The mechanical properties of deep-sea sediments during the driving process of crawler collectors are essential factors in the design of mining systems.In this study,a crawler load is divided into a normal compression ...The mechanical properties of deep-sea sediments during the driving process of crawler collectors are essential factors in the design of mining systems.In this study,a crawler load is divided into a normal compression load and a horizontal shear load.Then,the internal stress state of sedimentary soil is examined through a theoretical calculation and finite element numerical simulation.Finally,the driving of crawlers is simulated by changing the relative spatial position between the load and stress unit,obtaining the stress path of the soil unit.Based on the calculation results,the effect of the horizontal shear load on the soil stress response is analyzed at different depths,and the spatial variation law of the soil stress path is examined.The results demonstrate that the horizontal shear load has a significant effect on the rotation of the principal stress,and the reverse rotation of the principal stress axis becomes obvious with the increase in the burial depth.The stress path curve of the soil is different at various depths.The spatial variation rule of the stress path of the shallow soil is complex,whereas the stress path curve of the deep soil tends to shrink as the depth increases.The stress path of the corresponding depth should be selected according to the actual research purpose and applied to the laboratory test.展开更多
In order to improve the elbow passing performance and different diameter adaptability of pipeline robot,a supported crawler pipeline robot is designed,which adopts screw nut mechanism and hinge four-bar mechanism to a...In order to improve the elbow passing performance and different diameter adaptability of pipeline robot,a supported crawler pipeline robot is designed,which adopts screw nut mechanism and hinge four-bar mechanism to adapt to the complex environment such as variable diameter pipeline and elbow.The steering characteristics passing through the elbow are studied,the kinematic of pipeline robot bending steering is established,the geometric constraint(GC)and steering constraint(SC)in the elbow are analyzed,and the steering experiment is conducted.The results show that the robot can pass through the elbow by the SC model.The SC model can reduce the motor current and energy consumption when the robot passes through the elbow.展开更多
数据采集与网络爬虫具有应用范围广、实用性强等特点,学生普遍学习兴趣较高。但传统教学模式侧重知识传授,难以满足社会对大数据人才的需求。成果导向教育(Outcome based education,OBE)理念强调学习成果,这与人才能力导向需求相吻合。...数据采集与网络爬虫具有应用范围广、实用性强等特点,学生普遍学习兴趣较高。但传统教学模式侧重知识传授,难以满足社会对大数据人才的需求。成果导向教育(Outcome based education,OBE)理念强调学习成果,这与人才能力导向需求相吻合。计划–执行–检查–行动(Plan-Do-Check-Act,PDCA)循环是全面质量管理遵循的科学程序,它构成了持续改进的基本方法和框架。本文将OBE理念与PDCA循环相融合,以学生为核心,以成果为导向,以问题为抓手,对数据采集与网络爬虫课程中的教学设计、教学实施、教学评价和教学反思四个过程进行了创新设计,期望实现课程质量的持续改进,培养学生的编程能力、自主学习能力及分析解决问题的能力。展开更多
基金supported by the National Natural Science Foundation of China(Nos.U1906234,51822904,51579082)the Fundamental Research Funds for the Central Universities(No.2020MS027).
文摘The mechanical properties of deep-sea sediments during the driving process of crawler collectors are essential factors in the design of mining systems.In this study,a crawler load is divided into a normal compression load and a horizontal shear load.Then,the internal stress state of sedimentary soil is examined through a theoretical calculation and finite element numerical simulation.Finally,the driving of crawlers is simulated by changing the relative spatial position between the load and stress unit,obtaining the stress path of the soil unit.Based on the calculation results,the effect of the horizontal shear load on the soil stress response is analyzed at different depths,and the spatial variation law of the soil stress path is examined.The results demonstrate that the horizontal shear load has a significant effect on the rotation of the principal stress,and the reverse rotation of the principal stress axis becomes obvious with the increase in the burial depth.The stress path curve of the soil is different at various depths.The spatial variation rule of the stress path of the shallow soil is complex,whereas the stress path curve of the deep soil tends to shrink as the depth increases.The stress path of the corresponding depth should be selected according to the actual research purpose and applied to the laboratory test.
基金Supported by the National Natural Science Foundation of China(No.51775323).
文摘In order to improve the elbow passing performance and different diameter adaptability of pipeline robot,a supported crawler pipeline robot is designed,which adopts screw nut mechanism and hinge four-bar mechanism to adapt to the complex environment such as variable diameter pipeline and elbow.The steering characteristics passing through the elbow are studied,the kinematic of pipeline robot bending steering is established,the geometric constraint(GC)and steering constraint(SC)in the elbow are analyzed,and the steering experiment is conducted.The results show that the robot can pass through the elbow by the SC model.The SC model can reduce the motor current and energy consumption when the robot passes through the elbow.
文摘数据采集与网络爬虫具有应用范围广、实用性强等特点,学生普遍学习兴趣较高。但传统教学模式侧重知识传授,难以满足社会对大数据人才的需求。成果导向教育(Outcome based education,OBE)理念强调学习成果,这与人才能力导向需求相吻合。计划–执行–检查–行动(Plan-Do-Check-Act,PDCA)循环是全面质量管理遵循的科学程序,它构成了持续改进的基本方法和框架。本文将OBE理念与PDCA循环相融合,以学生为核心,以成果为导向,以问题为抓手,对数据采集与网络爬虫课程中的教学设计、教学实施、教学评价和教学反思四个过程进行了创新设计,期望实现课程质量的持续改进,培养学生的编程能力、自主学习能力及分析解决问题的能力。
