Feedback feed-forward linearization and decoupling for greenhouse environment control

Aiming at solving the problem of the nonlinear strong coupling between temperature and humidity in the greenhouse, this paper presents feedback feed-forward linearization and decoupling algorithm for climate control of greenhouses. Using this algorithm, the nonlinear multiple-input multiple-output (MIMO) system is transformed into two independent single-input single-output (SISO) first-order linear systems. Strong coupling between temperature and humidity is removed. The temperature and humidity control law that make the dynamic mass-energy balance equations of greenhouse system completely decoupled is easily calculated by this method, and a simulation experiment is conducted under the identified greenhouse model parameters. The simulation results show that good effect can be achieved through the two-factor coordinated control of greenhouse temperature and humidity based on the high-precision mechanism model.