Dynamic analysis of scissor hydraulic lift platform has been performed to invest/gate the key factors which determine size and shape of the platfolan. By using MATLAB, the position of hydraulic cylinder has been optim...Dynamic analysis of scissor hydraulic lift platform has been performed to invest/gate the key factors which determine size and shape of the platfolan. By using MATLAB, the position of hydraulic cylinder has been optimized to reduce jacking force of piston and the whole system. Thus structure deformation decreases which is beneficial to control accuracy. Additionally, a new proportion integration differentiation （PID） control mode based on BP neural network has been developed to improve the stability and accuracy for the pasitio^L control in this system. Compared with existing PID tuning meth~~ls and fuzzy self-adjusted PID controllers, the proposed back propagation （BP） based PID controller can achieve better performance for a wide range of complex processes and realize self-tuning of parameters. It was confirmed that the performance of the lift platform regarding the force variation and position accuracy was greatly enhanced by optimizing of the system both in structure and control. Considerable economic benefit can also be achieved thrangh the application of this intelligent PID system.展开更多
上海临港“荣耀之环”项目采用了“内环倒三角桁架+双层钢梁径向悬挑”体系,形成重心偏置、刚度差异的复杂传力路径。为解决大跨度圆环结构施工变形控制要求高、大跨度偏扭结构整体提升技术难度大的难题,通过应用基于建筑信息模型(build...上海临港“荣耀之环”项目采用了“内环倒三角桁架+双层钢梁径向悬挑”体系,形成重心偏置、刚度差异的复杂传力路径。为解决大跨度圆环结构施工变形控制要求高、大跨度偏扭结构整体提升技术难度大的难题,通过应用基于建筑信息模型(building information modeling,BIM)的钢结构幕墙一体化深化技术、基于自主研发的钢结构数字管控平台、新一代整体提升与姿态控制数字技术,高精度实现了变形控制要求,高效率完成整体提升作业,达到了超大体量、超高空、非规则的大跨度钢结构快速精准提升控制的目标。展开更多
In order to introduce clean environment and sustainable energy to traditional coastal fishing community, the objective of this study is to encourage the Indonesian traditional coastal fishing community to use green an...In order to introduce clean environment and sustainable energy to traditional coastal fishing community, the objective of this study is to encourage the Indonesian traditional coastal fishing community to use green and renewable energy in their fishing activities. Introducing solar power as the main source of energy for fish-attracting lights and boat propulsion can reduce the use of fossil fuels, and sustain clean and healthy environment. As the world’s largest archipelago, Indonesia accounts for a high percentage of traditional fishing communities spread out along its islands. This fishing communities use various traditional fishing boats, and platforms. The fishing platforms are usually made of bamboo and placed on top of supporting structures on the seabed. Diesel electric generators are used to obtain electricity needed for lighting to attract the fish at night, and as the source of power for lifting the fishing net. The structure and fuel used are neither environmentally friendly nor clean;thus, an innovation is introduced. Traditional fishing practices using a fishing platform were studied, including the common size of the platform and the power needed for the fishing light. Based on the gathered information, this study proposes a catamaran vessel with a special top structure designed for fish lifting outfitting, and equipped with photovoltaic solar cells as the energy source for the fishing lights and vessel propulsion. Through this innovative break through, the vessel can be moved to the shore and will not be a threat to ship navigation and the environment. Furthemore, powered by clean and sustainable energy, the vessel can be directed to the best fishing ground.展开更多
An S-lay crane barge,named CNOOC 201,has been built for pipe laying in deepwater oil/gas fields in the South China Sea.It is due to be commissioned by the end of the year 2010.A special lifting system is developed to ...An S-lay crane barge,named CNOOC 201,has been built for pipe laying in deepwater oil/gas fields in the South China Sea.It is due to be commissioned by the end of the year 2010.A special lifting system is developed to meet the challenge that installing deepwater risers from an S-lay barge is difficult and has not been achieved.The purpose of this paper was to investigate the model test on such an innovative system,which has to be done before field application.By applying the similarity theory,the movement of the S-lay barge is simulated through a six degrees-of-freedom motion platform,and a truncated model riser is utilized for the model testing.The displacement and force boundary conditions at the truncated position of the riser are obtained from the catenary governing equation and become realized by a slideway cart and a loading system designed to control the configuration of the model riser,which presents a similar configuration to a real riser in deepwater.The test results are in very good agreement with theoretical calculations,showing that the active truncated test is applicable for controlling the configuration of the deepwater riser in model testing investigation.展开更多
文摘Dynamic analysis of scissor hydraulic lift platform has been performed to invest/gate the key factors which determine size and shape of the platfolan. By using MATLAB, the position of hydraulic cylinder has been optimized to reduce jacking force of piston and the whole system. Thus structure deformation decreases which is beneficial to control accuracy. Additionally, a new proportion integration differentiation （PID） control mode based on BP neural network has been developed to improve the stability and accuracy for the pasitio^L control in this system. Compared with existing PID tuning meth~~ls and fuzzy self-adjusted PID controllers, the proposed back propagation （BP） based PID controller can achieve better performance for a wide range of complex processes and realize self-tuning of parameters. It was confirmed that the performance of the lift platform regarding the force variation and position accuracy was greatly enhanced by optimizing of the system both in structure and control. Considerable economic benefit can also be achieved thrangh the application of this intelligent PID system.
文摘上海临港“荣耀之环”项目采用了“内环倒三角桁架+双层钢梁径向悬挑”体系,形成重心偏置、刚度差异的复杂传力路径。为解决大跨度圆环结构施工变形控制要求高、大跨度偏扭结构整体提升技术难度大的难题,通过应用基于建筑信息模型(building information modeling,BIM)的钢结构幕墙一体化深化技术、基于自主研发的钢结构数字管控平台、新一代整体提升与姿态控制数字技术,高精度实现了变形控制要求,高效率完成整体提升作业,达到了超大体量、超高空、非规则的大跨度钢结构快速精准提升控制的目标。
基金funded by the PITTA Project Directorate of Research and Community Engagement,Universitas Indonesia No.842/UN2.R3.1/HKP.05.00/2017
文摘In order to introduce clean environment and sustainable energy to traditional coastal fishing community, the objective of this study is to encourage the Indonesian traditional coastal fishing community to use green and renewable energy in their fishing activities. Introducing solar power as the main source of energy for fish-attracting lights and boat propulsion can reduce the use of fossil fuels, and sustain clean and healthy environment. As the world’s largest archipelago, Indonesia accounts for a high percentage of traditional fishing communities spread out along its islands. This fishing communities use various traditional fishing boats, and platforms. The fishing platforms are usually made of bamboo and placed on top of supporting structures on the seabed. Diesel electric generators are used to obtain electricity needed for lighting to attract the fish at night, and as the source of power for lifting the fishing net. The structure and fuel used are neither environmentally friendly nor clean;thus, an innovation is introduced. Traditional fishing practices using a fishing platform were studied, including the common size of the platform and the power needed for the fishing light. Based on the gathered information, this study proposes a catamaran vessel with a special top structure designed for fish lifting outfitting, and equipped with photovoltaic solar cells as the energy source for the fishing lights and vessel propulsion. Through this innovative break through, the vessel can be moved to the shore and will not be a threat to ship navigation and the environment. Furthemore, powered by clean and sustainable energy, the vessel can be directed to the best fishing ground.
基金support from the National Natural Science Foundation of China (granted number 50979113)the National 863 Program of China (granted number 2006AA09A105)
文摘An S-lay crane barge,named CNOOC 201,has been built for pipe laying in deepwater oil/gas fields in the South China Sea.It is due to be commissioned by the end of the year 2010.A special lifting system is developed to meet the challenge that installing deepwater risers from an S-lay barge is difficult and has not been achieved.The purpose of this paper was to investigate the model test on such an innovative system,which has to be done before field application.By applying the similarity theory,the movement of the S-lay barge is simulated through a six degrees-of-freedom motion platform,and a truncated model riser is utilized for the model testing.The displacement and force boundary conditions at the truncated position of the riser are obtained from the catenary governing equation and become realized by a slideway cart and a loading system designed to control the configuration of the model riser,which presents a similar configuration to a real riser in deepwater.The test results are in very good agreement with theoretical calculations,showing that the active truncated test is applicable for controlling the configuration of the deepwater riser in model testing investigation.
