Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

This paper addresses a robust motion control design of a planar 1P-2P RP hybrid manipulator for performing the lower limb rehabilitation treatments. The effectiveness and performances of the proposed system along with the motion control scheme is demonstrated using the real-time experiments. Further the robustness and sensitivity of the proposed control scheme is analyzed under different working conditions. In addition, the applicability of the proposed system is demonstrated successfully on an in-house fabricated prototype as a continuous passive sitting type lower limb rehabilitation mechanism in terms of clinical gait pattern generation and the gait-tracking task. © 2018, Springer Nature B.V.

World University root node

Department of Mechanical Engineering

Journal of Intelligent and Robotic Systems: Theory and Applications

Design and Robust Motion Control of a Planar 1P-2P RP Hybrid Manipulator for Lower Limb Rehabilitation Applications

This paper presents a task-space pose decomposition motion control scheme for a mobile manipulator to simplify the complexity of the conventional task-space pose control. The proposed scheme is decomposing the task-space pose vector (positions and orientation of the end effector) into a position vector and an orientation vector. Further the decomposed position vector (end effector position) is controlled through the task-space control and the orientation vector is controlled by using a joint-space control. The efficacy of the proposed control scheme is demonstrated numerically on a planar mobile manipulator (consists of a mobile platform and two link revolute (2R) serial planar manipulator) and the proposed scheme is compared with the conventional task-space pose control scheme. © Springer Nature Singapore Pte Ltd. 2019.

Advances in Intelligent Systems and Computing

Task-space pose decomposition motion control of a mobile manipulator

The proposed design named as the hybrid propulsion underwater robotic vehicle (HPURV)is a novel underwater vehicle with a hybridized propulsion for minimum energy consumption in ocean observations. This development is aimed at the comparison of different types of propulsion techniques in both vertical and horizontal directions of the motion to choose an optimum strategy for propulsion. The horizontal motion is achieved using the bio-inspired method of fish propulsion using caudal fin or a pair of pectoral fins or both. The tail design is made modular such that the caudal fin can be replaced by a conventional miniature thruster to understand the performance characteristics of the vehicle under similar operating conditions. The diving/climbing, pitching and rolling motions are achieved using three different mechanisms for, viz., (1)pitch and dive using pectoral fins, (2)pitch and dive by varying buoyancy of the vehicle and (3)pitch, dive, and roll by using a moving mass and a rolling mass mechanisms, respectively. All these mechanisms are assembled in the same vehicle and controlled independently or using a combination of two or more different mechanisms for the performance comparison of the vehicle in similar operating conditions. This paper also presents a dynamic model of the HPURV and a motion control scheme using a conventional Proportional-Derivative (PD)control technique to track a given complex spatial trajectory. © 2019 Elsevier Ltd

Ocean Engineering

Conceptual design of a hybrid propulsion underwater robotic vehicle with different propulsion systems for ocean observations

Department of Physics

APS March Meeting Abstracts 2019, F59.

States of self stress in disordered solids: memory, heterogeneity and yielding

Burnishing is a chipless secondary finishing operation which yields excellent surface finish. The present work focuses on multi-response optimization of diamond burnishing on 17-4 precipitation hardenable stainless steel under dry environment by using Taguchi based grey relation analysis (TGRA) to simultaneously minimize surface roughness and maximize surface hardness. The effect of the process parameters such as burnishing speed, burnishing feed and burnishing force on performance characteristics like surface roughness and surface hardness were studied. Taguchi's L9 orthogonal array has been adopted for the experimental design. The optimal burnishing process parameters were found to be burnishing speed of 73 m/min, burnishing feed of 0.048 mm/rev and burnishing force of 150 N. Burnishing feed is the most significant parameter on burnishing performance characteristics. It has been proved that the performance characteristics of a diamond burnishing process have been improved by effective use of this technique. © Published under licence by IOP Publishing Ltd.

IOP Conference Series: Materials Science and Engineering

Analysis of surface hardness and surface roughness in diamond burnishing of 17-4 PH stainless steel

Monolayer nanostructured thin films of TiSiN & TiAlSiN were deposited on WC-Co milling inserts using RF magnetron sputtering for metal cutting. The alloy targets of TiSi (80/20 at%) & TiAlSi (34/56/10 at%) were used for the deposition in an Ar + N atmosphere. The deposition time and parameters are optimized to develop a uniform and homogenous coating. The mechanical and metallurgical properties are characterized to analyze the wear resistance of the coating. The machinability studies on MDN 250 maraging steel is carried out using TiSiN and TiAlSiN coated WC-Co inserts under dry and wet environment. The machining responses such as surface roughness, cutting force, tool wear and tool life are analyzed by varying spindle speed. The results showed that TiAlSiN coating had a higher wear resistance and machining performance compared to the TiSiN coating owing to the high hardness and plasticity index of the coating. © 2020 IOP Publishing Ltd.

Fulltext

Materials Research Express

Characterisation and performance evaluation of TiSiN &amp;tiAlSiN coatings by RF magnetron sputtering deposition during end milling of maraging steel

17-4 precipitation-hardenable (PH) stainless steel is one of the widely used materials in various applications of engineering practices owing to their excellent corrosion resistance and high strength. The components such as automotive body, aerospace compressor blades, turbine blades and molds demand higher load carrying capacity and improved fatigue strength, which is possible to achieve by surface severe plastic deformation. Diamond burnishing process is an appropriate technique to produce such components which improves the surface integrity characteristics of the material. This article presents a comprehensive examination of the surface integrity of cryogenic diamond burnished 17-4 PH stainless steel using a novel diamond burnishing tool. The impact of diamond burnishing control factors on subsurface microhardness, surface roughness, surface hardness, surface topography, residual stress and surface morphology has been analyzed. The optimal control factor setting ensures the least surface roughness of 0.03 µm by the application of one factor at a time approach. Cryogenic diamond burnished surface achieves the exceptional surface finish and the surface hardness in tool-tip of 8 mm and 6 mm, respectively. The maximum surface hardness of 413 HV was attained using 6-mm tool-tip diameter. The subsurface microhardness improvement of 2% and 4% has been observed while using a tool-tip diameter of 6 mm in contrast to 8 mm and 10 mm. Compressive residual stresses have been generated at the top surface layer of the specimen. The attained experimental results prove that cryogenic diamond burnishing can be successfully applied to 17-4 PH stainless steel to enhance its surface integrity characteristics. © 2019, The Brazilian Society of Mechanical Sciences and Engineering.

Journal of the Brazilian Society of Mechanical Sciences and Engineering

Enhancement of surface integrity by cryogenic diamond burnishing toward the improved functional performance of the components

The hot deformation behavior of sintered Al-4%B4C composites was studied in this work. The main aim of this work is to estimate the effect of initial relative density (IRD), deformation temperature and strain rate on the hot deformation behavior and development of constitutive equations for predicting the hot deformation behavior. For this purpose, upsetting was performed in a hydraulic press for obtaining true stress-true strain curve data of sintered Al-4%B4C composites. The tests were carried out at different IRDes of 80%, 85% and 90% for various temperatures of 573 K, 673 K and 773 K and strain rates of 0.1 s-1, 0.2 s-1 and 0.3 s-1. The test reveals that the effect of IRD, deformation temperature and strain rate on flow stress curves is significant. The constitutive equations have been developed for predicting the flow stress behavior during the hot upsetting of sintered Al-4%B4C composite and it's validated with experiments. In addition, the required activation energies (Q) of sintered Al-4%B4C composites during the hot upsetting were calculated for various IRDes of 80%, 85%, and 90% was 161.06, 172.28 and181.05 KJ/mol, respectively, which is higher than the value of pure aluminum (144.3 KJ mol-1). © 2020 IOP Publishing Ltd.

Modeling flow behavior of sintered Al-4%B4C composite during high-temperature upsetting

We discuss SL(N, ℂ) Chern-Simons higher spin gauge theories in Euclidean AdS3. With appropriate boundary term, we derive the higher spin generalization of Schwarzian on-shell action. We investigate gravitationally dressed bi-locals, and we study the soft higher spin mode expansion to obtain soft mode eigenfunctions. We also derive the spin-s eigenfunction from Ward identity of W-algebra and a recursion relation. Using the on-shell action, we evaluate the contributions of the soft higher spin modes to the out-of-time-order correlators, and the corresponding Lyapunov exponent of SL(N) higher spin gravity is found to be 2πβ(N−1). © 2019, The Author(s).

Journal of High Energy Physics

Chaos in three-dimensional higher spin gravity

This article has been withdrawn by the authors. The authors identified some issues and brought them to the attention of the Journal. After careful analysis of all of the original data used for preparing the figures in the publication, the following errors were identified. The actin immunoblot from Fig. 6B was reused in Figs. 9C, 10C, and 11H. The actin immunoblot in Fig. 8B was reused in Fig. 11 (A and E). The actin immunoblot in Fig. 11B was reused in Fig. 11G. The authors submitted to the Journal all of the correct actin immunoblots for all of the figures listed above. Given these issues, the authors state that the responsible course of action would be to withdraw the article to maintain the high standards and rigor of scientific literature from the authors' group as well as the Journal. The authors apologize to the scientific community for what they state are inadvertent mistakes and will seek to republish the article with suitable modifications in due course. © 2019 by The American Society for Biochemistry and Molecular Biology, Inc. Published in the U.S.A.

Biological Sciences and Engineering

Journal of Biological Chemistry

Erratum: Cooperative regulation of NOTCH1 protein-phosphatidylinositol 3-kinase (PI3K) signaling by NOD1, NOD2, and TLR2 receptors renders enhanced refractoriness to transforming growth factor-β (TGF-β)- or cytotoxic T-lymphocyte antigen 4 (CTLA-4)-mediated impairment of human dendritic cell maturation (Journal of Biological Chemistry (2011) 286 (31347-31360) DOI: 10.1074/jbc.M111.232413)