基于L-M算法的正交Stewart平台位姿正解的初值补偿  

Forward kinematics of orthogonal Stewart platform based on L-M algorithm

作　　者：王启明[1] 苏建[1] 张兰[1] 陈秋雨[1] 徐观[1] WANG Qi-ming SU Jian ZHANG Lan CHEN Qiu-yu XU Guan(College of Transportation, Jilin University, Changchun 130022, China)

机构地区：[1]吉林大学交通学院,长春130022

出　　处：《吉林大学学报（工学版）》2017年第1期97-104,共8页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(51478204)

摘　　要：针对牛顿拉夫逊迭代法求解正交Stewart六自由度平台位姿正解对迭代初值依赖的问题,提出基于Levenberg-Marquardt(L-M)算法改进的BP神经网络模型,进而实现对Stewart平台位姿正解的迭代初值补偿值计算,并与基于BFGS拟牛顿算法、SCG量化共轭梯度算法、GDA梯度下降自适应算法所建立的BP神经网络模型进行对比分析,重点分析模型的适应性、预测输出、误差性能等。结果表明:采用提出的基于L-M算法改进的BP神经网络模型对正交Stewart六自由度平台位姿正解的迭代初值校正后,收敛速度有显著提升,初始值校正误差低于0.1%,校正结果满足预期要求。Aiming at the problem of high sensitivity to iteration initial guess when using NewtonRaphson iteration method to compute the forward kinematic solution of orthogonal Stewart-6Dplatform,a compensation method based on Levenberg-Marquardt（L-M）algorithm of back propagation model iteration initial guess was proposed.The adaptation,the output prediction and error performance of the proposed algorithm were analyzed in comparison with the back propagation model based BFGS quasi-Newton algorithm,back propagation model based scale conjugate gradient,back propagation model based gradient descent with adaptive Ir algorithm.With the help of inverse solution model based Simulink and SolidWorks,successful training samples were established.1000 groups of data were randomly and comprehensively picked up.900 groups were used for training the net and the other 100 groups were used for testing whether the trained net is qualified.Simulation results show that the initial guess modified L-M algorithm of back propagation model was significantly calibrated.The convergent speed of the iteration modified algorithm was improved.The angle anddisplacement calibrating error rate was less than 0.1%.The test results of the improved BP Neural net can meet the requirement.

关 键 词：铁路运输 位姿正解 轨道车辆 位姿测量系统 LEVENBERG-MARQUARDT算法 牛顿拉夫逊迭代法 

分 类 号：U266[机械工程—车辆工程]