scholarly journals Workspace Analysis of a Mobile Manipulator with Obstacle Avoidance in 3D Printing Tasks

2021 ◽  
Vol 11 (17) ◽  
pp. 7923
Author(s):  
Robert Guamán Rivera ◽  
Rodrigo García Alvarado ◽  
Alejandro Martínez-Rocamora ◽  
Fernando Auat Cheein
Keyword(s):  
3D Printing ◽  
Robotic Systems ◽  
Mobile Manipulator ◽  
Construction Site ◽  
Robotic Platform ◽  
Construction Sites ◽  
Height Variation ◽  
Workspace Analysis ◽  
Construction Tasks ◽  
Essential Resource

The knowledge of the workspace for a robotic system on construction sites represents an essential resource to ensure the work progress, guarantee the safety of the construction tasks, and avoid robot damage. Despite the dramatic development of 3D printing technologies with robotic systems in recent years, these are still several challenges to consider, such as the size of the printing profile and obstacles in the construction site. This work presents the results from evaluating the workspace of a mobile manipulator in 3D printing tasks on construction sites. The methodology analyses the printing workspace based on the workspace of the mobile manipulator, considering fixed obstacles and possible collisions between the robot and obstacles during 3D printing tasks. The results showed that the shape of the printing profile defined as a building element changes the shape of the printing workspace. Furthermore, the obstacles in the construction site and height variation of the printing profile cause changes in the displacement of the robotic platform and values of rotation of its joints, which also modify the shape of the printing workspace.

Kinematics of a Cable-Driven Robotic Platform for Large-Scale Additive Manufacturing

2021 ◽  
pp. 1-17
Author(s):  
Phillip Chesser ◽  
Peter Wang ◽  
Joshua Vaughan ◽  
Randall Lind ◽  
Brian Post
Keyword(s):  
Additive Manufacturing ◽  
Large Scale ◽  
Robotic Systems ◽  
Robotic Platform ◽  
Intended Application ◽  
Rigid Link ◽  
Physical Implementation

Abstract Concrete additive manufacturing (AM) is a growing field of research. However, on-site, large-scale concrete additive manufacturing requires motion platforms that are difficult to implement with conventional rigid-link robotic systems. This paper presents a new kinematic arrangement for a deployable cable-driven robot intended for on-site AM. The kinematics of this robot are examined to determine if they meet the requirements for this application, the wrench feasible workspace (WFW) is examined, and the physical implementation of a prototype is also presented. Data collected from the physical implementation of the proposed system is analyzed, and the results support its suitability for the intended application. The success of this system demonstrates that this kinematic arrangement is promising for future deployable AM systems.

scholarly journals Safety Assessment and Risk Management in Indian Building Construction Sites

2019 ◽  
Vol 8 (4S2) ◽  
pp. 8-12
Keyword(s):  
Safety Assessment ◽  
Building Construction ◽  
Construction Site ◽  
Construction Sites ◽  
Safety Measures ◽  
Severity Rating ◽  
Key Factor ◽  
Incident Rate ◽  
Observation Method ◽  
Unsafe Condition

Construction sites records high accident and incident rate due to lack of safety measures. Safety assessment rating is significant for every construction site to know safety status of the particular site. In this research TR safety observation method is used to assess the site performance. As unsafe condition is the key factor in every construction site, this research considers the possible unsafe conditions to assess the site performance. A questionnaire survey is done with the workers to know the existing safe conditions. Results showed that the safety performance of the site is 39%. Then every unsafe condition is ranked with respect to severity rating for detailed analysis. Furthermore bowtie analysis is used to identify the causes and consequences of the unsafe conditions. Through this analysis the owner can reduce the risk of every event and improve the site performance.

scholarly journals A Recursive Algorithm for the Forward Kinematic Analysis of Robotic Systems Using Euler Angles

Robotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Fernando Gonçalves ◽  
Tiago Ribeiro ◽  
António Fernando Ribeiro ◽  
Gil Lopes ◽  
Paulo Flores
Keyword(s):  
Recursive Algorithm ◽  
Kinematic Chain ◽  
Robotic Systems ◽  
Mobile Manipulator ◽  
Euler Angles ◽  
Joint Angles ◽  
Main Research ◽  
Kinematic Chains ◽  
Research Fields ◽  
Forward Kinematic

Forward kinematics is one of the main research fields in robotics, where the goal is to obtain the position of a robot’s end-effector from its joint parameters. This work presents a method for achieving this using a recursive algorithm that builds a 3D computational model from the configuration of a robotic system. The orientation of the robot’s links is determined from the joint angles using Euler Angles and rotation matrices. Kinematic links are modeled sequentially, the properties of each link are defined by its geometry, the geometry of its predecessor in the kinematic chain, and the configuration of the joint between them. This makes this method ideal for tackling serial kinematic chains. The proposed method is advantageous due to its theoretical increase in computational efficiency, ease of implementation, and simple interpretation of the geometric operations. This method is tested and validated by modeling a human-inspired robotic mobile manipulator (CHARMIE) in Python.

scholarly journals Rebar Worker Analysis Using a 3-Axis Accelerometer

2021 ◽  
Vol 7 ◽  
Author(s):  
Takuma Akaki ◽  
Tomoyuki Gondo
Keyword(s):  
Body Movement ◽  
Building Construction ◽  
Accelerometer Data ◽  
Construction Site ◽  
Work Intensity ◽  
Construction Sites ◽  
Repetitive Tasks ◽  
The Difference ◽  
Total Body ◽  
Large Building

The purpose of the present study is to grasp the situation of construction sites easily by distinguishing the movements of construction workers at construction sites from the accelerometer data attached to their waists. For the construction manager to accurately perceive the active or inactive state of his workers, their movements were classified into three distinct categories: walking, standing, and sitting. We tracked and observed two rebar workers for 5 days at a large building construction site. Their movements were classified by two-axis plots of (1) the difference between the maximum and minimum absolute values and (2) the value of acceleration at each second, and visualized by a heatmap among others for this trial. The results showed that despite the difficulty in distinguishing rebar work without a total body movement while sitting, the accuracy of discrimination was 60–80% in walking and sitting. From this analysis, we were able to identify repetitive tasks and the differences between morning and afternoon tasks. Furthermore, by applying simple visualization, we could concisely represent changes in work intensity over a relatively long period.

scholarly journals Strategies for effective management of health and safety in confined site construction

2013 ◽  
Vol 13 (4) ◽  
pp. 50-64 ◽  
Author(s):  
John Spillane ◽  
Lukumon O. Oyedele
Keyword(s):  
Practical Implication ◽  
Health And Safety ◽  
Construction Site ◽  
Construction Sector ◽  
Effective Management ◽  
Construction Sites ◽  
Safety Issues ◽  
Individual Interviews ◽  
Site Design ◽  
Managerial Strategies

Purpose: The overall aim of this research is to identify and catalogue the numerous managerial strategies for effective management of health and safety on a confined, urban, construction site. Design/Methodology/Approach: This is achieved by utilising individual interviews, focus groups discussion on selected case studies of confined construction sites, coupled with a questionnaire survey. Findings: The top five key strategies include (1) Employ safe system of work plans to mitigate personnel health and safety issues; (2) Inform personnel, before starting on-site, of the potential issues using site inductions; (3) Effective communication among site personnel; (4) Draft and implement an effective design site layout prior to starting on-site; and (5) Use of banksman (traffic co-ordinator) to segregate personnel from vehicular traffic. Practical Implication: The construction sector is one of the leading industries in accident causation and with the continued development and regeneration of our urban centres, confined site construction is quickly becoming the norm - an environment which only fuels accident creation within the construction sector. Originality/Value: This research aids on-site management that requires direction and assistance in the identification and implementation of key strategies for the management of health and safety, particularly in confined construction site environments.

scholarly journals Sustainable Ship Loading Planning for Prefabricated Products in the Construction Industry

2020 ◽  
Vol 12 (21) ◽  
pp. 8905
Author(s):  
Wen Yi ◽  
Robyn Phipps ◽  
Hans Wang
Keyword(s):  
Construction Industry ◽  
Large Scale ◽  
Transportation Cost ◽  
Sustainable Transportation ◽  
Construction Site ◽  
Integer Optimization ◽  
Construction Sites ◽  
Capacity Limits ◽  
Proposed Model

This paper focuses on sustainable transportation of prefab products from factories to construction sites by ship. Since the transportation cost for all the prefab products of a construction site is mainly dependent on the number of cargo holds used on ships, a loading plan for prefab products that minimizes the number of holds required is highly desirable. This paper is therefore devoted to the development of an optimal loading plan that decides which prefab products are loaded into each cargo hold and how to pack these prefab products into the holds so that as few holds as possible are used. We formulate the problem as a large-scale integer optimization model whose objective function is to minimize the total number of cargo holds used and whose constraints represent the cargo hold capacity limits. We develop a heuristic to solve the problem and obtain a high-quality solution. We have tested the model and algorithm on a case study that includes 20 prefab products. We find that different cargo holds carry prefab products that have quite different densities. Moreover, the orientations of many prefab products are different from their default orientations. The results demonstrate the applicability of the proposed model and algorithm.

MUSLE Evaluation of Soil Loss on a Construction Site by Using Gauging Weirs

2012 ◽  
Vol 446-449 ◽  
pp. 2718-2721 ◽  
Author(s):  
Siti Isma Hani Ismail ◽  
Hooi Min Yee
Keyword(s):  
Soil Loss ◽  
Loss Rate ◽  
Rainfall Intensity ◽  
Empirical Modeling ◽  
Storm Event ◽  
Construction Site ◽  
Construction Sites ◽  
Impervious Cover ◽  
Storm Rainfall ◽  
Soil Loss Rate

During urbanization, large areas of soil are exposed to the risk of soil erosion due to extensive earthworks and construction activities. Runoff from construction sites is known by far the largest source of sediment clogging our waterways. Erosion occurred from the study area due to removal of vegetation, high rainfall intensity, alteration of existing topography, and the covering of previously vegetated surfaces with impervious cover such as roads, driveways and buildings. The main objective of this study is to evaluate the soil loss due to storm rainfall and runoff on a construction site located at Sungai Ara, Penang State of Malaysia. A purpose-built hydraulic structure namely Sharp Crested Rectangular Weir was constructed and installed on site for more reliable estimates of flow during storms. The soil loss was then evaluated by using an empirical modeling known as the Modified Universal Soil Loss Equation (MUSLE). Results showed that large amount of sediment has being eroded from the study area during these activities. The highest soil loss rate was estimated was 64 ton/ha during a storm event.

scholarly journals Tension between Productivity and Respect for People in Construction

2020 ◽  
Vol 312 ◽  
pp. 05005
Author(s):  
Lesiba George Mollo ◽  
Fidelis Emuze ◽  
Nicholus Sishuba
Keyword(s):  
South Africa ◽  
Real Time ◽  
Construction Industry ◽  
Management System ◽  
Ethical Reasoning ◽  
Construction Site ◽  
Construction Sites ◽  
Factors Influencing ◽  
Major Factors ◽  
Structured Questionnaire

Productivity in the construction industry is declining in real-time. The decline in productivity is a source of worry for practitioners and researchers. The purpose of this paper is to ascertain major factors influencing productivity in relation to the notion of respects for people (RFP) in construction. The reviewed literature influences the semi-structured questionnaire used to survey construction professionals in Johannesburg, South Africa. The results reaffirm the tension productivity increment and the enhancement of RfP as both ideas appear to be moving in opposite directions on a typical construction site. It was discovered that respect for workers on a construction site is a major concern. The paper argues that ethical reasoning affects productivity. Therefore, an appropriate management system is required to improve the workers' perception of productivity and RfP working on construction sites.

scholarly journals Risk-based construction safety index as an integral indicator in the agricultural sector

2020 ◽  
Vol 175 ◽  
pp. 12001
Author(s):  
Tatiana Simankina ◽  
Marina Romanovich ◽  
Vladimir Sharmanov ◽  
Anton Mamaev ◽  
Angelina Blagodatskaya
Keyword(s):  
Agricultural Sector ◽  
Construction Safety ◽  
Complete Picture ◽  
Labor Protection ◽  
Construction Site ◽  
Safety Index ◽  
Construction Sites ◽  
Emerging Risk ◽  
Integral Indicator

A new indicator for monitoring the level of labor protection at construction sites in the agricultural sector is proposed – the construction safety index with consideration of risk, which combines the Elmery system and the Fine-Kinney method. This method shows a complete picture of ensuring the level of labor protection at the construction site, taking into account emerging risk situations in the dynamics of construction. The universality of this approach allows each enterprise, depending on its technological features, to determine the list of hazards that it is going to control, which will allow predicting the development of negative scenarios, as well as planning the amount of money to ensure the proper level of labor protection.

scholarly journals Probabilistic Fire Risk Framework for Optimizing Construction Site Layout

2020 ◽  
Vol 12 (10) ◽  
pp. 4065
Author(s):  
Rani El Meouche ◽  
Mohammed Abunemeh ◽  
Ihab Hijazi ◽  
Ahmed Mebarki ◽  
Fadi Fatayer ◽  
...  
Keyword(s):  
Fire Risk ◽  
Probability Of Failure ◽  
Construction Site ◽  
Construction Sites ◽  
Layout Planning ◽  
Fire Hazards ◽  
Site Layout ◽  
Planning Models ◽  
Risk Framework ◽  
Construction Site Layout

Purpose: This paper aims to develop an efficient model able to reduce catastrophic consequences and the significant number of victims resulting from fires at construction sites. The paper proposes probabilistic modeling aimed to minimize the probability of failure of a construction site. Methodology: The developed model in this paper consists of modeling fire hazards, the vulnerability of the potential targets, and the risk within construction sites. The optimization algorithm called “differential evolution” is used in order to determine the optimal site layout, which is characterized by having the smallest overall probability of failure. A numerical simulation is performed to delineate an appropriate probability density function of the failure of the site. In addition, a geographic information system (GIS) is used to display the spatial variability of fire risk on a construction site. Findings: The paper provides an efficient model to enhance site layout planning and assign locations for supporting temporary facilities at appropriate positions within a construction site. The model is examined through applying it on a simple case study containing numerous facilities. All these facilities are considered vulnerable targets and some of them are potential fire hazards, with different intensity values. Value: Most of the previous research focuses on travel cost distance in developing site layout planning models. This paper fulfills the development of a valuable model able to generate an optimized construction site layout by minimizing the probability of failure of the whole site. It will assist the decision makers and the risk managers in identifying the riskiest zones on a construction site.

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