Load Lifting Research Articles

Investigate the impact wear failure behavior of CoMoCr engine valve and valve seat pairs under harsh conditions

The wear of sealing face is one of the main reasons for the failure of engine valve and valve seat pair. Changes in engine combustion load, running time, temperature, and other operating conditions can affect the wear of valve-valve seat pair. In this work, the CoMoCr alloy cladding valves and valve seat were used as the pair, to investigate the influencing mechanism of combustion load and valve lift on wear. Three groups of tests under different combinations of combustion loads and valve lifts were completed on self-designed testing rig. The results demonstrate that the increase of combustion load and valve lift exacerbate the wear of the valve and valve seat, and valve lift has a more significant effect on wear than combustion load. The increased combustion load worsens the microslip process and intensifies the abrasive wear process. Whereas valve lift enhances the impact process, causing the dense tribofilm on the material surface to delaminate due to fatigue. Destruction of the tribofilm prevented effective protection of the underlying material, which increased wear process.

Modelling and dynamic analysis of a synchropter

This paper addresses the flight dynamics modeling, trim, and dynamic analysis of an intermeshing-rotor helicopter, indicated as synchropter. This configuration has gained a great interest for its suitability within heavy load lifting and transportation in extreme high temperature and altitude, and other harsh environments. The paper presents some relevant features related to synchropter's flight dynamics modeling of the interference between its two tilted main rotors. Trim results show the advantage of the synchropter in forward flight where the yawing moment is naturally balanced at almost all speeds and no lateral-directional compensation is needed. The synchropter's dynamic stability shows similarity to a conventional helicopter in the longitudinal phugoid. However, in the lateral phugoid, the synchropter is unstable at all flying speeds and therefore its vertical fin needs to be carefully designed.

Prevalence of Musculoskeletal Disorders in Railway Employees: A Survey Study

Background: Work-related musculoskeletal disorders (WMSD) related with repetitive and demanding working conditions continue to represent one of the biggest problems in industrialized countries. The railway employees have high possibility of showing musculoskeletal pain due to repetitive motions, lifting heavy loads, awkward posture which leads to bending and twisting injuries and static posture for long duration during. Aim and Objective: To determine the prevalence and risk factors of musculoskeletal disorders in railway employees. Methodology: The study was conducted among 100 railway employees. The data was collected using self-administered Questionnaire, Nordic Musculoskeletal Questionnaire and Perceived Stress Scale. Both male and female employees having at least 1 year of experience were includes. Result and Conclusion: the 12-month prevalence of musculoskeletal disorders among railway employees was 79%. Low back pain (26.6%) was found to be most prevalent followed by neck pain (22.8%) and knee pain (20.3%). The Gangmans/trackmans and Sahayaks were identified to have maximum impact which led to WMSDs. The occurrence of MSD was associated with factors such as age, nature of work, working hours, lifting, and lowering heavy loads, working at pace set by machine and prolonged standing. Thus, education about ergonomics and body posture awareness would be instrumented in prevention of MSDs, thus are recommended. Keywords: Prevalence, Musculoskeletal Disorders, Risk Factors, Railway Employees.

Assessing the Short-Term Effects of Dual Back-Support Exoskeleton within Logistics Operations

Logistics activities involve significant risk factors for the development of work-related musculoskeletal disorders (WMSD), particularly low back pain. Exoskeletons have emerged as potential solutions to mitigate these risks. This study assesses the short-term effects of dual passive back-support exoskeletons (Auxivo and Htrius) on WMSD risk factors in logistics operations. Two workstations were evaluated using self-report ratings, postural assessment, and surface electromyography (EMG). The results indicate that both exoskeletons provided relief and support during tasks, with Htrius showing a slight advantage. Exoskeletons reduced perceived exertion, especially during trunk flexion tasks, and improved posture, particularly in tasks involving manual lifting loads at lower height levels. While variations in muscular activity were observed, the Htrius exoskeleton showed a trend of reducing lumbar muscle activity. Overall, Htrius demonstrated promise in improving workers’ comfort, safety, and efficiency, potentially reducing WMSD risk and muscular fatigue. However, individual preferences and workplace-specific characteristics should be considered when selecting exoskeleton models. Future research should explore the effects on different loads, genders, and EMG of different muscles to further enhance the understanding and application of exoskeletons in occupational contexts.

Analysis of structures and movement parametres of self-climbing platforms and development prospects

Introduction. For high-rise building construction self-climbing platforms based on hydraulic drive are used, lifting the formwork for monolithic structures. These lifting mechanisms differ in structures, characteristics and parameters. There is a need to introduce high-tech equipment in the industry. To create self-climbing platforms for high-rise construction, it is necessary to conduct research in the field of operation of lifting vehicles.Materials and methods. Platforms based on climbing profile for the analysis were used. The design features of the specified type of platforms were considered. The main parameters were speed of lifting, maximum lifting height and load capacity.Results. Graphical data on the main structural elements and the lifting process were obtained the specified type of platforms. Graphical data on hydraulic system is provided and the mechanism of movement is considered in detail. The basic formulas for determining the platform lifting speed and maximum load capacity required for the choosing of specified lifting vehicles.Discussion and conclusion. Existence of factors affecting the lifting speed of platforms and their maximum load capacity provides grounds for the development of a method for calculating and designing the considered transport and technological equipment in Russian Federation. One of the ways to develop this lifting equipment is integration of accessory mechanisms into their structure for fulfilling additional works during the construction of high-rise buildings, in this way forming a single transport and technological complex.

Integrating physics-based simulations with gaussian processes for enhanced safety assessment of offshore installations

Installing large floating objects during offshore operations is a challenging and failure-prone task, especially when passing through the splash zone due to extreme lifting loads on the wire and the payload. For a safe operation, it is essential to predict the peak loads on the installation system and create an early decision-making scenario for the installation vessel before starting the real operation on site. To this end, the extreme loads that can lead to unsatisfactory performance of the system must be evaluated accurately; however, the operation involves a great deal of uncertainty and physics complexity that can lead to unreliable decision-making. It is also challenging to perform numerical calculations to support ongoing marine operations, as it usually takes hours to evaluate different environmental load cases. Thus, it is essential to create an efficient prediction method associated with the environment and the corresponding response levels. In this study, a model is proposed that integrates physics-based simulations with Gaussian Processes, for estimating peak loads in lifting wires. The model offers the advantage of addressing shorter simulation times while still maintaining accuracy in predicting extreme response levels and quantifying the loads uncertainty during the operation. Bayesian Inference is used to incorporate the uncertainty, estimating hyper-parameters and predict the peak loads for various marine environmental conditions. A real case study is considered to demonstrate the application of the proposed model. The results show good agreement with the simulations obtained from time-domain dynamic analysis. The current study provide insights for both onboard and pre-planned decision-making on installation conditions, thereby enhancing predictive accuracy and improving safety in complex marine lifting operations.

Lift modeling, load and vibration analysis of Magnus rotors

The method of theoretical combined with numerical simulation is employed to study the lift model and the optimal position of viscoelastic supports for the rotating cylindrical sail (short for Magnus rotor or rotor sail). Initially, using a numerical simulation method to modify the Magnus rotor lift model established based on the Kutta-Joukowski theory obtained a lift/drag model for the rotor. Subsequently, the lift/drag model is utilized as an external load, considering the rotor as a rotating cantilever beam with fixed support at one end. The finite element method is employed to study the vibration characteristics of the drive shaft under external excitation, analyzing the deflection characteristics of the cantilever beam, the stiffness of elastic support, and the span variation on the vibration characteristics of the drive shaft for different cross-sectional radii. Finally, for the investigated large-scale Magnus rotor, a modified lift model and the optimal design position for viscoelastic supports and the dimensions of the drive shaft are provided. Simulation results demonstrate that by appropriately adding viscoelastic supports to the structure, the vibrational deflection of the drive shaft's steady-state response can be significantly suppressed.

Фундаментальний аналіз та оптимізація (мінімізація) динамічних навантажень у пружних елементах механізмів підйому вантажу кранів. Частина І

The fundamental analysis and optimization (minimization) of dynamic loads in elastic elements (ropes) of load lifting mechanisms of cranes used in urban development is carried out. The basis of the analysis and methodology of optimization of motion modes of the mentioned mechanisms is the approach implemented in the classical calculus of variations, namely: the integral functional is minimized, which reflects undesirable properties of the mechanical system. Optimized modes of motion of the crane load lifting mechanism, which is represented in the paper by a mechanical system with a linear function of the position of its elements (the load on the rope and the drive mechanism). The significant influence of motion modes of exactly drive mechanisms on dynamic loads in elastic elements (ropes) of the load lifting mechanism of a city-building crane is shown. Usually separate typical modes of motion optimize only one certain property of the specified mechanism. In many practical cases, it is necessary to select modes of motion that optimize a set of properties of a machine or mechanism (respectively, a crane or a load lifting mechanism of a city-building crane). It is for the selection of such modes of motion of machines and mechanisms that dynamic criteria for their evaluation are needed. All existing criteria for evaluating machines and mechanisms can be conditionally divided into two classes: 1) positional (maximum values of kinematic characteristics of links, dynamic loads, amplitudes and frequencies of oscillations, dynamics coefficients, etc.); 2) integral (rms values of kinematic characteristics of links and dynamic loads, energy costs, etc.). In the work the fundamental analysis of the mentioned criteria is carried out and it is shown that for estimation of motion modes of hoisting machines, as well as mechanisms of cargo lifting cranes (boom, bridge, gantry, city cranes) it is necessary to use integral criteria, because they are the ones that estimate motion during the whole cycle. Integral criteria for evaluating urban construction cranes and load lifting mechanisms are presented, which fully reflect their dynamic properties, motion characteristics and, in particular, minimize dynamic loads on elastic elements (ropes). The results obtained in this study can be further used to clarify and improve the existing engineering methods of calculation of hoisting cranes used in urban planning, as well as their load lifting mechanisms, both at the design stages and in the modes of proper operation.

Фундаментальний аналіз та оптимізація (мінімізація) динамічних навантажень у пружних елементах механізмів підйому вантажу кранів. Частина ІІ

A scientifically substantiated methodology of optimization of motion modes of machines and mechanisms (in particular, city-building cranes) based on minimization of integral functionals, which reflect undesirable properties of mechanical systems, and terminal (initial/final) conditions of motion of the mechanism of lifting cargoes by cranes have a physical meaning and are based on Newton's laws of mechanics, is proposed. The modes of motion of specific mechanical systems with a linear function of the position of elements are optimized on the example of mechanisms of load-lifting city-building cranes. It is shown that the influence of motion modes of drive mechanisms on dynamic loads in elastic elements of the mechanism of lifting mechanism of a city-building crane (ropes) is essential. The parameters of such modes of functioning/movement of such systems, at which exactly dynamic stresses of ropes at the stages of start-up of mechanisms of lifting mechanism of cranes are minimized, are determined. The results obtained in the work can further serve to clarify and improve the existing engineering methods of calculation of load lifting mechanisms of urban cranes in order to minimize the dynamic stresses of their rope systems at the start-up stage, as well as to prevent the occurrence of possible emergency situations. Such an approach can be realized both at the stages of design of the mentioned mechanisms and in the modes of proper operation.

Capability of Machine Learning Algorithms to Classify Safe and Unsafe Postures during Weight Lifting Tasks Using Inertial Sensors.

Occupational ergonomics aims to optimize the work environment and to enhance both productivity and worker well-being. Work-related exposure assessment, such as lifting loads, is a crucial aspect of this discipline, as it involves the evaluation of physical stressors and their impact on workers' health and safety, in order to prevent the development of musculoskeletal pathologies. In this study, we explore the feasibility of machine learning (ML) algorithms, fed with time- and frequency-domain features extracted from inertial signals (linear acceleration and angular velocity), to automatically and accurately discriminate safe and unsafe postures during weight lifting tasks. The signals were acquired by means of one inertial measurement unit (IMU) placed on the sternums of 15 subjects, and subsequently segmented to extract several time- and frequency-domain features. A supervised dataset, including the extracted features, was used to feed several ML models and to assess their prediction power. Interesting results in terms of evaluation metrics for a binary safe/unsafe posture classification were obtained with the logistic regression algorithm, which outperformed the others, with accuracy and area under the receiver operating characteristic curve values of up to 96% and 99%, respectively. This result indicates the feasibility of the proposed methodology-based on a single inertial sensor and artificial intelligence-to discriminate safe/unsafe postures associated with load lifting activities. Future investigation in a wider study population and using additional lifting scenarios could confirm the potentiality of the proposed methodology, supporting its applicability in the occupational ergonomics field.

The relationship between the level of postural stress, Musculoskeletal Disorders, and chronic fatigue: A case study in the dairy industry.

Dairy industry workers face numerous ergonomic risk factors in their workplace, including improper posture, manual material handling, and musculoskeletal disorders (MSDs). Fewstudies have been conducted on the correlation of postural stress, MSDs, and chronic fatigue among workers in the dairy industry. This study aimed to investigate the relationship between the level of postural stress, MSDs, and chronic fatigue in a dairy company. In this cross-sectional study, 260 male workers were included in the research based on specific inclusion criteria. The Cornell Musculoskeletal Discomfort Questionnaire, Chalder Fatigue Scale, and a researcher-made demographic questionnaire were used to collect data. The posture of workers was evaluated using RULA and REBA software, and the evaluation of the manual lifting of loads was assessed using the WISHA lifting calculator. Finally, the collected data were entered into the SPSS software version 26.0 and analyzed. The findings revealed a significant statistical relationship between the level of postural stress and chronic fatigue and a significant positive correlation between MSDs and chronic fatigue. Furthermore, a statistically significant relationship was observed between MSDs, chronic fatigue, and ergonomics training experience. The results obtained in this study support the notion that high levels of postural stress and MSDs can produce an increase in chronic fatigue among workers, and lack of ergonomics training for workers can increase both MSDs and chronic fatigue. Therefore, it is necessary to carry out intervention measures in the field of ergonomics management in similar industries through the implementation of ergonomic intervention programs with a focus on proactive and preventive measures and the use of participatory ergonomic programs and educational demands assessment.

Design and fabrication of bioinspired pattern driven magnetic actuators

Additive manufacturing (AM) has drawn significant attention in the fabrication of soft actuators due to its unique capability of printing geometrically complex parts. This research presents the design and development of an AM process for bioinspired, deformable, and magnetic stimuli-responsive actuator arms. The actuator arms were fabricated via the material extrusion-based AM process with magnetic particle-polymer composite filaments. Inspired by the rhombus cellular structure found in nature, different design parameters, such as the line width of the interior rhombus sides, and 3D printing parameters were studied and optimized to fabricate actuator arms that exhibit enhanced flexibility while being magnetically actuated. The trigger distance and deformation experiments revealed that the width of the rhomboids’ sides played a critical role in magnetic and bending properties. It was found that the sample with a line width of 550 µm and printing layer thickness of 0.05 mm had the maximum deflection with a measured bending angle of 34 degrees. The magnetic property measurement exhibited that the sample with a line width of 550 µm showed the maximum magnetic flux density of 3.2 mT. The trigger distance results also supported this result. A maximum trigger distance of 8.25 mm was measured for the arm with a line width of 550 µm. Additionally, tensile tests showed that the sample exhibited a 17.7 MPa tensile strength, 1.8 GPa elastic modulus, and 1.3% elongation. Based on these results, we successfully fabricated a 3D printed magnetic gripper with two rhombus cellular structured arms which showed grasping and extensive load lifting capability (up to ∼140 times its weight).

Effects of stretching exercises on muscle tension, fatigue, strength, and lactic acid accumulation: A pre-experimental study among fish transport workers.

Fish transport workers in Indonesia lift loads more than the specified limits, both in weight and frequency. This could cause lactic acid accumulation, fatigue and reduced physical performance. The aim of this study was to assess the effect of stretching intervention on muscle tension, fatigue, strength, and lactic acid level in fish transport workers in Indonesia. A pre-experimental study design with one group (pre- and post-test) design was conducted among male fish transport workers at the Tawang fish auction, Weleri, Central Java, Indonesia, in June 2022 for two weeks. We created a 1.5-minute stretching exercise video based on the University of New Castle's Manual Handling guideline, involving hand, feet, and shoulder movements. Participants performed these exercises independently before and during work every two hours, guided by the video. Data on lactic acid, muscle tension, fatigue, and strength were collected before and after the 2-week intervention. Data analysis was performed using Wilcoxon and paired Student t-tests to compare the outcome between post- and pre-intervention. A total of 18 fish transport workers were included in the study. The results showed a statistically significant increase in lactic acid levels following the intervention (p=0.016). However, the increase in muscle tension was not statistically significant (p=0.292). There was a significant increase in fatigue levels after the intervention (p=0.000). This could suggest that the stretching intervention may have had an unintended effect of increasing fatigue among the participants. On the other hand, there was a statistically significant decrease in muscle strength after the intervention (p=0.003). In conclusion, this study suggests that while stretching exercises can affect lactic acid accumulation, fatigue, and muscle strength, they do not influence muscle tension. Therefore, it is advised for workers to incorporate stretching exercises into their daily routine to mitigate potential injury risks.

Design and Development of a Screw Jack: An Input Repair Tool for Light Vehicles

This study introduces an innovative investigation into the development and utilization of a specially designed jack screw tailored for lifting lightweight objects. While screw jacks are well-established for their efficacy in mechanical lifting applications, this research aims to broaden their adaptability by specifically addressing the unique demands of lifting lighter loads. The exploration encompasses a thorough examination of the design principles, materials, and operational facets associated with the proposed screw jack innovation. The primary impetus behind this research is to fill an existing void in lifting solutions that are customized to the requirements of tasks involving light objects. By delving into the intricacies of screw jack design, the study seeks to improve the efficiency and safety of lifting operations in diverse contexts, such as small-scale workshops, where precision and controlled lifting of lighter loads are crucial. Anticipated outcomes of this study include the development of a specialized screw jack prototype that provides a dependable, cost-effective, and ergonomic solution for lifting light objects. The research findings aim to contribute valuable insights to the fields of mechanical engineering and lifting technology, laying the groundwork for further advancements in the design and application of lifting devices tailored to specific load requirements. Based on the study's findings, the following conclusions were drawn: the device effectively raises objects with a 2-ton capacity, its safety has been successfully verified, and the materials used are locally available. However, it is essential to note that this design is limited to light loads. Therefore, in applications requiring a screw-type mechanical jack for heavy loads, a different design is necessary. Recommendations include adherence to the device's capacity, implementation of safety measures to prevent accidents during operation, and potential modifications for further enhancement in future research endeavors.

Structural assessment of 40 ft mini LNG ISO tank: Effect of structural frame design on the strength performance

Abstract Due to the escalating demand for liquefied natural gas (LNG) as a low-emission and environmentally friendly energy source, ISO tank containers have emerged as an innovative solution to facilitate efficient and cost-effective mass transportation. The 40 ft ISO tank container, which encompasses a pressure vessel structure, is a versatile intermodal unit that seamlessly integrates into sea and land transportation networks. The main objective of this study is to present a comprehensive analysis for assessing the various frame design scenarios of the 40 ft ISO tank container for mini LNG carrier operation. The assessment is conducted under the provisions outlined in ASME Section VIII Division I code, which governs the design standards for boilers and pressure vessels. The finite-element analysis (FEA) scrutinizes three different structural design alternatives: frame thickness, the addition of support plates, and the addition of saddle supports, which are subjected to various loading conditions: stacking, lifting, and racking load tests. The analysis offers a comparative assessment of the safety level provided by the ASME design guidance in contrast to the FEA judgments based on ISO standards. It can be found that stacking and longitudinal load tests are more critical operational load scenarios. Increasing the frame thickness of the LNG ISO tank is more practical in increasing structural weight savings than adding more saddle supports and support plates.

ДОСЛІДЖЕННЯ ПЕРЕДАТНИХ ВІДНОШЕНЬ ПЛАНЕТАРНИХ ПЕРЕДАЧ ПІДЙОМНО-ТРАНСПОРТНИХ МАШИН

Lifting and transporting machines (PTM) are one of the important equipment for the mechanization of work in various spheres of the national economy. In addition to the multi-rescue system, the cargo lifting mechanism also includes a winch. Winches with one drum, which have standard parameters - traction force from 3.2 to 125 KN at rope speed from 0.5 to 0.1 m/s, are most often used in PTM. Such winches include a two-stage gear reducer that connects the electric motor with the drum. Such a winch drive scheme is quite large and has considerable weight. One of the areas that will help reduce these indicators is the use of planetary gearboxes. They allow the use of winches in which the electric motor and gearbox are coaxial, and the planetary gearbox itself can be mounted in the drum. Such a drive scheme of the load lifting mechanism allows to reduce the dimensions and weight of the winch. The paper considers the calculation and compares the transmission ratios of planetary gears, which are used and can be used in lifting and transporting machines to reduce the dimensions and weight of cargo lifting mechanisms. Schemes of simple and closed planetary gears, as well as a scheme with three central gears, are given. The scheme of the planetary transmission with free gear wheels is considered. The presence of internal gears and several satellites makes planetary gears compact and light in weight. AII transmission with two internal gears and a free carrier allows to obtain significant transmission ratios with a small number of gears. Schemes of planetary gears with free gears allow you to change the angular speed of the output shaft.

Influence of a passive exoskeleton on kinematics, joint moments, and self-reported ratings during a lifting task

It was found that the Auxivo LiftSuit reduced the load on the back and hip muscles when lifting heavy loads, but its effect on lower body kinematics, joint moments, and self-reported ratings was unclear. The purpose of this study was to assess the effect of this passive lift-exoskeleton design, on lower body kinematics, joint moments, and self-reported ratings during lifting of heavy loads. Twenty healthy subjects performed lifting of heavy loads with and without the exoskeleton under surveillance of a motion capture system. Medium and maximum level adjustments of the exoskeleton, as well as no exoskeleton use were analyzed. Our results indicate significant reduction (p <.01) in pelvis segment tilt and hip flexion ROM with the exoskeleton at maximum level adjustment in males during lifting. Lumbosacral flexion moment ranges were significantly decreased (p <.013) with the exoskeleton at maximum and medium level adjustment in males during lifting. The general user impressions were mostly positive, with participants reporting that it was easier to perform the task with the exoskeleton than without it (p <.0.001), and preferring and recommending the exoskeleton for the task. Although our findings may suggest negative effects of the Auxivo LiftSuit in males and females due to a ROM restriction and loose fit, respectively, it does not mean that the Auxivo LiftSuit is not useful for lifting tasks. Further design improvements are required to allow full range of motion of hips and pelvis, as well to provide better adjustment and level of support in female users.

Analysis of Train-Track-Bridge Coupling Vibration Characteristics for Heavy-Haul Railway Based on Virtual Work Principle.

This paper introduces an innovative model for heavy-haul train-track-bridge interaction, utilizing a coupling matrix representation based on the virtual work principle. This model establishes the relationship between the wheel-rail contact surface and the bridge-rail interface concerning internal forces and geometric constraints. In this coupled system's motion equation, the degrees of freedom (DOFs) of the wheelsets in a heavy-haul train lacking primary suspension are interdependent. Additionally, the vertical and nodding DOFs of the bogie frame are linked with the rail element. A practical application, a Yellow River Bridge with a heavy-haul railway line, is used to examine the accuracy of the proposed model with regard to discrepancy between the simulated and measured displacement ranging from 1% to 11%. A comprehensive parametric analysis is conducted, exploring the impacts of track irregularities of varying wavelengths, axle load lifting, and the degradation of bridge stiffness and damping on the dynamic responses of the coupled system. The results reveal that the bridge's dynamic responses are particularly sensitive to track irregularities within the wavelength range of 1 to 20 m, especially those within 1 to 10 m. The vertical displacement of the bridge demonstrates a nearly linear increase with heavier axle loads of the heavy-haul trains and the reduction in bridge stiffness. However, there is no significant rise in vertical acceleration under these conditions.

Investigation on Generative Designs for Fast Connector Socket (FCS) Using High-Strength Low-Alloy (HSLA) Steel

This study appears to focus on the application of metal additive manufacturing and generative designs to create more efficient and sustainable metallic components. The methodology developed in this study takes a comprehensive approach, from component selection to validation of outputs, which can lead to more efficient use of metallic parts in the future. Here CATIA V5 R20 used to create three new models of a fast connector socket (FCS) components, and then using ANSYS Workbench 16.0 apply the working load limit of 4.5 ton load with AISI 4142 380 qt steel alloy material used to the models to analysis. The Autodesk Fusion 360 software was then used to create generative designs for the fast connector socket models, which aimed to reduce mass, size, and material of the model while maintaining its effectiveness. The generative design approach used in this study is inspired by nature's evolutionary design process and considers production processes and cost restrictions. This approach can lead to the creation of more efficient and sustainable metallic components that can be used in various applications, including mechanical, marine, mining, construction, load lifting, pulling, and holding. Overall, this study highlights of the potential benefits. The comprehensive methodology used in this study can be applied to other metallic component designs to improve their efficiency and sustainability.

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.