Constrained RPR Chains

Constrained RPR Chains _ Mark Plecnik

Six-bar mechanisms that include a prismatic joint can be synthesized as constrained RPR chains. These single degree of freedom constrained RPR chains are capable of reaching five task positions. The synthesis process begins by first specifying a serial, open, 3 DOF chain. The inverse kinematics are solved to find five positions of the RPR that […]

Spatial 5-SS Linkages

5 ss linkages

An algorithm has been created for the design of 5-SS linkages that reach 7 spatial task positions. 5-SS refers to the 5 spherical to spherical binary links that connect a moving platform to the fixed platform of these single degree of freedom mechanisms. Attached to that moving platform is an end effector frame. The goal […]

Configuration Space and Linkage Defects

configuration space and linkage defects

The design of linkages presents many challenges.  Most notably the nonlinearity of the design space. However, another challenge is created by the presence of defects in linkage designs. The regularly studied linkage defects are named order, branch, and circuit. See Balli and Chand. An effective method to eliminate linkage designs that possess branch and circuit defects […]

Function Generators

function generators

For 11 positions Function generation refers to the use of a linkage to coordinate angles. This has many useful applications and function generators are often installed as elements of other linkages, such as path generators. Designing function generators is a particular challenge because of the large degree of their design equations. We have solved the design […]

Path Generators

path generators mark plecnik

Designing a path generating linkage means designing a linkage to guide a point path in some particular manner.  We specifically have worked on designing six-bars.  Much work has been completed on four-bar path generators, but it wasn’t until 1992 that Wampler et al. [1] found a complete solution set of 4,326 to the general 9-point […]