Robótica colaborativa para melhorar a ergonomia no posto de trabalho: um estudo de caso na indústria automativa

Doctoral program in Industrial and Systems EngineeringA quarta revolução industrial desenvolveu sistemas inteligentes, nos quais os robôs colaborativos têm um papel principal. Os trabalhadores sofrem fadiga quando expostos aos fatores de risco que causam as lesões musculoesqueléficas relacionados ao trabalho (WMSD). Como os postos de trabalho manuais muitas vezes conduzem a más posturas e movimentos repetitivos, a implementação de sistemas de Colaboração Humano-Robô (HRC) é frequentemente escolhida como uma solução para melhorar a ergonomia no ambiente de trabalho. O Nivel de Colaboração (LoC) significa quais tarefas o robô é capaz de executar como um colega de equipe, o que varia desde o Nivel O ao Nivel 4. Os fatores fisicos, cognitivos e organizacionais interagem diretamente em questões relacionadas com as relações laborais em sistemas complexos. Dependendo do LoC para executar uma tarefa, esperam-se diferentes cargas de trabalho físicas e mentais sobre o ser humano. A Dinâmica de Sistemas (SD) é um método para abordar tais problemas com uma visão sistêmica, modelando, simulando e ajudando a tomada de decisões. Investigações prévias sobre postos de trabalho HRC não qualificam e quantificam os riscos ergonômicos variando com o LoC. Por isso, esta tese propõe um modelo de simulação computacional como parte de uma estrutura para tomada de decisões com objetivos de produtividade e redução do risco de WMSD ao implementar um HRC. Além disso, foi realizado um estudo de caso em um posto de trabalho para comparar resultados com as simulações computacionais. Foi escolhido o tempo de ciclo para medir a produtividade, o método ergonômico Rapid Upper Limb Assessment (RULA) para a avaliação da carga de trabalho fisico, e o questionário NASA Task Load Index (NASA-TU() para a avaliação da carga de trabalho mental. Os resultados mostram que a produtividade aumentou mais de 20% em média, as posturas e a carga de trabalho global melhoraram tanto em simulações computacionais como em simulações reais. Também indica que um LoC mais elevado não garante os melhores resultados em termos de produtividade e ergonomia. A conclusão foi que a estrutura para tomada de decisões baseada em SD, que também inclui avaliações técnicas e económicas, é fundamental para compreender o sistema e obter dados confiáveis. Os trabalhos futuros pretendem desenvolver ainda mais o modelo e aplicar esta estrutura em outras linhas de montagem que considerem a implementação de um sistema HRC.The fourth industrial revolution has seen fast developments in smart systems, in which collaborative robots have a main role. Workers start to fatigue when exposed to Work-related Musculoskeletal Disorders (WMSD) risk factors. As manual handling workstations often lead to awkward postures, repetitive movements and forceful exertions, the implementation of Human-Robot Collaboration (HRC) systems is often chosen as a solution to improve workplace ergonomics. The Level of Collaboration (LoC) means what tasks the robot is capable to perform as a teammate, which varies from Level 0 to Level 4. Physical, cognitive, and organizational factors interact directly on issues related to labor relations in complex systems. Depending on the LoC to perform a task, it is expected different physical and mental workloads over the human being. System Dynamics (SD) is a method to approach such problems with a systemic view by designing, modeling, simulating, and finally making good decisions. Prior research on HRC workstations does not find a solution for qualifying and quantifying ergonomic risks depending on the LoC. Therefore, this thesis proposes a computer simulation model as part of a decision-making framework to achieve productivity goals and to reduce the risk of WMSD when implementing an HRC. Moreover, a case study was conducted in a manual assembly workstation to compare results with the computational simulations. It was chosen cycle time to measure productivity, the ergonomic method Rapid Upper Limb Assessment (RULA) for the physical workload assessment, and the NASA Task Load Index (NASA-TLX) questionnaire for the mental workload assessment. Results show that productivity increased more than 20% on average, postures and the overall workload improved in both computational and real simulations. It also indicates that higher LoC does not guarantee the best results in terms of productivity and ergonomics. The conclusion was that the framework based on system dynamics that also includes technical and economic evaluations is key to understand the system and to make good decisions based on reliable data. Future works intend to further develop the model and to apply this framework in other assembly lines that consider the implementation of an HRC system

Decision-making framework for implementing safer human-robot collaboration workstations: system dynamics modeling

Human-Robot Collaboration (HRC) systems are often implemented seeking for reducing risk of Work-related Musculoskeletal Disorders (WMSD) development and increasing productivity. The challenge is to successfully implement an industrial HRC to manage those factors, considering that non-linear behaviors of complex systems can produce counterintuitive effects. Therefore, the aim of this study was to design a decision-making framework considering the key ergonomic methods and using a computational model for simulations. It considered the main systemic influences when implementing a collaborative robot (cobot) into a production system and simulated scenarios of productivity and WMSD risk. In order to verify whether the computational model for simulating scenarios would be useful in the framework, a case study in a manual assembly workstation was conducted. The results show that both cycle time and WMSD risk depend on the Level of Collaboration (LoC). The proposed framework helps deciding which cobot to implement in a context of industrial assembly process. System dynamics were used to understand the actual behavior of all factors and to predict scenarios. Finally, the framework presented a clear roadmap for the future development of an industrial HRC system, drastically reducing risk management in decision-making.This work was supported by European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project n◦ 39479; Funding Reference: POCI-01-0247-FEDER-39479] and by FCT - Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/202

Trabalho em altura: um estudo de caso do montador de andaime na indústria naval

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Produção, Florianópolis, 2018.Historicamente a indústria de construção como um todo possui uma das maiores taxas de acidentes, atualmente com mais de 60 mil mortes por ano no mundo, sendo as quedas as principais causadoras. Na indústria naval verificou-se que, dentre as áreas de construção e montagem (solda, estrutura, elétrica, andaime, pintura, instrumentação, comissionamento, tubulação e movimentação de carga), os montadores de andaimes são os trabalhadores que ficam expostos a maior quantidade de condições inseguras, pelos riscos inerentes ao trabalho em altura e o risco de quedas. Este estudo teve como objetivo analisar as condições de trabalho dos montadores de andaime, diagnosticar os meios de regulação trabalhador/ambiente e aplicar uma ferramenta de gestão da segurança. Para a coleta de dados, utilizou-se da observação direta da atividade, com vista a realizar a Análise Ergonômica do Trabalho (AET), e assim apurar o diagnóstico do contexto que abrange a rotina de trabalho dos montadores de andaime. Na sequência foi implantada a ferramenta ErgCCP (Ergonomia de Correção, Conscientização e Participação), onde a equipe de construção e montagem foi responsável por identificar as condições inseguras e solucioná-las. Foi elaborado um diagrama de causa e efeito baseando-se nos pilares Homem, Produtividade e Segurança, apresentando um mapa construído a partir dos artigos científicos da área e da experiência de trabalho na obra de construção e montagem. Da observação percebeu-se que o próprio trabalhador ultrapassa alguns limites do procedimento para atingir metas de produção, colocando em risco a si e aos outros. O ErgCCP registrou 599 condições inseguras na área de montagem de andaime. Contatou-se que a aplicação da AET associada ao ErgCCP para a atividade do montador de andaime se mostrou uma ferramenta importante no combate aos acidentes por queda de altura, onde as responsabilidades são compartilhadas para todos os trabalhadores da obra, mudando a conduta e percepção do risco.Abstract : Historically, the construction industry has one of the highest accident rates, with more than 60,000 deaths per year in the world, with falls being the main cause. In the naval industry it was found that, among the areas of construction and assembly (welding, structure, electrical, scaffolding, painting, instrumentation, commissioning, piping and load handling), scaffolders are the workers who are the most exposed to unsafe conditions, due to the risks inherent in working at heights and the risk of falls. The aim of this study was to analyze the working conditions of the scaffolders, to diagnose the means of worker / environment regulation and to apply a safety management tool. For the data collection, the direct observation of the activity was used, in order to perform the Ergonomic Analysis of Labor (EAL), and to ascertain the diagnosis of the context that covers the work routine of the scaffolders. The ErgCAP (Ergonomics of Correction, Awareness and Participation) tool was implanted, where the construction and assembly team was responsible for identifying the unsafe conditions and solving them. A cause and effect diagram was drawn up based on the Human, Productivity and Safety pillars, presenting a map built from the scientific articles of the area and work experience in the construction and assembly work. From the observation it was noticed that the worker himself goes beyond some limits of the procedure to achieve production goals, putting himself and others at risk. ErgCAP recorded 599 unsafe conditions in the scaffolding area. The application of the EAL associated with the ErgCAP to the scaffolder activity was shown to be an important tool against accidents due to fall from height, where responsibilities are shared for all workers, changing the behavior and perception of the risk

Aplicação de Indicadores da Qualidade na Avaliação do Setor de Obras da UFSC

O presente estudo de caso foi baseado em dados fornecidos pelo Departamento de Fiscalização de Obras da Pró-Reitoria de Planejamento e Orçamento – DFO/PROPLAN – da UFSC no período de 2009 a 2015. O objetivo é apresentar um modelo de avaliação da qualidade baseado em indicadores da qualidade (in-line, off-line e on-line). Estes indicadores são capazes de mensurar crescimento, impacto social e melhorias nos processos avaliados. Foram propostas melhorias no âmbito operacional, tático e estratégico, para atingir todos os níveis da organização. Os indicadores apresentam caráter objetivo na avaliação da utilização dos recursos financeiros do programa REUNI pela UFSC. Por fim, os autores almejam que a aplicação de indicadores da qualidade possa tornar a aplicação de recursos no Setor Público, onde a concorrência inexiste, mais eficiente

A computational assessment of ergonomics in an industrial human-robot collaboration workplace using system dynamics

An automotive company in Portugal has a high rate of sick leave due to occupational diseases where it is planned the insertion of an industrial Human-Robotic Collaboration (HRC) system to assist workers’ activities. As this system can result in physical and mental overload, depending on the different Levels of Collaboration (LoC), the aim of this paper is to predict what would be the best working condition between worker and robot. This descriptive research establishes a quantitative approach, since it prospects scenarios generated by computer simulation. It explores the outputs of sick leave rate by inserting an industrial HRC in the production line. The main results consist of the scenarios that graphically describe the evolution of the indicators over time. We conclude that counterintuitive effects can occur on these systems, and a computational simulation is useful to predict working condition scenarios when deciding which human-robot configuration fits better.FCT - Fundação para a Ciência e a Tecnologia(UIDB/00319/2020

Simulating human-robot collaboration for improving ergonomics and productivity in an assembly workstation: a case study

Objective: To simulate the interaction human-robot regarding productivity, physical and mental workload, involving the worker in the process of implementing a new Human-Robot Collaboration (HRC) system. Background: The guidelines for designing ergonomic and management of work systems are key to ensure worker safety, health, and wellbeing. It considers physical and mental workloads, including worker in the process of implementation. Method: Consists of comparing two workstations regarding physical demand, mental demand, and productivity with a sample size of 6 subjects. First workstation is a replica of a current situation, in which it is intended to implement an industrial HRC system. Second workstation is a human-robot simulated scenario, in which a human hand simulates the tasks being performed by a robot arm. Results: Robot-simulated scenario resulted in: 24.3% increase in productivity; posture exposure time reduced from 33.5% to 22.0%; overall workload felt by workers decreased from 44/100 to 38/100; and participatory ergonomics provided meaningful insights for better understanding the whole system. Conclusion: Robot-simulated improved ergonomic conditions and productivity compared to the replica-workstation and it is important to involve the worker in the implementation of a HRC system. Application: Assembly task workstations considering the inclusion of an industrial collaborative robot to perform tasks and lighten the burden on humans.This work is supported by: European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) Project n∘ 39479; and Funding Reference: POCI-01-0247-FEDER-39479; and by FCT - Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020

Assessment of work-related musculoskeletal disorders by observational methods in repetitive tasks - a systematic review

Repetitive movements play an important role in the growing and aggravation of the discomforts related to the musculoskeletal system. There are many different observational methods for risk assessment for repeated movements in literature. The main objective of this review is to identify the observational methods that have been used to assess repetitive movements risk in previous studies. A systematic literature review was performed using the PRISMA protocol, in journal databases such as Taylor & Francis, Science Direct, and Scopus. We retrieved 322 articles and, after classification, 45 of them were selected for full analysis. Results showed that the most applied method was the OCRA method, especially by researchers from Italy and Brazil. Besides this, RULA (Rapid Upper Limb Assessment), QEC (Quick Exposure Check), and REBA (Rapid Entire Body Assessment) were also methods well-known and extensively applied to assess ergonomic repetitive working tasks.This work is supported by: European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project no 39479; Funding Reference: POCI-01-0247-FEDER-39479] and by FCT—Fundação para a Ciência e Tecnologia within the RR&D Units Project Scope: UIDB/00319/2020