The main objective of this study is the control of the agricultural greenhouse in view of the economic interest generated by such an activity. A simulation model is developed, gathering all the external and internal c...The main objective of this study is the control of the agricultural greenhouse in view of the economic interest generated by such an activity. A simulation model is developed, gathering all the external and internal climatic conditions that influence the microclimate of the greenhouse to predict the temporal evolution of the state variables characterizing this microclimate. The fuzzy control is an alternative to the approaches proposed by the automatic for the control of complex systems. The performance objectives of the looped systems and the corresponding actions are summarized in the form of rules of expertise, which are spelled out in plain language. This technique thus makes it possible to dispense with the use of mathematical models which are sometimes difficult to obtain. Our objective is the multivariable strategy synthesis and the fuzzy application to a multivariate system （MIMO ~ such as the agricultural greenhouse.） First, the principles of fuzzy logic and fuzzy control are recalled. The origins of non-Linearitys of the command are explained. One of the practical problems of this technique is the combinatorial explosion of the rule base when the number of variables involved becomes large. A solution to simplify the complexity of the system is presented together with an optimization algorithm to automatically adjust the parameters of the fuzzy controller. The last part is devoted to the synthesis of an optimal control of the greenhouse in order to compare it to the fuzzy control implemented.展开更多
To model Skeletonema costatum blooms and their relationship with environmental parameters in situ, a S. costatum-specific zero-dimensional box model based on the mechanistic model Eco3M was established using physiolog...To model Skeletonema costatum blooms and their relationship with environmental parameters in situ, a S. costatum-specific zero-dimensional box model based on the mechanistic model Eco3M was established using physiological features. The parameters were calibrated using experimental counterparts, and simulations were compared with published laboratory findings. The resulting normalized objective function （NOF） values are less than 1.0 （and in most cases less than 0.58） and the values for the slope y （between 0.656 7-1.127 4） and R2 （between 0.806 8-0.971） are close to 1.0 for most of the sub-figures. This indicates good agreement between simulated and measured data and suggests that the model reproduces the general characteristics of S. costatum growth and use of nutrients under different N- or P-limiting conditions. The model is appropriate for further applications and can be used to test more scenarios using other nutrients.展开更多
文摘The main objective of this study is the control of the agricultural greenhouse in view of the economic interest generated by such an activity. A simulation model is developed, gathering all the external and internal climatic conditions that influence the microclimate of the greenhouse to predict the temporal evolution of the state variables characterizing this microclimate. The fuzzy control is an alternative to the approaches proposed by the automatic for the control of complex systems. The performance objectives of the looped systems and the corresponding actions are summarized in the form of rules of expertise, which are spelled out in plain language. This technique thus makes it possible to dispense with the use of mathematical models which are sometimes difficult to obtain. Our objective is the multivariable strategy synthesis and the fuzzy application to a multivariate system （MIMO ~ such as the agricultural greenhouse.） First, the principles of fuzzy logic and fuzzy control are recalled. The origins of non-Linearitys of the command are explained. One of the practical problems of this technique is the combinatorial explosion of the rule base when the number of variables involved becomes large. A solution to simplify the complexity of the system is presented together with an optimization algorithm to automatically adjust the parameters of the fuzzy controller. The last part is devoted to the synthesis of an optimal control of the greenhouse in order to compare it to the fuzzy control implemented.
基金Supported by the National Natural Science Foundation of China(Nos.40821004,41276186)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-YW-Q07-02)
文摘To model Skeletonema costatum blooms and their relationship with environmental parameters in situ, a S. costatum-specific zero-dimensional box model based on the mechanistic model Eco3M was established using physiological features. The parameters were calibrated using experimental counterparts, and simulations were compared with published laboratory findings. The resulting normalized objective function （NOF） values are less than 1.0 （and in most cases less than 0.58） and the values for the slope y （between 0.656 7-1.127 4） and R2 （between 0.806 8-0.971） are close to 1.0 for most of the sub-figures. This indicates good agreement between simulated and measured data and suggests that the model reproduces the general characteristics of S. costatum growth and use of nutrients under different N- or P-limiting conditions. The model is appropriate for further applications and can be used to test more scenarios using other nutrients.
