Ali Aldaiery Y. Control system for metal cutting power stabilization with increased dynamic precision

The dissertation is devoted to solving problems of improving mathematical models of the cutting process on a milling machine based on fractional integral calculus and the development of an automated control system with a limitation of cutting power in static and dynamic modes. Control systems with a fractional order provide better dynamic and static indicators for many technical objects in comparison with systems with integer order of astaticism. Based on the analysis of Bode diagrams, transient processes and a modified criterion for quality assessment, optimal relationships between parameters of the desired transfer function were obtained. Normalized transition functions of closed-loop systems with the order of astaticism from 1 to 2 were presented with overload less than 2...5 % on the basis of which parameters can be chosen and the controller structure determined. The process of stabilizing cutting power was analyzed for a milling machine as the systems with nonlinear parametric and structural dependencies in control and perturbation channels. It was shown that fractional integral-differentiating controllers make it possible to provide the order of astaticism from 1.3 to 1.7 and permissible level of overregulation in a wide range of external perturbing influences.