Compensation of dry friction impact on the accuracy and stability of electromechanical systems with cable-block transmissions

• Published in: Известия Томского политехнического университета: Промышленная кибернетика Vol. 2; no. 4; pp. 13 - 20
• Main Author: Sergey A. Gayvoronskiy
• Format: Journal Article
• Language: English
• Published: Tomsk Polytechnic University 01.12.2024
• Subjects: adaptive dry friction compensator; cable-block system; drive block; dry friction; passive block; robust phase-advancing pseudo-linear device
• ISSN: 2949-5407
• DOI: 10.18799/29495407/2024/4/73

The paper considers the electromechanical systems with cable-block transmissions. Their blocks have a small mass and are inertialess. In such transmissions, as a rule, one block is connected to the electric drive and serves as a drive block for transmitting forces, and the remaining movable and stationary transmitting blocks are passive. In this case, dry friction moments with previously unknown values ​​act in all blocks. The author has carried out the analysis of the effect of dry friction in blocks of both types on the accuracy and stability of electromechanical systems. As a result of the mathematical description, taking into account the accepted assumptions, it is established that the effect of dry friction in the drive block is equivalent to the action of a relay β-link with a leading hysteresis characteristic. The effect of dry friction in passive inertialess blocks corresponds to the effect of backlashes with lagging hysteresis characteristics. A conclusion is made about the negative effect of dry friction in blocks of both types on the accuracy of electromechanical systems and the deterioration of their stability as a result of dry friction in passive blocks. The author developed the control algorithms that reduce the established negative effect of dry friction on the dynamics of electromechanical systems. The first adaptive algorithm is capable of accelerating the start of electromechanical system motion from a state of rest with an uncertain moment of dry friction, as well as when changing the direction of rotation of the blocks due to the rapid overcoming of the total moment of dry friction. The second robust algorithm implements a pseudo-linear law of correction of the phase-frequency characteristic of the system and creates a constant frequency-independent phase advance of the required value in it.