为了优化基于设计图纸建立的结构有限元模型,得到结构的基准有限元模型,提出了一种基于牛顿插值法的高维模型表示(High-dimensional Model representation based on Newton Interpolation, NEWTHDMR)的结构有限元模型修正方法。NEWT-HDM...为了优化基于设计图纸建立的结构有限元模型,得到结构的基准有限元模型,提出了一种基于牛顿插值法的高维模型表示(High-dimensional Model representation based on Newton Interpolation, NEWTHDMR)的结构有限元模型修正方法。NEWT-HDMR可以描述结构参数与响应之间的黑箱函数关系以取代有限元软件,联合结构真实响应残差和构造目标函数;结合Jaya算法,通过迭代求解结构待修正参数的修正值,进而修正结构有限元模型。利用简支梁数值模型验证本文提出方法的有效性,并分析对比一阶NEWT–HDMR和二阶NEWT-HDMR在修正精度上的差异。结果表明,NEWT-HDMR模型修正结果可以满足工程要求且二阶NEWT-HDMR修正精度更高,验证该方法在结构有限元模型修正中应用的可行性和可靠性。展开更多
Output measurement for nonlinear optimal control problems is an interesting issue. Because the structure of the real plant is complex, the output channel could give a significant response corresponding to the real pla...Output measurement for nonlinear optimal control problems is an interesting issue. Because the structure of the real plant is complex, the output channel could give a significant response corresponding to the real plant. In this paper, a least squares scheme, which is based on the Gauss-Newton algorithm, is proposed. The aim is to approximate the output that is measured from the real plant. In doing so, an appropriate output measurement from the model used is suggested. During the computation procedure, the control trajectory is updated iteratively by using the Gauss-Newton recursion scheme. Consequently, the output residual between the original output and the suggested output is minimized. Here, the linear model-based optimal control model is considered, so as the optimal control law is constructed. By feed backing the updated control trajectory into the dynamic system, the iterative solution of the model used could approximate to the correct optimal solution of the original optimal control problem, in spite of model-reality differences. For illustration, current converted and isothermal reaction rector problems are studied and the results are demonstrated. In conclusion, the efficiency of the approach proposed is highly presented.展开更多
Cargo airdrop has long been one of the most important measures to deal with urgent immediate needs, such as providing as- sists in military operations and sending relief to disaster areas, just to name a few. Because ...Cargo airdrop has long been one of the most important measures to deal with urgent immediate needs, such as providing as- sists in military operations and sending relief to disaster areas, just to name a few. Because it is carried out during flight, it is necessary to investigate the influences of the drop process on flight characteristics to ensure successful execution of the task. This article mainly studies the modeling of flight systems in large flying transport planes with cargo moving in it. By buildi...展开更多
为解决多基站定位模型中基站之间同步代价高的问题,提出了一种基于多根长馈线天线基站的到达时间差(Time Difference of Arrival,TDOA)定位模型,给出了模型方程和求解方法,该方法将复杂的3对距离差方程组转化为1个一元八次方程,然后采用...为解决多基站定位模型中基站之间同步代价高的问题,提出了一种基于多根长馈线天线基站的到达时间差(Time Difference of Arrival,TDOA)定位模型,给出了模型方程和求解方法,该方法将复杂的3对距离差方程组转化为1个一元八次方程,然后采用Aberth-Newton迭代法来迭代求解方程。通过计算机仿真验证了基于多根长馈线天线基站的TDOA定位模型和解法的有效性,并对该模型的多解问题进行了分析,用优化基站布局的方案,解决了定位模型的唯一解问题。本定位模型在覆盖范围数百米时,定位精度可达分米级。展开更多
文摘为了优化基于设计图纸建立的结构有限元模型,得到结构的基准有限元模型,提出了一种基于牛顿插值法的高维模型表示(High-dimensional Model representation based on Newton Interpolation, NEWTHDMR)的结构有限元模型修正方法。NEWT-HDMR可以描述结构参数与响应之间的黑箱函数关系以取代有限元软件,联合结构真实响应残差和构造目标函数;结合Jaya算法,通过迭代求解结构待修正参数的修正值,进而修正结构有限元模型。利用简支梁数值模型验证本文提出方法的有效性,并分析对比一阶NEWT–HDMR和二阶NEWT-HDMR在修正精度上的差异。结果表明,NEWT-HDMR模型修正结果可以满足工程要求且二阶NEWT-HDMR修正精度更高,验证该方法在结构有限元模型修正中应用的可行性和可靠性。
文摘Output measurement for nonlinear optimal control problems is an interesting issue. Because the structure of the real plant is complex, the output channel could give a significant response corresponding to the real plant. In this paper, a least squares scheme, which is based on the Gauss-Newton algorithm, is proposed. The aim is to approximate the output that is measured from the real plant. In doing so, an appropriate output measurement from the model used is suggested. During the computation procedure, the control trajectory is updated iteratively by using the Gauss-Newton recursion scheme. Consequently, the output residual between the original output and the suggested output is minimized. Here, the linear model-based optimal control model is considered, so as the optimal control law is constructed. By feed backing the updated control trajectory into the dynamic system, the iterative solution of the model used could approximate to the correct optimal solution of the original optimal control problem, in spite of model-reality differences. For illustration, current converted and isothermal reaction rector problems are studied and the results are demonstrated. In conclusion, the efficiency of the approach proposed is highly presented.
基金National Natural Science Foundation of China (60134010)Aeronautical Science Foundation of China (2007ZD53053)
文摘Cargo airdrop has long been one of the most important measures to deal with urgent immediate needs, such as providing as- sists in military operations and sending relief to disaster areas, just to name a few. Because it is carried out during flight, it is necessary to investigate the influences of the drop process on flight characteristics to ensure successful execution of the task. This article mainly studies the modeling of flight systems in large flying transport planes with cargo moving in it. By buildi...
文摘为解决多基站定位模型中基站之间同步代价高的问题,提出了一种基于多根长馈线天线基站的到达时间差(Time Difference of Arrival,TDOA)定位模型,给出了模型方程和求解方法,该方法将复杂的3对距离差方程组转化为1个一元八次方程,然后采用Aberth-Newton迭代法来迭代求解方程。通过计算机仿真验证了基于多根长馈线天线基站的TDOA定位模型和解法的有效性,并对该模型的多解问题进行了分析,用优化基站布局的方案,解决了定位模型的唯一解问题。本定位模型在覆盖范围数百米时,定位精度可达分米级。
