The Research Of Optimal Adjustment Of Environmental Factors In Greenhouse Based On Information Fusion

The control technology for greenhouse is an important part of greenhouse engineering construction.Greenhouse adjustment based on multi-information fusion is the core of greenhouse intelligent control.Greenhouse environmental control technologies have developed rapidly in Japan,the Netherlands,the United States, Israel and other countries,and the domestic has done a lot of research in this area too. However,the research on greenhouse adjustment for the purpose of economic optimization in greenhouse control system is still a hard nut to crack.Information fusion technology is applied to solve the nonlinear decision-making problem in greenhouse environmental factors adjustment system.A decision-making method for co₂ or temperature adjustment is put forward to achieving the profit maximization.Though studying on the changes of greenhouse environmental factors and their impact on crop growth and researching on diurnal variation of crop photosynthesis in different seasons and weather,a prediction model is set up for forecasting plant growth rate by neural network,and a market price model is established for forecasting plant market price by polynomial fitting function.In terms of the above two models and the cost of co₂ enrichment,the pure profit rates of photosynthate are obtained at different co₂ concentrations.Then the optimal set-point of co₂ concentration for maximums profit would be found out by the method of translation and tangent.Similarly,the maximums profit for temperature adjustment in greenhouse would be acquired too.Through theoretical analysis and experimental results,the models can be established:the prediction model of crop photosynthetic rate about co₂ concentration, the prediction model of photosynthetic rate about temperature,the model of co₂ damage cost,the model of temperature regulation cost,the model of heat loss cost, and the market price model based on the law of seasonal price change.In a certain light intensity,through the prediction models,the laws of photosynthetic rate can be obtained as co₂ concentration and temperature changes.The prediction models have a higher accuracy,which provide theories for the decision-making of environmental factors adjustment in greenhouse control system.