The solution region-based synthesis methodology for a 1-DOF eight-bar linkage

Abstract

This study formulates a methodology to design an eight-bar linkage for four specified positions of an open 4R chain, by adding three RR (double revolute joint) constraints to the chain. The methodology is based on the solution region theory. An infinite number of mechanism solutions can be expressed in the solution region. Since defective solutions do not have the capacity to move continuously through four positions, these defective solutions need to be eliminated from the solution region by using a defect analysis method. After additional design requirements were considered and imposed, the useful solution region is established. Consequently, designers can directly select useful linkages from the useful solution region. An example is provided to illustrate that the synthesis method is simple, highly accessible, and convenient to design an eight-bar linkage for four specified positions.