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Article
Publication date: 6 June 2019

Hao Wang, GuoHua Gao, Qixiao Xia, Han Ren, LianShi Li and Yuhang Zheng

The purpose of this paper is to present a novel stretch-retractable single section (SRSS) continuum manipulator which owns three degrees of freedom and higher motion range…

Abstract

Purpose

The purpose of this paper is to present a novel stretch-retractable single section (SRSS) continuum manipulator which owns three degrees of freedom and higher motion range in three-dimension workspace than regular single continuum manipulator. Moreover, the motion accuracy was analyzed based on the kinematic model. In addition, the experiments were carried out for validation of the theory.

Design/methodology/approach

A kinematics model of the SRSS continuum manipulator is presented for analysis on bending, rotating and retracting in its workspace. To discuss the motion accuracy of the SRSS continuum manipulator, the dexterity theory was introduced based on the decomposing of the Jacobian matrix. In addition, the accuracy of motion is estimated based on the inverse kinematics and dexterity theory. To verify the presented theory, the motion of free end was tracked by an electromagnetic positioning system. According to the comparison of experimental value and theoretical analysis, the free end error of SRSS continuum manipulator is less than 6.24 per cent in the region with favorable dexterity.

Findings

This paper presents a new stretch-retractable continuum manipulator that the structure was composed of several springs as the backbone. Thus, the SRSS continuum manipulator could own wide motion range depending on its retractable structure. Then, the motion accuracy character of the SRSS continuum manipulator in the different regions of its workspace was obtained both theoretically and experimentally. The results show that the high accuracy region distributes in the vicinity of the outer boundary of the workspace. The motion accuracy gradually decreases with the motion position approaching to the center of its workspace.

Research limitations/implications

The presented SRSS continuum manipulator owns three degrees of freedom. The future work would be focused on the two-section structure which will own six degrees of freedom.

Practical implications

In this study, the SRSS continuum manipulator could be extended to six degrees of freedom continuum robot with two sections that is less one section than regular six degrees of freedom with three single section continuum manipulator.

Originality/value

The value of this study is to propose a SRSS continuum manipulator which owns three degrees of freedom and could stretch and retract to expend workspace, for which the accuracy in different regions of the workspace was analyzed and validated based on the kinematics model and experiments. The results could be feasible to plan the motion space of the SRSS continuum manipulator for keeping in suitable accuracy region.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 19 February 2018

GuoHua Gao, Han Ren, QiXiao Xia, Hao Wang and LianShi Li

The purpose of this paper is to present a stretched backboneless continuum manipulator, which aims to provide sufficient inner room for potential transportation of objects…

Abstract

Purpose

The purpose of this paper is to present a stretched backboneless continuum manipulator, which aims to provide sufficient inner room for potential transportation of objects or fixture of necessary devices, and to reduce the number of motors for reduction of the weight of the system.

Design/methodology/approach

A mathematical model of the presented manipulator is established in this paper. To verify the presented theory, the position of the free end was recorded by a high-resolution digital camera in experiment. According to the comparison of experimental values and theoretical values, the error is less than 2.5 per cent. It shows that the mathematical model and theoretical analysis are reasonable; the presented continuum manipulator can reach to desired postures and positions.

Findings

This paper presents a new stretched backboneless continuum manipulator supported and driven by cannula tendons. The cannula tendons are composed of rubber tubes and glass fibers. The upper section and the lower section of the presented manipulator are driven by same motors. For steering the manipulator, switched driving strategy is developed based on the presented kinematics model. The presented manipulator possesses six degrees of freedom (DOFs) and has good performance in dealing with complex working environment. The experiment verifies the presented driving strategy.

Research limitations/implications

The presented backboneless continuum manipulator has only two sections and is supported by cannula tendons. Extending this structure to further more sections is a challenge and is left for future research.

Originality/value

The value of this study is to propose a stretched backboneless continuum manipulator, which can provide inner room as large as possible for potential usage and halve the number of motors, for which a switched driving strategy is put forward. As a result, the weight and complexity of the manipulator are decreased. The presented manipulator is able to move in potential complex environments and approach its objects in different postures in virtue of its high flexibility and its six DOFs.

Details

Industrial Robot: An International Journal, vol. 45 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 March 2002

Jaroslav Mackerle

Gives a bibliographical review of the finite element analyses of sandwich structures from the theoretical as well as practical points of view. Both isotropic and composite…

3341

Abstract

Gives a bibliographical review of the finite element analyses of sandwich structures from the theoretical as well as practical points of view. Both isotropic and composite materials are considered. Topics include: material and mechanical properties of sandwich structures; vibration, dynamic response and impact problems; heat transfer and thermomechanical responses; contact problems; fracture mechanics, fatigue and damage; stability problems; special finite elements developed for the analysis of sandwich structures; analysis of sandwich beams, plates, panels and shells; specific applications in various fields of engineering; other topics. The analysis of cellular solids is also included. The bibliography at the end of this paper contains 655 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1980 and 2001.

Details

Engineering Computations, vol. 19 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

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