矢量控制感应电机参数变化的影响研究

在感应电机数学模型的基础上,分析了在转子磁场定向恒磁通矢量控制感应电机控制系统中转子电阻和电机电感变化的影响,证明了电机电感的变化对电机转速和电磁转矩不产生影响,建立了考虑电机参数变化时电机矢量控制的数学模型,仿真结果表明该模型具有结构简单和分析方便等优点。     

陀螺仪安装误差的测量方法研究

介绍了一种用于测量平台式惯性导航系统陀螺安装误差的陀螺轴扰动技术,该技术无需增加惯导系统的硬件设施,通过对平台框架施加特定的控制力矩,使其按照要求的规律运动,然后采集有关的数据并通过适当的算法即可得到陀螺的安装误差角,理论分析和仿真结果表明,利用该技术可以有效的提高惯导系统的导航精度。     

线性约束多目标规划的非单调信赖域算法

构造了一个解线性约束多目标优化问题的数值算法,该算法把一种非单调技巧与信赖域方法结合起来,从理论上分析,在一般条件下,算法全局收敛于问题的K—T点。     

Numerical analysis of fatigue striations

A computational model was developed to numerically analyse fatigue striations. The inclined strip yield model with continuous distributions of infinitesimal dislocations was utilized to express the crack tip plasticity in this model. The fatigue crack tip blunting process was approximated by sequential activation of two slip lines under loading, and crack closure during unloading was taken into account. The plastic zone at a growing fatigue crack tip at the maximum load was independent of the crack growth up to ten cycles while the reversed plastic zone decreased in a size to one twentieth of that at the maximum load as the crack grew. The ratio of these plastic zone sizes and also the crack tip opening displacement were quite different from the simple prediction by J.R. Rice for a stationary crack. The computed striation spacings were compared with the observed ones and moderate agreement between them obtained.     

Reactions of hydroxyl radicals with polystyrene

The reaction of polystyrene with hydroxyl radicals, generated by the photolysis (λ > 300 nm) of H₂O₂, has been studied at 25° in dichloromethane solution, both under vacuum conditions and in presence of O₂. Spectroscopic analyses suggest the presence of phenols and hydroxymucondialdehydes (when O₂ is present) among the reaction products, indicating that OH addition occurs at the phenyl groups of the polymer. By comparison with initiated oxidation reactions under the same conditions, it is concluded that the OH radicals undergo mainly addition reactions. A mechanism has been produced to account for the products. The significance of OH addition reactions in the oxidation of polystyrene is considered, the OH radicals being produced by hydroperoxide decomposition during oxidation, and the products having been previously identified as containing mucondialdehydes.     

Variational principles for scattering in the generator coordinate method

The generator coordinate method (GCM) wave function is used as a trial function in a Kohn type variational principle for scattering phase shifts. It is shown that a GCM trial function is a solution of the variational equations if the Hill-Wheeler integral equation is satisfied subject to an appropriate boundary condition. A new method for introducing the scattering boundary condition is presented. There is a uniqueness theorem for the phase shift.     

液压跑偏控制系统的增载优化

分析了进口卷取机跑偏控制系统 （ Ｅ Ｐ Ｃ 系统）的特点,指出增大油缸工作面积 Ａ 会减小 Ｅ Ｐ Ｃ 系统的速度,提出了适合该系统的约束归纳优化法．介绍了 Ｅ Ｐ Ｃ 系统优化中约束归纳的过程和网络算法的原理,同时对优化结果进行了仿真分析．增载改造的实践,证明了该优化结果的正确．     

导叶开口对混流水轮机尾水管压力脉动的影响

将水压力脉动测试、流场测试以及初生空化观测等实测结果进行对比分析,研究水轮机活动导叶开口的变化对尾水管水压力脉动的影响,为进一步研究并建立尾水管水压力脉动数学模型提供依据     

一类工业过程的神经元智能控制

研究了基于自适应神经元的一类工业过程控制问题，分析了闭环系统稳定性与神经元控制器参数的关系，给出了闭环系统稳定的充分条件及神经元学习参数初值的一种方法及学习的收敛性证明。理论分析表明，神经元智能过程控制系统有很强的鲁棒性和适应性，仿真结果表明了其优良的性能。