Most target grabbing problems have been dealt with by computer vision system, however, computer vision method is not always enough when it comes to the precision contact grabbing problems during the teleoperation proc...Most target grabbing problems have been dealt with by computer vision system, however, computer vision method is not always enough when it comes to the precision contact grabbing problems during the teleoperation process, and need to be combined with the stiffness display to provide more effective information to the operator on the remote side. Therefore, in this paper a more portable stiffness display device with a small volume and extended function is developed based on our previous work. A new static load calibration of the improved stiffness display device is performed to detect its accuracy, and the relationship between the stiffness and the position is given. An effective target grabbing strategy is presented to help operator on the remote side to judge and control and the target is classified by multi-class SVM(supporter vector machine). The teleoperation system is established to test and verify the feasibility. A special experiment is designed and the results demonstrate that the improved stiffness display device could greatly help operator on the remote side control the telerobot to grab target and the target grabbing strategy is effective.展开更多
Gearing is one of the most critical components in mechanical power transmission systems. This article examines the various stresses and deflection developed in sun gear tooth of planetary gearbox which is used in Grab...Gearing is one of the most critical components in mechanical power transmission systems. This article examines the various stresses and deflection developed in sun gear tooth of planetary gearbox which is used in Grabbing Crane. Article includes checking sun gear wear stresses and bending stresses using IS 4460 equations. Also calculate various forces acting on gear tooth. In this study, perform the calculation for sun gear tooth to calculate bending, shear, wear & deflection using theoretical method. 3D model is created of circular root fillet & trochoidal root fillet of gear tooth for simulation using ProE Wildfire 3. In Pro-E, the geometry is saved as a file and then it is transferred from Pro-E to ANSYS 10 in IGES format. The results of the 3 D analyses from ANSYS are compared with the theoretical values. Comparison of ANSYS results in circular root fillet & trochoidal root fillet also carry out.展开更多
A prototype of a novel hybrid hand is developed by combing a parallel wrist with three flexible fingers.Its dynamics model is established,its grabbed forces are measured,and its grabbing performances are analyzed.Firs...A prototype of a novel hybrid hand is developed by combing a parallel wrist with three flexible fingers.Its dynamics model is established,its grabbed forces are measured,and its grabbing performances are analyzed.First,Jacobian and Hessian matrices of the moving platform in the parallel wrist are derived,the kinematics formulas for solving the general velocity and the general acceleration of the moving platform are derived.Second its dynamics model is established for solving the dynamic actuation forces,the dynamic constrained forces of the developed hybrid hand.Third,its simulation mechanism is constructed in Matlab,and the theoretical solutions of the kinematics and the dynamics of the developed hybrid hand are verified to be correct using its simulation mechanism.Finally,when objects with different mass are grabbed by prototype of hybrid hand in different poses,the grabbed forces are measured,and the grabbing performances are discovered and analyzed to verify its merits.展开更多
Using the firsthand materials collected during on-site fieldworks and in-depth interviews,this paper examines the dimensions,especially the motives,for driving Chinese firms to invest in agriculture overseas from the ...Using the firsthand materials collected during on-site fieldworks and in-depth interviews,this paper examines the dimensions,especially the motives,for driving Chinese firms to invest in agriculture overseas from the macro(or government’s)-and micro(or firms’)-perspectives,as well as the impact of Chinese firms’agricultural outward foreign direct investment(OFDI)from the multistakeholder perspective.From the perspective of China’s central government,the goal of encouraging domestic enterprises’overseas investment in agriculture is not to ensure national grain security,but to stabilise the domestic supply of strategic agricultural products.From the micro-perspective,the impetuses for driving Chinese firms to invest in agriculture overseas are diverse and land exploitation is just one of them.They may wish to compete with local producers and some of the enterprises do not have a strong awareness of environmental protection and social responsibility.This is not the whole story.Chinese enterprises’agricultural OFDI increases agricultural investment and reduces poverty in the host countries,and expands the supply of agricultural products of the local markets.In the long run,the growing presence of Chinese firms with advanced technology will yield the benefits of competition:an expansion of local supplies while providing cheap technology that can be duplicated by local farmers.Only a very small proportion of the agricultural products grown abroad is sold back to China,while a large part is sold domestically or exported to a third market.Therefore,Chinese firms’agricultural OFDI has offered little direct,but some indirect,help in guaranteeing China’s food security.Perhaps,China’s diplomatic and political benefits obtained through agricultural OFDI outweigh the benefits of ensuring food security.Chinese enterprises’agricultural OFDI is a win-win situation for the host countries and for China.展开更多
In the last two decades, the global interest on farmland grew at a remarkable pace. As a consequence, million hectares of land exchanged hands. The ways the transfers happened combined with their geographic concentrat...In the last two decades, the global interest on farmland grew at a remarkable pace. As a consequence, million hectares of land exchanged hands. The ways the transfers happened combined with their geographic concentration in Sub-Saharian Africa, have earned the phenomenon the name of ＂land grab＂. The agricultural sector considered a ＂sunset industry＂ when commodities prices were declining, is now attractive to financial investors. These foreign investments may be good as they may improve agricultural productivity or instead bad as they may benefit only financial investors. Some results in terms of environmental and local communities＇ worsening conditions have already emerged. This paper aims to investigate what drives the big size transfers of land, to empirically estimate their effects in terms of local employment and to assess the environmental effects produced by the rapid transformation in the use of vast amount of land in terms of CO2 emissions. It is also proposed to use the estimation in terms of local employment impact as a way of distinguishing between foreign direct investment and land grabbing.展开更多
Robot grabbing has been successfully applied to a range of challenging environments but met the resource bottleneck. To answer this question, a hybrid cloud-based robot grabbing system is proposed, which supports cent...Robot grabbing has been successfully applied to a range of challenging environments but met the resource bottleneck. To answer this question, a hybrid cloud-based robot grabbing system is proposed, which supports centralized bin-picking management and deployment, large-scale storage, and communication technologies. The hybrid cloud combines the powerful computational capabilities through massive parallel computation and higher data storage facilities in the public cloud with data privacy in the private data center. The benchmark tasks against a public cloud based on robot grabbing method are evaluated, whose results indicate that the whole system reduces the data collection time and increases elastic resource scheduling and is adapted in the real industry.展开更多
基金partially supported by the National Natural Science Foundation of China(61663027,61325018,81501560)the Science and Technology Department of Jiangxi Province of China(20151BAB207050)
文摘Most target grabbing problems have been dealt with by computer vision system, however, computer vision method is not always enough when it comes to the precision contact grabbing problems during the teleoperation process, and need to be combined with the stiffness display to provide more effective information to the operator on the remote side. Therefore, in this paper a more portable stiffness display device with a small volume and extended function is developed based on our previous work. A new static load calibration of the improved stiffness display device is performed to detect its accuracy, and the relationship between the stiffness and the position is given. An effective target grabbing strategy is presented to help operator on the remote side to judge and control and the target is classified by multi-class SVM(supporter vector machine). The teleoperation system is established to test and verify the feasibility. A special experiment is designed and the results demonstrate that the improved stiffness display device could greatly help operator on the remote side control the telerobot to grab target and the target grabbing strategy is effective.
文摘Gearing is one of the most critical components in mechanical power transmission systems. This article examines the various stresses and deflection developed in sun gear tooth of planetary gearbox which is used in Grabbing Crane. Article includes checking sun gear wear stresses and bending stresses using IS 4460 equations. Also calculate various forces acting on gear tooth. In this study, perform the calculation for sun gear tooth to calculate bending, shear, wear & deflection using theoretical method. 3D model is created of circular root fillet & trochoidal root fillet of gear tooth for simulation using ProE Wildfire 3. In Pro-E, the geometry is saved as a file and then it is transferred from Pro-E to ANSYS 10 in IGES format. The results of the 3 D analyses from ANSYS are compared with the theoretical values. Comparison of ANSYS results in circular root fillet & trochoidal root fillet also carry out.
基金This study was funded by MajorResearch Project of National Natural ScienceFoundationof China(Grant number 91748125)Natural Science Foundation of Hebei,China(Grant number E2020203010).
文摘A prototype of a novel hybrid hand is developed by combing a parallel wrist with three flexible fingers.Its dynamics model is established,its grabbed forces are measured,and its grabbing performances are analyzed.First,Jacobian and Hessian matrices of the moving platform in the parallel wrist are derived,the kinematics formulas for solving the general velocity and the general acceleration of the moving platform are derived.Second its dynamics model is established for solving the dynamic actuation forces,the dynamic constrained forces of the developed hybrid hand.Third,its simulation mechanism is constructed in Matlab,and the theoretical solutions of the kinematics and the dynamics of the developed hybrid hand are verified to be correct using its simulation mechanism.Finally,when objects with different mass are grabbed by prototype of hybrid hand in different poses,the grabbed forces are measured,and the grabbing performances are discovered and analyzed to verify its merits.
文摘Using the firsthand materials collected during on-site fieldworks and in-depth interviews,this paper examines the dimensions,especially the motives,for driving Chinese firms to invest in agriculture overseas from the macro(or government’s)-and micro(or firms’)-perspectives,as well as the impact of Chinese firms’agricultural outward foreign direct investment(OFDI)from the multistakeholder perspective.From the perspective of China’s central government,the goal of encouraging domestic enterprises’overseas investment in agriculture is not to ensure national grain security,but to stabilise the domestic supply of strategic agricultural products.From the micro-perspective,the impetuses for driving Chinese firms to invest in agriculture overseas are diverse and land exploitation is just one of them.They may wish to compete with local producers and some of the enterprises do not have a strong awareness of environmental protection and social responsibility.This is not the whole story.Chinese enterprises’agricultural OFDI increases agricultural investment and reduces poverty in the host countries,and expands the supply of agricultural products of the local markets.In the long run,the growing presence of Chinese firms with advanced technology will yield the benefits of competition:an expansion of local supplies while providing cheap technology that can be duplicated by local farmers.Only a very small proportion of the agricultural products grown abroad is sold back to China,while a large part is sold domestically or exported to a third market.Therefore,Chinese firms’agricultural OFDI has offered little direct,but some indirect,help in guaranteeing China’s food security.Perhaps,China’s diplomatic and political benefits obtained through agricultural OFDI outweigh the benefits of ensuring food security.Chinese enterprises’agricultural OFDI is a win-win situation for the host countries and for China.
文摘In the last two decades, the global interest on farmland grew at a remarkable pace. As a consequence, million hectares of land exchanged hands. The ways the transfers happened combined with their geographic concentration in Sub-Saharian Africa, have earned the phenomenon the name of ＂land grab＂. The agricultural sector considered a ＂sunset industry＂ when commodities prices were declining, is now attractive to financial investors. These foreign investments may be good as they may improve agricultural productivity or instead bad as they may benefit only financial investors. Some results in terms of environmental and local communities＇ worsening conditions have already emerged. This paper aims to investigate what drives the big size transfers of land, to empirically estimate their effects in terms of local employment and to assess the environmental effects produced by the rapid transformation in the use of vast amount of land in terms of CO2 emissions. It is also proposed to use the estimation in terms of local employment impact as a way of distinguishing between foreign direct investment and land grabbing.
文摘Robot grabbing has been successfully applied to a range of challenging environments but met the resource bottleneck. To answer this question, a hybrid cloud-based robot grabbing system is proposed, which supports centralized bin-picking management and deployment, large-scale storage, and communication technologies. The hybrid cloud combines the powerful computational capabilities through massive parallel computation and higher data storage facilities in the public cloud with data privacy in the private data center. The benchmark tasks against a public cloud based on robot grabbing method are evaluated, whose results indicate that the whole system reduces the data collection time and increases elastic resource scheduling and is adapted in the real industry.
