(1. 中南大学 有色金属成矿预测教育部重点实验室，长沙 410083；
2. 中南大学 地球科学与信息物理学院，长沙 410083)
摘 要: 粒子群优化算法是一种启发式的全局优化算法，将其与BP神经网络结合，能够有效地改善BP神经网络在进行电阻率层析反演中的收敛速度和求解质量。提出一种基于混沌振荡的粒子群算法，使用混沌振荡曲线来自适应调整惯性权重w以提高PSO算法的全局寻优能力，并使用其训练和优化BP神经网络的权值和阈值。比较不同隐含层节点数目和惯性权重w值对反演结果的影响，并给出混沌振荡PSO-BP算法非线性反演的具体实现方案。对均匀半空间中异常体理论模型进行反演，实验结果表明：混沌振荡PSO-BP不依赖初始模型，在稳定性和准确性上优于BP反演和标准PSO-BP反演，成像质量优于最小二乘法反演的。
关键字: 电阻率层析成像；非线性反演；粒子群优化；反向传播网络；混沌序列
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education, Central South University, Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China）
Abstract:The particle swarm optimization (PSO) is a heuristic global optimization method, which can effectively improve the convergence speed and the results quality with the BP neural network in resistivity tomography 2-D nonlinear inversion. A chaotic oscillation PSO algorithm was presented, and the chaos oscillation curve was used to adjust the inertia weight adaptively and improve the global optimum capability of PSO. And this algorithm was used to train and optimize the weights and threshold values of the BP neural network. The impacts of different numbers of the hidden layer nodes and types of the inertia weight to the inversion result were compared, and an implementation of chaotic oscillation PSO-BP algorithm was given. The half space abnormity synthetic model was inversed. The results show that the chaotic oscillation PSO-BP algorithm that is independent of the initial model has better performance than BP and standard PSO-BP algorithm in stability and accuracy, and has higher imaging quality than least square inversion.
Key words: electrical resistivity tomography; nonlinear inversion; particle swarm optimization; back propagation network; chaotic sequences
