Abstract: The dynamic/control synthetic properties of the servo driving system used extensively as driving manipulators are analysed. A concept of the feedback constraint is produced. The study indicates that when the motion of the structure is controlled, constraint modes may be changed and corresponding constraint equations are also changed. However, the constraint equations express generally complex nonlinear modes. It has been proved that the constraint on the sense of mechanics is essentially that the action of the regulation due to position and speed feedback in the servo system changes boundary conditions of the motion of the structure. Through analysis we get such a description of feedback constraint closed loop curve for this kind of constraint property. The analysis shows that the characteristics of the constraint is of gap-type nonlinearity.

Key words: Boundary condition, Constraint, Dynamics, Feedback, Structure and controlling coupling system