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1 – 4 of 4Stephen Fox, Olli Aranko, Juhani Heilala and Päivi Vahala
Exoskeletons are mechanical structures that humans can wear to increase their strength and endurance. The purpose of this paper is to explain how exoskeletons can be used to…
Abstract
Purpose
Exoskeletons are mechanical structures that humans can wear to increase their strength and endurance. The purpose of this paper is to explain how exoskeletons can be used to improve performance across five phases of manufacturing.
Design/methodology/approach
Multivocal literature review, encompassing scientific literature and the grey literature of online reports, etc., to inform comprehensive, comparative and critical analyses of the potential of exoskeletons to improve manufacturing performance.
Findings
There are at least eight different types of exoskeletons that can be used to improve human strength and endurance in manual work during different phases of production. However, exoskeletons can have the unintended negative consequence of reducing human flexibility leading to new sources of musculoskeletal disorders (MSD) and accidents.
Research limitations/implications
Findings are relevant to function allocation research concerned with manual production work. In particular, exoskeletons could exacerbate the traditional trade-off between human flexibility and robot consistency by making human workers less flexible.
Practical implications
The introduction of exoskeletons requires careful health and safety planning if exoskeletons are to improve human strength and endurance without introducing new sources of MSD and accidents.
Originality/value
The originality of this paper is that it provides detailed information about a new manufacturing technology: exoskeletons. The value of this paper is that it provides information that is comprehensive, comparative and critical about exoskeletons as a potential alternative to robotics across five phases of manufacturing.
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Gabriel Dämmer, Hartmut Bauer, Rüdiger Neumann and Zoltan Major
This study aims to investigate the suitability of a multi-step prototyping strategy for producing pneumatic rotary vane actuators (RVAs) for the development of lightweight robots…
Abstract
Purpose
This study aims to investigate the suitability of a multi-step prototyping strategy for producing pneumatic rotary vane actuators (RVAs) for the development of lightweight robots and actuation systems.
Design/methodology/approach
RVAs typically have cast aluminum housings and injection-molded seals that consist of hard thermoplastic cores and soft elastomeric overmolds. Using a combination of additive manufacturing (AM), computer numerical control (CNC) machining and elastomer molding, a conventionally manufactured standard RVA was replicated. The standard housing design was modified, and polymeric replicas were obtained by selective laser sintering (SLS) or PolyJet (PJ) printing and subsequent CNC milling. Using laser-sintered molds, actuator seals were replicated by overmolding laser-sintered polyamide cores with silicone (SIL) and polyurethane (PU) elastomers. The replica RVAs were subjected to a series of leakage, friction and durability experiments.
Findings
The AM-based prototyping strategy described is suitable for producing functional and reliable RVAs for research and product development. In a representative durability experiment, the RVAs in this study endured between 40,000 and 1,000,000 load cycles. Frictional torques were around 0.5 Nm, which is 10% of the theoretical torque at 6 bar and comparable to that of the standard RVA. Models and parameters are provided for describing the velocity-dependent frictional torque. Leakage experiments at 10,000 load cycles and 6 bar differential pressure showed that PJ housings exhibit lower leakage values (6.8 L/min) than laser-sintered housings (15.2 L/min), and PU seals exhibit lower values (8.0 l/min) than SIL seals (14.0 L/min). Combining PU seals with PJ housings led to an initial leakage of 0.4 L/min, which increased to only 1.2 L/min after 10,000 load cycles. Overall, the PU material used was more difficult to process but also more abrasion- and tear-resistant than the SIL elastomer.
Research limitations/implications
More work is needed to understand individual cause–effect relationships between specific design features and system behavior.
Originality/value
To date, pneumatic RVAs have been manufactured by large-scale production technologies. The absence of suitable prototyping strategies has limited the available range to fixed sizes and has thus complicated the use of RVAs in research and product development. This paper proves that functional pneumatic RVAs can be produced by using more accessible manufacturing technologies and provides the tools for prototyping of application-specific RVAs.
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This study aims to test the role of the state of occupation, represented in Israel, as one of the most significant challenges, which faces the Jordanian water security. Where…
Abstract
Purpose
This study aims to test the role of the state of occupation, represented in Israel, as one of the most significant challenges, which faces the Jordanian water security. Where Israel expands in its policy and ideology everyday its hydro-hegemony over the Jordanian waters. Hence, its acts result in negative consequences on the Jordanian water and food security, which in turn affects the Jordanian national security as a whole.
Design/methodology/approach
This study relied on the following two approached to tackle its problem: first: descriptive approach: the descriptive approach depends on defining the apparent features and describing their nature and the type of the relationship between its variables. It aims to achieving a better and deeper understanding on the situation of its future policies and measures. And research uses the system analysis approach to handle the subject matter. Given the influence of water on the development, Jordan, as an organic or a political and social state, takes into account the reasons and causes of development. Jordan turns into an active political state, with water as an influencing factor on it. This premise represents the core of the system analysis approach.
Findings
The research concluded that the Israeli theft of the Jordanian waters is the main factor in the Jordanian water crisis. If Jordan had received its usurped water rights by Israel, it could have been able to solve its water issue represented in the increasing deficit in its water balance. Therefore, the Israeli hydro-hegemony on the Jordanian water resources caused the imbalance in its water security and, in turn, caused the development process to falter in general.
Originality/value
The value of the research lies in the fact that it addresses the most important reasons behind the water crisis in Jordan, represented in the Israeli control over the Jordanian water resources and the research shows that the amount of water stolen by Israel is enough to solve the water crisis in Jordan.
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