The vibratory alignment of the parts in robotic assembly

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.

Research on the Residual Vibration Suppression of a Controllable Mechanism Robot

“…For a micro element dV , the stored strain energy is: 11) where σ x , σ y and σ z are normal stress components; τ xy , τ yz and τ zx are shear stress components; ε x , ε y and ε z are normal strain components; and γ xy , γ yz and γ zx are shear strain components. Substituting equation (10) into equation (11), the strain energy of Timoshenko SBE considering axial force, torque, transverse force and bending moment is as follows:…”

“…It is therefore of great significance to suppress the residual vibration of robots. The spot welding robot [5], [6] and assembly robot [7]- [9] need to wait until the residual vibration of the working arm is reduced before they can perform their next work task [10], [11]. To enable industrial robots to complete maneuvering tasks both quickly and accurately, many researchers have conducted extensive and in-depth research on the residual vibration of robots from different aspects [12]- [14].…”

Investigating the Conditions of Automatic Assembly of Polyhedral Joints

“…The problem of robotic assembly was considered by many researchers. In particular, the application of high-frequency oscillations (up to 9000 Hz) for directional alignment of cylindrical and prismatic parts with and without chamfers is described in (Baksys & Kilikevicius, 2011), (Baksys, et al, 2017) and (Sadauskas & Baksys, 2013). In contrast to the present paper, the study object is press-fit joints, in which the base part has free location, and the shaft is fixed in a gripper with elastic elements.…”

Investigating the Conditions of Automatic Assembly

“…Where: Many researchers considered the problem of robotic assembly. The application of high-frequency oscillations (up to 9000 Hz) for directional alignment of cylindrical and prismatic parts with and without chamfers is described in [8], [9], [10]. In this research, the study object is press-t joints in the base part that have an accessible location and the gripper holds the shaft with elastic elements.…”