Description of displacement subgroup for structure transformations of metamorphic mechanisms

In order to analyze configurations of metamorphic mechanisms, a description method of displacement subgroup for structure transformations of metamorphic mechanisms is proposed. Methods of representation and calculation of displacement subgroup for adjacent and non-adjacent link combinations are presented. And methods of representation and calculation of displacement subgroup matrix for metamorphic transformations are also presented. A spatial 8-SSSS parallel metamorphic mechanism is proposed as well. Its structure transformation is represented and calculated by methods of displacement subgroup and its matrix. The effectiveness and correctness of the proposed method are further proved. The method can transform issues of metamorphic transformations into the representation and calculation of displacement subgroup. Furthermore, the applicability of the description method for structure transformations of metamorphic mechanisms is extended from topological structure to geometric structure.