RESEARCH OF THE AUTOMATED CONTROL SYSTEM OF THE FEEDING ELECTRIC DRIVE IN THE MILLING MACHINE

Abstract

Fractional PI^aD^b-regulators in astatic closed-loop control systems allow to significantly improve the dynamic performance due to the increase in stability stocks with simultaneous expansion of the bandwidth of the circuit. In addition, when an object can be described by fractional-differential equations, or in its mathematical model power functions of fractional order are present, such regulators more accurately compensate for such features of the object. The purpose of the work is to study the automated control system of the feeding electric drive in the milling machine with a fractional order of astatism taking into account the essential inertial and nonlinear elements. The research of dynamic characteristics of the closed control system of the feeding of the milling machine during the stabilization of the cutting power, taking into account a number of significant differences from idealized linear systems - several small time constants (electric drive, electric motor of the main motion as a power sensor, a filter in the feedback circuit), nonlinear equivalent gain, which depends on the feed and depth of the cutting, and the fractional differential equation, which describes the dynamic properties of the cutting process. It is also taken into account that the system needs to stabilize the power of cutting, but not the filtered smoothed signal, which is fed to an analog-to-digital converter in a microprocessor control system. It is shown that in a system with a fractional order of astatism by minor changes in the configuration parameters provide the same small (up to 3%) overregulation, as in the reference linearized system. This allows you to recommend the received parity of parameters for setting up the studied class of automated control systems.