Sensing in Advanced Robotic Assembly

Abstract

Sensors are typically added to programmable assembly cells in order to enable correct operation when components are imprecisely positioned, and when fixtures, actuators and other cell resources are non-ideal. The assembly operation and the environment can be monitored so that any errors can be detected and recovery actions can be selected automatically. In an ideal world the synthesis of such a system for a given assembly problem would be simple, quick to undertake and foolproof. Such systems could then be applied to rapidly changing small-batch production environments. However, in practice, the synthesis of sensory assembly systems is non-trivial, time-consuming and error prone. The paper categorizes the use of sensors in assembly with illustrations from practical assembly projects. This then leads to ideas about sensor selection and how sensory information can be used in decision-making. An outline is given of a probabilistic framework which can be used as a basis for both of these tasks.