A new type of pit supporting structure, which was tested and verified using the sensor monitoring technology, was presented. The new supporting structure is assembled by prefabricated steel structural units. The adjac...A new type of pit supporting structure, which was tested and verified using the sensor monitoring technology, was presented. The new supporting structure is assembled by prefabricated steel structural units. The adjacent steel structural units are jointed with fasteners, and each steel structural unit has a certain radian and is welded by two steel tubes and one piece of steel disc. In order to test and verify the reliability of the new supporting structure, the field tests are designed. The main monitoring programs include the hoop stress of supporting structure, lateral earth pressure, and soil deformation. The monitoring data of the field tests show that the new supporting structure is convenient, reliable and safe.展开更多
The paper design a double eccentric mass driven spherical robot, the ball is also subject to eccentric force and inertia force that generate by internal drive units in movement. Due to the unique spherical shell, the ...The paper design a double eccentric mass driven spherical robot, the ball is also subject to eccentric force and inertia force that generate by internal drive units in movement. Due to the unique spherical shell, the robot in the dynamic state transition process, Friction cannot offset the robot motion state change due to internal driving motion error of small units. In order to make linear movement of the spherical robot that can smooth start, stop and speed control, the paper design a method for linear motion driven spherical robot with double eccentric mass control. The improved driving eccentric mass of robot total mass ratio is larger, that can provide the eccentric torque and inertia moment more, the robot has higher motion velocity.展开更多
A novel approach,which can be used for dynamic characteristics analysis of machine tools based on unit structure(US),is reported in this paper.The concepts of unit structures for design of machine tools are defined.In...A novel approach,which can be used for dynamic characteristics analysis of machine tools based on unit structure(US),is reported in this paper.The concepts of unit structures for design of machine tools are defined.In order to satisfy the dynamic characteristics requirement of high natural frequency and light-weight of US,a design method of multi-disciplinary optimization of NSGA-II about unit structures driven by natural frequency and mass is developed.Through analyzing the unit structures,key factors affecting the natural frequency and mass are extracted,and the mathematical models of natural frequency and mass about unit structures are also established by using central composite design and response surface model.The goal of high natural frequency and light-weight is reached by using the multi-objective genetic algorithms.The Pareto optimal set is also obtained.The dynamic behavior of US is investigated by the experimental modal analysis.To show the efficiency of the proposed novel method,the example of YKW51250 gear shaping machine bed is used.Through optimization of NSGA-II about US of YKW51250 machine bed,the natural frequency of YKW51250 gear shaping machine bed is increased by 30.4%and its mass decreased by 5.2%comparing with the original design.By studying the dynamic characteristics of the simplified machine tools bed,useful laws are obtained,and these laws can be used in primary design of NC machine tools structures.The optimal method based on US can be also applied to the dynamic optimal design of machine tools and other similar equipments.展开更多
基金Project(41202220) supported by the National Natural Science Foundation of ChinaProject(20120022120003) supported by the Research Fund for the Doctoral Program of Higher Education, China+1 种基金Project(2-9-2012-65) supported by the Fundamental Research Funds for the Central Universities, ChinaProject(2013006) supported by the Research Fund for Key Laboratory on Deep GeoDrilling Technology, Ministry of Land and Resources, China
文摘A new type of pit supporting structure, which was tested and verified using the sensor monitoring technology, was presented. The new supporting structure is assembled by prefabricated steel structural units. The adjacent steel structural units are jointed with fasteners, and each steel structural unit has a certain radian and is welded by two steel tubes and one piece of steel disc. In order to test and verify the reliability of the new supporting structure, the field tests are designed. The main monitoring programs include the hoop stress of supporting structure, lateral earth pressure, and soil deformation. The monitoring data of the field tests show that the new supporting structure is convenient, reliable and safe.
文摘The paper design a double eccentric mass driven spherical robot, the ball is also subject to eccentric force and inertia force that generate by internal drive units in movement. Due to the unique spherical shell, the robot in the dynamic state transition process, Friction cannot offset the robot motion state change due to internal driving motion error of small units. In order to make linear movement of the spherical robot that can smooth start, stop and speed control, the paper design a method for linear motion driven spherical robot with double eccentric mass control. The improved driving eccentric mass of robot total mass ratio is larger, that can provide the eccentric torque and inertia moment more, the robot has higher motion velocity.
基金partially supported by the Leading Talent Project of Guangdong Province of Chinathe National Key S&T Special Projects of China on CNC machine tools and fundamental manufacturing equipments(Grant No.2010ZX04001-191 and 2011ZX04002-032)
文摘A novel approach,which can be used for dynamic characteristics analysis of machine tools based on unit structure(US),is reported in this paper.The concepts of unit structures for design of machine tools are defined.In order to satisfy the dynamic characteristics requirement of high natural frequency and light-weight of US,a design method of multi-disciplinary optimization of NSGA-II about unit structures driven by natural frequency and mass is developed.Through analyzing the unit structures,key factors affecting the natural frequency and mass are extracted,and the mathematical models of natural frequency and mass about unit structures are also established by using central composite design and response surface model.The goal of high natural frequency and light-weight is reached by using the multi-objective genetic algorithms.The Pareto optimal set is also obtained.The dynamic behavior of US is investigated by the experimental modal analysis.To show the efficiency of the proposed novel method,the example of YKW51250 gear shaping machine bed is used.Through optimization of NSGA-II about US of YKW51250 machine bed,the natural frequency of YKW51250 gear shaping machine bed is increased by 30.4%and its mass decreased by 5.2%comparing with the original design.By studying the dynamic characteristics of the simplified machine tools bed,useful laws are obtained,and these laws can be used in primary design of NC machine tools structures.The optimal method based on US can be also applied to the dynamic optimal design of machine tools and other similar equipments.
