Determination of the model of a powered air-purifying respirator for researching its operational modes

Abstract

Purpose. Justification of technical decisions when creating an experimental equipment of a powered air-purifying respirator (PAPR), development of a research system, planning and conducting an experiment, determining the structure of the object and its parameters, confirming the adequacy of the obtained simulation model of the PAPR to the control object in accordance with the conditions of the technological process. Methodology. The research was carried out on experimental equipment by means of an active experiment. It is proposed to use a sensor with an analog output and a controller for data registration to control the pressure. By varying the rotation speed of the fan, the value of the pressure in the respirator mask was determined. Structural and parametric identification and verification of the obtained model for adequacy to the control object according to the Fisher criterion were carried out on the basis of the obtained data. Findings. Based on the results of the study, it was established that the PAPR is an asymmetric object according to the "fan rotation speed - pressure in the mask" channel. The processes of pressure increase and decrease correspond in form to exponential functions and can be described by aperiodic links of the first order with different time constants. Based on the analysis of the structure of the control object, a corresponding asymmetric model was created in which aperiodic links are represented in the state space. Theprocess time constants and amplification factor of the model were determined by parameter estimation. The adequacy of the obtained simulation model to the control object was confirmed by Fisher's criterion. Originality. For the first time, a continuous transfer function of a PAPR was obtained in the form of a complex of two firstorder aperiodic links with different time constants. Practical value. A universal method of obtaining simulated models of PAPRs by using the developed experimental equipment and simulation environment of the MATLAB. The obtained simulation model of the PAPR allows to research its operating modes in order to determine the requirements for the control system and its further synthesis using various regulators.