6,686 research outputs found

    'There's lots of suffering in here, but some people are suffering more': Age, Gender and the Pains of Imprisonment

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    Older offenders are the fastest growing group in the prison population in England and Wales. While most age groups of prisoners have been falling the number of prisoners over the age of 50 has continued to increase. Older prisoners have different needs to the general prison population; however, at the time of writing, the government has yet to implement a policy outlining standards of care for this group of prisoners. This thesis is the result of and nine-month long ethnography that took place in two prisons, a man's, and a woman's, in England from June 2017 to February 2018. It explores the challenges faced by older people in prison, and how this lack of policy impacted on the older prisoner population. It also examines if those difficulties were experienced equally by the older men and women or if, in a system designed for young men, there were gendered differences in the challenges they faced. The findings highlight how the older men and women suffered from three additional pains of imprisonment as a result of their incarceration: the Pains of Isolation, the Pains of Loss and the Pains of Ageing and Deteriorating Health. These additional pains, experienced by the older people, were exacerbated by a prison system that did not make any accommodation for their additional needs. However, these ageing pains of imprisonment were not felt equally by the older prisoner population. There was a gendered aspect to many of them and the older women experienced additional gendered ageing pains of imprisonment. Where possible, the older people attempted to mitigate their ageing pains of imprisonment; by forming social networks, by working, or by finding a benefit to their incarceration. However, their ability to use their limited agency was impacted by the policies of the prison regime. This thesis considered if institutional thoughtlessness assisted in understanding why older people were experiencing additional ageing pains of imprisonment; but concluded that, as a concept, institutional thoughtlessness could not sufficiently explain why these prisoners' needs were overlooked. Moving beyond institutional thoughtlessness, the thesis explores the concept of institutional ageism and how it manifests itself at a macro, meso and micro level; concluding that the ageist policies of the prison service were making the time of older people in prison more difficult and increasing their additional ageing pains of imprisonment. Moreover, when these ageist policies intersected with gender, the ageing pains of imprisonment were experienced more keenly by the older women

    Vulnerability, decision-making and the protection of prisoners in Scotland and England

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    Vulnerable and protection prisoners currently make up a sizeable proportion of the prison populations in England and Scotland, and designated physical space to house them, an approach that has developed significantly in both countries since the 1960s, remains under studied. Within research on prisons, vulnerability has been predominantly associated with risks to the self, for example, mental health problems, self-harm and suicide, internal vulnerabilities that prisoners either bring into an establishment or which are a consequence of the stressors of prison life. This literature further tends to focus on certain categories of prisoner, namely those who have committed sexual crimes. This framing of vulnerability in prison means academic research typically studies vulnerability as a settled status, and there has been a move away from exploring meanings, experiences and determinations of vulnerability as these arise and change at different points of a person’s journey through prison. This study addresses these gaps by sharing the perspectives directly from those at risk of victimization in prison as well as from those in charge of deciding who will get protection from risks. The focus is on prisoner and staff decisions to relocate to protective housing (vulnerable prisoner units (VPU) in England and protection halls in Scotland). This research utilised qualitative methods, interviewing staff (13) involved in designating or managing vulnerability in prison as well as prisoners (23) who had been identified as needing protective housing. The research was conducted in one prison in England and two prisons in Scotland. It highlights the significant levels of victimization, trauma and fear experienced by prisoner research participants, and in doing so complicates prevailing ideas of vulnerability in prison. The findings chapters show: staff perspectives on what counts as a valid basis of vulnerability and therefore how it is managed and to some extent rationed (Chapter 5); the importance of journeys into and through prisons which shape and intensify experiences of vulnerability (Chapter 6); the perspectives of prisoners housed in a VPU in England which reinforced the idea that vulnerability is fluid and that there are some common factors affecting decisions to relocate from mainstream wings, but ultimately each decision is situated in the personal circumstances of an individual (Chapter 7); the perspectives of prisoners housed in protection halls in Scotland highlighting the factors that influence decisions to seek out or resist protective accommodation where, like England, common factors influenced decisions but were situated in highly individual circumstances (Chapter 8), and how these feelings were managed. The conclusion (Chapter 9) summarises key findings and calls for a sociology of the vulnerable prisoner (building on a conceptualisation of vulnerability in Chapter 3) to understand not only how they navigate risk from others and the prison itself, but how they make sense of their newly acquired yet further stigmatized identity. Finally, it sets out some implications and suggestions for policy based on its new contribution to a sociology of vulnerability

    B/order work: recomposing relations in the seamful carescapes of health and social care integration in Scotland

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    As people, ageing and living with disabilities, struggle with how care is enacted through their lives, integrated care has gained policy purchase in many places, especially in the United Kingdom. Accordingly, there have been various (re)forms of care configurations instigated, in particular, promoting partnership and service redesign. Despite integrations apparent popularity, its contribution to improved service delivery and outcomes for people has been questioned, exposing ongoing uncertainties about what it entails and its associated benefits. Nonetheless, over decades, a remarkably consistent approach to integrated care has advanced collaboration as a solution. Equally, any (re)configurations emerge through wider infrastructures of care, in what might be regarded as dis-integrated care, as complex carescapes attempt to hold and aporias remain. In 2014, the Scottish Public Bodies (Joint Working) (Scotland) Act mandated Health and Social Care Integration (HSCI), as a means to mend fraying carescapes; a flagship policy epitomising public service reform in Scotland, in which normative aspirations of collaboration are central. What then are the accomplishments of this ambitious legislation? From the vantage point of 2021, HSCI has been assessed as slow and insubstantial, but this is not the complete picture. Narratives about failing to meet expectations obscure more complicated histories of cooperation and discord, successes and failures, and unintended consequences. Yet given collaborative ubiquity, if partnerships are contested how then are they practiced? To answer this question, I embarked on an interorganisational ethnography of the enactment of a Health and Social Care Partnership (HSCP), which went ‘live’ on April 1st, 2016; in a place I call ‘Kintra’. I interrogate what happened when several managers (from the NHS and Council) endeavoured to implement HSCI according to the precepts of the Act; working to both (re)configure and hold things together behind care frontiers; away from the bodywork of direct care, immersed in everyday arrangements in the spaces of governance and operations. I chart their efforts to comply with regulations, plan, and build governance apparatuses through documents. I explore through coalescent objects how distributed forms of governance, entwined in policy implementation, were subsequently both sustained, and challenged. I observed for seven months actors struggling to (re)configure care services embedded in a collaborative approach, as well as establish the legitimacy of the HSCP; exemplified through the fabrication of what was understood as a 'must-do' commissioning plan. In tracing documents, I show the ways in which HSCI was simultaneously materialised and constituted through documentation. I reveal how, in the mundane mattering of document manufacturing, possibilities for (re)forming the carescape emerged. By delving into inconspicuous, ‘seamful’ b/order work that both sustained distinctions between the NHS and Council and enabled b/order crossings, I expose how actors were knotted, and how this shaped efforts to recompose the contours of the carescape. While ‘Kintra’s story might be familiar, situated in concerns that may resonate across Scotland; I reveal how collaboration-as-practice is tangled in differing organisational practices, emerging from quotidian intra-actions in meeting rooms, offices, car parks and kitchenettes. I deploy a posthuman practice stance to show not only the way in which public administration ‘does’ care, but it’s world-making through a sociomaterial politics of anticipation. I was told legislation was the only way to make HSCI in ‘Kintra’ happen, nevertheless, there was resistance to limit the breadth and depth of integrating. Consequently, I show how the (re)organising of b/orders was an always-ongoing act of maintenance and repair of a (dis)integrating carescape; as I learnt at the end of my fieldwork, ‘it’s ‘Kintra, ‘it’s aye been!

    Tiger! Tiger! What is the experience of trauma and transition into adulthood of African refugee and asylum-seeking care leavers?

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    This study explores the experiences of trauma and transition into adulthood of African refugee and asylum-seeking care leavers in the UK. It aims to help practitioners better understand the impact of trauma on these young people and give them voice. Giving voice generates better research and develops the confidence of refugees (Temple and Moran, 2006). These young people make perilous journeys to the UK and battle traumatic experiences with the challenges of transitioning in a hostile environment. Supporting them is a challenge for local authorities. Despite these issues, there is little previous research interest about the experiences of trauma and transition into adulthood of African refugee and asylum-seeking care leavers in the UK. Psychoanalytically informed Free Association Narrative Interviews (FANI) were used to explore six young people’s unconscious processes. Cross-case analysis identified similarities in their stories but there were divergences and complexities in their trajectories. The young people felt relieved for telling their stories. Their mental health issues can be difficult to detect and transition into adulthood could deteriorate if faced with restrictions and barriers. Immigration status could impact their trajectories. Pre-migratory trauma, separation from family and adapting to a new system could exacerbate their trauma. They rated emotional support highly and felt that trauma could make them stronger. Their closeness or openness to the researcher is non-linear. The study concluded that the young people’s experience is complex. Practitioners need to be attentive to their inner world and external circumstances to better understand and support them. A more open practice and development of a psychosocial approach is recommended. Also, opportunities for the young people to tell their stories and be treated as individuals. It recommends future comparative study of the experiences and trajectories of young people coming to Western Europe from Africa with those from other continents and between those from British and non-British colonies

    Maternal thyroid hormones role in Zebrafish neural development

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    Thyroid hormones (TH) are essential for proper embryonic development of the central nervous system. During this period maternal supply of TH is the only source of these hormones to the embryo. Using a zebrafish MCT8 knockdown model, with consequent inhibition of maternal thyroid hormones (MTH) uptake to the target cells, the aim of this thesis is to start a comprehensive understanding of the role of MTH during embryonic neural development. We characterised the transcriptome in 25hpf CTRL and MCT8MO zebrafish embryos and found 4,343 differentially expressed genes. Reactome analysis show that MTH regulate the expression of core developmental pathways such as NOTCH, SHH and WNT. The cellular distribution of neural MTH-target genes demonstrated their cell specific action on neural stem cells and differentiated neuron classes. We identified a series of genes involved in several key neurogenic processes to be modulated by MTH. By analysing these genes by qPCR in a temporal series, from the start of segmentation through hatching, we determined the developmental time-window where MTH are required for appropriate CNS development. We show MTH are involved in the regulation of NOTCH pathway components such as notch1a, dla, dld, her2 and her4 during neurogenesis, whereas neuroectodermal genes are not affected. Response to MTH begins at 12hpf, and the time window between 22-25hpf is particularly sensitive to MTH action. Overall, these results, show that MTH is not involved in neuroectoderm specification nor CNS compartmentalisation but stress the involvement of MTH in the early stages of neurogenesis by promoting the maintenance of specific neural progenitor populations. Analyzing the cytoarchitecture of the spinal cord we found that by the end of embryogenesis cells populating the spinal cord of control and MCT8 MO zebrafish are substantially different. Lack of thyroid hormone uptake leads to a generalized disorganization of the neural tissue, together with a decrease in: neural stem cells population, subpopulations of neuron progenitor cells, radial glial cells, mature glial cells and oligodendrocyte precursors, while the primary motor neuron domain was maintained. Colocalization analysis of neural progenitors with thraa, thrab and mct8 allowed identifying cells under the regulation of MTH via MCT8. Survival and proliferation of neural progenitor cells are compromised in MCT8MO, which could later impact on the diversity of neural cell populations obtained in the end of embryogenesis. Analysis of cell autonomous Notch activation showed it cannot rescue the phenotype induced by the lack of MTH demonstrating the niche importance in the regulation of TH action. Given that MTH regulate several important morphogenetic pathways it is likely that its action occurs as an integrator enabling an adequate equilibrium between all these signals in a time a context dependent manner. MTH actions are reflected on the timely development of neurons and glial cells. It is of great interest to continue to explore the significance of these findings to further clarify the genetic and cellular causes underlying human AHDS syndrome. In conclusion with this work, we show that thyroid hormone transferred from the mother to the embryo allows the enrichment of neural progenitor pools and the generation of cell diversity necessary to produce a fully functional central nervous tissue.As hormonas da tiróide (TH) são essenciais para o correto desenvolvimento embrionário do sistema nervoso central (CNS). Durante este período o fornecimento de hormona da tiróide pela via materna é a única fonte destas hormonas para o embrião, uma vez que a produção endógena desta hormona é iniciada apenas numa fase posterior do desenvolvimento. Evidências mostram que mesmo níveis baixos de deficiência de hormona da tiróide na mãe estão associados a desordens neurológicas e psiquiátricas nos filhos. No entanto os mecanismos moleculares envolvidos na ação desta hormona no embrião e feto continuam amplamente desconhecidos. Em humanos, mutações no principal transportador celular de TH, MCT8, causa a síndrome de Herndon-Dudley (AHDS). Esta síndrome é caracterizada pelo atraso mental, atraso global no desenvolvimento, impossibilidade de falar e uma deficiência neuromotora severa. O MCT8 é o principal transportador de hormona da tiróide presente no embrião. No presente trabalho utilizamos o “knockdown” deste transportador, inibindo a sua tradução, no modelo de peixe zebra. Este modelo foi previamente estabelecido e possui características semelhantes à síndrome AHDS humana. Neste modelo o transporte da hormona da tiróide materna (MTH) para as células alvo é bloqueado, uma vez que o MCT8 está ausente, inibindo a ação da hormona. O objetivo desta tese é começar a compreender o papel destas hormonas durante o desenvolvimento neural embrionário. Para isso caracterizamos o transcriptoma de peixe-zebra CTRL e MCT8MO às 25 horas pósfertilização (hpf) por RNA-seq. Foram encontrados 4343 genes diferencialmente expressos. A análise utilizando o Reactome revelou que a MTH está envolvida direta ou indiretamente na expressão de genes pertencentes a importantes vias de sinalização, incluindo Notch, Shh e Wnt. A análise da distribuição celular de genes alvo da MTH por hibridação in-situ revelou uma ação celular específica em células estaminais neurais, mas também sobre várias classes de neurónios diferenciados. A análise transcriptómica revelou também que uma série de genes envolvidos em vários passos de processos-chave da neurogénese são modulados pela MTH. Analisando alguns destes genes numa série temporal desde a fase da segmentação até à eclosão do embrião de peixe-zebra por qPCR, determinamos a janela temporal na qual a MTH é necessária para um correto desenvolvimento do sistema nervoso central no peixezebra. Mostramos que a MTH está envolvida na regulação de componentes da sinalização Notch, tais como notch1a, dla, dld, her2 e her4 durante o processo de neurogénese, enquanto que genes envolvidos na formação e manutenção da neuroectoderme não são regulados pela MTH. A resposta à ausência de MTH inicia-se às 12hpf, sendo que a janela de desenvolvimento entre as 22 e 25hpf parece ser particularmente sensível à ação da MTH. Globalmente estes resultados mostram que a MTH não está envolvida na indução neural, nem na compartimentalização do sistema nervoso central. No entanto é demonstrada a importância da MTH na fase inicial da neurogénese pela promoção da manutenção de populações de células progenitoras neurais. A análise à citoarquitectura da medula espinhal revelou que na fase final do desenvolvimento embrionário as células neurais presentes em embriões CTRLMO e MCT8MO diferem substancialmente. A diminuição de transporte de MTH para as células alvo leva a uma desorganização geral do tecido neural, para além duma redução em células estaminais neurais, subpopulações de células progenitoras de neurónios, células radiais gliais, células da glia maduras e progenitoras de oligodendrócitos; enquanto que a população de neurónios motores primários é mantida na ausência de MTH. Análise de colocalização de células progenitoras neurais her2(+), dla(+) e fabp7a(+) com RNAm de componentes do metabolismo da hormona da tiroide, nomeadamente recetores (thraa e thrab) e o transportador mct8, permitiu a identificação de células que estão sob a regulação da MTH. Um dos papeis clássicos da TH envolve a sobrevivência a proliferação celulares, no entanto a sua função varia com o tipo celular, o estadio de desenvolvimento e contexto celular. Verificámos que em embriões MCT8MO a sobrevivência e proliferação de células progenitoras neurais her2(+) e dla(+) estava comprometida, tanto na medula espinhal como no romboencéfalo. Este facto pode impactar a diversidade das células neurais obtidas no final da embriogénese. Na verdade, a divisão assimétrica de células progenitoras originando células da glia ou progenitoras intermediárias está diminuída nos embriões MCT8MO, mostrando um possível papel da MTH na sua formação. Com vista a esclarecer o papel da MTH sobre a sinalização Notch procedeu-se à ativação da sinalização Notch em células neurais da espinhal medula de embriões MCT8MO e CTRLMO. Esta sobre-expressão celular isolada da sinalização Notch em células individuais mostrou ser insuficiente para recuperar o fenótipo induzido pela falta de MTH, demonstrando a importância do nicho celular na regulação da ação da MTH. A ação da MTH parece estar envolvida no memanismo de divisão assimétrica de células neuroepiteliais. Este tipo de divisão está na origem da diversidade de células neurais obtidas. Um reflexo da perda deste tipo de divisões na espinhal medula pode ser a perda de progenitores intermediários que expressam neurogenina 1 e neurod6b. Dado que a MTH regula várias vias morfogenéticas é provável que a sua ação seja a de integradora entre estas vias, permitindo o equilíbrio entre estes sinais num determinado tempo e contexto celular específicos. As ações da MTH refletem-se no desenvolvimento correto e atempado de neurónios e células da glia. É de grande interesse continuar a explorar o significado destas descobertas, nomeadamente para esclarecer as causas genéticas e celulares que causam a síndrome de Herdnon-Dudley (AHDS). Foi desenvolvido um modelo de ação da MTH durante o desenvolvimento no peixe zebra, em que em subpopulações de células progenitoras contendo MCT8 e recetores da hormona da tiroide (sensíveis a TH) na ausência desta sofrem apoptose e/ou redução na proliferação em momentos distintos do desenvolvimento neural. As células progenitoras não responsivas à TH prosseguem o seu desenvolvimento. O balanço final será uma diminuição da diversidade de progenitores neurais e consequente perda na variedade de neurónios e células da glia maduros. Este efeito a nível celular terá efeito na função do CNS. Em conclusão este trabalho mostra que a hormona da tiroide transmitida da mãe para o embrião e que dá entrada nas células alvo através do MCT8 permite o desenvolvimento de populações de progenitores neurais e o consequente enriquecimento da diversidade celular, necessária à formação de um sistema nervoso central funcional.This study received Portuguese national funds from operational programmes CRESC Algarve 2020 and COMPETE 2020 through project EMBRC.PT ALG-01-0145-FEDER- 022121. The author was a recipient of a FCT PhD grant SFRH/BD/111226/201

    Preaching and the Revelatory Plot: An Alternative to the Resolution Plot in Narrative Preaching

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    Abstract This thesis presents the case for the revelatory plot as a framework for narrative preaching. It offers an alternative to the resolution plot with its arc from conflict to climax and resolution and its emphasis on action and event. The revelatory plot is a more open form that prioritizes character and thought, with insights gained through earthed particulars. It is a minor plot form from literature and drama, but this thesis contends it is a significant form in some styles of art, from which preachers can learn. This synthesis of art, homiletics and the revelatory plot constitutes a new and deeply embodied approach. A revelatory sermon form is developed that unfolds biblical narratives in order to expose emotional, physical, social-economic, political and spiritual realities that are frequently assumed but not stated in the text. This displays the faith of biblical characters practised in the complexities of life and creates a form of preaching where relevance is achieved through identification and recognition. The revelatory style uses language that carries a sense of the reality of God working in the everyday world and engages imagination in all its functions. A cooperative hermeneutic — where author, text and reader create an arena to progress meaning — provides the hermeneutical underpinning. The epistemological foundation is a form of personal knowledge, and critical realism provides the philosophical standpoint. Theologically, this thesis draws on understandings of creation, the imago Dei and incarnation to affirm the material world and humanity as potential ways to learn about God. This is developed in a theology of revelation, with understandings of God coming through general revelation within an interpretive framework of special revelation. The central thesis is that sermons using a revelatory plot can deliver invitational, relevant and embodied preaching that affirms ordinary faith and embraces the complexity of Christian faith lived in the world

    Iran-U.S. military-security relations in the 1970s

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    The subject of this dissertation is "Iran-U.S. Military-Security Relations in the 1970s". The dissertation consists of seven chapters and a conclusion. In the first chapter an attempt is made to layout the main factors which contribute to arms transfers in the international system, from the perspectives of both the donor and recipient states. Moreover, the impact of arms sales on third world societies are described in this same chapter. The second chapter deals with the historical evolution of Iran-U.S. military security ties, inception during the Second World War up to 1969. genesis and since their Discussion in the third chapter focuses on the main factors which determined the shape and pace of Iran-U.S. military-security ties in the 1970s, including that in the area of arms supply relationship. The exposition of capability in the chapter. the 1970s increase in is the main Iran's purpose order-of-combat of the fourth The main purpose of chapter five is the delineation of various debates within and between the various branches of U.S. government for or against Iran's arms purchases. Chapter six discusses Iran's regional security policy in the 1970s. The final chapter deals with the various contacts between members of the U.S. government and Iran's new revolutionary regime, from revolution's success in February 1979 up to the seizure of American embassy in November 1979, with the emphasis being on military-security dealings between the two countries. In the conclusion an attempt is made to draw from the past some broad lessons for Iran's security and, bearing in mind the material in chapter one, to highlight a few insights into arms transfer as a phenomena in the international system

    Propuesta de inclusión de esfuerzos en el control de un brazo robot para asegurar el cumplimiento de la rugosidad superficial durante operaciones de lijado en diferentes materiales

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    Tesis por compendio[ES] El mecanizado con brazos robots ha sido estudiado aproximadamente desde los años 90, durante este tiempo se han llevado a cabo importantes avances y descubrimientos en cuanto a su campo de aplicación. En general, los robots manipuladores tienen muchos beneficios y ventajas al ser usados en operaciones de mecanizado, tales como, flexibilidad, gran área de trabajo y facilidad de programación, entre otras, frente a las Máquinas Herramientas de Control numérico (MHCN) que necesitan de una gran inversión para trabajar piezas muy grandes o incrementar sus grados de libertad. Como desventajas, frente a las MHCN, los brazos robóticos poseen menor rigidez, lo que combinado con las altas fuerzas producidas en los procesos de mecanizado hace que aparezcan errores de precisión, desviaciones en las trayectorias, vibraciones y, por consiguiente, una mala calidad en las piezas fabricadas. Entre los brazos robots, los brazos colaborativos están en auge debido a su programación intuitiva y a sus medidas de seguridad, que les permiten trabajar en el mismo espacio que los operadores sin que estos corran riesgos. Como desventaja añadida de los robots colaborativos se encuentra la mayor flexibilidad que estos tienen en sus articulaciones, debido a que incluyen reductores del tipo Harmonic drive. El uso de un control de fuerza en procesos de mecanizado con brazos robots permite controlar y corregir en tiempo real las desviaciones generadas por la flexibilidad en las articulaciones del robot. Utilizar este método de control es beneficioso en cualquier brazo robot; sin embargo, el control interno que incluyen los robots colaborativos presenta ventajas que permiten que el control de fuerza pueda ser aplicado de una manera más eficiente. En el presente trabajo se desarrolla una propuesta real para la inclusión del control de esfuerzos en el brazo robot, así como también, se evalúa y cuantifica la capacidad de los robots industriales y colaborativos en tareas de mecanizado. La propuesta plantea cómo mejorar la utilización de un control de fuerza por bucle interior/exterior aplicado en un brazo colaborativo cuando se desconocen los pares reales de los motores del robot, así como otros parámetros internos que los fabricantes no dan a conocer. Este bucle de control interior/exterior ha sido utilizado en aplicaciones de pulido y lijado sobre diferentes materiales. Los resultados indican que el robot colaborativo es factible para realizar tales operaciones de mecanizado. Sus mejores resultados se obtienen cuando se utiliza un bucle de control interno por velocidad y un bucle de control externo de fuerza con algoritmos, Proporcional-Integral-Derivativo o Proporcional más Pre-Alimentación de la Fuerza.[CA] El mecanitzat amb braços robots ha estat estudiat aproximadament des dels anys 90, durant aquest temps s'han dut a terme importants avanços i descobriments en el que fa al seu camp d'aplicació. En general, els robots manipuladors tenen molts beneficis i avantatges al ser usats en operacions de mecanitzat, com ara, flexibilitat, gran àrea de treball i facilitat de programació, entre d'altres, davant de Màquines Eines de Control Numèric (MECN) que necessiten d'una gran inversió per treballar peces molt grans o incrementar els seus graus de llibertat. Com a desavantatges, enfront de les MECN, els braços robòtics posseeixen menor rigidesa, el que combinat amb les altes forces produïdes en els processos de mecanitzat fa que apareguin errors de precisió, desviacions en les trajectòries, vibracions i, per tant, una mala qualitat en les peces fabricades. Entre els braços robots, els braços col·laboratius estan en auge a causa de la seva programació intuïtiva i a les seves mesures de seguretat, que els permeten treballar en el mateix espai que els operadors sense que aquests corrin riscos. Com desavantatge afegida als robots col·laboratius es troba la major flexibilitat que aquests tenen en les seves articulacions, a causa de que inclouen reductors del tipus Harmonic drive. L'ús d'un control de força en processos de mecanitzat amb braços robots permet controlar, i corregir, en temps real les desviacions generades per la flexibilitat en les articulacions del robot. Utilitzar aquest mètode de control és beneficiós en qualsevol braç robot, però, el control intern que inclouen els robots col·laboratius presenta avantatges que permeten que el control de força es puga aplicar d'una manera més eficient. En el present treball es desenvolupa una proposta real per a la inclusió del control d'esforços en el braç robot, així com s'avalua i quantifica la capacitat dels robots industrials i col·laboratius en tasques de mecanitzat. La proposta planteja com millorar la utilització d'un control de força per bucle interior/exterior aplicat en un braç col·laboratiu, quan es desconeixen els parells reals dels motors del robot, així com altres paràmetres interns que els fabricants no donen a conèixer. Aquest bucle de control interior/exterior ha estat utilitzat en aplicacions de polit sobre diferents materials. Els resultats indiquen que el robot col·laboratiu és factible de realitzar aquestes operacions de mecanitzat. Els seus millors resultats s'obtenen quan s'utilitza un bucle de control intern per velocitat i un bucle de control extern de força amb els algoritmes Proporcional-Integral-Derivatiu o Proporcional més Pre-alimentació de la Força.[EN] Machining with robot arms has been studied approximately since the 90s; during this time, important advances and discoveries have been made in its field of application. In general, manipulative robots have many benefits and advantages when they are used in machining operations, such as flexibility, large work area, and ease of programming, among others, compared to Numerical Control Machine Tools (NCMT) that need a great investment to work very large pieces or increase their degrees of freedom. As for disadvantages, compared to NCMT, robotic arms have lower rigidity, which, combined with the high forces produced in machining processes, causes precision errors, path deviations, vibrations, and, consequently, poor quality in the manufactured parts. Among robot arms, collaborative arms are on the rise due to their intuitive programming and safety measures, which allow them to work in the same space without risk for the operators. An added disadvantage of collaborative robots is their flexibility in their joints because they include Harmonic drive type reducers. The use of force control in machining processes with robot arms makes possible to control and correct, in real-time, the deviations generated by the flexibility in the robot's joints. The use of this control method is beneficial for any robot arm. However, the internal control included in collaborative robots has advantages that allow the force control to be applied more efficiently. In this work, a real proposal is developed to include effort control in the robot arm. The capacity of industrial and collaborative robots in machining tasks is evaluated and quantified. The proposal recommends how to improve the use of an inner/outer force control loop applied in a collaborative arm, when the real torques of the robot's motors are unknown and other internal parameters that manufacturers do not disclose. This inner/outer control loop has been used in polishing and sanding applications on different materials. The results indicate that the collaborative robot is feasible to perform such machining operations. Best results are obtained using an internal velocity control loop and external force control loop with Proportional-Integral-Derivative or Proportional plus Feed Forward.The authors are grateful for the financial support of the Spanish Ministry of Economy and European Union, grant DPI2016-81002-R (AEI/FEDER, UE). This work was funded by the CONICYT PFCHA/DOCTORADO BECAS CHILE/2017 – 72180157.Pérez Ubeda, RA. (2022). Propuesta de inclusión de esfuerzos en el control de un brazo robot para asegurar el cumplimiento de la rugosidad superficial durante operaciones de lijado en diferentes materiales [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/182000TESISCompendi
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