals that, among the 30 mobile crane operators, 83.3% of operators reported discomfort in the lower back, and 20.0% reported in the upper back. In other parts, 23.3% to 63.3% of operators reported discomfort. Considering the severity level of discomfort reported by the operators, the highest discomfort is seen in the lower back and neck region. The operator’s age also has a significant influence on body discomfort sensed by mobile crane operators. Concluded that the main effected body parts are lower back and neck and the risk factors that may cause this discomfort are an awkward posture and whole-body vibration.

Spatial Sensing and Hazard Detection for Safe Crane Operation

Spatial Sensing and Hazard Detection for Safe Crane Operation

Detecting people around a suspended load using images for safe crane operation

Detecting people around a suspended load using images for safe crane operation

Discomfort in movable material handling equipment operation and its impact

Lot of troubles have been solved using mobile cranes, but affects lifting equipment workers’ safety and health. The goal of this article is to narrate the stage of distress of the mobile lifting equipment worker and entity muscle damage to the psychosomatic cause. Distress evaluation was conceded among the lifting equipment workers Seven various manufacturer’s cranes and 40 crane operators were taken for the examination. The operator’s compartment was studied in detail, the position of the seat, its height, width, seating, backrest, location of controls and pedals from seating etc., to find out the suitability of the compartment and comfort of the operation. The rate of recurrence, concentration of distress, and intervention intensity of suffering examined, 21.8% of the workers indicated distress one or two time, 27.4% face distress in a week 3 to 4 time, daily 34.4% experience distress, and 16.4% account distress a number of times in a day. The rate of recurrence and concentration of the distress in every body part is linked to the location of the controls. The ergonomically considered seats and gearshift can diminish distress of the worker, and improve on the whole protection and fitness.

XBLOC-PLUS: THE INTERLOCKING, PATTERN PLACED AND EFFICIENT ARMOUR UNIT

Most breakwaters are built with randomly placed single layer armour units as these are most cost-efficient. Most single layer blocks require random unit orientations, which requires the crane operator to assess the orientation of each individual unit during placement. DMC noticed the desire for an interlocking block which can be placed in a regular pattern as many crane operators find it easier to place units uniformly, which requires less intuition. Fifteen years after the introduction of Xbloc, DMC introduces a new interlocking breakwater armour unit called XblocPlus which is placed with uniform block orientations.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/oEb1vsYfjL8

Image-based onsite object recognition for automatic crane lifting tasks

The construction industry is suffering from aging workers and frequent accidents, as well as low productivity. Automation and robotics is regarded as a promising approach for enhancing the development of the industry, and the automatic operation of cranes, as an important aspect of construction, is attracting increasing attention. However, due to the complexity and dynamics of construction sites, it is difficult for cranes to automatically recognize and locate lifting objects (e.g., precast facades and partitions) on site. To solve this problem, an image-based automated onsite object recognition approach for the automatic operation of cranes is developed in this study. This is a fusion of Faster-R-CNN (Region-based Convolutional Neural Network), Canny, Hough Transformation, Endpoint clustering analysis and Vertex-based Determining Model, to uniquely locate a lifting object with exact pose and extract its features (e.g., centroid coordinates, size, and color). Based on the extracted features, the lifting object can be retrieved in the database with the IFC (Industry Foundation Classes) format of BIM (Building Information Modeling) to obtain more features for the automatic operation of a crane. It is shown from a field experiment that the developed approach is workable and has the potential to support the automatic operation of cranes. This contributes a basic approach to the automatic operation of cranes and promotes the rapid development of construction automation and robotics.

Vision-Based System for 3D Tower Crane Monitoring

Cranes play an important role in the industry sectors worldwide, such as construction, transport, shipping and cargo industry. For the safety of loading and unloading materials there are definitely ongoing improvements in the crane industry. However, there still remains issues related to the crane operation and control measures given by the pendulum swing while the crane is moving. To solve this problem a vision-based movement control of a 3 degrees of freedom (3 DOF) crane system, using both an analytical and experimental models based on displacements and adaptive optimization algorithms was proposed. The framework consists of three steps, more precise recognition, detection and tracking a set of targets within the image to compute the payload displacement. A prepossessing process was applied in order to enhance the image improving both the color information and the edge extraction task. Then, a set of targets within the image were detected to estimate the displacement. Then to solve the problem given by the displacement, a tracking task was implemented using a second order filter. This paper introduces a new strategy to determine the relationship between the movement of the spin in the jib and position of the markers within the image. Regression analysis was carried out to take into account the motion of the cart and the payload. In Results Section is shown a set of real-time experiment, obtaining euclidean errors of 1.41 pixel, 2 pixels and 3.16 pixels for Cart, Jib and Hoist, respectively.

СТАТИСТИЧНИЙ АНАЛІЗ РЕЗУЛЬТАТІВ ГЕОДЕЗИЧНИХ ЗЙОМОК КОЛІЙ МОСТОВИХ КРАНІВ У ВИРОБНИЧИХ БУДІВЛЯХ

Abstract. The studies were carried out in order to develop effective methodology for the statistical analysis of the results of geodetic surveys of the rails of overhead cranes. The findings will provide generalization of the measurement results, demonstration of their changes over time, as well as comparison with the permissible values of deviations from the design position. The analysis includes the results of geodetic surveys of the position of the rails of overhead cranes in machine-building shops during four years. The position of the heads of the crane rails was determined using a level, a transit theodolite, and a laser sight. In accordance with the requirements of regulatory documents for the operation of overhead cranes, three parameters of the position of the crane rail heads were controlled: the height difference on adjacent pillars of the same row; height difference on pillars of different rows in one transverse frame; deviation of the distance between the rails from the design value. The controlled parameters are random variables that should be analyzed by statistical methods. Deviations of the distance between the axes of the crane rails from the design value are presented in the form of a random variable with the normal distribution law. The differences in the elevation marks of the heads of the crane rails, which are monitored without taking into account the sign, are described by the distribution law of the modulus of a random variable. As a generalized characteristic of the state of crane rails, it is proposed to use the probabilities of horizontal and vertical deviations of the crane rails beyond maximum permissible values established by the norms. Based on the results of the research, conclusions were drawn about the need for systematic control of the position of overhead crane rails by geodetic methods, the applicability of the above distributions for the probabilistic description of deviations of crane rails from the design position, as well as the feasibility of using the probability of deviations of the crane rails geometry beyond the permissible values established by the norms.

Automated replacement scheme of DC transformer bushing based on laser scanning profile: Design and experiment

The valve-side bushing is an important part of the ultra-high voltage (UHV) converter transformer. The bushing needs to be replaced at the converter station if the bushing is damaged. The bushing replacement of the existing project needs to be carried out by crane and manual operation. However, the replacement process takes a long time and the lifting accuracy is poor, which may cause damage to the bushing. A scheme based on a 2D laser profile scanner for automatic bushing replacement applied to direct-current (DC) converter transformer is proposed in this paper, which can replace any damaged bushing in the valve hall without removing other equipment. An initial value of the cylinder fitting algorithm based on the 2D laser profile is proposed in order to solve the position of the bushing, which fully considers the characteristics of the laser profile scanner, and uses the circle and straight-line fitting algorithm to solve the initial value. It is proved that the algorithm can improve the efficiency of cylinder fitting by comparing with the results of the mean value method. Industrial robots are used to implement the replacement scheme by using this algorithm, and the feasibility of the replacement scheme is verified.

Co-Design of a Playful Mixed Reality Installation: An Interactive Crane in the Museum of Marble Crafts

Interactive installations in museums usually adopt hybrid technologies that combine physical elements with digital content, and studies so far show that this approach enhances the interest and engagement of visitors compared to non-interactive media or purely digital environments. However, the design of such systems is complicated, as it involves a large number of stakeholders and specialists. Additionally, the functional components need to be carefully orchestrated to deliver a rich user experience. Thus, there is a need for further research on tools and methods that facilitate the process. In this paper we present the design and development of a mixed reality installation for the Museum of Marble Crafts in Tinos island in Greece, which places visitors in the role of the crane operator and they have to complete challenges in a gamified version of the old quarry. The system lets users operate a tangible controller and their actions are executed by digital workers in a rich 3D environment. Our design approach involved iterative prototyping, research and co-design activities. The creative process has been supported by a series of organized workshops. The evaluation results indicate that mixed reality can be a promising medium for rich interactive experiences in museums that combine tangible and intangible heritage.

Assessment of occupational health risk for employees of the main occupations of aluminum production

Introduction. The Russian aluminum industry is one of the world’s leading producers of aluminum. At the same time, the features of aluminum production technology contribute to the formation of unfavorable working conditions and increased risk to the health of workers. In this regard, an urgent but insufficiently studied issue in the production of aluminum is the assessment of occupational risks that establish the likelihood of health disorders in workers. Material and methods. The basis of the assessment of occupational risks was the existing regulatory documents (Guidelines) issued by the Federal Center for Hygiene and Epidemiology of Russian Consumer Health and Epidemiology. Existing methodical recommendations and medical technologies were used to calculate occupational risks and allowable working time (experience) under the chemical factor. The values of the annual volume of the air inhaled by the individual of the production environment and the average annual concentrations of toxicants, determined in the air of the working zone of the employees of the main occupational groups, were used. Occupational risk calculations were carried out over a period of 25 years. The total risk assessment for individual occupational groups was conducted under the probability (risk) rule calculated for individual chemicals. Results. Studies have found the average annual concentrations of harmful substances in the air of the working area over the past 5 years to be significantly lower when using the upgraded electrolysis technology (UET) compared to the traditional technology of self-burning anodes (SBA). The exception was hydrofluoride, whose concentrations did not depend on the technologies used, exceeding the MPC by 1.7 - 3.0 times. The total health risk for employees of the main occupations over a period of 25 years was in the range of 7.2 to 22.1% when using SBA, which is almost 2 times higher than when using UET (from 3.7 to 11.6 %). The highest levels of risk were observed in the group of workers using SBA and operators of electrolysis baths with UET, and the lowest - in the crane operators using both technologies. Conclusion. The use of indices of occupational risk and acceptable working hours under the influence of adverse production factors allows identifying a contingent of employees with an increased level of exposure to occupational hazards. Based on the obtained data, it is possible to predict the levels of occupational morbidity and evaluate the effectiveness of measures to improve working conditions, which plays an important role in managing occupational risk.

Експериментальні дослідження режимів руху крана-маніпулятора з вантажем при суміщені рухів

In order to increase the productivity and reliability of a hydraulic-powered loader crane, according to the normative-technical documentation regulating the safe operation of multi-link cranes, it is allowed to combine movements with the simultaneous movement of several links of the boom system. As a result, the paper considers a technique for conducting experimental studies in the plane of changing the boom system of a loader crane with a load. Experimental studies were carried out under the condition of simultaneous angular movement of the jib and a decrease in the linear movement of the telescopic section. To carry out experimental studies, an experimental installation of a hydraulic-driven loader crane was designed and manufactured. Measuring and recording equipment has been selected and adjusted. In the framework of experimental studies of the dynamics of movement of the boom system of a loader crane with a load, a control system for drive mechanisms has been developed, which makes it possible to realize the optimal modes of movement of the links of the boom system. As a result, experimental studies were carried out under the condition of the simultaneous movement of the jib and the telescopic section with a load at the end of the boom system. A package of data on real and optimal modes of movement of the links of the boom system of the loader crane was received. The processed data are presented in graphical form and a comparative analysis with real and optimal modes of movement is carried out. The developed method of experimental research has made it possible to determine the effect of the simultaneous movement of the boom and jib on the oscillations of the load, and the effect of the oscillations of the load on the dynamic loads arising in the boom system and the drive mechanisms of the loader crane.

Examination of erection safety of precast beam assembly using a slanted beam section based on assembly test

ABSTRACT Assembling precast frames subjected to heavy construction loads may require a significant crane operation time when they were assembled by conventional steel joints having a straight beam cut. This study proposed a method that will provide a facile and rapid assembly of heavy precast frames, having the temporary bolting be established as noncritical path. Lower flanges of wide flange beam installed at end of precast beams were partially removed to prevent bottom flange of steel beam from running into flanges of L-shaped guide pockets when steel beam was inserted in L-shaped guide pockets. Permanent connections are made by bolting L-shaped guide pockets. Stable behavior was observed during an erection test of the proposed connection. This study also aimed to investigate an assembly safety of steel beam-column joints with a skewed beam section based on a nonlinear finite element analysis. Strain and stress analysis also demonstrated that stable structural behavior of joint elements was ensured during an assembly of precast frames.

A digital twins concept model for integrated maintenance: a case study for crane operation

The paper presents an Integrated Maintenance Decision Making Model (IMDMM) concept for cranes under operation especially into the container type terminals. The target is to improve cranes operational efficiency through minimizing the risk of the Gantry Cranes Inefficiency (GCI) results based on the implementation of the Digital Twins concept for maintenance purposes. The proposed model makes a joint transportation process and crane maintenance scheduling, relevant to assure more robust performances in stochastic environments, as well as to assess and optimize performances at different levels, from components and transport device to production systems (container terminal). The crane operation risk is estimated with a sequential Markov chain Monte Carlo simulation model and the optimization model behind of IMDMM is supported through the Particle Swarm Optimization algorithms because the objective function a non-linear stochastics problem with bounded constrains. The developed model allows the container terminal operators (management process) to obtain a maintenance schedule that minimizes the GCI (holistic indicator), as well as establishing the desired level of risk. The paper demonstrates the effectiveness of the proposed maintenance decision making concept model for cranes under operation using data from of a real container terminal (case study).

Economical Auto Moment Limiter for Preventing Mobile Cargo Crane Overload.

This study presents a computational method called economical auto moment limiter (eAML) that prevents a mobile cargo crane from being overloaded. The eAML detects and controls, in real time, crane overload without using boom stroke sensors and load cells, which are expensive items inevitable to existing AML systems, hence, being competitive in price. It replaces these stroke sensors and load cells that are used for the crane overload measurement with a set of mathematical formula and control logics that calculates the lifting load being handled under crane operation and the maximum lifting load. By calculating iterative them using only a pressure sensor attached under the derrick cylinder and the boom angle sensor, the mathematical model identifies the maximum descendible angle of the boom. The control logic presents the control method for preventing the crane overload by using the descendible angle obtained by the mathematical model. Both the mathematical model and the control logic are validated by rigorous simulation experiments using MATLAB on two case instances each of which eAML is used and not used, while changing the pressures on the derrick cylinder and the boom angle. The effectiveness and validity of the method are confirmed by comparing the outputs obtained by the controlled experiments performed by using a 7.6 ton crane on top of SCS887 and a straight-type maritime heavy-duty crane along with eAML. The effects attributed to the load and the wind speed are quantified to verify the reliability of eAML under the changes in external variables.

An exact algorithm for the unidirectional quay crane scheduling problem with vessel stability

This paper addresses the quay crane scheduling problem (QCSP) with vessel stability constraints. Vessel stability is essential to improve quay crane operations in container terminals, but it significantly complicates the basic QCSP and the corresponding solutions methods. We describe a novel mathematical formulation for the unidirectional QCSP with vessel stability, and we propose an exact algorithm based on logic-based Benders decomposition to solve the problem efficiently. The problem is decomposed into two subproblems, e.g., a task-assignment master problem without vessel stability constraints, and a time-allocation problem, aimed at determining the operation time of each task under the premise of the vessel stability requirements. The proposed algorithm is tested on benchmark instances derived from the literature, and the effectiveness of the proposed model and solution approach is demonstrated.

Organization of propaganda for the safe work production of a signaller and an automobile crane operator

Violations of the labor safety regulation and disregard of the rules concerning work performance are the main causes of industrial accidents. Labor safety propaganda should be organized at each enterprise. Propaganda teaches workers to have clearly perceived need to comply with the requirements for safe work performance, and is also an integral part of injury prevention. The paper presents the results of improving the safety of the work of the signaler and an automobile crane operator by means of promoting labor safety. The main traumatic factors for the above professions were identified. They are: the work of the machine operator, not performed at the signal of the signaler; work with a faulty safety lock, as well as work with faulty safety devices and faulty equipment; unloaded cargo at the end of work and during work breaks, excess load capacity; performance of works when there are people in the danger zone (unfenced territory), and as a result, presence of the injured person in the danger zone of the crane work; contact with electric current, in the absence of grounding of the crane. For each identified factor, a poster was developed reminding of the need to comply with labor safety rules. The developed posters were introduced into production during the operation of automobile cranes in the Izhevsk branch of Federal State Unitary Enterprise “Main Military Construction Directorate No. 7” (FGUP “GVSU No. 7”).

RETRACTED: Optimization of storage location assignment in automated warehouse

To effectively manage the automated warehouse, aiming at the optimization of goods location assignment, an optimization function for the assignment of storage location was established with the shelf stability and access efficiency as the goal according to the principle of storage space allocation. To optimize the picking location of the roadway stacker when exiting the warehouse, a mathematical function model was established by analyzing the picking strategy of the warehouse delivery operation. The research results showed that the optimization of the cargo space and the optimization of the stacker crane operation route can improve the overall operating efficiency. It is concluded that the model can reduce the cost of goods handling and storage, the time lost in the storage process and handling process, thereby decreasing logistics costs and increasing revenue.