Using a fuzzy logic-based apparatus for damping vibrations of a flexible load

Abstract

THE RELEVANCE of the research lies in the need to improve existing control systems for industrial mechanisms with minimal investment in reconstruction, as well as the demand for reliable control systems, the use of which can increase the service life of the device as a whole.THE PURPOSE. To develop a simple and at the same time effective control system for an industrial facility that allows damping vibrations of a flexible load. On overhead cranes, one of the mechanisms for moving cargo around the workshop is the trolley mechanism. The overhead crane trolley is used to move cargo along the bridge span, and the transported cargo can have either a rigid or flexible suspension. The use of a flexible suspension leads to vibrations in the form of rocking of the moved load. These vibrations are a negative phenomenon that has a negative impact on the mechanical structure of the crane and on the electrical control system of the electric drive of the trolley. An asynchronous motor with a squirrel-cage rotor is installed on the mechanism under consideration; based on the research carried out, a vector system was selected to control it, into which, in order to suppress load fluctuations, it was proposed to introduce a controller operating on the basis of fuzzy logic. The proposed fuzzy controller adjusts the engine speed depending on the angle of deflection of the flexible load; its uniqueness lies in its ease of implementation and the minimum number of control signals. Regulators of this type have proven themselves well, as they have high speed, good response in dynamics, and allow optimization of the control system by indirectly determining parameters.METHODS. During the study, mathematical modeling techniques were used to solve the identified problems. The study of the control system was carried out in the MATLAB modeling environment in the Simulink subsystem.RESULTS. The article reflects the significance of the research topic and discusses the available methods for damping vibrations of a flexible load. For the study, a system was developed containing a subsystem whose functions include tracking the dynamics of the movement of the cart and cargo. This article proposes a control controller operating on the basis of fuzzy logic rules. The controller is simple to implement, has one control signal, while fuzzy logic allows you to flexibly configure the control system, which makes it possible to obtain the required control characteristics.CONCLUSION. Simulation of the trolley operation process in the MATLAB Simulink environment took place with a change in the mass of the load and the length of the suspension; the analysis of all modeling options led to the conclusion that the proposed controller based on fuzzy logic makes it possible to dampen load fluctuations for various initial parameters.

Keywords

• vibration damping
• vector control
• flexible suspension
• electric drive
• fuzzy controller