A new approach to gain-scheduling of H∞controllers is proposed for a cruise missile with variableswept wings( VSW) in bank-to-turn( BTT) mode. A nonlinear dynamic model is established and anticipant performance crite...A new approach to gain-scheduling of H∞controllers is proposed for a cruise missile with variableswept wings( VSW) in bank-to-turn( BTT) mode. A nonlinear dynamic model is established and anticipant performance criterions are given at first. For the selected operating points,feedback robust controllers of threechannels are designed independently to restrain cross-channel couple disturbances and aerodynamic perturbations. Then,the sweepback and Ma number are selected to schedule controller gains iteratively to ensure all closed-loop poles locating inside the desired region. The proposed method here attempts to extend the performance of initial design obtained for a single arbitrary point to the whole linearized domain while maintaining the expected stability over the entire range of sweepback and full flight envelope. Some time-domain analysis procedures based on the proposed method are carried out and assessed,while the performance of tracking and robustness to aerodynamic perturbations in different situations are contrasted by some nonlinear simulations. Finally,the numerical simulations demonstrate that the proposed autopilot design method has better tracking performance and is robust,effective and feasible.展开更多
目的本研究旨在探讨T_(2)WI信号强度及钆贝葡胺(gadobenate dimeglumine,Gd-BOPTA)肝胆期参数与肝功能分级的相关性,并分别分析它们单独和联合诊断肝功能的价值。方法回顾性收集我院2019年6月-2024年9月行T_(2)WI及Gd-BOPTA增强MRI检查...目的本研究旨在探讨T_(2)WI信号强度及钆贝葡胺(gadobenate dimeglumine,Gd-BOPTA)肝胆期参数与肝功能分级的相关性,并分别分析它们单独和联合诊断肝功能的价值。方法回顾性收集我院2019年6月-2024年9月行T_(2)WI及Gd-BOPTA增强MRI检查的肝硬化患者57例。在肝门层面,分别在T_(2)WI、平扫及肝胆期90 min MRI图像上,于肝左叶、肝右前叶及右后叶各放置大小相同感兴趣区域。测量T_(2)WI信号强度值(T_(2)WI signal intensity,SI_(T2))、T_(1)WI信号强度值(T_(1)WI signal intensity,SI_(平扫))及肝胆期信号强度(hepatobiliary phase signal intensity,SI_(肝胆期)),计算得到相对增强度(relative enhancement,RE)。比较不同Child-Pugh分级间各参数的差异;探讨各参数与Child-Pugh分级间的相关性;分析各有意义参数单独及联合诊断Child-Pugh B+C级的效能,同时比较各诊断效能间的差异性。结果不同Child-Pugh分级间的SI_(T2)、SI_(肝胆期)及RE差异均具有统计学意义(P<0.05)。SI_(T2)与Child-Pugh分级呈正相关(r=0.408,P=0.002);SI_(肝胆期)及RE均与Child-Pugh分级呈负相关(r=-0.365、-0.376,P=0.005、0.004);而SI_(平扫)与Child-Pugh分级不具有相关性(P=0.753);SI_(T2)、SI_(肝胆期)、RE及三者联合诊断Child-Pugh B+C组的AUC分别为0.715、0.707、0.757及0.846。SI_(T2)+SI_(肝胆期)+RE的AUC高于SI_(肝胆期),差异有统计学意义(P<0.05)。结论SI_(T2)、Gd-BOPTA肝胆期参数SI_(肝胆期)及RE与肝硬化患者肝功能分级相关,各自诊断肝功能分级有一定价值,三者联合诊断能拥有更高的效能。展开更多
基金Sponsored by Armament Department Pre-Research Foundation of China(Grant No.9140A31010114JB25465)Natural Science Foundation of Jiangsu Province(Grant No.BK20140795)Chinese Aerospace CAST Innovation Foundation(Grant No.CAST2014-27)
文摘A new approach to gain-scheduling of H∞controllers is proposed for a cruise missile with variableswept wings( VSW) in bank-to-turn( BTT) mode. A nonlinear dynamic model is established and anticipant performance criterions are given at first. For the selected operating points,feedback robust controllers of threechannels are designed independently to restrain cross-channel couple disturbances and aerodynamic perturbations. Then,the sweepback and Ma number are selected to schedule controller gains iteratively to ensure all closed-loop poles locating inside the desired region. The proposed method here attempts to extend the performance of initial design obtained for a single arbitrary point to the whole linearized domain while maintaining the expected stability over the entire range of sweepback and full flight envelope. Some time-domain analysis procedures based on the proposed method are carried out and assessed,while the performance of tracking and robustness to aerodynamic perturbations in different situations are contrasted by some nonlinear simulations. Finally,the numerical simulations demonstrate that the proposed autopilot design method has better tracking performance and is robust,effective and feasible.
文摘目的本研究旨在探讨T_(2)WI信号强度及钆贝葡胺(gadobenate dimeglumine,Gd-BOPTA)肝胆期参数与肝功能分级的相关性,并分别分析它们单独和联合诊断肝功能的价值。方法回顾性收集我院2019年6月-2024年9月行T_(2)WI及Gd-BOPTA增强MRI检查的肝硬化患者57例。在肝门层面,分别在T_(2)WI、平扫及肝胆期90 min MRI图像上,于肝左叶、肝右前叶及右后叶各放置大小相同感兴趣区域。测量T_(2)WI信号强度值(T_(2)WI signal intensity,SI_(T2))、T_(1)WI信号强度值(T_(1)WI signal intensity,SI_(平扫))及肝胆期信号强度(hepatobiliary phase signal intensity,SI_(肝胆期)),计算得到相对增强度(relative enhancement,RE)。比较不同Child-Pugh分级间各参数的差异;探讨各参数与Child-Pugh分级间的相关性;分析各有意义参数单独及联合诊断Child-Pugh B+C级的效能,同时比较各诊断效能间的差异性。结果不同Child-Pugh分级间的SI_(T2)、SI_(肝胆期)及RE差异均具有统计学意义(P<0.05)。SI_(T2)与Child-Pugh分级呈正相关(r=0.408,P=0.002);SI_(肝胆期)及RE均与Child-Pugh分级呈负相关(r=-0.365、-0.376,P=0.005、0.004);而SI_(平扫)与Child-Pugh分级不具有相关性(P=0.753);SI_(T2)、SI_(肝胆期)、RE及三者联合诊断Child-Pugh B+C组的AUC分别为0.715、0.707、0.757及0.846。SI_(T2)+SI_(肝胆期)+RE的AUC高于SI_(肝胆期),差异有统计学意义(P<0.05)。结论SI_(T2)、Gd-BOPTA肝胆期参数SI_(肝胆期)及RE与肝硬化患者肝功能分级相关,各自诊断肝功能分级有一定价值,三者联合诊断能拥有更高的效能。
