An oscillatory method for identifying the characteristics of friction pairs of drive systems is considered. It is based on the use of mechatronic systems with a controlled "electric spring" and allows us to investigate dissipative characteristics in the regime of forced steady oscillations in the operating frequency range, with low laboriousness and high accuracy. The mechatronic oscillatory system is realized on the basis of a synchronous electric machine with permanent magnets on the rotor and a control system for the oscillation regime. The peculiarity of the method and the technical means realized on its basis is that the determination of the moment of frictional forces occurs not in the static state of the system, but under conditions close to the operational ones, i.e. with continuous motion by changing the direction of motion.

Effect of friction on the motion control processes in mechatronic systems is considered. The analysis of modern friction modeling methods is carried out. Features of processes at low speeds: accuracy, oscillations and stability have been studied on base of macroscopic models of friction. Friction in the mechatronic system causes the formation of complex nonlinear speed feedback, which depends on many factors and has different signs at different speeds. Oscillations and a violation of the stability of the system are possible with positive feedback at low speed. The conditions of stable operation under frictional load for a DC motor are derived. Correction methods for mechatronic systems with friction are considered. Effective control in mechatronic systems achieve using the principle of subordinate coordinate control. The results of modeling systems with the main feedback on the angular speed and angle of rotation are presented.