Techniques for automatic assembly
Thesis DisciplineMechanical Engineering
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
The objective of the research work carried out was the development of techniques useful in automated assembly. In particular, methods were sought which would allow the extension of simple robot capabilities from the "pick and place" function to the less ordered domain of assembly. Three approaches towards correcting the gross misalignment of a peg and hole are described. An established method of facilitating assembly involves the vibration of the contacting misaligned components. This technique was studied with respect to the behaviour of an elastically constrained peg under the action of a rotating force. The study was limited initially to a relatively straightforward analysis of simplified situations, then, in order to allow the prediction of the behaviour of practical systems a program was developed which simulated the behaviour of a general nine degree-of-freedom assembly system. This work led to the second approach where the possibility of using the vibrational motion of the contacting components as feedback for position sensing was investigated. The third technique involved determining the spatial relationship between the components on the basis of contact forces sensed in their respective coordinate systems. Finally a six degree-of-freedom force-displacement sensor, able to be used for, either vibratory position sensing, or contact force position sensing, was developed.