| There are many situations in which a linkage interacts with its environment through physical contact and exerts forces and moments. This thesis presents a methodology for the rational analytical design, of series (i.e. open-loop) and in-parallel linkages, in which the specified exerted forces are used to determine the linkage parameters. The emphasis is on model-formulation and on determining the maximum number of design specifications for any given force-based design problem. The design equations are obtained from static equilibrium conditions of the linkage at the design positions. The resulting equations are generally systems of multivariate polynomials.;We study the design of series linkages with revolute, prismatic, helical, cylindric, pin-in-sphere and spherical joints. The design equations for series linkages are obtained by taking appropriate components of the force and moment balance equations along the joint axes of the linkage. The in-parallel linkages dealt with in this thesis are of special geometry. As a result the design equations for these in-parallel linkages may be easily obtained from the static equilibrium equations of a coupler link only. This thesis also introduces the notion of incompletely-specified wrench synthesis, a topic which covers design situations in which some of the components of the wrench to be exerted on the environment are not crucial to the task at hand and are therefore left unspecified. Other variations of the basic wrench-design problem such as "design for combined motion-force constraints" and "design of linkages with springs" are also presented. |
