Parameter Self-Tuning PID Control for Greenhouse Climate Control Problem

Abstract

The difficulty of the greenhouse climate control is the great uncertainties of the weather and greenhouse climate. Although many control approaches have been proposed to solve this problem, the structures of the controllers are usually complex, and the reliability of the controllers is usually not good in practice. Therefore, to improve the reliability of the controllers, this paper proposes a parameter self-tuning PID control approach (STPID). In this PID control scheme, three environmental outputs including the inside temperature, humidity and CO 2 concentration are firstly transformed into four equivalent unit outputs, and the equivalent outputs are controlled by four PID controllers respectively. Thus, each PID controller and the corresponding equivalent output construct a single closed-loop system, and the original system can be decoupled. To ensure the desired control performance, the Levenberg-Marquart (LM) algorithm is introduced to tune the PID parameters. Based on the real weather data, a simulation was performed to illustrate the effectiveness of the proposed method, and a comparison study was done to observe the performance of the proposed method. The results indicate that control performance is good.

A microenvironment prediction model for Chinese solar greenhouses based on the bond graph approach

“…The R and C elements compute flow and potential functions, respectively, by using Eq (1) [ 30 , 31 ]: where ϕ R and ϕ c depend on the geometric conditions and thermal physical parameters of the model; e i represents the potential function; and f i corresponds to the flow function. Se and Sf, which are known variables of the model, represent the potential source and flow source, respectively.…”

“…Abbes et al applied the bond graph model to plastic greenhouses and heating systems in the Northern Hemisphere [ 28 , 29 ]. Su et al [ 30 ] presented a bond graph model including floor, concrete, heat exchanger and soil. Bot et al [ 31 ] published a greenhouse bond graph model without considering the impact of wavelength.…”

A direct nonlinear humidity and temperature tracking controller for an air-handling unit based on backstepping scheme

“…And two controllers were established for a multizone building [20] and dual duct systems [21], respectively. Using four PID controllers to decouple the greenhouse climate system, a parameter self-tuning controller was constructed [22], which simplified controller design and conquered the issue of great uncertainties of greenhouse climate and weather. Considering the effect of temperature on semiconductor manufacturing, a frequency loop-shaping approach was applied and had a good control accuracy [23].…”

“…Considering the effect of temperature on semiconductor manufacturing, a frequency loop-shaping approach was applied and had a good control accuracy [23]. The PID control technology was involved in these achievements [22][23][24][25]. Combining fuzzy logics and PID technology, the fuzzy PID controllers were established to achieve the control of a minimum nonlinear phase model of an AHU [26] and energy management in buildings [27].…”

Smart Dome 4.0: Low-Cost, Independent, Automated Energy System for Agricultural Purposes enabled by Machine Learning

“…To enable these two areas there are several key technologies involves, which are (1) smart controllers which can adjust the condition inside the SDD by means of regulating what have been measured by sensors into fulfilling certain target parameters by activating several actuators and (2) artificial intelligence (AI) subsystem which can optimize the operation of the controller and predict the system parameters or set points according to collected historical data. There are several control platforms and algorithms ranging from logic controller, proportional integral derivatives (PID) controller [16][17][18], as well as cutting edge soft computing controllers such as fuzzy logic [19], genetic algorithms [20] and model predictive control (MPC) [21,22]. All these controllers may be based on a certain set point value to be maintained which can be static or adaptive.…”