PERFORMANCE EVALUATION OF INTERNAL MODEL CONTROL BASED PROPORTIONAL INTEGRAL DERIVATIVE CONTROLLER FOR AVIONICS BAY TEMPERATURE CONTROL

Avionic bay equipment tends to malfunction or fail out rightly when they operate in an environment with temperature outside the required range. Thus, it becomes imperative to device means by which this temperature may be controlled. In this paper, Boeing 747 (B747) aircraft is taken as a case study. Boeing 747 utilizes cooling from the Environmental control system (ECS) to control avionics temperature. This is however a very expensive process for the aircraft in terms of fuel consumption and weight increase. The modelling, numerical simulation and intelligent control of the ECS are performed in this study by comparing the ambient temperature and desired avionics temperature range per time. The model equation is obtained based on the principles of heat transfer using First law of thermodynamics. The simulation of the developed Internal Model Control (IMC) based Proportional Integral Derivative (PID) model is done using MATLAB 8.5 (R2018a). The parameters of the PID controller are tuned using IMC. A comparative analysis with other tuning techniques such as ZieglerNichols (Z-N) and Cohen-Coon (CC) was also carried out. The performance evaluation of the methods is done using rise time, settling time and percentage overshoot as metrics. Results obtained from the analysis are presented in a graphical and tabular format, which shows that the developed IMC-PID controller model could be of significance to the Avionic Engineers as it gives better results compared with the conventional ZN-PID and CC-PID controller models.