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Article
Publication date: 16 October 2017

Bronius Baksys, Jolanta Baskutiene and Saulius Baskutis

This paper aims to consider the experimental and theoretical investigation of the vibratory alignment of the peg-hole, when the peg is fixed in the remote centre…

Abstract

Purpose

This paper aims to consider the experimental and theoretical investigation of the vibratory alignment of the peg-hole, when the peg is fixed in the remote centre compliance (RCC) device, and the vibrations are provided either to the hole or to the peg.

Design/methodology/approach

The experimental analysis of the circular and rectangular peg-hole vibratory alignment using the attached to the robot arm RCC device, under vibratory excitation of the hole, has been performed. The parameters of the vibratory excitation and the part-to-part pressing force influence on the alignment process have been analysed. The mathematical approach of the vibratory alignment using the passive compliance device with the vibrations provided to the peg has been proposed, and the simulation has been carried out.

Findings

The research has approved the applicability of the RCC device for both of the vibratory alignments of the non-chamfered peg-hole parts either circular or rectangular ones. The compensation of the axial misalignments has been resulted by the directional displacement of the peg supported compliantly. To perform the successful alignment of the parts, it has been necessary to adjust the frequency and the amplitude of the vibrations, the pressing force, the lateral, as well as the angular stiffness of the device.

Research limitations/implications

The experiments on the vibratory alignment of the rectangular peg-hole parts have been carried out considering only the translational misalignment moved into one direction. The non-impact regime of the vibratory alignment has been analysed.

Practical implications

The obtained results can be applied in designing the reliable and efficient devices of the vibratory assembly for the alignment of the non-chamfered peg-hole parts, as well as for chamfered ones, if the axial misalignment exceeds the width of the chamfer. The vibratory technique and passive compliance provide possibility to accomplish the assembly operations using the non-expensive low accuracy robots.

Originality/value

The new method and the mathematical approach of the vibratory assembly using the RCC device can ensure the reliable alignment of the non-chamfered parts, chamfered circular and the rectangular ones, in case the axial misalignment exceeds the assembly clearance, and prevent jamming and wedging.

Details

Industrial Robot: An International Journal, vol. 44 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 27 February 2007

Bronius Baksys and Nomeda Puodziuniene

The paper aims to investigate theoretically and experimentally vibrational alignment of parts in an assembly position under kinematical excitement of the movably based part.

Abstract

Purpose

The paper aims to investigate theoretically and experimentally vibrational alignment of parts in an assembly position under kinematical excitement of the movably based part.

Design/methodology/approach

Presents developed mathematical model for vibrational alignment when the kinematical excitement of movable part is applied along the insertion axis. Dependencies of alignment duration on stiffness of basing elements and excitation frequency were defined numerically solving the mobile‐based part alignment equations. Alignment experiments of rectangular cross‐section and cylindrical parts under kinematical excitement were carried out.

Findings

The mathematical model and the experiments have demonstrated that alignment of the parts being assembled happens due to directed displacement of the movable part resulted by certain parameters of the system and excitement. In the course of the displacement, mating surfaces are aligned and the final mutual orientation of the parts before insertion is realized. Experiments have proved validity of the developed mathematical model. This process reduces allowable axial non‐coincidence and angular misfit of the parts to be assembled.

Research limitations/implications

Impact and non‐impact regimes of the displacement exist depending on the excitement amplitude and initial contact force between the parts. Also, during the vibrational alignment it is possible to control dry friction force between parts by additional high frequency vibrations. Besides, the vibrational excitement can be not only harmonic, but also impulse, bi‐harmonic, etc. Only non‐impact regime of the motion without dry friction force control was investigated and presented in the paper.

Practical implications

The paper investigates the vibrational alignment method based on the directed vibrational displacement of the connecting part, which does not require high preciseness of the interdependent position of the parts in the assembly position.

Originality/value

Vibrational assembly devices of directional action enable compensation of errors of the parts' mutual positioning without use of sensors, feedback systems and control algorithms.

Details

Assembly Automation, vol. 27 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 9 September 2014

Edvardas Sadauskas and Bronius Baksys

The paper aims to theoretically and experimentally investigate vibratory peg-bush alignment using elastic vibrations of the peg, when the peg is axially excited by a…

Abstract

Purpose

The paper aims to theoretically and experimentally investigate vibratory peg-bush alignment using elastic vibrations of the peg, when the peg is axially excited by a pressed piezoelectric vibrator on the upper end.

Design/methodology/approach

Experimental research of part alignment using elastic vibrations was performed and dependencies of alignment duration on excitation signal parameters and initial pressing force were defined for rectangular and circular cross-section parts. Mathematical model of two-mass dynamic systems with elastic contact model representing alignment process was created. Dependencies of system parameters on the alignment duration were obtained by numerically solving systems differential equations.

Findings

Theoretical and experimental investigation approved the usage of elastic vibrations for alignment of chamferless circular and rectangular cross-section parts. This novel method of part alignment compensates axial misalignment between mating parts by directional displacement of movably based bush.

Research limitations/implications

Impact and non-impact interaction between bush and peg is possible; however, only non-impact regime was investigated. Static and dynamic coefficients of friction between the parts are equivalent and do not depend on relative velocity of parts.

Practical implications

The results are useful in designing reliable and effective assembly equipment with vibratory assistance alignment for peg-bush operations, which do not require auxiliary sensors and feedback systems. Use of a piezoelectric resonator for peg excitation makes this system easily adaptable to the existing automated assembly equipment.

Originality/value

The proposed method is a new approach to vibratory alignment. The data obtained during investigation expand the insight of the physical processes that drive bush to the axial alignment direction.

Details

Assembly Automation, vol. 34 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 2 August 2011

Sigitas Kilikevicius and Bronius Baksys

The paper aims to investigate theoretically and experimentally the process of compliantly supported peg insertion into a bush for high‐speed assembly, when vibrations are…

Abstract

Purpose

The paper aims to investigate theoretically and experimentally the process of compliantly supported peg insertion into a bush for high‐speed assembly, when vibrations are provided to the bush in the axial direction, and to analyse the influence of the parameters of the dynamic system and excitation on the assembly process.

Design/methodology/approach

The mathematical model of parts vibratory insertion process is formed and the simulation is performed using a numerical computing software environment. The model includes inertia, compliance, dry friction, insertion speed and vibratory excitation. The three‐dimensional simulation of peg‐in‐hole insertion is accomplished using motion analysis software to test the influence of vibratory excitation on assembly failures, such as jamming and wedging. The experimental setup for the robotic vibratory assembly and the investigation methodology were presented. The experimental analysis of the vibratory insertion process of cylindrical parts with clearance is performed when the compliantly supported peg is inserted by the robot into the bush, which is excited in the axial direction.

Findings

The vibratory excitation allows preventing the balance between the insertion force and frictional forces and so to avoid jamming and wedging. It is advantageous to select such the frequency of vibrations under which the resonance state of the compliantly supported peg does not occur. The parameters of vibratory excitation and initial assembly state are defined which have the principal influence on the insertion duration and the success of the process. The experimental results show the applicability of the mathematical approach.

Research limitations/implications

The assumption is made that the chamferless rigid peg moves in a plane in respect of the rigid bush with a chamfer. Also, it is considered that there is no impact during the peg and bush contact. The dynamic and static friction coefficient between the parts is equivalent and the insertion speed is constant.

Practical implications

The results can be useful aiming to design the reliable high‐performance vibratory assembly equipment for peg‐hole type parts, which does not require sensors, feedback systems and control algorithms.

Originality/value

The proposed method of applying the vibratory excitation during the peg‐in‐hole insertion process allows to avoid jamming and wedging, and to minimize the duration of the process.

Details

Assembly Automation, vol. 31 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

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