Abstract: A generalized expression of position errors of spatial linkage mechanisms is derived from the loop equation. The parameters of motion of the links are described by H-D matrix, and the differential matrices take the forms of pre-multiplying and post-multiplying matrices. The unknown variables of errors can be conveniently solved by an appropriate selection of the first member and the end member of the mechanism, as well as the premultiplying and post-multiplying differential matrices.

Key words: 空间机构, 运动误差