A new approach to control of moving mechanical systems with nonrigid construction on the basis of formation of the intelligent diagnostic subsystem and the base algorithm current tuning is suggested. This approach makes it possible to design the systems that guarantee stabilization both the object main ("rigid") movement and the vibrations of its construction. At that it is assumed that the control is real-ized in the class of discrete systems with piecewise constant control actions. In the general case these actions can be as the cause of appearance and growth of the vibrations of the moving object construction. The model of the nonlinear controller actions on the vibrations is described. The notion of a "model function" of the base control influence on the vibrations when a dominant mode occurs is in-troduced. Synthesis of adaptive system with the elements of the intelligent diagnostic is carried out.