Temperature compensation for humidity sensor based on improved GA-BP neural network
Aiming at the problem that the measurement accuracy of HMP45D humidity sensor adopted in automatic weather stations is vulnerable to the influence of temperature,this paper studies and improves the encoding method,fitness function and parameters in genetic algorithm; uses the improved genetic algorithm (GA) to optimize the initial weights and threshold in back propagation(BP) neural network;performs searching in larger range;then uses the back propagation algorithm to carry out fine tuning in smaller range, and optimize the network and structure parameters at the same time. A new method is proposed,which uses the improved genetic algorithm to optimize BP neural network. Based on the measured data of humidity sensor in various temperature conditions,we carried out study on the temperature compensation model established using this method and performed analysis and comparison with general BP neural network method. The experimental results show that the proposed method has global optimization ability,high compensation precision,fast convergence speed;can effectively compensate the influence of temperature on humidity sensor and improve the measurement accuracy of humidity sensor greatly.