|Robust Sliding Mode Control of a Vapor Compression Cycle
Nakhoon Kim, Yunki Park, Jung E. Son, Seongjin Shin, Byounghyuk Min, Hyungjin Park, Seokhyun Kang, Hyun Hur, Man Yeoung Ha, and Min Cheol Lee*
International Journal of Control, Automation, and Systems, vol. 16, no. 1, pp.62-78, 2018
Abstract : "This paper deals with the development of a mathematical dynamic model and observer-based set point
control of a vapor compression cycle (VCC) system. The mean void fraction and moving boundary control volumes
in a heat exchanger (HEX) are used for a lumped parameter model of an air conditioning system. A multi-input
multi-output (MIMO) dynamic model of the VCC is presented in a nonlinear state space representation and is reformulated
into a linearized regular form for control design. A modified observer-based controller with sliding mode
control (SMC) is introduced to attenuate the effects of observing approximation errors and external disturbances. In
the design of the discontinuous controller, a new type of gain function is introduced to reduce the time to reach the
sliding mode compared to a conventional discontinuous gain. The proposed control methodology ensures uniformly
ultimately bounded tracking results of the desired low pressure and suction superheat. A simulation of controlling
the VCC illustrates the effectiveness and performance in the presence of disturbances."
Mean void fraction, moving boundary, robust stability, sliding mode control.