Получение исходных данных для проведения эксперимента по управлению температурой объекта с помощью ШИМ-модуляции и предсказывающего фильтра

Abstract

Доклад посвящен анализу проблем теплового управления, а также подготовке исходных данных для реализации управления температурой инерционного объекта в заданной точке с помощью широтно-импульсной модуляции и предсказывающего фильтра Представлены результаты натурных экспериментов по снятию разгонных кривых, а также характеристик с длительностью управляющих воздействий, кратных величине выбранного по теореме Котельникова периода дискретизации. Предложен математический аппарат для расчетов коэффициентов перехода от натурной модели к математической.

This report is dedicated to the analysis of problems of thermal control and preparing the source data for implementation a temperature control of inertial object at a given point with pulse-width modulation and prediction filter. Presented the results of natural experiments for receiving the overclocking curves, characteristics with a duration equal to the value of sampling period u t selected by the theorem of Kotelnikov. Getting the overclocking curves is the solution of the direct problem of heat conduction. Its solution is to find an object’s temperature that satisfies the differential equation of heat conduction and the conditions of the uniqueness. The determination of the boundary conditions, including the thermal flux density, according to the available information about the temperature of the object is a subject of solving the inverse heat conduction problem. A steel pipe has been taken as the test object. Overall dimensions, mm: length – 355; diameter – 32; length of the wound heater at the beginning – 82. Sensors data have been fixed every 5 seconds. Transition features are obtained for the object with five equidistant sensors and a heater. The first sensor was chosen to investigate the method and located approximately 50 mm away from the bottom of the heater. The capabilities of transition features are similar to behavior of an aperiodic link. These curves are identical to those that shows thermal objects with bad insulation. Proposed mathematical apparatus for the calculation transmission coefficients of thermal effects (Formula 2) for transition from a full scale model to a mathematical. The calculated coefficients of proportionality are confirmed the fact that the object is linear, therefore, for it is possible to apply the principle of superposition and implement control the temperature of the object by the proposed method — PWM modulation with using prediction filter.