The efficient manufacture technique involves a high-speed control of platform mobile system. A linear acutor is presented in this paper. The linear acutor is constructed as a linear stepper motor. However, to sustain ...The efficient manufacture technique involves a high-speed control of platform mobile system. A linear acutor is presented in this paper. The linear acutor is constructed as a linear stepper motor. However, to sustain both high accuracy and high speed for the position and speed control, A single-stack computer system is constructed and a special control algorithm is prescribed to controled the linear actuator continuously. In this paper, the nonlinear errors resulted from the magnetic saturation and the hysteresis is anaysis and discussed. In the view of electromagnetic propotional control, the actuator is a stage proportional magnet, because the driving current to the linear acuator changes for a number of cycles and a series of reset points will occur as the current undergoes cyclic changes. At each reset point the original starting characteristics of the system are re-established. A large number of reset points across the full stroke of the platform results in a significant reduction in the nonlinear behavior. The stage control is first discussed. Experiments carried out to obtain the characteristics of the mobile platform control system. It is demonstrated that with the introduction of stage control, nonlinearities, such as saturation and hysteresis, are greatly reduced, system stiffness is increased, and the positioning accuracy and resolution are improved. The effect of dither due to a "digital fragment" signal is also examined and found to be crucial in reducing the hysteresis and in improving the resolution accuracy.展开更多
Ultrasonic-vibration-assisted milling(UVAM)is an advanced method for the efficient and precise machining of difficult-to-machine materials in modern manufacturing.However,the milling efficiency is limited because the ...Ultrasonic-vibration-assisted milling(UVAM)is an advanced method for the efficient and precise machining of difficult-to-machine materials in modern manufacturing.However,the milling efficiency is limited because the ultrasonic vibration toolholder ER16 collet has a critical cutting speed.Thus,a 2D UVAM platform is built to ensure precision machining efficiency and improve the surface quality without changing the milling toolholder.To evaluate this 2D UVAM platform,ultrasonic-vibration-assisted high-speed dry milling(UVAHSDM)is performed to process a titanium alloy(Ti-6Al-4V)on the platform,and the milling temperature,surface roughness,and residual stresses are selected as the important indicators for performance analysis.The results show that the intermittent cutting mechanism of UVAHSDM combined with the specific spindle speed,feed speed,and vibration amplitude can reduce the milling temperature and improve the texture of the machined surface.Compared with conventional milling,UVAHSDM reduces surface roughness and peak-groove surface profile values and extends the range of residual surface compressive stresses from−413.96 MPa to−600.18 MPa.The excellent processing performance demonstrates the feasibility and validity of applying this 2D UVAM platform for investigating surface quality achieved under UVAHSDM.展开更多
Since trim and sinkage are significant while vessels are advancing forward with high speed, the predicted vessel resistance based on restrained model theory or experiment may not be real resistance of vessels during v...Since trim and sinkage are significant while vessels are advancing forward with high speed, the predicted vessel resistance based on restrained model theory or experiment may not be real resistance of vessels during voyage. It is necessary to take the influence of hull gesture into account for oredicting the resistance of high-speed ship. In the present work the resistance problem of high speed ship is treated with the viscous flow theory, and the dynamic mesh technique is adopted to coincide with variation of hull gesture of high speed vessel on voyage. The simulation of the models of S60 ship and a trimaran moving in towing tank with high speed are conducted by using the above theory and technique. The corresponding numerical results are in good agreement with the experimental data. It indicates that the resistance prediction for high speed vessels should take hull gesture into consideration and the dynamic mesh method proposed here is effective in calculating the resistance of high speed vessels.展开更多
针对2023年度广东省国库渔船AIS通导设备在线率不足50%的问题,本文研制了渔船安全作业的光伏智能监管装置,支持5、9.5、12、24 V 4种规格电源输出和剩余电量、运行状态显示,具有SOP、SOH和SOC等电池安全保护策略、故障诊断、光伏充电均...针对2023年度广东省国库渔船AIS通导设备在线率不足50%的问题,本文研制了渔船安全作业的光伏智能监管装置,支持5、9.5、12、24 V 4种规格电源输出和剩余电量、运行状态显示,具有SOP、SOH和SOC等电池安全保护策略、故障诊断、光伏充电均衡、北斗短报文通信功能;同时开发渔船“光伏电碳中和”一张图管理平台,具备船载光伏智能监管装置定位和运行状态监控、渔船动态轨迹监控、船只回港测算、台风预报、渔船档案信息管理多种功能,实现渔船的实时监控和安全管理。设备及其平台已在惠州市惠阳区大亚湾渔港、汕尾市陆丰市甲子渔港、深汕特别合作区鲘门渔港、江门市台山市横山渔港、珠海市香洲区洪湾渔港开展示范应用,获得相关渔政部门和用户一致好评,有效提升了渔船安全作业水平。展开更多
针对目前船厂实习路途遥远、实习内容有限、成本高且安全风险大等问题,基于互联网的开放共享特性、VR技术和可穿戴设备的沉浸式仿真效果,应用Unity3D和Visual Studio C#设计了虚拟船厂、船舶交互仿真实验教学系统。组建了学习、漫游、...针对目前船厂实习路途遥远、实习内容有限、成本高且安全风险大等问题,基于互联网的开放共享特性、VR技术和可穿戴设备的沉浸式仿真效果,应用Unity3D和Visual Studio C#设计了虚拟船厂、船舶交互仿真实验教学系统。组建了学习、漫游、考评一体化的实验平台,将“互联网+”概念应用到特色实验教学中去,结合传统实验教学,探索了一种新型实验教学和考核模式,克服了教学手段缺乏改革创新、学生学习兴趣不高、优质教学资源匮乏等问题。展开更多
文摘The efficient manufacture technique involves a high-speed control of platform mobile system. A linear acutor is presented in this paper. The linear acutor is constructed as a linear stepper motor. However, to sustain both high accuracy and high speed for the position and speed control, A single-stack computer system is constructed and a special control algorithm is prescribed to controled the linear actuator continuously. In this paper, the nonlinear errors resulted from the magnetic saturation and the hysteresis is anaysis and discussed. In the view of electromagnetic propotional control, the actuator is a stage proportional magnet, because the driving current to the linear acuator changes for a number of cycles and a series of reset points will occur as the current undergoes cyclic changes. At each reset point the original starting characteristics of the system are re-established. A large number of reset points across the full stroke of the platform results in a significant reduction in the nonlinear behavior. The stage control is first discussed. Experiments carried out to obtain the characteristics of the mobile platform control system. It is demonstrated that with the introduction of stage control, nonlinearities, such as saturation and hysteresis, are greatly reduced, system stiffness is increased, and the positioning accuracy and resolution are improved. The effect of dither due to a "digital fragment" signal is also examined and found to be crucial in reducing the hysteresis and in improving the resolution accuracy.
基金Funding was provided by the National Key R&D Program of China(Grant No.2020YFB2010500).
文摘Ultrasonic-vibration-assisted milling(UVAM)is an advanced method for the efficient and precise machining of difficult-to-machine materials in modern manufacturing.However,the milling efficiency is limited because the ultrasonic vibration toolholder ER16 collet has a critical cutting speed.Thus,a 2D UVAM platform is built to ensure precision machining efficiency and improve the surface quality without changing the milling toolholder.To evaluate this 2D UVAM platform,ultrasonic-vibration-assisted high-speed dry milling(UVAHSDM)is performed to process a titanium alloy(Ti-6Al-4V)on the platform,and the milling temperature,surface roughness,and residual stresses are selected as the important indicators for performance analysis.The results show that the intermittent cutting mechanism of UVAHSDM combined with the specific spindle speed,feed speed,and vibration amplitude can reduce the milling temperature and improve the texture of the machined surface.Compared with conventional milling,UVAHSDM reduces surface roughness and peak-groove surface profile values and extends the range of residual surface compressive stresses from−413.96 MPa to−600.18 MPa.The excellent processing performance demonstrates the feasibility and validity of applying this 2D UVAM platform for investigating surface quality achieved under UVAHSDM.
文摘Since trim and sinkage are significant while vessels are advancing forward with high speed, the predicted vessel resistance based on restrained model theory or experiment may not be real resistance of vessels during voyage. It is necessary to take the influence of hull gesture into account for oredicting the resistance of high-speed ship. In the present work the resistance problem of high speed ship is treated with the viscous flow theory, and the dynamic mesh technique is adopted to coincide with variation of hull gesture of high speed vessel on voyage. The simulation of the models of S60 ship and a trimaran moving in towing tank with high speed are conducted by using the above theory and technique. The corresponding numerical results are in good agreement with the experimental data. It indicates that the resistance prediction for high speed vessels should take hull gesture into consideration and the dynamic mesh method proposed here is effective in calculating the resistance of high speed vessels.
文摘针对2023年度广东省国库渔船AIS通导设备在线率不足50%的问题,本文研制了渔船安全作业的光伏智能监管装置,支持5、9.5、12、24 V 4种规格电源输出和剩余电量、运行状态显示,具有SOP、SOH和SOC等电池安全保护策略、故障诊断、光伏充电均衡、北斗短报文通信功能;同时开发渔船“光伏电碳中和”一张图管理平台,具备船载光伏智能监管装置定位和运行状态监控、渔船动态轨迹监控、船只回港测算、台风预报、渔船档案信息管理多种功能,实现渔船的实时监控和安全管理。设备及其平台已在惠州市惠阳区大亚湾渔港、汕尾市陆丰市甲子渔港、深汕特别合作区鲘门渔港、江门市台山市横山渔港、珠海市香洲区洪湾渔港开展示范应用,获得相关渔政部门和用户一致好评,有效提升了渔船安全作业水平。
文摘针对目前船厂实习路途遥远、实习内容有限、成本高且安全风险大等问题,基于互联网的开放共享特性、VR技术和可穿戴设备的沉浸式仿真效果,应用Unity3D和Visual Studio C#设计了虚拟船厂、船舶交互仿真实验教学系统。组建了学习、漫游、考评一体化的实验平台,将“互联网+”概念应用到特色实验教学中去,结合传统实验教学,探索了一种新型实验教学和考核模式,克服了教学手段缺乏改革创新、学生学习兴趣不高、优质教学资源匮乏等问题。
