中文摘要：

基于拟牛顿法原理,结合同时扰动随机逼近算法特性提出了一种搜索方向dk的计算方法,从而提高了同时扰动随机逼近算法的收敛速度和逼近精度.针对典型优化问题分别比较了改进后的同时扰动随机逼近算法、标准同时扰动随机逼近算法及二阶同时扰动随机逼近算法的优化性能,数值分析结果表明：改进后的算法在逼近精度上均优于其他两种算法,收敛速度介于其他两种算法之间.

英文摘要：

In order to improve convergence speed and approximation precision of simultaneous perturbation stochastic approximation（SPSA）,lessons were drawn from Broyden-Fletcher-Goldfarb-Shanno（BFGS）quasi-Newton method,and a computing method of search direction dkbased on SPSA was provided.A typical optimization problem as numerical analysis case was used,and characteristics of the improved SPSA were compared with standard SPSA and the second order SPSA.The results of numerical analysis indicate that the improved SPSA is better than the other two methods at approximation precision aspect,and the performance of convergence speed is between basic SPSA and the second order SPSA.