... [20]). To control HVAC systems, the traditional method is the on/off control at the level of HVAC components, for example an air-conditioning unit. This kind of control is a very low-level control. ... Figure 3. The input signal and the step responses According to the superimposition principle of the linear system, suppose the original output value of the system at k is y0 (k), the control ... the DMC controller. First, the DMC controller is a local controller which can only guarantee the stability of the system in a local area. Second, the DMC controller is a model-based controller...