关键词: 反向传播（BP）算法, 激励函数, 陡度因子, 局部式反传网络, 协调器

Abstract: According to the shortcomings of slow convergence of the standard BP （Back-Propagation） algorithm, its main causes are analyzed and the improved algorithm of BP algorithm with the partial counter propagation network is proposed. Through increasing steepness factor of activation functions and increasing coordinator to modify weights when the error is in the back propagation, a full back-propagation type network becomes local-style back-propagation network by means of the analysis of the sensitivity of the network, so as to achieve the purpose of enhancing the learning speed and accuracy. Improved BP algorithm is applied to identification of the stable platform on steerable drilling system. Simulation comparison results show that, in a given accuracy requirement and its convergence speed, this improved BP neural network is superior to traditional BP network, so it has good research and application value.

Key words: Back-Propagation（BP） algorithm, activation function, steepness factor, local-style counter-propagation network, coordinator