Off-line programming （OLP） system becomes one of the most important programming modules for the robotic belt grinding process, however there lacks research on increasing the grinding dexterous space depending on the...Off-line programming （OLP） system becomes one of the most important programming modules for the robotic belt grinding process, however there lacks research on increasing the grinding dexterous space depending on the OLP system. A new type of grinding robot and a novel robotic belt grinding workcell are forwarded, and their features are briefly introduced. An open and object-oriented off-line programming system is developed for this robotic belt grinding system. The parameters of the trimmed surface are read from the initial graphics exchange specification （IGES） file of the CAD model of the workpiece. The deBoor-Cox basis function is used to sample the grinding target with local contact frame on the workpiece. The numerical formula of inverse kinematics is set up based on Newton＇s iterative procedure, to calculate the grinding robot configurations corresponding to the grinding targets. After the grinding path is obtained, the OLP system turns to be more effective than the teach-by-showing system. In order to improve the grinding workspace, an optimization algorithm for dynamic tool frame is proposed and performed on the special robotic belt grinding system. The initial tool frame and the interval of neighboring tool frames are defined as the preparation of the algorithm. An optimized tool local frame can be selected to grind the complex surface for a maximum dexterity index of the robot. Under the optimization algorithm, a simulation of grinding a vane is included and comparison of grinding workspace is done before and after the tool frame optimization. By the algorithm, the grinding workspace can be enlarged. Moreover the dynamic tool frame can be considered to add one degree-of-freedom to the grinding kinematical chain, which provides the theoretical support for the improvement of robotic dexterity for the complex surface grinding.展开更多
The model of Dabieshan crustal structure has been obtained on the basis of the deep seismic sounding data in thisarea. The 2-D crustal structure shows the feature of the collision orogens and provides some deep geophy...The model of Dabieshan crustal structure has been obtained on the basis of the deep seismic sounding data in thisarea. The 2-D crustal structure shows the feature of the collision orogens and provides some deep geophysicalevidences of the ultra-high pressure (UHP) metamorphic belt. The 3-D upper-crustal velocity struCture reveals thatthe velocity distribution at 2 km deep obviously relates to the surface geological setting and the UHP metarnorphicbelt has the higher velocity at 5~10 km deep. The observed data of Bouguer gravity anomalies reveal a largerrange of negative anomalies in Dabieshan area while the positive anomalies in the UHP metamorphic belt is calculated from the 3-D upper-crustal velocity structure. The 2-D crustal model along the seismic profile shows thatthe 'root' beneath the orogen is only 4-5 km thick and the velocity in the uppermost mantle changes a little in thelateral direction. The inconsistency between the observed and calculated Bouguer gravity anomalies mainly resultsfrom the crust, and at least the middle-upper crust should yield the negative anomalies. The material density of thecrust in the UHP metamorphic belt should be lower than that in the surrounding areas. This material with lowerdensity relates to the collision processes in which Yangtze crust subducted nor'thward to 100 km deep and thenreturned to the crust.展开更多
A Continuously Variable Transmission (CVT) is a type of transmissions that provides a continuous range of speed ratios, thus it allows increasing the overall powertrain efficiency by running the engine at the optimal ...A Continuously Variable Transmission (CVT) is a type of transmissions that provides a continuous range of speed ratios, thus it allows increasing the overall powertrain efficiency by running the engine at the optimal operating points. This paper investigates implementing a model based hydraulic pressure controller to achieve the desired CVT gear ratio. A map of desired gear ratios was estimated using the Optimal Operating Line (OOL) strategy, which minimizes the engine fuel consumption according to a defined cost function and a set of systems constraints. The controller was implemented in a complete vehicle model that includes driver, powertrain and road load models. The model was subjected to two different driving cycles and the results demonstrate the effectiveness of the control strategy and the pressure controller in keeping the engine at the most efficient operating regions.展开更多
Since the 18 th National Congress of the Communist Party of China,the central government has implemented several regional development plans,including the Belt and Road Initiative and the Yangtze River Economic Belt,ai...Since the 18 th National Congress of the Communist Party of China,the central government has implemented several regional development plans,including the Belt and Road Initiative and the Yangtze River Economic Belt,aiming to reshape the economic geography of China.This paper is based on the Belt and Road Initiative and the Yangtze River Economic Belt and outlines the pattern of opening up.To analyze the impact of the pattern of opening up on the regional integration of China's economic geography,this paper has developed a new economic geography model comprised of four regions and two countries.From this,it draws some conclusions.First,the change of pattern of opening up will lead to shifting centripetal and centrifugal forces from the international market.The greater the scale of neighboring markets,the stronger the agglomeration force will be; the more product varieties made in neighboring countries,the more potent its dispersion force.Second,developing an inland international trade corridor will decentralize industry distribution and reduce the impact of external market integration on home countries.Third,the inland international trade corridor could alter the effect of domestic market integration on the economic geography.When domestic integration occurs prior to international integration,further integration of a domestic market leads to greater industrial distribution along a bell-shaped curve,which describes economic activities from dispersion to agglomeration to decentralization.Therefore,developing an integrated market system of major countries and opening a corridor between China and Europe is not only the key to reshaping China's economic geography but also the path to solving the problems of the Heihe-Tengchong Line.展开更多
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2007AA04Z2443)State Key Laboratory for Man ufacturing Systems Engineering of Xi’an Jiaotong University of China
文摘Off-line programming （OLP） system becomes one of the most important programming modules for the robotic belt grinding process, however there lacks research on increasing the grinding dexterous space depending on the OLP system. A new type of grinding robot and a novel robotic belt grinding workcell are forwarded, and their features are briefly introduced. An open and object-oriented off-line programming system is developed for this robotic belt grinding system. The parameters of the trimmed surface are read from the initial graphics exchange specification （IGES） file of the CAD model of the workpiece. The deBoor-Cox basis function is used to sample the grinding target with local contact frame on the workpiece. The numerical formula of inverse kinematics is set up based on Newton＇s iterative procedure, to calculate the grinding robot configurations corresponding to the grinding targets. After the grinding path is obtained, the OLP system turns to be more effective than the teach-by-showing system. In order to improve the grinding workspace, an optimization algorithm for dynamic tool frame is proposed and performed on the special robotic belt grinding system. The initial tool frame and the interval of neighboring tool frames are defined as the preparation of the algorithm. An optimized tool local frame can be selected to grind the complex surface for a maximum dexterity index of the robot. Under the optimization algorithm, a simulation of grinding a vane is included and comparison of grinding workspace is done before and after the tool frame optimization. By the algorithm, the grinding workspace can be enlarged. Moreover the dynamic tool frame can be considered to add one degree-of-freedom to the grinding kinematical chain, which provides the theoretical support for the improvement of robotic dexterity for the complex surface grinding.
文摘The model of Dabieshan crustal structure has been obtained on the basis of the deep seismic sounding data in thisarea. The 2-D crustal structure shows the feature of the collision orogens and provides some deep geophysicalevidences of the ultra-high pressure (UHP) metamorphic belt. The 3-D upper-crustal velocity struCture reveals thatthe velocity distribution at 2 km deep obviously relates to the surface geological setting and the UHP metarnorphicbelt has the higher velocity at 5~10 km deep. The observed data of Bouguer gravity anomalies reveal a largerrange of negative anomalies in Dabieshan area while the positive anomalies in the UHP metamorphic belt is calculated from the 3-D upper-crustal velocity structure. The 2-D crustal model along the seismic profile shows thatthe 'root' beneath the orogen is only 4-5 km thick and the velocity in the uppermost mantle changes a little in thelateral direction. The inconsistency between the observed and calculated Bouguer gravity anomalies mainly resultsfrom the crust, and at least the middle-upper crust should yield the negative anomalies. The material density of thecrust in the UHP metamorphic belt should be lower than that in the surrounding areas. This material with lowerdensity relates to the collision processes in which Yangtze crust subducted nor'thward to 100 km deep and thenreturned to the crust.
文摘A Continuously Variable Transmission (CVT) is a type of transmissions that provides a continuous range of speed ratios, thus it allows increasing the overall powertrain efficiency by running the engine at the optimal operating points. This paper investigates implementing a model based hydraulic pressure controller to achieve the desired CVT gear ratio. A map of desired gear ratios was estimated using the Optimal Operating Line (OOL) strategy, which minimizes the engine fuel consumption according to a defined cost function and a set of systems constraints. The controller was implemented in a complete vehicle model that includes driver, powertrain and road load models. The model was subjected to two different driving cycles and the results demonstrate the effectiveness of the control strategy and the pressure controller in keeping the engine at the most efficient operating regions.
基金a staged research result of "Studies on New Strategic Regions Contributing to China’s Economic Growth in the Future"(14ZDA024)a major program of the National Social Science Fund of China+3 种基金"Studies on Regional Integration and Welfare Compensation on the Basis of Dynamic CGE and DCI Models"(71173101)a program funded by the National Natural Science Foundation of China"Studies on Path and Mechanism to Improve Economic Performance and Quality in Jiangsu Province from the Perspective of the Supply Side"(BRA2017358)a Jiangsu "333" High-level Cultivation Program
文摘Since the 18 th National Congress of the Communist Party of China,the central government has implemented several regional development plans,including the Belt and Road Initiative and the Yangtze River Economic Belt,aiming to reshape the economic geography of China.This paper is based on the Belt and Road Initiative and the Yangtze River Economic Belt and outlines the pattern of opening up.To analyze the impact of the pattern of opening up on the regional integration of China's economic geography,this paper has developed a new economic geography model comprised of four regions and two countries.From this,it draws some conclusions.First,the change of pattern of opening up will lead to shifting centripetal and centrifugal forces from the international market.The greater the scale of neighboring markets,the stronger the agglomeration force will be; the more product varieties made in neighboring countries,the more potent its dispersion force.Second,developing an inland international trade corridor will decentralize industry distribution and reduce the impact of external market integration on home countries.Third,the inland international trade corridor could alter the effect of domestic market integration on the economic geography.When domestic integration occurs prior to international integration,further integration of a domestic market leads to greater industrial distribution along a bell-shaped curve,which describes economic activities from dispersion to agglomeration to decentralization.Therefore,developing an integrated market system of major countries and opening a corridor between China and Europe is not only the key to reshaping China's economic geography but also the path to solving the problems of the Heihe-Tengchong Line.
