Determining the characteristics of the initial fixed-focus of laser beam riding guidance information field

Determining characteristics of the initial fixed-focus are a key technique for the design of laser beam riding guidance missile. Through analyzing the effects of the initial cone information field in guidance and control system of missile,those effects are considered as an approximate lead compensation network. The position and time of guidance spot initial fixed-focus can be designed. This method is applied to determine the characteristics of the initial fixed-focus of laser information field for a laser beam guidance gun-launched missile. The results of design and simulation show that the initial cone information field apparently speeds up convergence on the initial trajectory,and provides a guarantee for the implementation of minimum range index of a missile system.     

纳米SiO2改性聚合物水泥砂浆力学性能及干缩性能研究

研究了不同掺量的纳米SiO₂对改性聚合物水泥砂浆力学性能的影响规律,用掺量分别为0.5%、1.0%、1.5%、2.0%纳米SiO₂对改性聚合物水泥砂浆的力学性能(抗压强度、抗折强度)、养护条件和干缩性能进行了评价。试验表明,与聚合物水泥砂浆相比,纳米SiO₂的加入有效改善了砂浆的力学性能,但增加了砂浆的干缩性。1.5%掺量下的纳米SiO₂可使聚合物水泥砂浆达到最佳的力学性能。对于养护条件的研究表明,早期干燥养护对砂浆力学影响较大,后期干湿循环更有利于砂浆的养护。     

导弹线性分式变换模型及其在Hoo增益调度自动驾驶仪设计中的应用

釆用图形法建立了导弹线性分式变换(LFT)模型，将导弹动カ学明确描述为确定性与不确定性两部分，构造了线性参数时变（LPV)/μ控制结构，运用D-K-D迭代算法设计了导弹H∞增益调度自动驾驶仪。LPV/μ控制技术明确考虑了导弹的时变特性，设计生成的控制器能够在导弹飞行过程中自动进行参数调节，适应导弹动力学特性的变化，从而稳定自动驾驶仪的动カ学特性。_仿真结果表明：建立的线性分式变换模型能够准确描述导弹的动力学特性，同时所设计的H00增益调度自动驾驶仪的动力学特性基本与导弹飞行条件的变化无关。     

西部高烈度地区某小学综合楼隔震设计及性能研究

为完善隔震技术的理论应用,最大限度地减轻地震灾害损失,变被动救灾为主动防灾.本文以某小学建设项目为例对西部高烈度地区隔震设计及性能进行了深入研究,采用两条天然波El-Centro波、Taft波和一组人工模拟波通过振型分解反应谱法和时程分析法对隔震前后的地震反应进行了计算分析.结果表明:综合楼隔震后的地震响应显著下降,隔...     

Motion planning of UAV group using modified gyroscopic force for guidance and avoidance

It is comment that unmanned aerial vehicles （UAVs） have limitation on information cap- turing in reality applications. Therefore, online method of motion planning is necessary for such UA- Vs. Gyroscopic force （GF） is used for obstacle avoidance as an online method. However, classical GF has shortcoming in generating orbit for UAV with high velocity because the GF results in a time- varying turning radius. Modified gyroscopic force （MGF） given by function of velocity can overcome this shortcoming and help get a more practical control law for avoidance. MGF can also be used to implement the guidance of UAV by designing particular active conditions. Interactions in forms of stress function and damping force are introduced so that an UAV group can have coordinated motion. By combining controls of MGF and interactions, motion planning of UAV group in obstacle environ- ment can be implemented.     

Trajectory design and simulation in injection phase for hyper-velocity kinetic energy missile

A movement law of laser beam facula is designed for the injection trajectory of hyper-velocity kinetic energy missile to eliminate the influence of motor exhaust smoke on laser signal transmission.Taking guidance loop of hyper-velocity kinetic energy missile as plant,a closed loop control system with desired step response characteristics is constructed and the movement law of laser beam facula for the missile injection trajectory is designed based on the output signal of the closed loop controller under a step input.Six degree-of-freedom trajectory simulations show that by the guidance of the laser beam facula moving with designed law,the missile can finish transition from the initial trajectory to a stable tracking trajectory without overshoot within the required time.     

滚转导弹动态失稳的机理分析

将滚转导弹动力学系统描述为一个具有动态负反馈的闭环系统,分析了滚转导弹动态失稳的机理.基于滚转导弹扰动运动方程组,绘制了滚转导弹扰动运动结构图,经过简化,将滚转导弹描述为由2个二阶环节构成的具有动态负反馈的闭环系统.由此系统的开环特性出发,基于对数频率稳定性判据给出了马格努斯效应导致滚转导弹动态失稳的原因.给出了算例,结果表明,由开环稳定性分析得到的导弹动态稳定转速边界与采用基于闭环极点位置约束的通用转速边界计算公式所得到的结果是相同的.     

空面导弹弹道仿真方法研究

提出了一种空面导弹下滑段、俯冲攻击段的弹道优化设计方案，以及一种实现航向动态跟踪的具体方法。大量算例表明，采用本文中的空面导弹控制方案可以设计，调试出较满意的弹道，达到获取导弹飞行性能数据并验证导弹总体设计参数的目的。     

三点法导引导弹初始段弧形弹道优化设计及实现

为防止由发动机羽烟效应或冲击波产生的尘云引起前视红外的匿隐和目标的遮蔽,采用三点法导引导弹在初始段沿偏离瞄准线的弧形弹道飞行.通过非线性规划的直接方法优化得到最优的初始段弧形弹道,提出了采用加PI校正的过载驾驶仪对导弹进行控制.结果表明,与标准过载驾驶仪和加积分校正的过载驾驶仪相比,PI校正的过载驾驶仪具有较好的响应速度,能消除跟踪误差,具有良好的性能.利用优化得到的控制指令进行了初始段弹道仿真,验证了该方法的可行性.     

基于神经网络动态逆的巡逻导弹自动驾驶仪设计

针对巡逻导弹,讨论一种将神经网络与非线性动态逆相结合的自动驾驶仪设计方法。基于双时标假设,将弹体动力学分为慢变子系统和快变子系统,并分别进行动态逆设计。为克服模型不精确和参数摄动引起的逆误差对动态逆控制的不利影响,引入神经网络对逆误差进行在线补偿。推导了神经网络权值调整规律,并证明系统的闭环稳定性。通过仿真验证,采用神经网络能弥补动态逆控制的不足,提高控制系统的鲁棒性,是一种有效的非线性设计方法。