Computer simulation of the microprocessor liquid level automatic control system

Abstract

Today, automation occupies a leading place in most branches of modern society, in almost all types of industry and economy. One of the main tasks of designing modern automatic control systems is the realization of high indicators in terms of accuracy, control range, and speed, taking into account the features of the control object itself. The purpose of the work –researching the microprocessor system of automatic control of the liquid level by means of computer modeling, taking into account the transport delay, the nonlinearity of the control characteristic of the pump and the presence of an insensitivity zone. To achieve the goal, the following tasks were solved: a computer model of a closed microprocessor system for automatic control of the liquid level wasdeveloped, taking into account the nonlinearity of the characteristics of the pumping unit and transport delay; a number of experiments were conducted to find the values of PI-regulator coefficients that bring the transient process of a real system with a transport delay as close as possible to the transient process of a system in which there is no transport delay; search for optimal values of the coefficients of the PI controller by minimizing the functional of the root mean square deviation of the real from the specified transient processes. As a result of research, it was established that the minimum points of the functional for the control signal and the liquid level do not coincide. At the same time, at the minimum point of the functional for the liquid level, a larger amplitude of oscillations of the control signal is observed, and at the minimum point of the functional for the control signal –an increase in the duration of the transient process. Therefore, the final decision should be based on the selection of priorities or optimal ratios between the speed and wear of the equipment, which is due tothe instability of the control signal.