Classification and type synthesis of 1-DOF remote center of motion mechanisms

Type synthesis of 1-DOF remote center of motion (RCM) mechanisms is the preliminary for research on many multi-DOF RCM mechanisms. Since types of existing RCM mechanisms are few, it is necessary to find an efficient way to create more new RCM mechanisms. In this paper, existing 1-DOF RCM mechanisms are first classified, then base on a proposed concept of the planar virtual center (VC) mechanism, which is a more generalized concept than a RCM mechanism, two approaches of type synthesis for 1-DOF RCM mechanisms are addressed. One case is that a 1-DOF parallel or serial–parallel RCM mechanism can be constructed by assembling two planar VC mechanisms; the other case, a VC mechanism can be expanded to a serial–parallel RCM mechanism. Concrete samples are provided accordingly, some of which are new types.