Design of phosphorus flows control systems in enclosed agroecosystems

• Main Authors: Lin, Wen Ze, 林文澤
• Other Authors: Liao, Zhong Ming
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/93974796158677849364

碩士 === 國立臺灣大學 === 農業工程研究所 === 83 === An analytical framework for the design of an enclosed agro- ecosystem via the view point of engineering control systems is described. The terminology and the framework are deve- loped within the context of that description to interpret a pig farm environmental control mechanism in which a partially or a fully autonomous production capacity is assigned. 　 Based on the framework noted above and the linear systems theory, a system control model is develpoed to describe the dynamic behavior of energy/material flows in an enclosed ag- roecosystem. Linear quadratic regulators (LQRs) with output feedback of a linear-invariant system are chosen for this study. The optimization and suboptimization are defined to determine an output control loop such that the integral qua- dratic cost function meets its minimum value. Both impulse and step disturbances are taken into account and optimal pro- portional (P) and proportional plus integral (PI) feedback controllers are synthesized. To illustrate this procedure, the design is applied to control residual phosphorus concen- tration in a typical pig farm located at Yun-Lin, Taiwan. The simulations were done in complied PC-MATLAB. Numerical results from the model implementation that the optimal choice of wei- ghting parameters and the resulting costs vary with desired equilibrium state. The designed optimal feedback controllers, when suitable tuned, give satisfactory control of residual phosphorus concentrations in the pig farm.