On the conjunction practical stability and controllability of large-scale impulsive control systems

We studied the conjunction practical stability and controllability of large-scale impulsive control systems by using the comparison systems and vector Lyapunov fimctions. Then the less conservative sufficient conditions for conjunction practical stability and controllability of large-scale impulsive control system were obtained.

Theoretical Analysis and Numerical Simulation of the Static and Dynamic Characteristics of Hydrostatic Guides Based on Progressive Mengen Flow Controller

The oil film thickness of oil hydrostatic guide with constant pressure supply based on capillary restrictor is greatly affected by load, and this kind of hydrostatic guide is usually applied to the machine tools with moderate load. The static and dynamic characteristics of the guide have been studied by using some theoretical, numerical and experimental approaches, and some methods and measures have been proposed to improve its performances. The hydrostatic guide based on progressive mengen（PM） flow controller is especially suitable for the heavy numerical control（NC） machine tools. However, few literatures about the research on the static and dynamic characteristics of the hydrostatic guides based on PM flow controller are reported. In this paper, the formulae are derived for analyzing the static and dynamic characteristics of hydrostatic guides with rectangle pockets and PM flow controller according to the theory of hydrostatic bearing. On the basis of the analysis of hydrostatic bearing with circular pocket, some equations are derived for solving the static pressure, volume pressure and squeezing pressure which influence the dynamic characteristics of hydrostatic guides with rectangle pocket. The function and the influencing factors of three pressures are clarified. The formulae of amplitude-frequency characteristics and dynamic stiffness of the hydrostatic guide system are derived. With the help of software MATLAB, programs are coded with C＋＋ language to simulate numerically the static and dynamic characteristics of the hydrostatic guide based on PM flow controller. The simulation results indicate that the sensitive oil volume between the outlet of the PM flow controller and the guide pocket has the greatest influence on the characteristics of the guide, and it should be reduced as small as possible when the field working condition is met. Choosing the oil with a greater viscosity is also helpful in improving the dynamic performance of hydrostatic guides. The research work has instructing significance for analyzing and designing the guide with PM flow controller.

HYDRAULIC ACTIVE GUIDE ROLLER SYSTEM FOR HIGH-SPEED ELEVATOR BASED ON FUZZY CONTROLLER

Increase of elevator speed brings about amplified vibrations of high-speed elevator. In order to reduce the horizontal vibrations of high-speed elevator, a new type of hydraulic active guide roller system based on fuzzy logic controller is developed. First the working principle of the hydraulic guide system is introduced, then the dynamic model of the horizontal vibrations for elevator cage with active guide roller system and the mathematical model of the hydraulic system are given. A fuzzy logic controller for the hydraulic system is designed to control the hydraulic actuator. To improve the control performance, preview compensation for the controller is provided. Finally, simulation and experiments are executed to verify the hydraulic active guide roller system and the control strategy. Both the simulation and experimental results indicate that the hydraulic active guide roller system can reduce the horizontal vibrations of the elevator effectively and has better effects than the passive one, and the fuzzy logic controller with preview compensation can give superior control performance.

Output-feedback based partial integrated missile guidance and control law design

An output-feedback based partial integrated guidance and control (IGC) law for missile interceptor is proposed with the smooth finite time convergence property. Firstly, a novel outputfeedback based smooth sliding mode control is proposed for a class of nonlinear systems in the presence of immeasurable state and disturbance. The finite time convergence property of this control scheme is proved based on the Lyapunov stability and homogeneous principle. Then, the proposed control method is applied to the design of partial IGC law. A kind of scaling methods is also developed to reach the rapid convergence of the system. An important dominance of this control scheme is the smooth characteristic, which may result in chattering free convergence. The simulation results indicate the high precision and smooth elevator deflection of the proposed output feedback base partial IGC law. © 2016 Beijing Institute of Aerospace Information.

Quality Control in Laboratory Hemostasis and Thrombosis

Introdution Laboratory diagnosis in medical practice,the position has been established,hernostasis and thrombosis.expefimental testing is no different.Experimental test of information not only for early diagnosis and guide treatment,prognosis and estimated recurrence.

Optimal Gliding Guidance of Vertical Plane for Standoff Released Guided Bomb Unit

Optimal gliding guidance for a guided bomb unit in the vertical plane is studied based on nonlinear dynamics and kinematics.The guidance law is designed under minimum energy loss index.To avoid the complexity in solving two-point-boundary-value problems,the steady-state solutions of the adjoint states in regular equations are suggested to be used.With these considerations,a quasi-closed,optimal gliding guidance law is obtained.The guidance law is described by the angle of attack in a simple nonlinear equation.An iterative computation method can be easily used to get the optimal angle of attack.The further simplified direct computation algorithm for the optimal angle of attack is also given.The guidance properties are compared with those of maximum lift-to-drag angle of attack control.The simulation results demonstrate that the quasi-closed,optimal gliding guidance law can improve the gliding phase terminal performance with significant increase in the altitude and much little decrease in the speed.

空间天文望远镜自适应精密稳像闭环控制

针对空间天文望远镜低频段视轴扰动补偿问题,提出了一种基于主动光学技术的自适应精密稳像闭环控制方法。该方法以精细导星仪(Fine Guide Sensor,FGS)为高精度视轴扰动检测器,以四点支撑压电驱动大口径快摆镜机构(Fast Steering Mirror,FSM)为视轴扰动补偿器。首先,采用位置式PID控制器串联积分环节进行精密稳像闭环控制,得到补偿FGS检测出的二维视轴扰动所需FSM的二维摆动角度,进而根据驱动结构转换为每个支撑点的压电陶瓷执行器(Piezoelectric actuators,PZT)的伸缩量。然后,利用基于广义Bouc-Wen逆模型的压电动态迟滞前馈补偿方法进行高精度的压电陶瓷执行器定位控制。最后,根据有监督的Hebb学习规则,利用具有自学习和自适应能力单神经元对PID控制器参数进行调整,从而得到最优控制器参数。实验结果表明,所提控制方法能够有效地补偿空间天文望远镜的视轴偏差,可以将精细导星仪X方向和Y方向的星点质心位置偏差功率谱密度在0~6 Hz频段内积分值分别抑制了98.54%和98.62%。

ICU护士血管导管相关感染预防与控制知识的现状调查

目的调查重症医学科(intensive care unit,ICU)护士血管导管相关感染(vessel catheter associated infection,VCAI)预防与控制知识的现状,为提高ICU护理质量提供改进依据。方法采用便利抽样方法,选取2022年11—12月厦门大学附属第一医院ICU 60名在职护士作为调查对象。采用一般资料调查表、VCAI预防与控制知识现状调查表和学习情况调查表对其进行调查,并调查2020—2022年ICU的VCAI发生率。结果60名护士VCAI预防与控制知识总得分为10~27分,平均(20.57±3.50)分,平均得分率为76.18%,处于中等水平,各维度知识掌握水平不等。2020年发生1例VCAI,发生率为3.19‰;2021年发生2例VCAI,发生率分别为2.52‰、2.91‰;2022年未发生VCAI。结论ICU护士对VCAI知识掌握程度处于中等水平,应进一步加强对护士相关知识的培训和考核,规范操作流程,提高ICU护理质量。

传道授业——物理污染控制工程引导式课程思政设计

课程思政是高等教育从业者面临的时代命题。物理污染控制工程是环境工程专业重要专业课之一。该文在分析课程思政元素类型的基础上,论述了基于若干知识单元教学内容的思政教育整体设计,集专业知识与思政教育于一体。以案例分析课为例,说明引导式课程思政实施方式和方法,通过逐层设问,层层推进,在完成教学内容、达到教学目标的同时,体现专业理论知识对实践的重大指导作用、解决问题须抓住矛盾特性和主要方面、安全和环境法律意识三个思政元素,对该课程的思政教学具有较大的参考意义。

大尺度圩田水网地区特色生态空间单元解析及传承策略研究——以高淳为例

我国幅员辽阔,各个地区的乡村空间各具特色。在诸如江浙一带的圩田水网地区便形成了独特的生态-聚落空间布局模式。文章以大尺度高淳水网地区的聚落空间为研究对象,在分析现状水系网络、农田体系、圩堤陆路等生态要素共同作用下的乡村特色空间基础上,从维持水田格局的特色性、分类引导聚落选址和堤路网体系优化布局三个方面,分别探究传承乡村特色空间的策略与导控方法,旨在为我国其他相似圩田水网地区的乡村特色空间传承提供实践指导方法和参考借鉴意义。

管道中激发L(0,2)导波的EMAT结构设计及优化

超声导波在管道中传播时具有多模态特性,导致超声导波检测的回波信号复杂难以分辨。依据EMAT激发机理和纵向超声导波的波结构特性,设计一种周期性永磁铁组以增大洛伦兹力轴向分量、减小径向分量,激励纯净的L(0,2)模态导波。研究永磁铁宽度对L(0,1)模态抑制效果的影响规律,得到控制效果较好的永磁铁宽度。结果表明:相比传统EMAT,新型EMAT对L(0,1)模态抑制效果显著,L(0,2)模态与L(0,1)模态峰值之比是传统EMAT的7.62倍。

计划行为理论指导下的认知干预在高血压三级患者中的应用

目的探讨计划行为理论指导下的认知干预在高血压三级患者中的应用效果。方法采用便利抽样法选择2021年9月至2022年12月诊治的高血压3级患者116例,随机数字表法分为对照组和观察组,每组58例。对照组接受常规认知干预,观察组接受计划行为理论指导下的认知干预。比较2组血压控制达标情况、高血压治疗态度与信念、自我管理能力。结果干预3个月时,观察组收缩压下降值、舒张压下降值和血压控制达标率均高于对照组,差异有统计学意义(P<0.05)。2组高血压治疗态度与信念各维度及总分均较干预前升高,且观察组高于对照组,差异有统计学意义(P<0.05)。2组自我管理能力各维度及总分均较干预前升高,且观察组高于对照组,差异有统计学意义(P<0.05)。结论计划行为理论指导下的认知干预可有效加强高血压3级患者的治疗态度和信念及自我管理能力,进而有效控制血压水平、达标率更高。

赞比亚卢安夏难浸铜矿石扼酸控杂浸出技术研究

赞比亚卢安夏穆利亚希氧化铜矿石性质复杂,原采用常规加温搅拌浸出工艺处理,但浸出液中杂质离子含量高,影响了后续萃取—电积作业。为实现该矿石的高效清洁利用,开展了分支加酸扼酸控杂浸出试验研究。结果表明:在磨矿细度-200目占70%、硫酸用量45 kg/t、矿浆浓度40%、搅拌强度300 r/min,浸出温度65℃的条件下,对矿石进行常规浸出试验,铜的浸出率为80.35%,铁的浸出率为8.81%,锰的浸出率为39.38%;采用分支加酸工艺,在硫酸用量37.5 kg/t,各段加酸比例分别为30%、25%、20%、15%、10%、0,各段浸出时间均为40 min的条件下,分支加酸浸出试验的铜浸出率为83.29%,铁浸出率为7.78%,锰浸出率为34.86%。与常规加酸工艺相比,硫酸总用量减少了7.5 kg/t,铜的浸出率提高了2.94个百分点,铁和锰的浸出率分别下降了1.03和4.52个百分点;现场应用分支加酸技术,在铜浸出率不低于82%的前提下,吨铜硫酸用量降低0.6 t,浸出液中铁离子和锰离子的浓度分别下降0.75 g/L和0.70 g/L;新工艺在不新增设备和药剂的情况下即可达到提铜降酸控杂的目的,有效降低了吨铜生产成本,提高了料液质量,可为实现同类氧化铜矿的高效清洁浸出提供新的研究思路。

大攻角条件下制导弹滚转稳定控制方法

制导弹跨域飞行过程中,伴随着大攻角下的涡流非对称以及跨音速气动转捩,这些干扰将引起控制失稳,进一步增大脱靶量。针对以上问题,考虑气动模型强非线性、强参数不确定性及强外界干扰,建立制导弹滚转通道动力学模型,进而提出一种基于滑模观测器与非奇异终端滑模的滚转姿态组合控制方法。以此为基础框架,结合微分跟踪器设计一种反步控制方法,以补偿执行机构动力学。利用Lyapunov稳定性理论证明了闭环系统稳定性及有限时间收敛特性。通过仿真实验验证了所设计控制方法的优越性及普适性。

一种新型后舵尾控修正弹的弹道控制仿真

为增强修正弹控制舵的快速响应能力和弹道修正效果,且理论上减弱舵片在高旋状态下对弹体的气动扰流影响,设计一种控制舵置于质心后部、与弹尾部高度配合的新型二维修正弹。建立弹体模型,设计以优化后的新式制导方案和比例微积分控制法为主体的组合控制策略,分析无控和有控状态下关键变量参数的变化规律,对基于参数最优值下的弹道修正过程进行仿真计算;采用蒙特卡洛打靶法分析扰动状态下的落点散布情况。仿真结果表明:此控制策略下后舵尾控弹的实际滚转角吻合于输入指令,整个过程速度高低角和方向角的变化范围仅为2°和7°,基于最优值的控制修正过程和扰动状态下的最终落点情况也保证了弹体进行平稳运动的同时具备更优的偏差修正能力,进一步证实了设计的新型弹体模型具有较高的可行性和参考价值。

超声导波目标模式的激励方法研究

超声导波检测过程中不同模态导波信号与各类损伤之间的相互作用存在差异性,直接影响了损伤检测及定位成像结果的可靠性。因此,系统研究导波目标模式的激励方法从而获得理想的导波信号,有助于实现多类型损伤的精准检出以及获得高分辨率定位成像结果。该研究基于理论分析、有限元仿真和试验测量开展了超声导波目标模式的激励方法研究。理论分析导波目标模式激励的条件,并且构建二维多物理场仿真模型进行导波目标模式激励方法的验证。试验过程中将梳状换能器与锆钛酸铅压电陶瓷(piezoelectric ceramic, PZT)进行比较分析,结果表明,梳状换能器相较于PZT压电片具有良好的模式选择能力。另外,设计制作四分之一全向和全向梳状换能器,使其进行目标模式导波信号激励的同时实现传播方向的调控。

一种基于轨迹预测的滑翔制导炮弹时间约束末制导律扩展方法

针对滑翔制导炮弹末制导过程中的攻击角度与攻击时间控制问题,为简化制导律设计、方便工程应用,提出了一种将现有高性能非时间约束制导律扩展为可处理时间约束形式的方案。该方案以非线性导引模型为基础、现有制导律作用下的弹丸飞行轨迹为参考轨迹,通过为弹丸预设合理的飞行时间并结合轨迹预测的方法,将滑翔制导炮弹的末制导过程分为2个阶段。第一阶段制导炮弹在扩展后的制导律作用下飞行,通过增加参考轨迹曲率、延长弹丸飞行时间的方式使攻击时间误差在有限时间内收敛至零;第二阶段制导炮弹在原始制导律作用下飞行,直至命中目标以满足脱靶量与攻击角约束。同时,通过不同工况下的大量仿真,研究了设计参数的取值范围对第一阶段中弹丸攻击时间误差收敛性能的影响。该扩展方案的推导过程无需现有制导律的显式表达,具有一定的通用性。研究结果表明:通过合理的参数设置,扩展方案可以在现有制导律的基础上实现攻击时间控制,且制导指令光滑,需用过载较小,符合作战任务要求。

A Novel Prescribed-Performance Path-Following Problem for Non-Holonomic Vehicles

The issue of achieving prescribed-performance path following in robotics is addressed in this paper,where the aim is to ensure that a desired path within a specified region is accu-rately converged to by the controlled vehicle.In this context,a novel form of the prescribed performance guiding vector field is introduced,accompanied by a prescribed-time sliding mode con-trol approach.Furthermore,the interdependence among the pre-scribed parameters is discussed.To validate the effectiveness of the proposed method,numerical simulations are presented to demonstrate the efficacy of the approach.

消风散加减联合奥洛他定治疗儿童过敏性结膜炎临床观察

目的:观察消风散加减联合奥洛他定治疗儿童过敏性结膜炎的疗效。方法:72例按照随机数字表法分为两组各36例,两组均用奥洛他定治疗,研究组加用消风散加减。结果:研究组总有效率高于对照组(P<0.05),症状和体征评分及降钙素原(PCT)、C反应蛋白(CRP)、白细胞计数(WBC)水平低于对照组(P<0.05),临床症状改善优于对照组(P<0.05)。结论:消风散加减联合奥洛他定治疗儿童过敏性结膜炎效果较好,且安全。