Definition of Two Kinds of the Degree of Freedom in Constraint State and Its Application to Assembly Planning

Abstract

In this paper, two kinds of the Degree Of Freedom in Constraint State (CSDOF) are defined for motion of an object in contact with an immobile environment, and then application to planning of assembly tasks is discussed. The CSDOF of the first kind is defined as the number of independent directions in which the object can move keeping the current contact conditions of contact state. The CSDOF of the second kind is defined as the number of independent derections in which the object can move freely when it is allowed to break the current contact conditions and to go away from the current contact state. Then we discuss the difficulty of state transition by considering the two kinds of CSDOF as well as the Degree Of Constraint in Constraint State (CSDOC) and give a criterion function for state transitions. Lastly, we show some applications of the two kinds of CSDOF to the planning of contact state transitions in assembly operations.