Applications of DMC-PID algorithm in the measurement and control system for the greenhouse environmental factors

Considering the characteristics of time-delay, nonlinear and difficult established precise mathematics model in greenhouse climate, and a control system based on predictive-PID cascade control is proposed. It combines the cascade control structure with predictive control algorithm, the inner loop uses a general proportion adjuster and the outer loop uses a Dynamic Matrix Control (DMC). The control system not only keeps the strong robustness and fast tracking performance of the predictive control algorithm, but also rejects the interference rapidly. Simulation result shows that the control quality and the robustness of the system are superiors to the general PID system.