Passive compliance versus active compliance in robot‐based automated assembly systems

Industrial robots have found great potential in applications to assembly‐line automation. Programmable robot‐based assembly systems are often needed, in particular for circumstances in which special assembly equipments is not available or well‐trained operators could not be employed economically. Robots with enough compliance can perform not only classic automation tasks, such as spot welding, cargo carrying, etc., but also can operate those tasks which demand the compliant motion capacity of robots. Therefore, the research on robot compliance is especially important for parts assembly by robots, where robot compliant motions and manipulations are essential requirements. This paper presents a number of important issues in robot compliance research, including the specification of robot end‐effector compliance; properties of a robot compliance matrix at its end‐effector; discussions on passive compliance and active compliance and their comparisons; and derivation of the compliance at the end‐effector required for tasks.