Force control for a rigid dual peg-in-hole assembly

2017 ◽  
Vol 37 (2) ◽  
pp. 200-207 ◽  
Author(s):  
Kuangen Zhang ◽  
MinHui Shi ◽  
Jing Xu ◽  
Feng Liu ◽  
Ken Chen
Keyword(s):  
Force Control ◽  
Design Methodology ◽  
Control Strategies ◽  
Contact Forces ◽  
Experimental Results ◽  
Assembly Process ◽  
Automatic Assembly ◽  
Content Type ◽  
Assembly Task

Purpose This paper aims to realize the automatic assembly process for multiple rigid peg-in-hole components. Design/methodology/approach This paper develops fuzzy force control strategies for the rigid dual peg-in-hole assembly. Firstly the fuzzy force control strategies are presented. Secondly the contact states and contact forces are analyzed to prove the availability of the force control strategies. Findings The rigid dual peg-in-hole assembly experimental results show the effectiveness of the control strategies. Originality/value This paper proposes fuzzy force control strategies for a rigid dual peg-in-hole assembly task.

Analyses of peg‐hole jamming in automatic assembly machines

2011 ◽  
Vol 31 (4) ◽  
pp. 358-362 ◽  
Author(s):  
Ryspek Usubamatov ◽  
K.W. Leong
Keyword(s):  
Mathematical Model ◽  
Boundary Condition ◽  
Design Methodology ◽  
Manufacturing Industry ◽  
Critical Depth ◽  
Assembly Process ◽  
Automatic Assembly ◽  
Content Type ◽  
The Mathematical Model ◽  
Practical Implications

PurposeThe purpose of this paper is to investigate theoretically the process of jamming in the peg‐hole type parts and to derive a mathematical model of jamming.Design/methodology/approachThe mathematical model of the jamming of the peg‐hole type parts in assembly process was performed and its boundary conditions, which lead to jamming, defined.FindingsThe equation of the critical angles of declination for the peg, which leads to the peg‐hole jam, was derived. The boundary condition of the angles of declination and the depth of the peg insertion into the hole were defined.Research limitations/implicationsA mathematical model is developed for rigid parts with a hole and for the peg clamped in the rigid assembly mechanisms. The research has not considered flexible deformations and stiffness of the assembly mechanisms, which result in the peg's declination in the assembly process.Practical implicationsThe results are represented in the form of the peg's critical angles of declination and critical depth of insertion into the hole, which leads to jamming of the peg‐hole type parts to be assembled. On the basis of the obtained results, it is possible to formulate the tolerances of the declination angles for the assembly mechanisms, which clamp the peg‐type parts.Originality/valueThe proposed method calculating the critical angles of the peg's declination and critical depth of the peg's insertion into the hole for assembly of the peg‐hole type parts, enables one to increase the reliability of the assembly process in the manufacturing industry.

“Please tidy up before leaving”: nudging Airbnb guests toward altruistic behavior

2019 ◽  
Vol 13 (4) ◽  
pp. 524-530 ◽  
Author(s):  
Paul Ranson ◽  
Daniel Guttentag
Keyword(s):  
Social Presence ◽  
Design Methodology ◽  
Field Experiments ◽  
Experimental Results ◽  
Altruistic Behavior ◽  
Content Type ◽  
The Social ◽  
Relationship Model ◽  
Social Market ◽  
Practical Implications

Purpose This study aimed to investigate whether increasing the social presence within an Airbnb lodging environment could nudge guests toward altruistic cleaning behaviors. Design/methodology/approach The study was based around a theoretical framework combining the social-market versus money-market relationship model, nudge theory and social presence theory. A series of three field experiments were conducted, in which social presence was manipulated to test its impact on guest cleaning behaviors prior to departure. Findings The experimental results confirmed the underlying hypothesis that an Airbnb listing’s enhanced social presence can subtly induce guests to help clean their rental units prior to departure. Originality/value This study is the first to examine behavioral nudging in an Airbnb context. It is also one of the first field experiments involving Airbnb. The study findings offer clear theoretical and practical implications.

Fabrication and performance evaluation of two multi-layer passive micromixers

Sensor Review ◽  
2018 ◽  
Vol 38 (3) ◽  
pp. 321-325 ◽  
Author(s):  
Xueye Chen ◽  
Jienan Shen ◽  
Zengliang Hu
Keyword(s):  
Reynolds Number ◽  
Performance Evaluation ◽  
Design Methodology ◽  
Experimental Results ◽  
Microfluidic Chips ◽  
Mixing Index ◽  
Number Range ◽  
Content Type ◽  
Chaotic Convection ◽  
And Performance

PurposeThe purpose of this study is to provide a micromixer for achieving effective mixing of two liquids. The mixing of two liquids is difficult to achieve in microfluidic chips because they cannot form turbulence at small dimensions and velocities.Design/methodology/approachIn this paper, four kinds of passive micromixers based on splitting–recombination and chaotic convection are compared. First, a better E-shape mixing unit based on the previous F-shape mixing unit has been designed. Then, the E-shape mixing units are further combined to form three micromixers (i.e. E-mixer, SESM and FESM).FindingsFinally, the mixing experimental results show that the mixing indexes of E-mixer, SESM and FESM are more than those of F-mixer when the Reynolds number range is from 0.5 to 100. And at Re = 15, the lowest mixing index of E-mixer is 71%, which is the highest of the four micromixers.Originality/valueAt Re = 80, the highest mixing index of F-mixer and E-mixer is 92 and 94 per cent, respectively, and then it begins to decrease. But the mixing index of SESM and FESM remains close to 100 per cent.

Using fractional order weakening buffer operator to forecast the main indices of online shopping in China

2019 ◽  
Vol 9 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Xiao Hui Gao ◽  
Lifeng Wu
Keyword(s):  
Fractional Order ◽  
High Speed ◽  
Design Methodology ◽  
Online Shopping ◽  
Experimental Results ◽  
Order Number ◽  
Growth Trend ◽  
Content Type ◽  
Economic Indices ◽  
Expansion Period

Purpose The purpose of this paper is to predict the main economic indices of online shopping in China. Design/methodology/approach A fractional order weakening buffer operator (WBO) for the GM(1,1) model is put forward in order to solve the problem of limited nonlinear data. The order number of WBO can adjust in line with the scenario. Findings The experimental results indicate that the proposed method can consider the scenario and obtain more accurate forecasting results. Originality/value This study found that the slowdown of growth trend after the previous high speed expansion period will continue, and the online shopping sellers should make more efforts to develop potential consumers to increase its turnover.

A survey on design and development of an unmanned aerial vehicle (quadcopter)

2016 ◽  
Vol 4 (2) ◽  
pp. 70-106 ◽  
Author(s):  
Deepak B B V L ◽  
Pritpal Singh
Keyword(s):  
Control Systems ◽  
Motion Control ◽  
Design Methodology ◽  
Dynamic Models ◽  
Control Strategies ◽  
Content Type ◽  
Military Applications ◽  
Previous Decade ◽  
Potential Applications ◽  
Aerial Vehicle

Purpose – In the previous decade, unmanned aerial vehicles (UAVs) have turned into a subject of enthusiasm for some exploration associations. UAVs are discovering applications in different regions going from military applications to activity reconnaissance. The purpose of this paper is to overview a particular sort of UAV called quadrotor or quadcopter. Design/methodology/approach – This paper includes the dynamic models of a quadrotor and the distinctive model-reliant and model-autonomous control systems and their correlation. Findings – In the present time, focus has moved to outlining autonomous quadrotors. Ultimately, the paper examines the potential applications of quadrotors and their part in multi-operators frameworks. Originality/value – This investigation deals with the review on various quadrotors, their applications and motion control strategies.

Cooperative control of dual-arm robots in different human-robot collaborative tasks

2019 ◽  
Vol 40 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Xinbo Yu ◽  
Shuang Zhang ◽  
Liang Sun ◽  
Yu Wang ◽  
Chengqian Xue ◽  
...  
Keyword(s):  
Cooperative Control ◽  
Force Feedback ◽  
Control Strategies ◽  
Experimental Results ◽  
Distant Object ◽  
Content Type ◽  
Human Arm ◽  
Dual Arm Robot ◽  
Dual Arm ◽  
Robot Platform

Purpose This paper aims to propose cooperative control strategies for dual-arm robots in different human–robot collaborative tasks in assembly processes. The authors set three different regions where robot performs different collaborative ways: “teleoperate” region, “co-carry” region and “assembly” region. Human holds the “master” arm of dual-arm robot to operate the other “follower” arm by our proposed controller in “teleoperation” region. Limited by the human arm length, “follower” arm is teleoperated by human to carry the distant object. In the “co-carry” region, “master” arm and “follower” arm cooperatively carry the object to the region close to the human. In “assembly” region, “follower” arm is used for fixing the object and “master” arm coupled with human is used for assembly. Design/methodology/approach A human moving target estimated method is proposed for decreasing efforts for human to move “master” arm, radial basis functions neural networks are used to compensate for uncertainties in dynamics of both arms. Force feedback is designed in “master” arm controller for human to perceive the movement of “follower” arm. Experimental results on Baxter robot platform show the effectiveness of this proposed method. Findings Experimental results on Baxter robot platform show the effectiveness of our proposed methods. Different human-robot collaborative tasks in assembly processes are performed successfully under our cooperative control strategies for dual-arm robots. Originality/value In this paper, cooperative control strategies for dual-arm robots have been proposed in different human–robot collaborative tasks in assembly processes. Three different regions where robot performs different collaborative ways are set: “teleoperation” region, “co-carry” region and “assembly” region.

Advances in robotic prostheses

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rob Bogue
Keyword(s):  
Signal Processing ◽  
Design Methodology ◽  
Sensory Feedback ◽  
Control Strategies ◽  
Short Introduction ◽  
Content Type ◽  
Non Invasive ◽  
Computer Interfaces ◽  
Prosthesis Control ◽  
Robotic Prosthesis

Purpose This paper aims to provide details of recent advances in robotic prostheses with the emphasis on the control and sensing technologies. Design/methodology/approach Following a short introduction, this paper first discusses the main robotic prosthesis control strategies. It then provides details of recent research and developments using non-invasive and invasive brain–computer interfaces (BCIs). These are followed by examples of studies that seek to confer robotic prostheses with sensory feedback. Finally, brief conclusions are drawn. Findings A significant body of research is underway involving electromyographic and BCI technologies, often in combination with advanced data processing and analysis schemes. This has the potential to yield robotic prostheses with advanced capabilities such as greater dexterity and sensory feedback. Originality/value This illustrates how electromyographic, BCI, signal processing and sensor technologies are being used to create robotic prostheses with enhanced functionality.

Improving stability in physical human–robot interaction by estimating human hand stiffness and a vibration index

2019 ◽  
Vol 46 (4) ◽  
pp. 529-540 ◽  
Author(s):  
Feifei Bian ◽  
Danmei Ren ◽  
Ruifeng Li ◽  
Peidong Liang
Keyword(s):  
Time Delay ◽  
Real Time ◽  
Time Domain ◽  
Design Methodology ◽  
Interaction Force ◽  
Human Robot Interaction ◽  
Experimental Results ◽  
Human Hand ◽  
Robot Interaction ◽  
Content Type

Purpose The purpose of this paper is to eliminate instability which may occur when a human stiffens his arms in physical human–robot interaction by estimating the human hand stiffness and presenting a modified vibration index. Design/methodology/approach Human hand stiffness is first estimated in real time as a prior indicator of instability by capturing the arm configuration and modeling the level of muscle co-contraction in the human’s arms. A time-domain vibration index based on the interaction force is then modified to reduce the delay in instability detection. The instability is confirmed when the vibration index exceeds a given threshold. The virtual damping coefficient in admittance controller is adjusted accordingly to ensure stability in physical human–robot interaction. Findings By estimating the human hand stiffness and modifying the vibration index, the instability which may occur in stiff environment in physical human–robot interaction is detected and eliminated, and the time delay is reduced. The experimental results demonstrate significant improvement in stabilizing the system when the human operator stiffens his arms. Originality/value The originality is in estimating the human hand stiffness online as a prior indicator of instability by capturing the arm configuration and modeling the level of muscle co-contraction in the human’s arms. A modification of the vibration index is also an originality to reduce the time delay of instability detection.

A partial name prefix merging and shortening for name lookup in named data networking

2017 ◽  
Vol 34 (7) ◽  
pp. 2300-2310
Author(s):  
Jenq-Muh Hsu ◽  
Jui-Yang Chang ◽  
Chih-Hung Wang
Keyword(s):  
Design Methodology ◽  
Experimental Results ◽  
Access Time ◽  
Named Data Networking ◽  
Content Type ◽  
Memory Space ◽  
Fixed Length ◽  
Content Centric Network ◽  
Name Lookup ◽  
Data Networking

Purpose Named Data Networking (NDN) is a content-centric network differing from the traditional IP-based network. It adopts the name prefix to identify, query and route the information content instead of IP-based addressing and routing. NDN provides a convenient way to access the content without knowing the originated location of the requested information. However, the length of name prefix varies. It is not like the fixed-length IP addresses that makes handling queries or searching the requested information in NDN easier. An efficient name lookup mechanism of name prefix will efficiently increase the performance of prefix identifying, name searching and content retrieving. Therefore, this paper aims to propose a partial name prefix merging and shortening scheme for enhancing the efficiency of name lookup in NDN. Design/methodology/approach To reduce the work involved in name prefix identifying, querying, storing and routing, this work adopts a cyclic redundancy check-based encoding scheme to shorten the variable length of the name prefix into a proper and fixed length of encoded numerical information. In fact, the structure of a name prefix is presented in a combination of word segments with the slash symbol. The shortening procedure of name prefix can also be applied to adjacent word segments forming fixed-length encoded data for further efficiently matching the name prefix for name lookup in NDN. Findings The experimental results show that the shorter length of encoded name prefix can effectively reduce the access time of name lookup and increasingly retrieve the corresponding named content in NDN. Through partial merging and shortening of name prefix, the length of encoded prefix name may be larger than the whole encoding of name prefix. It retains the information differences from different parts of various name prefixes. Thus, it can avoid collision problems with the same encoded information from various name prefixes. Originality/value From the experimental results, it is observed that partial merging and shortening of name prefix is useful for name look up in NDN. It can increase the efficiency of name prefix matching and retrieving in NDN. It can also save memory space to store the name prefix in an NDN node.

Force and position deviations estimation for ultra-thin tube assembly

2016 ◽  
Vol 36 (4) ◽  
pp. 405-411 ◽  
Author(s):  
Chao Shao ◽  
Xin Ye ◽  
Zhijing Zhang ◽  
Dengyu Zhou ◽  
Yuhong Liu
Keyword(s):  
Process Parameters ◽  
Visual Information ◽  
Force Sensor ◽  
Contact Forces ◽  
Assembly Process ◽  
Content Type ◽  
Multi Scale ◽  
Thin Tube ◽  
Mechanic Calculation ◽  
Tube Assembly

Purpose Micro ultra-thin tubes have important implications in aerospace, nuclear energy and other fields. In microassembly process, these parts are characterized by following reasons: the small size can easily lead to damage when gripping, even for low intensity and the parts are mainly affected by the instability of light source, for vision-based systems, the visual information about ultra-thin tubes is difficult to gather and the contact state is hard to monitor. Design/methodology/approach The paper presents a new method to adjust the position deviations based on contact forces during microassembly processes. Specific research is such that the assembly model was established based both on mechanic calculation and numerical simulation; the assembly task was carried out on an in-house microassembly system with coaxial alignment function (MSCA), the contact statements were controlled based on force sensor feedback signals and the model of the relationship between contact force and assembly deviations was established. Through a comparative study, the results of experiment and simulation differ by less than 11 per cent, validating the accuracy and feasibility of the method. Findings The model of assembly force and position deviations of micro ultra-thin tubes based on MSCA has been built. Besides, the assembly force threshold, and the assembly process parameters have been obtained. Originality/value The assembly process parameters obtained from experiments can be applied in the precision assembly and provide theoretical guidance and technical support to the precision assembly of the multi-scale parts.

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