Yinglong Chen, Wenshuo Li and Yongjun Gong
The purpose of this paper is to estimate the deformation of soft manipulators caused by obstacles accurately and the contact force and workspace can be also predicted.
Abstract
Purpose
The purpose of this paper is to estimate the deformation of soft manipulators caused by obstacles accurately and the contact force and workspace can be also predicted.
Design/methodology/approach
The continuum deformation of the backbone of the soft manipulator under contact is regarded as two constant curvature arcs and the curvatures are different according to the fluid pressure and obstacle location based on piecewise constant curvature framework. Then, this study introduces introduce the moment balance and energy conservation equation to describe the static relationship between driving moment, elastic moment and contact moment. Finally, simulation and experiments are carried out to verify the accuracy of the proposed model.
Findings
For rigid manipulators, environmental contact except for the manipulated object was usually considered as a “collision” which should be avoided. For soft manipulators, an environment is an important tool for achieving manipulation goals and it might even be considered to be a part of the soft manipulator’s end-effector in some specified situations.
Research limitations/implications
There are also some limitations to the presented study. Although this paper has made progress in the static modeling under environmental contact, some practical factors still limit the further application of the model, such as the detection accuracy of the environment location and the deformation of the contact surface.
Originality/value
Based on the proposed kinematic model, the bending deformation with environmental contact is discussed in simulations and has been experimentally verified. The comparison results show the correctness and accuracy of the presented SCC model, which can be applied to predict the slender deformation under environmental contact without knowing the contact force.
Details
Keywords
Susai Rajendran, A. Peter Pascal Regis and D.C. Trivedi
Benzamide has been made to undergo Hofmann rearrangement, in the presence of hypochlorite (OCl‐) generated in situ, by the electrolysis of sodium chloride solution using…
Abstract
Benzamide has been made to undergo Hofmann rearrangement, in the presence of hypochlorite (OCl‐) generated in situ, by the electrolysis of sodium chloride solution using platinised titanium anode and graphite cathode. The product is not a pure primary amine, namely aniline; but a polymeric aniline derivative is produced. It has a free amino end; and/or a free amino end is generated during the process of diazotisation. The product has been diazotised and coupled with naphthols to give dyes. The nature of the dyes have been analysed by uv‐visible spectral studies. The dyes are slightly different from the dyes prepared from pure aniline.
Details
Keywords
Zhixiong Yang, Bin Zhao, Liang Bo, Xiangyang Zhu and Kai Xu
Pick-and-place tasks are common across many industrial sectors, and many rigid-linked robots have been proposed for this application. This paper aims to alternatively present the…
Abstract
Purpose
Pick-and-place tasks are common across many industrial sectors, and many rigid-linked robots have been proposed for this application. This paper aims to alternatively present the development of a continuum robot for low-load medium-speed pick-and-place tasks.
Design/methodology/approach
An inversion of a previously proposed dual continuum mechanism, as a key design element, was used to realize the horizontal movements of the CurviPicker’s end effector. A flexible shaft was inserted to realize rotation and translation about a vertical axis. The design concept, kinematics, system descriptions and proof-of-concept experimental characterizations are elaborated.
Findings
Experimental characterizations show that the CurviPicker can achieve satisfactory accuracy after motion calibration. The CurviPicker is easy to control due to its simple kinematics, while its structural compliance makes it safe to work with, as well as less sensitive to possible target picking position errors to avoid damaging itself or the to-be-picked objects.
Research limitations/implications
The vertical translation of the CurviPicker is currently realized by moving the flexible shaft. Insertion of the flexible shaft introduces possible disturbances. It is desired to explore other form of variations to use structural deformation to realize the vertical translation.
Practical implications
The proposed CurviPicker realizes the Schöenflies motions via a simple structure. Such a robot can be used to increase robot presence and automation in small businesses for low-load medium-speed pick-and-place tasks.
Originality/value
To the best of the authors’ knowledge, the CurviPicker is the first continuum robot designed and constructed for pick-and-place tasks. The originality stems from the concept, kinematics, development and proof-of-concept experimental characterizations of the CurviPicker.
Details
Keywords
Leila Bousbia, Ammar Amouri and Abdelhakim Cherfia
Continuum robots modeling, be it from a hard or soft class, is giving rise to several challenges compared with rigid robots. These challenges are mainly due to kinematic…
Abstract
Purpose
Continuum robots modeling, be it from a hard or soft class, is giving rise to several challenges compared with rigid robots. These challenges are mainly due to kinematic redundancy, dynamic nonlinearity and high flexibility. This paper aims initially at designing a hard class of continuum robots, namely, cable-driven continuum robot (CDCR) and equally at developing their kinematic and dynamic models.
Design/methodology/approach
First, the CDCR prototype is constructed, and its description is made. Second, kinematic models are established based on the constant curvature assumption and inextensible bending section. Third, by using the Lagrange method, the dynamic model is derived under some simplifications and based on the kinematic equations, in which the flexible backbone’s elasticity modulus was identified experimentally. Finally, the static model of the CDCR is also derived based on the dynamic model.
Findings
Numerical examples are carried out using Matlab software to verify the static and dynamic models. Moreover, the static model is validated by comparing the simulation’s results to the real measurements that have been provided with satisfactory results.
Originality/value
To reduce the complexity of the dynamic model’s expressions and avoid the numerical singularity when the bending angle is close to zero, some simplifications have been taken, especially for the kinetic energy terms, by using the nonlinear functions approximation. Hence, the main advantage of this analytical-approximate solution is that it can be applied in the bending angle that ranges up to 2p with reasonable errors, unlike the previously proposed techniques. Furthermore, the resulting dynamic model has, to some extent, the proprieties of simplicity, accuracy and fast computation time. Ultimately, the obtained results from the simulations and real measurements demonstrate that the considered CDCR’s static and dynamic models are feasible.
Details
Keywords
Susai Rajendran, A. Peter Pascal Regis and D.C. Trivedi
Aqueous sodium chloride solution, containing benzamide was electrolysed (pH = 2), using platinised titanium anode and graphite cathode. The filtrate of the reaction mixture (pH …
Abstract
Aqueous sodium chloride solution, containing benzamide was electrolysed (pH = 2), using platinised titanium anode and graphite cathode. The filtrate of the reaction mixture (pH = 4.5) was diazotised and coupled with α‐naphthol in NaOH and also with β‐naphthol in NaOH. Dyes were produced. These dyes were matched with the standard dyes prepared from aniline. Uv‐visible absorption spectral study reveals that the dyes produced are slightly different from the standard dyes. During the course of the reaction benzamide is converted into aniline with a long chain polymeric unit having a free amino end; and/or a polymeric unit which generates a free amino end during the process of diazotisation.
Details
Keywords
Mingge Li, Zhongjun Yin, Xiaoming Huang, Jie Ma and Zhijie Liu
The purpose of this paper is to propose a casting process for the production of double-chamber soft fingers, which avoids the problems of air leakage and fracture caused by…
Abstract
Purpose
The purpose of this paper is to propose a casting process for the production of double-chamber soft fingers, which avoids the problems of air leakage and fracture caused by multistep casting. This proposed method facilitates the simultaneous casting of the inflation chamber and the jamming chamber.
Design/methodology/approach
An integrated molding technology based on the lost wax casting method is proposed for the manufacture of double-chamber soft fingers. The solid wax core is assembled with the mold, and then liquid silicone rubber is injected into it. After cooling and solidification, the mold is stripped off and heated in boiling water, so that the solid wax core melts and precipitates, and the integrated soft finger is obtained.
Findings
The performance and fatigue tests of the soft fingers produced by the proposed method have been carried out. The results show that the manufacturing method can significantly improve the fatigue resistance and stability of the soft fingers, while also avoiding the problems such as air leakage and cracking.
Originality/value
The improvement of the previous multistep casting method of soft fingers is proposed, and the integrated molding manufacturing method is proposed to avoid the problems caused by secondary bonding.
Details
Keywords
Deepak Doreswamy, Abhijay B.R., Jeane Marina D’Souza, Sachidananda H.K. and Subraya Krishna Bhat
Soft actuators using pneumatic-chamber (PneuNet)-based designs have been of interest in the area of soft robotics with scope of application in the area of biomedical assistance…
Abstract
Purpose
Soft actuators using pneumatic-chamber (PneuNet)-based designs have been of interest in the area of soft robotics with scope of application in the area of biomedical assistance and smart agriculture. Researchers have attempted to investigate multiple chambers in parallel to examine their deformation characteristics. However, there is a lacuna for investigation of the deformation characteristics of four parallel chambered soft actuators. The purpose of this study is to comprehensively investigate the different possible actuation scenarios and the resulting bending/deformation behaviours.
Design/methodology/approach
Therefore, in this study, a four-chambered PneuNet actuator is numerically investigated to evaluate the effects of pressurization scenarios and pressure levels on its performance, operating reaching and working volume.
Findings
The results of this study revealed that two-adjacent chamber equal pressurization and three-chamber pressurizations result in increased bending. However, two-opposite chamber pressurization reduces the bending angle with pressure levels in the lower pressure chamber. The maximum bending angle of 97° was achieved for single-chamber pressurization of 300 kPa. The two-adjacent chamber unequal pressurization can achieve a sweeping motion in the actuator along with bending. The working volume and reaching capability analysis revealed that the actuator can reach around 71% of the dimensional operating space.
Practical implications
The results provide fundamental guidance on the output nature of motion which can be obtained under different pressurization scenarios using the four-chambered design soft actuator, thereby making it a practical guide for implementation for useful applications.
Originality/value
The comprehensive pressurization scenarios and pressure level variations reported in this study will serve as fundamental operating guidelines for any practical implementation of the four-chambered PneuNet actuator.
Details
Keywords
Shiwei Zhao, Daochun Li and Jinwu Xiang
The purpose of this study is to propose an improved design of PneuNets bending actuator which aims at obtaining larger deflection with the same magnitude of pressure. The PneuNets…
Abstract
Purpose
The purpose of this study is to propose an improved design of PneuNets bending actuator which aims at obtaining larger deflection with the same magnitude of pressure. The PneuNets bending actuator shows potential application in the morphing trailing edge concept.
Design/methodology/approach
Finite element method is used to investigate the characteristics of the improved design bending actuator. Multiobjective optimal design of the PneuNets bending actuator is proposed based on the Gauss process regression models.
Findings
The maximum deflection is obtained when the height of the beams is smaller than half the height of the chambers. The spacing between chambers (beam length) has little effect on the deflection. Larger spacing could be used to reduce the actuator weight.
Originality/value
With the same pressure magnitude, the deflection of the improved design bending actuator is much larger than that of the baseline configuration. PneuNets bending actuator could increase the continuity of the aerodynamic surface compared to other actuators.
Details
Keywords
A. Ravi, T. Praveen, Chepuri R.K Rao, Ramanuj Narayan and K.V.S.N. Raju
The purpose of this paper is to get the insulating polyurethane (PU) as conductive type polymer by compositing with oligoanilines, namely, tetraaniline (TANi) with an implication…
Abstract
Purpose
The purpose of this paper is to get the insulating polyurethane (PU) as conductive type polymer by compositing with oligoanilines, namely, tetraaniline (TANi) with an implication of its use as anti-corrosion coating material.
Design/methodology/approach
Water dispersion of PU was prepared and used as a host material for TANi for composite formulation.
Findings
The composites are very useful as anti-corrosion coating on mild steel as evident from Tafel polarisation studies.
Research limitations/implications
The solubility of TANi is limited in other organic solvents; because of this, a high-boiling solvent like N-methyl-2-pyrrolidone (NMP) is used.
Practical implications
It can be used as a good anti-corrosion coating on mild steel. Apart from anti-corrosion material, this can be used as conductive-based sensor material and also electrostatic dissipation (ESD) or electromagnetic interference (EMI) shield.
Originality/value
The work is original.
Details
Keywords
Mihir Patel and Darshak Arunbhai Desai
The purpose of this paper is to capture the status of implementation of Six Sigma in various manufacturing industries and also examine the success of the Six Sigma by using…
Abstract
Purpose
The purpose of this paper is to capture the status of implementation of Six Sigma in various manufacturing industries and also examine the success of the Six Sigma by using different performance indicators.
Design/methodology/approach
The methodology of critical review involves the selection and classification of 112 research articles on the implementation of Six Sigma in different manufacturing industries. The selected articles are categorized by the following: articles distribution based on the year of publication, publication database, various journals, contribution of authors, continent, scale of industry, implemented approaches, focused industry, tools and techniques used in phases of Six Sigma methodology, and performance indicators used in Six Sigma implementation. Then after, future scopes of research opportunities are derived based on significant findings.
Findings
The literature revealed that: Very few work was undertaken on the implementation of Six Sigma in various manufacturing industries like ceramic, paper, gems and jewelry, cement, furniture, stone, fertilizer, forging, paper and surface treatment industries. Most of the researchers have considered very few performance indicators to identify the improvement after Six Sigma implementation. But, there is no clue regarding overall improvement in different perspectives after the implementation of Six Sigma. The financial indicators, personnel indicators, process indicators and customer indicators are useful to measure the overall improvement after the implementation of Six Sigma in the manufacturing sector.
Research limitations/implications
The study was carried out on the implementation of Six Sigma methodology in various manufacturing industries, and various performance indicators were identified while implementing the Six Sigma methodology. Case studies pertaining to service industries were not covered here.
Originality/value
Very little research has been carried out to measure the overall success of implementing Six Sigma methodology in manufacturing industries. This paper will provide value to students, researchers and practitioners of Six Sigma by providing insight into the implementation of Six Sigma in manufacturing industries.