Adaptive anti-disturbance control for an air handling unit with compound disturbances

In this paper, an adaptive anti-disturbance temperature and humidity control method using backstepping is proposed for air handling units (AHU), which are multi-input and multi-output (MIMO) nonlinear systems. The humidity source strength and heat load are considered as disturbances and described by a new form, such that they can be estimated by a compound disturbance observer without known amplitudes of themselves and their derivatives up to n. The proposed controller is designed and compared with the feedback linearised and PID controllers. The results show that the developed control scheme has better robustness and tracking performance.