Peg-hole assembly; an investigation into tactile methods
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
The search for a flexible automatic assembly machine for industry has involved researchers in the quest for a man-like robot. Extensive work is being done in the fields of visual feedback and pseudo-human tactile sensing. Is this artificial man with its complex automata theory and reliance on high computer usage necessary? Or perhaps a lower degree of intelligence, supported by well designed peripherals, will enable a ‘robot’ to perform its assembling tasks. It is in this mid-range between the extremes of a simple pick-and-place machine and a fully flexible, highly complex, and costly robot, that a solution is sought. The crux of the assembly problem is, of course, in the fitting stage; for example, the actual fitting of a peg into its hole. So the approach that has been adopted is an extensive survey into the mechanics of the assembly problem. Limited work has been done on the conditions for jamming, misalignments, and chamfer effects in the static mode. This is continued and furthered into dynamic domain. Modes of misalignment were modelled and the resultant contact forces and moments derived: the possibility of simple tactile feedback was investigated. Armed with these basics various techniques of alignment were derived for the peg-hole problem. In particular, was one using simple tactile feedback and invariant planes contact. Invariant planes contact is a system whereby general misalignment is reduced to a planar problem through the contacting of two invariant plane surfaces.