Towards Robust and Effective Passive Compliance Design of End-Effectors for Robotic Train Fluid Servicing

Copyright © 2023 by the authors. Without mechanical compliance robots rely on controlled environments and precision equipment to avoid clashes and large contact forces when interacting with an external workpiece, e.g., a peg-in-hole (PiH) task. In such cases, passive compliance devices are used to reduce the insertion force (and in turn the robot payload) while guiding corrective motions. Previous studies in this field are limited to small misalignments and basic PiH geometries inapplicable to prevalent robotic and autonomous systems (RASs). In addition to these issues, our work argues that there is a lack of a unified approach to the development of passive compliance systems. To this end, we propose a higher-level design approach using robust engineering design (RED) methods. In a case study, we demonstrated this general approach with a Taguchi design framework, developing a remote centre compliant (RCC) end-effector for robotic train fluid servicing. For this specific problem, a pseudo-rigid-body model (PRBM) is suggested in order to save enormous computation time in design, modelling, and optimisation. Our results show that the compliant end-effector is capable of significantly reducing the insertion force for large misalignments up to 15 mm and 6 degrees.Rail Safety and Standards Board (RSSB), under contract RSSB 2675, and from EPSRC Impact Acceleration Account, under the Grant No. EP/X525510/1

Preliminary study on end-effector compliance in automated fluid coupling for trains

The whole Proceedings of TMCE 2020 are available for open access at https://tmce.io.tudelft.nl/proceedingsIn order to improve train availability and workplace safety standards, the rail industry is keen to modernise maintenance of trains through increased use of Robotic Autonomous Systems (RAS). Our research aims to address the mechanical challenges of automated fluid coupling in future applications of train-fluid servicing. Depending on the intricacy of the servicing RAS, a degree of misalignment will always exist between the robot end-effector and train fluid ports. Compliant end-effectors can generate flexing motions that facilitate misaligned insertions. Present work focuses on understanding the role of passive compliance within the end-effector of our demonstrator train-fluid servicing robot. Physical experiments were performed and using Design of Experiments we identify the effect of end-effector compliance parameters on misaligned insertions. Results show that maximum insertion force and work done increase exponentially with increasing misalignment. Certain arrangements of compliance parameters can significantly improve the coupling performance under misalignments. Nonetheless, forces observed are still too large and our research will continue to develop compliant end-effectors for better automated coupling that will reduce RAS force requirements.Rail Safety and Standards Board (RSSB

Preliminary Study of End-Effector Compliance for Reducing Insertion Force in Automated Fluid Coupling for Trains

Rail Safety and Standards Board (RSSB) (contract RSSB 2675)

Development and optimization of a new suspension system for lower limb prosthesis

The increasing rate of lower limb amputations reinforces the need to develop a new suspension system that provides a better quality of life for the lower limb amputees. This study aimed to present a novel suspension system that improves amputee’s satisfaction in terms of donning and doffing process of the prosthetic lower limb. The design of the proposed suspension system was developed following the design methodology, to establish the amputee’s needs, objectives, functions, requirements and specifications in order to op-timize the final solution. The final solution is a combination of a guiding and fixation mechanisms that improve the donning and doffing process by driv-ing the serrated pin to the fixation system. The proposed suspension system is a good alternative to improve the quality of life of amputees with lower activity level on the daily basis.(undefined

Multidimensional simple waves in fully relativistic fluids

A special version of multi--dimensional simple waves given in [G. Boillat, {\it J. Math. Phys.} {\bf 11}, 1482-3 (1970)] and [G.M. Webb, R. Ratkiewicz, M. Brio and G.P. Zank, {\it J. Plasma Phys.} {\bf 59}, 417-460 (1998)] is employed for fully relativistic fluid and plasma flows. Three essential modes: vortex, entropy and sound modes are derived where each of them is different from its nonrelativistic analogue. Vortex and entropy modes are formally solved in both the laboratory frame and the wave frame (co-moving with the wave front) while the sound mode is formally solved only in the wave frame at ultra-relativistic temperatures. In addition, the surface which is the boundary between the permitted and forbidden regions of the solution is introduced and determined. Finally a symmetry analysis is performed for the vortex mode equation up to both point and contact transformations. Fundamental invariants and a form of general solutions of point transformations along with some specific examples are also derived.Comment: 21 page

Type 1 diabetes genetic risk score discriminates between monogenic and Type 1 diabetes in children diagnosed at the age of < 5 years in the Iranian population

This is the final version. Available on open access from Wiley via the DOI in this recordAim To examine the extent to which discriminatory testing using antibodies and Type 1 diabetes genetic risk score, validated in European populations, is applicable in a non‐European population. Methods We recruited 127 unrelated children with diabetes diagnosed between 9 months and 5 years from two centres in Iran. All children underwent targeted next‐generation sequencing of 35 monogenic diabetes genes. We measured three islet autoantibodies (islet antigen 2, glutamic acid decarboxylase and zinc transporter 8) and generated a Type 1 diabetes genetic risk score in all children. Results We identified six children with monogenic diabetes, including four novel mutations: homozygous mutations in WFS1 (n=3), SLC19A2 and SLC29A3, and a heterozygous mutation in GCK. All clinical features were similar in children with monogenic diabetes (n=6) and in the rest of the cohort (n=121). The Type 1 diabetes genetic risk score discriminated children with monogenic from Type 1 diabetes [area under the receiver‐operating characteristic curve 0.90 (95% CI 0.83–0.97)]. All children with monogenic diabetes were autoantibody‐negative. In children with no mutation, 59 were positive to glutamic acid decarboxylase, 39 to islet antigen 2 and 31 to zinc transporter 8. Measuring zinc transporter 8 increased the number of autoantibody‐positive individuals by eight. Conclusions The present study provides the first evidence that Type 1 diabetes genetic risk score can be used to distinguish monogenic from Type 1 diabetes in an Iranian population with a large number of consanguineous unions. This test can be used to identify children with a higher probability of having monogenic diabetes who could then undergo genetic testing. Identification of these individuals would reduce the cost of treatment and improve the management of their clinical course.Wellcome TrustDiabetes U

The impact of COVID-19 pandemic on stress and anxiety of non-infected pregnant mothers

Background: The newly emerging COVID-19 has caused severe anxiety around the world and it is infecting more people each day since there is no preventive measure or definite therapy for the diseases. The present study aimed to evaluate its effect on anxiety and stress of pregnant mothers during perinatal care. Methods: Three�hundred pregnant mothers without COVID�19 infection who were referred to the hospitals affiliated to Iran University of Medical Sciences for delivery during April 2020, based on negative clinical symptoms and the results of polymerase chain reaction (rt-PCR) for COVID�19, were recruited by census method and asked to complete the Persian version of the perceived stress scale (PSS); participants views about their anxiety level and the role of COVID�19 as the source of their stress and worries were recorded. Women who refused to continue the study were excluded. The frequency of variables and mean scores were calculated using SPSS v. 21. Results: Mean age of mothers was 30.20±16.19 years; 31.3 were primigravida and mean gestational age was 38.00±4.14 weeks. Moreover, 16.3 asked for earlier pregnancy termination and 39 requested Cesarean section (C/S). Assessing the mothers� anxiety revealed a high/very high level of anxiety in 51.3. The majority felt worried and frustrated because of COVID�19 (86.4). Social media had a great impact on the level of stress among these mothers (60.3). Conclusion: COVID-19 pandemic is an important source for the increased anxiety and stress among healthy pregnant mothers. © 2021 Avicenna Research Institute. All rights reserved

An otoprotective role for the apoptosis inhibitor protein survivin

Hearing impairment caused by ototoxic insults, such as noise or gentamicin is a worldwide health problem. As the molecular circuitries involved are not yet resolved, current otoprotective therapies are rather empirical than rational. Here, immunohistochemistry and western blotting showed that the cytoprotective protein survivin is expressed in the human and guinea pig cochlea. In the guinea pig model, moderate noise exposure causing only a temporary hearing impairment transiently evoked survivin expression in the spiral ligament, nerve fibers and the organ of Corti. Mechanistically, survivin upregulation may involve nitric oxide (NO)-induced Akt signaling, as enhanced expression of the endothelial NO synthase and phosphorylated Akt were detectable in some surviving-positive cell types. In contrast, intratympanic gentamicin injection inducing cell damage and permanent hearing loss correlated with attenuated survivin levels in the cochlea. Subsequently, the protective activity of the human and the guinea pig survivin orthologs against the ototoxin gentamicin was demonstrated by ectopic overexpression and RNAi-mediated depletion studies in auditory cells in vitro. These data suggest that survivin represents an innate cytoprotective resistor against stress conditions in the auditory system. The pharmacogenetic modulation of survivin may thus provide the conceptual basis for the rational design of novel therapeutic otoprotective strategies