Measurement of force sensory information for the automation of ultra-precision assembly tasks

Automation of assembly tasks has previously been tackled by many researchers. They mostly focused on the geometric constraints related to a considered task, e.g., relative configuration change between the peg and the hole in peg insertion task, This approach, however, seems valid only when the dimensional tolerance is fairly large so that it allows to change the relative configuration of the two mating parts in an obvious fashion. This paper investigates how highly precise assembly tasks can be automated. Tolerance considered in the present study is in the range of 3 mum 9 mum. We focus on force sensory information involved in high-precision peg-in-a-hole task of a polygon mirror unit because a position-based analysis under such a narrow dimensional tolerance seems inappropriate. A variety of insertion experiments are conducted by skilled and unskilled subjects for comparison purposes in which force information is measured and analyzed.