Structural Synthesis of a Class of Metamorphic Parallel Mechanisms with Variable Mobility

In this paper, a systematic approach is presented for the structural synthesis of a class of metamorphic parallel mechanisms which possess variable mobility. The metamorphic parallel mechanisms are constructed using limbs with lockable joints. When different joints are locked, the mechanisms will have different mobility from single degree of freedom to full six degrees of freedom. First, the feasible limbs are enumerated based on constraint analysis. Then a metamorphic parallel mechanism constructed with feasible limbs is presented as example and its ability to perform variable mobility is demonstrated. The metamorphic parallel mechanisms presented in this paper will be perfect suitable in the complex process of industrial production.