INFLUENCE OF CONTROL SYSTEM PARAMETERS ON THE DYNAMIC CHARACTERISTICS OF AN ELECTROHYDRAULIC DRIVE WITH PASSIVE LOAD
Abstract
The article considers the influence of control system parameters on the dynamic characteristics of an electrohydraulic drive operating with a passive load. The object of the study is an electrohydraulic drive with a proportional electrohydraulic directional valve and a double-acting hydraulic cylinder, in which the controlled coordinate is the displacement of the cylinder rod. The study is carried out for operating conditions in which the passive load forms an external force disturbance and affects the inertial properties of the actuator. Such conditions are typical for technological and mobile machines, where positioning quality depends on the coordination of the hydraulic part, the load and the control algorithm. A mathematical model of a closed-loop position control system is developed. The model takes into account the dynamics of the proportional valve, the oscillatory properties of the hydraulic system, the inertia of moving masses, the integrating action of the hydraulic cylinder and the influence of the external load. Based on this model, a simulation study of transient processes is performed for proportional, proportional-integral and proportional-integral-differential control laws. The analysis focuses on how changes in the controller structure and its components affect the response speed, oscillatory behavior, overshoot and steady-state error of the system. The operation of the drive is also analyzed under conditions in which the mass of the passive load changes while the control parameters remain unchanged. This approach makes it possible to evaluate the sensitivity of the closed-loop system to changes in operating conditions and to describe the nature of the load influence on transient characteristics. The article presents the sequence of model development, the selection of the control system structure, comparative simulation procedures and the analysis of relationships between controller parameters, hydraulic system properties and passive load.