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1 – 10 of over 5000Wei Wang, Robert N.K. Loh and Edward Y. Gu
Industrial robots have found great potential in applications to assembly‐line automation. Programmable robot‐based assembly systems are often needed, in particular for…
Abstract
Industrial robots have found great potential in applications to assembly‐line automation. Programmable robot‐based assembly systems are often needed, in particular for circumstances in which special assembly equipments is not available or well‐trained operators could not be employed economically. Robots with enough compliance can perform not only classic automation tasks, such as spot welding, cargo carrying, etc., but also can operate those tasks which demand the compliant motion capacity of robots. Therefore, the research on robot compliance is especially important for parts assembly by robots, where robot compliant motions and manipulations are essential requirements. This paper presents a number of important issues in robot compliance research, including the specification of robot end‐effector compliance; properties of a robot compliance matrix at its end‐effector; discussions on passive compliance and active compliance and their comparisons; and derivation of the compliance at the end‐effector required for tasks.
N.F. Edmondson and A.H. Redford
A compliance device combining passive and active compliance has been tested and developed for an anthropomorphic robot for use during assembly operations. The device has the…
Abstract
A compliance device combining passive and active compliance has been tested and developed for an anthropomorphic robot for use during assembly operations. The device has the ability to correct for angular and lateral misalignments between mating parts, resulting in no equipment or part damage. The method of control, the design features of the device and the modifications made to enable the device to be used by an anthropomorphic robot are described and future modifications which will enable the device to operate more effectively are discussed.
Guoteng Zhang, Zhenyu Jiang, Yueyang Li, Hui Chai, Teng Chen and Yibin Li
Legged robots are inevitably to interact with the environment while they are moving. This paper aims to properly handle these interactions. It works to actively control the joint…
Abstract
Purpose
Legged robots are inevitably to interact with the environment while they are moving. This paper aims to properly handle these interactions. It works to actively control the joint torques of a hydraulic-actuated leg prototype and achieve compliant motion of the leg.
Design/methodology/approach
This work focuses on the modelling and controlling of a hydraulic-actuated robot leg prototype. First, the design and kinematics of the leg prototype is introduced. Then the linearlized model for the hydraulic actuator is built, and a model-based leg joint torque controller is presented. Furthermore, the virtual model controller is implemented on the prototype leg to achieve active compliance of the leg. Effectiveness of the controllers are validated through the experiments on the physical platform as well as the results from simulations.
Findings
The hydraulic joint torque controller presented in this paper shows good torque tracking performance. And the actively compliant leg successfully emulates the performance of virtual passive components under dynamic situations.
Originality/value
The main contribution of this paper is that it proposed a model-based active compliance controller for the hydraulic-actuated robot leg. It will be helpful for those robots that aim to achieve versatile and safe motions.
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Junxia Jiang, Chen Bian and Yinglin Ke
The purpose of this paper is to design a new method to realize automatic assembly of aircraft components with large shafts such as canard and vertical tail. The assembly structure…
Abstract
Purpose
The purpose of this paper is to design a new method to realize automatic assembly of aircraft components with large shafts such as canard and vertical tail. The assembly structure of component with large shaft and fuselage is a mating assembly structure, and it is a challenge to satisfy the precision and assembly requirement.
Design/methodology/approach
According to the assembly structure features and process requirements of an aircraft component with large shaft, the operating principle of precise assembly system for shaft-hole mating is analyzed in this paper. The model of compliant assembly for shaft-hole mating is constructed, and force condition analysis of the compliant assembly is performed. An automatic precise shaft-hole assembly method for aircraft assembly using 5 degrees of freedom spatial mechanism, compliance technology and servo feeding system is put forward based on the analysis. A 5 degrees of freedom passive compliant experimental equipment has been developed.
Findings
Application test results of the 5 degrees of freedom passive compliant experimental equipment show that the simulated canard can be mated automatically and accurately through this method with high efficiency and high quality as long as the tip of shaft enters into the range of hole’s chamfer.
Practical implications
This method has been used in an aircraft assembly project. The practical results show that the aircraft components with large shafts can be mated automatically and accurately through this method with high efficiency and high quality.
Originality/value
This paper presents a new method and designs a new assembly system to realize the assembly of the aircraft components with large shafts. The research will promote the automation of fuselage assembly.
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Aiming at the problems of geometric precision misalignment and unconsidered physical constraints between large components during the measurement-assisted assembly, a self-adaptive…
Abstract
Purpose
Aiming at the problems of geometric precision misalignment and unconsidered physical constraints between large components during the measurement-assisted assembly, a self-adaptive alignment strategy based on the dynamic compliance center (DCC) is proposed in this paper, using force information to guide alignment compliantly.
Design/methodology/approach
First, the self-adaptive alignment process of large components is described, and its geometrical and mechanical characteristics are analyzed based on six-dimensional force/torque (F/T). The setting method of DCC is studied and the areas of DCC are given. Second, the self-adaptive alignment platform of large components driven by the measured six-dimensional F/T is constructed. Based on this platform, the key supporting technologies, including principle of self-adaptive alignment, coordinate transfer, calculation of six-dimensional F/T and alignment process control, are illustrated.
Findings
Using the presented strategy, the position and orientation of large component is adjusted adaptively responding to measured six-dimensional F/T and the changes of contact states are consistent with the strategy. Through the setting of DCC, alignment process runs smoothly without jamming.
Practical implications
This strategy is applied to the alignment experiment of large components muff coupling. The experimental results show that the proposed alignment strategy is correct and effective and meets the real-time requirement.
Originality/value
This paper proposed a novel way to apply force information in large component self-adaptive alignment, and the setting method of DCC was presented to make the alignment process more feasible.
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The purpose of this paper is to investigate how resort managers respond to employment legislation (Law No. 02/2008).
Abstract
Purpose
The purpose of this paper is to investigate how resort managers respond to employment legislation (Law No. 02/2008).
Design/methodology/approach
The qualitative case study data from seven self-contained tourist resorts in the Maldives were used to investigate the managerial responses to employment legislation.
Findings
Resort managers’ responses ranged from passive compliance to active resistance, with decoupling through opportunism as the dominant strategy used to circumvent the legislation. Some human resource management (HRM) practices emerged from resort managers’ interactions with external stakeholders and employees. Strategic responses and HRM practices were driven by a search for legitimacy or efficiency and sometimes both. The findings show that there are differences between strategic responses and HRM practices by organisational subfield, local resorts and international hotel chains. The resorts’ market orientation also influenced resort managers’ responses and HRM practices.
Research limitations/implications
The findings of this paper have limitations because it was limited to a single industry/sector and to a particular piece of legislation. However, it demonstrates the complexity of the relationship between institutional context and HRM.
Originality/value
This paper shows that responding to employment legislation entails a high level of interplay between the institutional environment and HR actors, and between stakeholders (e.g. employees) and HR actors. It demonstrates the difficulty of reconciling institutional requirements with the preferences of different stakeholders and organisational interests. HR actors actively make sense of institutional requirements and modify HRM practices to accommodate stakeholders’ varying perspectives and preferences. This suggests that in countries such as the Maldives, uneven institutional coverage (e.g. incomplete employment legislation) allows room for organisations to innovate – for better or worse.
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Irene Nikandrou and Nancy Papalexandris
The purpose of this paper is to examine the factors affecting the course of action that employees in acquired firms choose to follow. Loyalty, compliance, voice and neglect (LCVN…
Abstract
Purpose
The purpose of this paper is to examine the factors affecting the course of action that employees in acquired firms choose to follow. Loyalty, compliance, voice and neglect (LCVN) are four employee behaviors in acquired companies.
Design/methodology/approach
Two questionnaires were designed: one was administered to employees of the acquired company and the other to a member of the post‐acquisition managerial team. One hundred and thirty‐five administrative employees in 27 acquired companies in Greece participated in the research.
Findings
The results of the study support that employees decide their course of action based on the cost of their action, the effectiveness of the behaviour and the attractiveness of the company.
Research limitations/implications
This study concentrated at the individual level to examine the factors affecting employee behaviours. Future research is needed to examine behavioural changes over time and the factors that make employees move from one behavioural category to the other.
Practical implications
The findings in the paper have implications for organization members facing the challenge of managing human issues in the sensitive phases of an acquisition. Evidence of specific behavioural responses and the factors affecting them is presented.
Originality/value
The present study provides a model for understanding the complex and multiple behavioral choices employees have after an acquisition.
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Mingyang Li, Zhijiang Du, Xiaoxing Ma, Wei Dong, Yongzhi Wang, Yongzhuo Gao and Wei Chen
This paper aims to propose a robotic automation system for processing special-shaped thin-walled workpieces, which includes a measurement part and a processing part.
Abstract
Purpose
This paper aims to propose a robotic automation system for processing special-shaped thin-walled workpieces, which includes a measurement part and a processing part.
Design/methodology/approach
In the measurement part, to efficiently and accurately realize the three-dimensional camera hand-eye calibration based on a large amount of measurement data, this paper improves the traditional probabilistic method. To solve the problem of time-consuming in the extraction of point cloud features, this paper proposes a point cloud feature extraction method based on seed points. In the processing part, the authors design a new type of chamfering tool. During the process, the robot adopts admittance control to perform compensation according to the feedback of four sensors mounted on the tool.
Findings
Experiments show that the proposed system can make the tool smoothly fit the chamfered edge during processing and the machined chamfer meets the processing requirements of 0.5 × 0.5 to 0.9 × 0.9 mm2.
Practical implications
The proposed design and approach can be applied on many types of special-shaped thin-walled parts. This will give a new solution for the automation integration problem in aerospace manufacturing.
Originality/value
A novel robotic automation system for processing special-shaped thin-walled workpieces is proposed and a new type of chamfering tool is designed. Furthermore, a more accurate probabilistic hand-eye calibration method and a more efficient point cloud extraction method are proposed, which are suitable for this system when comparing with the traditional methods.
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Rossitza Setchi and Daniel Bratanov
Limited precision of manufactured parts and limited repeatability of industrial robots are the two main sources of uncertainty in the automated assembly environment. Different…
Abstract
Limited precision of manufactured parts and limited repeatability of industrial robots are the two main sources of uncertainty in the automated assembly environment. Different accommodation techniques are used to improve the reliability of the assembly process. Simplified representation of the accommodation task environment, especially for precision assembly tasks, however, does not allow a reliable assessment of the possibilities for successful assembly. Presents a method for 3D simulation of the accommodation of round, rigid parts with clearance during their single or multiple insertions into a base part. The approach used considers the accommodation process to be a sequence of discreet contact events that is modelled as a transition from one contact situation to another. The simulation is performed in a MatLab environment. The 3D simulation of accommodation presented enables engineers to visualise the insertion process and improve its quality by designing effective accommodation devices. It creates a basis for a systematic and generic approach to assembly task analysis.
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The purpose of this paper is to introduce the physical structure and the control mechanism of human motor nervous system to the robotic system in a tentative manner to improve the…
Abstract
Purpose
The purpose of this paper is to introduce the physical structure and the control mechanism of human motor nervous system to the robotic system in a tentative manner to improve the compliance/flexibility/versatility of the robot.
Design/methodology/approach
A brief review is focused on the concept of compliance, the compliance-based methods and the application of some compliance-based devices. Combined with the research on the physical structure and the control mechanism of human motor nervous system, a new drive structure and control method is proposed.
Findings
Introducing the physical structure and the control mechanism of human motor nervous system can improve the compliance/flexibility/versatility of the robot, without bringing in more complexity or inefficiency to the system, which helps in the assembly automation tasks.
Originality/value
The proposed drive structure and control method are useful to build up a novel, low-cost robotic assembly automation system, which is easy to interact and cooperate with humans.
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