A direct nonlinear humidity and temperature tracking controller for an air-handling unit based on backstepping scheme

Abstract

Aim at an air-handling unit (AHU), this article describes a direct design scheme for humidity and temperature tracking control. The nonlinear dynamic model of the AHU is treated directly by backstepping strategy, which can reserve the modeling qualifications and make better use of known information than proportion integration differentiation (PID) and other non-model-based schemes. Simultaneously, the linearization technique is not adopted, so that the model structure is not changed, which can retain the original system model restrictions to variables and does not lose useful conditions about the system model. These two points ensure the developed controller to achieve higher accuracy and better tracking performance, which is verified by stability analysis and comparisons of simulation results.