Stiffness Matrix of Compliant Parallel Mehanisms

Starting from the definition of a stiffness matrix, the authors present the Cartesian stiffness matrix of parallel compliant mechanisms. The proposed formulation is more general than any other stiffness matrix found in the literature since it can take into account the stiffness of the passive joints and remains valid for large displacements. Then, the validity, the conservative property, the positive definiteness and the relation with other stiffness matrices of this matrix are discussed theoretically. Finally, a numerical example is given in order to illustrate the correctness of this matrix.