This textbook introduces a systematic methodology for the creation and classification of mechanisms. The approach is partly analytical and partly algorithmic.
It is based on the idea that, during the conceptual design phase, some of the functional
requirements of the desired mechanism can be transformed into structural characteristics that can be employed for the systematic enumeration of mechanisms.
The kinematic structure of a mechanism contains the essential information about which link is connected to which other link by what type of joint.
Using graph theory, combinatorial analysis, and computer algorithms, kinematic structures of the same nature, i.e., the
same the number of degrees of freedom, type of motion (planar or spatial), and complexity can be enumerated in an essentially systematic and unbiased manner.
Then each mechanism structure is sketched and evaluated with respect to the remaining functional requirements. This results in a class of feasible mechanisms that can be subject to dimensional synthesis, kinematic and dynamic analyses, design optimization, and design details.
This textbook is organized as follows:
Chapter 1 provides a brief review of the design process and a systematic methodology for the creation of mechanisms. Some terminologies related to the kinematics of the mechanism are defined. Mechanisms are classified according to the nature of motion into planar, spherical, and spatial mechanisms.
Chapter 2 is concerned with the basic concepts of graph theory, which is essential for
structural analysis and structural synthesis of mechanisms. This material is extremely
important since the design methodology employs graphs to represent the mechanism
structure and mechanism structures are enumerated with the aid of graph theory.
Chapter 3 introduces several methods of representation of the kinematic structure
of mechanisms. The kinematic structure, which contains the essential information
about which link is connected to which other links by what types of joint, will be used
for the enumeration of mechanisms.
Chapter 4 examines the structural characteristics of mechanisms. The correspondence between graph and mechanism is established, from which several important
mechanism structural characteristics are derived. The degrees of freedom of a mechanism, the loop-mobility criterion, the concept of structural isomorphism, and various
methods of identification of structural isomorphism are described.
Chapter 5 deals with the enumeration of graphs of kinematic chains. Systematic
algorithms for the enumeration of contracted and conventional graphs are presented.
Atlases of contracted graphs and conventional graphs are developed. Using these
atlases, an enormous number of mechanisms can be developed.