ABSTRACT
A mechanism is defined as the assembly of rigid members, also known as links, connected by kinematic joints. A kinematic chain is commonly known as a linkage if it is made from a series of links connected by only lower pair joints. The number of degrees of freedom of a mechanism is normally called the mobility, which is the number of inputs required to determine the position of all the links, also known as outputs, with respect to a fixed reference frame, sometimes referred to as ground. In general, mechanisms are three dimensional. However, there are circumstances where the mechanisms, and in particular the way they are analysed, can be simplified. This leads to two specific types of mechanisms, namely the planar and spherical mechanisms. The simplest and most effective method for the analysis of planar mechanisms is the vector method involving complex numbers, which was first introduced by Bloch.
