针对实际档案库房操作空间的动态约束性,常见的运动规划算法难以满足快速在线规划的问题,分别从规划速度和动态空间在线规划两个方向进行研究.首先,提出一种新型快速搜索随机树法(rapidly-exploring random trees,RRT),基于剪枝和路径...针对实际档案库房操作空间的动态约束性,常见的运动规划算法难以满足快速在线规划的问题,分别从规划速度和动态空间在线规划两个方向进行研究.首先,提出一种新型快速搜索随机树法(rapidly-exploring random trees,RRT),基于剪枝和路径细化策略能够大幅减少无用节点计算和冗余路径运动.其次,将人工势场法与RRT算法相结合,新节点拓展时会受到期望为当前势场合力的高斯分布的影响,在满足对动态障碍物的在线运动规划的同时提高了算法的拓展能力.最后,通过仿真结果证明,新型RRT算法在拓展效率上的高效性和混合运动规划算法在动态规划和探索效率上的优越性.展开更多
对于间歇过程变量深层特征提取困难,以及变量的时序性、非线性、动态特性所导致质量预测精度不高的问题,提出了一种基于卷积-时空注意力的双层长短期神经网络(convolutional neural networks spatial and temporal attention with doubl...对于间歇过程变量深层特征提取困难,以及变量的时序性、非线性、动态特性所导致质量预测精度不高的问题,提出了一种基于卷积-时空注意力的双层长短期神经网络(convolutional neural networks spatial and temporal attention with double long short term memory networks,CNN-STA-DLSTM)的间歇过程质量预测模型。首先,对间歇过程数据沿着变量的方向展开成二维矩阵,对二维数据采用Max-Min法归一化,接着,使用PLS对原始数据降维,保留与质量变量相关性较强的变量,使用CNN挖掘过程数据的潜在特征,提高质量相关特征信息的关注;其次,引入时间注意力机制和空间注意力机制构建双层LSTM的编码器-解码器结构网络,利用注意力机制自适应地学习时间步长的相关历史信息,以提高模型的长期记忆能力,并加强过程变量与质量变量之间的时空相关性;然后,采用随机-网格搜索法寻找预测模型合适的超参数,并构建了预测模型;最后,使用青霉素发酵仿真平台和带钢热连轧生产过程数据进行实验验证,结果表明所提模型具有更精准的预测效果。展开更多
Rockburst is a common geological disaster in underground engineering,which seriously threatens the safety of personnel,equipment and property.Utilizing machine learning models to evaluate risk of rockburst is graduall...Rockburst is a common geological disaster in underground engineering,which seriously threatens the safety of personnel,equipment and property.Utilizing machine learning models to evaluate risk of rockburst is gradually becoming a trend.In this study,the integrated algorithms under Gradient Boosting Decision Tree(GBDT)framework were used to evaluate and classify rockburst intensity.First,a total of 301 rock burst data samples were obtained from a case database,and the data were preprocessed using synthetic minority over-sampling technique(SMOTE).Then,the rockburst evaluation models including GBDT,eXtreme Gradient Boosting(XGBoost),Light Gradient Boosting Machine(LightGBM),and Categorical Features Gradient Boosting(CatBoost)were established,and the optimal hyperparameters of the models were obtained through random search grid and five-fold cross-validation.Afterwards,use the optimal hyperparameter configuration to fit the evaluation models,and analyze these models using test set.In order to evaluate the performance,metrics including accuracy,precision,recall,and F1-score were selected to analyze and compare with other machine learning models.Finally,the trained models were used to conduct rock burst risk assessment on rock samples from a mine in Shanxi Province,China,and providing theoretical guidance for the mine's safe production work.The models under the GBDT framework perform well in the evaluation of rockburst levels,and the proposed methods can provide a reliable reference for rockburst risk level analysis and safety management.展开更多
文摘针对实际档案库房操作空间的动态约束性,常见的运动规划算法难以满足快速在线规划的问题,分别从规划速度和动态空间在线规划两个方向进行研究.首先,提出一种新型快速搜索随机树法(rapidly-exploring random trees,RRT),基于剪枝和路径细化策略能够大幅减少无用节点计算和冗余路径运动.其次,将人工势场法与RRT算法相结合,新节点拓展时会受到期望为当前势场合力的高斯分布的影响,在满足对动态障碍物的在线运动规划的同时提高了算法的拓展能力.最后,通过仿真结果证明,新型RRT算法在拓展效率上的高效性和混合运动规划算法在动态规划和探索效率上的优越性.
文摘对于间歇过程变量深层特征提取困难,以及变量的时序性、非线性、动态特性所导致质量预测精度不高的问题,提出了一种基于卷积-时空注意力的双层长短期神经网络(convolutional neural networks spatial and temporal attention with double long short term memory networks,CNN-STA-DLSTM)的间歇过程质量预测模型。首先,对间歇过程数据沿着变量的方向展开成二维矩阵,对二维数据采用Max-Min法归一化,接着,使用PLS对原始数据降维,保留与质量变量相关性较强的变量,使用CNN挖掘过程数据的潜在特征,提高质量相关特征信息的关注;其次,引入时间注意力机制和空间注意力机制构建双层LSTM的编码器-解码器结构网络,利用注意力机制自适应地学习时间步长的相关历史信息,以提高模型的长期记忆能力,并加强过程变量与质量变量之间的时空相关性;然后,采用随机-网格搜索法寻找预测模型合适的超参数,并构建了预测模型;最后,使用青霉素发酵仿真平台和带钢热连轧生产过程数据进行实验验证,结果表明所提模型具有更精准的预测效果。
基金Project(52161135301)supported by the International Cooperation and Exchange of the National Natural Science Foundation of ChinaProject(202306370296)supported by China Scholarship Council。
文摘Rockburst is a common geological disaster in underground engineering,which seriously threatens the safety of personnel,equipment and property.Utilizing machine learning models to evaluate risk of rockburst is gradually becoming a trend.In this study,the integrated algorithms under Gradient Boosting Decision Tree(GBDT)framework were used to evaluate and classify rockburst intensity.First,a total of 301 rock burst data samples were obtained from a case database,and the data were preprocessed using synthetic minority over-sampling technique(SMOTE).Then,the rockburst evaluation models including GBDT,eXtreme Gradient Boosting(XGBoost),Light Gradient Boosting Machine(LightGBM),and Categorical Features Gradient Boosting(CatBoost)were established,and the optimal hyperparameters of the models were obtained through random search grid and five-fold cross-validation.Afterwards,use the optimal hyperparameter configuration to fit the evaluation models,and analyze these models using test set.In order to evaluate the performance,metrics including accuracy,precision,recall,and F1-score were selected to analyze and compare with other machine learning models.Finally,the trained models were used to conduct rock burst risk assessment on rock samples from a mine in Shanxi Province,China,and providing theoretical guidance for the mine's safe production work.The models under the GBDT framework perform well in the evaluation of rockburst levels,and the proposed methods can provide a reliable reference for rockburst risk level analysis and safety management.
