| Summary: | 碩士 === 國立宜蘭大學 === 生物機電工程學系碩士班 === 105 === This thesis used a hybrid control system as the modeling scheme combined with the dynamic model of a temperature-humidity environmental system. This work respectively employed the virtual instrument control techniques compiled in a LabVIEW software and the entity instrument control techniques with the programmable logical controller (PLC) to implement the predicted simulator and online controller system of dynamic indoor temperature-humidity environment for use in a tree seedling greenhouse. In order to effectively incorporate external, internal heat load and indoor humidity load into the dynamic model’s computation of a temperature-humidity environmental system in a greenhouse, this thesis adopted a set of nonlinear state-space differential equations based on the mass-energy equilibrium principles combined with dry air, moisture and enthalpy of air to describe the indoor dynamic temperature-humidity environment. The mixed logical dynamic system (MLDS) was used to approach to this controlled indoor dynamic temperature-humidity environmental system under the state of discrete time. By using piecewise linear functions, which could discrete and approach such a nonlinear temperature-humidity environmental dynamic system, this method solved the complex mathematical problem issued from a set of nonlinear state-space differential equations. This study integrated physical laws, logic rules and operating constrains to deduce the finite state machine for controlling the dynamic temperature-humidity environment in a greenhouse. The combining use of Boolean logics and linear inequalities was adopted to build the systemic mechanism to completely present the complex logical rules existing in temperature–humidity environmental control procedures. The above mentioned systemic mechanism was systematically transformed to the compiled LabVIEW programing and PLC’s executing program to implement the virtual and entity instrument control techniques, respectively. The outcomes of simulated prediction and entity operation both demonstrated that the course of the virtual and entity control in two systems could modulate the temperature-humidity environment in a greenhouse according to expected target ranges to provide suitable growth conditions for tree seedlings, and also verify the equivalent of the estimate of power consumption in this virtual control system as well as the power use in the entity instrument control. This thesis confirms that the virtual instrument control techniques compiled in a LabVIEW software could implement the emulation analysis of dynamic temperature–humidity environmental control in a greenhouse to reduce the developing costs, time and errors on systemic manufacturing procedures.
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