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Article
Publication date: 1 April 1993

Hubert K. Rampersad

The assembly is often a weak link in the production process. It is an enterprise activity which is responsible for a substantial part of the production costs and the throughput…

Abstract

The assembly is often a weak link in the production process. It is an enterprise activity which is responsible for a substantial part of the production costs and the throughput time. Robot assembly systems in addition offer legitimate possibilities to rationalize the assembly activities, because of the increasing product diversity, and the more severe demands concerning the reliability of delivery. Unfortunately several bottlenecks hinder the widespread application of robot assembly systems. Figure 1 gives an overview of the bottlenecks and the development tendencies in robotic assembly.

Details

Assembly Automation, vol. 13 no. 4
Type: Research Article
ISSN: 0144-5154

Article
Publication date: 29 July 2014

Yanfeng Xing and Yansong Wang

The purpose of this paper is to propose a new assembly variation analysis model to analyze assembly variation for sheet metal parts. The main focus is to analyze assembly

1739

Abstract

Purpose

The purpose of this paper is to propose a new assembly variation analysis model to analyze assembly variation for sheet metal parts. The main focus is to analyze assembly processes based on the method of power balance.

Design/methodology/approach

Starting with issues in assembly variation analysis, the review shows the critical aspects of tolerance analysis. The method of influence coefficient (MIC) cannot accurately analyze the relationship between part variations and assembly variations, as the welding point is not a point but a small area. Therefore, new sensitivity matrices are generated based on the method of power balance.

Findings

Here two cases illustrate the processes of assembly variation analysis, and the results indicate that new method has higher accuracy than the MIC.

Research limitations/implications

This study is limited to assembly variation analysis for sheet metal parts, which can be used in auto-body and airplane body.

Originality/value

This paper provides a new assembly variation analysis based on the method of power balance.

Details

Assembly Automation, vol. 34 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 1 March 2018

Zhengping Deng, Shuanggao Li and Xiang Huang

For the measurement of large-scale components in aircraft assembly, the evaluation of coordinate transformation parameters between the coordinate frames of individual measurement…

Abstract

Purpose

For the measurement of large-scale components in aircraft assembly, the evaluation of coordinate transformation parameters between the coordinate frames of individual measurement systems to the assembly frame is an essential task, which is usually completed by registration of the enhanced reference system (ERS) points. This paper aims to propose an analytical method to evaluate the uncertainties of transformation parameters considering both the measurement error and the deployment error of ERS points.

Design/methodology/approach

For each measuring station, the measured coordinates of ERS points are first roughly registered to the assembly coordinate system using the singular value decomposition method. Then, a linear transformation model considering the measurement error and deployment error of ERS points is developed, and the analytical solution of transformation parameters’ uncertainties is derived. Moreover, the covariance matrix of each ERS points in the transformation evaluation is calculated based on a new uncertainty ellipsoid model and variance-covariance propagation law.

Findings

For the transformation of both single and multiple measuring stations, the derived uncertainties of transformation parameters by the proposed analytical method are identical to that obtained by the state-of-the-art iterative method, but the solution process is simpler, and the computation expenses are much less.

Originality/value

The proposed uncertainty evaluation method would be useful for in-site measurement and optimization of the configuration of ERS points in the design of fixture and large assembly field. It could also be applied to other registration applications with errors on both sides of registration points.

Details

Sensor Review, vol. 38 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 14 October 2020

Qiushuang Zhang, Xin Jin, Zhihua Liu, Zhijing Zhang, Yan Fang, Zhongqing Zhang and Yann Ledoux

The modern manufacturing industry has put forward higher requirements for the assembly accuracy of components with the development of the industrial technology. For precision…

Abstract

Purpose

The modern manufacturing industry has put forward higher requirements for the assembly accuracy of components with the development of the industrial technology. For precision assembly, the traditional assembly process study based on tolerance has had difficulty in meeting these requirements. Hence, the distribution of the form errors must be considered. The registration between the two mating surfaces with form errors determines the parts’ assembly position, and is the basis for the prediction and control of the assembly accuracy. This study aims to provide a new surfaces registration method which takes form errors into consideration.

Design/methodology/approach

This study presents a new registration approach based on the minimum potential energy. A unique set of contact points on mating surfaces that meet the actual conditions can be obtained and the spatial position of the assembled part is calculated.

Findings

The experimental results show that the calculated values are in good agreement with the experimental values. Furthermore, the root mean square error is within 2%, which proves the validity and accuracy of the approach.

Originality/value

This paper provides an effective and new method for precision assembly which takes form errors into consideration. The method can give the optimal solution of the contact points, which is more consistent with the actual assembly situation and provides a basis for predicting assembly accuracy.

Details

Assembly Automation, vol. 40 no. 6
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 17 November 2022

Mukunthan S., Manu R. and Deepak Lawrence K.

This paper aims to propose a method to automate the tolerance analyses of mechanical assembly using STandard for the Exchange of Product model data-Application Protocol Part 242…

90

Abstract

Purpose

This paper aims to propose a method to automate the tolerance analyses of mechanical assembly using STandard for the Exchange of Product model data-Application Protocol Part 242 (STEP AP 242) files derived from the 3-D computer-aided design (CAD) models.

Design/methodology/approach

Product manufacturing information and mating information available in ISO 10303 STEP AP242 files resulting from the 3-D CAD model of mechanical assembly are extracted. The extracted geometric attributes, geometric dimensioning and tolerancing (GD&T) and mating information are used to automatically generate assembly graph and mating edges required for the tolerance analyses of the mechanical assembly by using the matrix approach.

Findings

The feasibility of the proposed method is verified through two mechanical assembly case studies. The results of manual calculations and tolerance values computed by the automated method are very closely matching.

Practical implications

Tolerance analysis is an integral part of product development that directly influences the cost and performance of a product. Apart from the academic interest, the work is expected to have positive implications for the digital design and smart manufacturing industry that involve in the development of solutions for automation of design and manufacturing system functions.

Originality/value

The approach presented in the paper that aids the automation of tolerance analyses of mechanical assembly is an innovative application of the STEP AP 242 file. The automation of tolerance analyses would improve the productivity and efficiency of the product realization process.

Details

Assembly Automation, vol. 42 no. 6
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 19 June 2017

Mingdong Tang, Youlin Gu, Yunjian Zhang and Shigang Wang

The purpose of this paper is to present a dual manipulator system for aloft hot-line assembly tasks of connection fittings in 110-kv intelligent substation, which is significant…

Abstract

Purpose

The purpose of this paper is to present a dual manipulator system for aloft hot-line assembly tasks of connection fittings in 110-kv intelligent substation, which is significant to the research on hot-line working robots.

Design/methodology/approach

This paper addresses the challenges of the task and presents a dual manipulator system which can overcome these challenges to realize the robotic assembly of connection fittings in narrow space without impacting the safe distance of both phase to phase and phase to ground. Two manipulators share a same global reference coordinate. The mission of Manipulator 1 is to position the fixed part of connection fittings and screw the bolts on it. Visual computing provides the approximately position for the end-effector of Manipulator 2, after which The Manipulator 2 carries the removable part of connection fittings to this position. Then, the assembly task could be completed with the posture of the Manipulator 2 adjusted following the guidance by force-position control.

Findings

The dual manipulator system can position the target under different illumination conditions and complete fast assembly of connect fittings in 110-kV substation. No strong arc discharge or surface erosion phenomenon has been observed.

Practical implications

This dual manipulator system will be particularly useful for the hot-line assembly of connection fittings in 110-kv intelligent substation, as well as some assembly tasks where uncertain target position and complex contact surface such as cylindrical hole is involved.

Originality/value

This study presents a dual manipulator system used by a field robot working in 110-kv intelligent substation. The system is able to achieve the connection fittings assembly task under energized simulation experimental system. Unlike other peg-in-hole assembly strategy, it does not require high stability of manipulator or plane contact surface around the hole.

Details

Industrial Robot: An International Journal, vol. 44 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 27 June 2019

Guijiang Duan, Zhibang Shen and Rui Liu

This paper aims to promote the integration of the relative position accuracy (RPA) measurement and evaluation in digital assembly process by adopting the model-based method. An…

Abstract

Purpose

This paper aims to promote the integration of the relative position accuracy (RPA) measurement and evaluation in digital assembly process by adopting the model-based method. An integrated framework for RPA measurement is proposed based on a model-based definition (MBD) data set. The study also aims to promote the efficiency of inspection planning of RPA measurement by improving the reusability and configurability of the inspection planning.

Design/methodology/approach

The works have been carried out on three layers. In the data layer, an extended MBD data set is constructed to describe the objects and data for defining RPA measurement items; In definition layer, a model based and hierarchical structure for RPA item definition is constructed to support quick definition for RPA measurement items. In function layer, a toolset consisting three modules is constructed in a sequence from measurement planning to RPA value solving to visualized displaying again. Based on this framework, a prototype system is developed.

Findings

The paper provides an identified practice of model-based inspection. It suggests that MBD is valuable in promoting both the integration and efficiency of digital inspection.

Research limitations/implications

The templates and constructed geometry objects given in this paper are still limited in a scenario of aircraft assembly. The integrity and universality of them still need follow-up works.

Practical implications

The paper includes implications for the model based digital inspection, the digital assembly and the extended application of MBD.

Originality/value

This paper expands the application of MBD in inspection and fulfils the need to promote the integration and efficiency of digital inspection in large-scale component assembly.

Article
Publication date: 17 May 2023

Lulu Huang, Xiang Huang and Shuanggao Li

Large size of aircraft assembly tooling structure and complex measurement environment exist. The laid enhanced reference points (ERS) are subject to a combination of nonuniform…

Abstract

Purpose

Large size of aircraft assembly tooling structure and complex measurement environment exist. The laid enhanced reference points (ERS) are subject to a combination of nonuniform temperature fields and measurement errors, resulting in increased measurement registration errors. In view of the nonuniform temperature field and measurement errors affecting the ERS point registration problem, the purpose of this paper is to propose a neural network-based ERS point registration compensation method for large-size measurement fields under a nonuniform temperature field.

Design/methodology/approach

The approach is to collect ERS point information and temperature data, normalize the collected data to complete the data structure design and complete the construction of the neural network prediction model by data training. The data learning is performed to complete the prediction model construction, and the prediction model is used to complete the compensation analysis of ERS points. Finally, the algorithm is verified through experiments and engineering practice.

Findings

Experimental results show that the proposed neural network-based ERS point prediction and compensation method for nonuniform temperature fields effectively predicts ERS point deformation under nonuniform temperature fields compared with the conventional method. After the compensation analysis, the registration error is effectively reduced to improve registration accuracy. Reducing the combined effect of environmental nonuniform temperature field and measurement error has apparent advantages.

Originality/value

The method reduces the registration error caused by combining a nonuniform temperature field and measurement error. It can be used for aircraft assembly site prediction and registration error compensation analysis, which is essential to improve measurement accuracy further.

Details

Robotic Intelligence and Automation, vol. 43 no. 2
Type: Research Article
ISSN: 2754-6969

Keywords

Article
Publication date: 14 August 2018

Mingdong Tang, Youlin Gu, Shigang Wang, Qinghua Liang and Xiaoxi Wang

The purpose of this paper is to provide a safe control strategy for aloft hot-line assembly of connection fittings in 110kV intelligent substations, which is significant to…

Abstract

Purpose

The purpose of this paper is to provide a safe control strategy for aloft hot-line assembly of connection fittings in 110kV intelligent substations, which is significant to research on hot-line working robots.

Design/methodology/approach

This paper addresses challenges of the task and establish the contact models of connection fittings. By using this control strategy, neither high precision vision positioning nor preset global reference coordinate system is required. Visual computing only needs to provide an approximately position for the manipulator end-effector, after which the connection fittings assembly task could be completed with the posture of the manipulator adjusted following the guidance by force-position control. The authors also analyze the influence of the intervention of manipulators on the very non-uniform electric field during the operation.

Findings

This strategy will be particularly useful for the hot-line assembly of connection fittings in 110kV intelligent substations as well as some assembly tasks where uncertain target position and complex contact surface such as cylindrical hole is involved.

Practical implications

This assembly strategy is tested in energized simulated experimental system. The experiment results show that the robot can replace the manual operation to complete the assembly task safely and efficiently.

Originality/value

This assembly strategy is able to achieve the assembly task of connection fittings. Unlike other peg-in-hole assembly strategy, it does not require high stability of manipulator or plane contact surface around the hole.

Details

Industrial Robot: An International Journal, vol. 45 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 11 June 2018

Yanfeng Xing and Yansong Wang

Dimensional quality of sheet metal assemblies is an important factor for the final product. However, the part tolerance is not easily controlled because of the spring back…

Abstract

Purpose

Dimensional quality of sheet metal assemblies is an important factor for the final product. However, the part tolerance is not easily controlled because of the spring back deformation during the stamping process. Selective assembly is a means to decrease assembly tolerance of the assembly from low-precision components. Therefore, the purpose of this paper is to propose a fully efficient method of selective assembly optimization based on an improved genetic algorithm for optimization toolbox (IGAOT) in MATLAB.

Design/methodology/approach

The method of influence coefficient is first applied to calculate the assembly variation of sheet metal components since the traditional rigid assembly variation model cannot be used due to welding deformation. Afterwards, the IGAOT is proposed to generate optimal selective groups, which consists of advantages of genetic algorithm for optimization toolbox (GAOT) and simulated annealing.

Findings

The cases of two simple planes and the tail lamp bracket assembly are used to illustrate the flowchart of optimizing combinations of selective groups. These cases prove that the proposed IGAOT has better precision than that of GAOT with the same parameters for selective assembly.

Originality/value

The research objective of this paper is to evaluate the changes from rigid bodies to sheet metal parts which are very complex for selective assembly. The method of IGAOT was proposed to the selected groups which has better precision than that of current optimization algorithms.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 11 no. 2
Type: Research Article
ISSN: 1756-378X

Keywords

1 – 10 of over 31000