Study on Control of Pneumatic Selecting and Shifting Actuators Using Rapid Control Prototyping

A gearbox in-the-loop control platform using dSPACE real-time system is designed for the study on the control technology of pneumatic selecting and shifting actuators based on rapid control prototyping.The operational principle of such actuators was analyzed using dSPACE hardware and software,resulting in a better knowledge of the logical relationship among solenoid valves,gear positions of cylinders and system input/output.Based on these,a control model was developed under the Matlab/Simulink environment and rapidly improved to meet requirements through experiments.Relevant tests have shown that analysis efficiency on selecting and shifting actuators could be raised and development of control strategy facilitated.

An Integrated Control Framework for Torque Vectoring and Active Suspension System

Four-wheel independently driven electric vehicles(FWID-EV)endow a flexible and scalable control framework to improve vehicle performance.This paper integrates the torque vectoring and active suspension system(ASS)to enhance the vehicle’s longitudinal and vertical motion control performance.While the nonlinear characteristic of the tire model leads to a relatively heavier computational burden.To facilitate the controller design and ease the load,a half-vehicle dynamics system is built and simplified to the linear-time-varying(LTV)model.Then a model predictive controller is developed by formulating the objective function by comprehensively considering the safety,energy-saving and comfort requirements.The in-wheel motor efficiency and the power loss of tire slip are treated as optimization indices in this work to reduce energy consumption.Finally,the effectiveness of the proposed controller is verified through the rapid-control-prototype(RCP)test.The results demonstrate the enhancement of the energy-saving as well as comfort on the basis of vehicle stability.

Properties of Rapid Hardening Controlled Low Strength Material Made of Recycled Fine Aggregate from Urban Red Brick Construction Waste

In some cases of emergency backfill engineering projects, traditional backfill materials cannot meet the requirements of fast construction due to their long curing time. This study presents a new kind of rapid hardening controlled low strength material, which utilizes both rapid hardening sulphoaluminate cement and recycled fine aggregate from urban red brick construction waste. Totally, sixteen mixtures were prepared for the experiment with different cement-to-sand ratios and water-to-solid ratios. The flowability and bleeding rate of fresh mixture were measured to evaluate its workability, and the compressive strength of hardened mixture was tested to evaluate its rapid hardening and mechanical properties. Test results indicate that rapid hardening controlled low strength material containing recycled fine aggregate from urban red brick construction waste can achieve the desirable flowability, but the bleeding rate increases with the increase of flowability. In addition, 2-hour compressive strength can reach 0.08 - 0.12 MPa, and 4-hour compressive strength is 0.32 - 1.54 MPa, which can meet the requirements of emergency backfill construction. At last, based on the derived compressive strength, a fitting model for predicting compressive strength evolution of this new rapid hardening backfill material is developed, which fits accurately with these experimental data.

Temperature Compensation Algorithm for Hydraulic System Pressure Control

In this paper the control mechanism of solenoid valve is analyzed,which shows the solenoid valve control is actually the control of coil current.The response characteristic of coil current is related to coil inductance and resistance.The coil resistance is influenced greatly by the ambient temperature and the self-heating of coil,which affects the control precision of coil current.First,considering the heat dissipation mode of coil,the coil temperature model is established from the perspective of heat conduction,and a temperature compensation algorithm for hydraulic system pressure control is put forward.Then the hardware-in-the-loop testbed is set up by using the dSPACE platform,carrying out wheel cylinder pressurization tests with inlet valve fully opened at-40℃ and 20℃,and testing the actual pressure of wheel cylinder with the target pressures at-40℃ and 6 000 kPa/s(pressurization rate).The results show that the pressure control temperature compensation algorithm proposed in this paper accurately corrects the influence of resistance temperature drift on the response accuracy of wheel cylinder pressure.After the correction,the pressure difference is less than 500 kPa,which can meet the control accuracy requirements of solenoid valve,enriching the linear control characteristic of solenoid valve.

Simulation and experimental research of digital valve control servo system based on CMAC-PID control method

Digital valve control servo system is studied in this paper. In order to solve the system problems of poor control precision and slow response time,a CMAC-PID( cerebellar model articulation controller-PID) compound control method is proposed. This compound controller consists of two components: one is a traditional PID for the feedback control to guarantee stability of the system; the other is the CMAC control algorithm to form a feed-forward control for achieving high control precision and short response time of the controlled plant. Then the CMAC-PID compound control method is used in the digital valve control servo system to improve its control performance. Through simulation and experiment,the proposed CMAC-PID compound control method is superior to the traditional PID control for enhancing stability and robustness,and thus this compound control can be used as a new control strategy for the digital valve control servo system.

变速抽蓄机组有功分阶段多档位控制策略

变速抽蓄机组具有优越的快速有功支撑能力,是协助新能源消纳和保障新型电力系统安全稳定运行的重要手段,但其有功调节中存在功率响应差额问题以及励磁单元与调速器响应速度差异造成的功率失衡会导致转速反调波动,从而影响机组长期安全稳定运行,而目前协调有功和转速的控制策略无法充分发挥变速抽蓄机组有功快速响应能力。为此,设计了有功参考值整定单元,解决了有功调节的差额问题;提出了有功分阶段多档位控制策略,考虑转速安全范围对有功进行分阶段控制,充分协调转速反调和有功快速调节之间的矛盾;基于Simulink仿真平台,验证了所提出的策略能有效提高有功调节精度,且可在抑制转速反调的基础上有效提升功率调节性能,有利于充分发挥变速抽蓄机组调频优势,保障机组长期安全稳定运行。

高空台进气环境模拟系统固定时间自抗扰复合解耦控制

针对高空台进气环境模拟系统(IESS)存在压力与温度双变量强耦合及发动机快速过渡态试验带来的强总和扰动问题,设计一种新型固定时间滑模控制器(FxTSMC)并结合固定时间扩张状态观测器(FxTESO),提出一种固定时间自抗扰复合解耦控制(FxT-ADRCDC)方法。具体地,采用静态解耦方法将IESS解耦为两个单输入、单输出系统,实现IESS温度和压力的独立控制。在总扰动估计与抑制方面,利用固定时间扩张状态观测器快速准确估计系统状态与包含系统动态耦合在内的总扰动,并提出一种能够避免奇异问题且快速收敛的新型FxTSMC,将总扰动补偿到FxTSMC中,得到FxT-ADRCDC方法。设计Lyapunov函数证明了闭环控制系统的固定时间稳定性,得到不依赖于初始条件的稳定时间上限。搭建高置信度IESS仿真平台开展发动机过渡态飞行任务试验,对比了本文所提出方法与线性自抗扰解耦控制(LADRDC)方法。结果显示,FxT-ADRCDC方法控制下的进气压力、温度的绝对积分误差比LADRDC方法平均减少约70.3%和70.7%,且阀门摆动量符合实际工程要求,有效实现了进气压力、温度的高品质解耦控制,为提升IESS的快速、精确的动态模拟能力提供有力的技术支撑。

基于冗余执行器的航空发动机推力快速响应控制方法研究

面向飞/推一体化控制需求,开展涡扇发动机推力快速响应控制研究,提出了适用于推力最小相位系统的冗余控制方案。研究内容包括:(1)借鉴阀位控制思想,提出在传统燃油流量(Wf)回路基础上增设尾喷口喉道面积(A8)回路,通过挖掘冗余执行器变化速率潜力,提高推力响应速度,降低了对于燃油泵快速作动的需求,同时该方法可以使喷口在推力响应过程逐渐回中,系统具备持续的推力快速调节能力;(2)分析了A8调节推力的物理机理,指出容腔压力动力学主导的部件间流量匹配过程使得A8对推力具有直馈作用,是提高推力响应速度的有效途径。基于发动机部件级模型的评估结果表明,本文提出的方法在执行机构存在速率限制的情况下,实现了推力10 rad/s闭环带宽和A8回中的设计目标,方法可行、有效。在推力响应过程中,A8直馈作用对推力变化的贡献度最高时超过50%。随着对于推力控制模式和推力响应速度的日趋关注,应对容腔内的压力动态过程给予充分的重视。

基于Links-RT的数字液压风力机半实物仿真系统设计

数字液压风力机可根据风速大小使相应排量液压泵参与工作,使液压风力机在整个工作风速范围内始终保持高效。由于大型风力机不具备开展实验研究的条件,且风力机中的液压系统具有较强的非线性,为了准确研究数字液压风力机多泵切换时系统工作特性的变化规律,提出了一种基于Links-RT的数字液压风力机半实物仿真系统,并对数字液压风力机风轮特性模拟和最大功率跟踪控制进行设计。通过风速阶跃变化、恒定风速时多泵切换、渐变风速多泵切换3种工况下数字液压风力机工作特性的实时仿真测试,验证了数字液压风力机半实物仿真系统的正确有效性,为数字液压风力机的稳定运行和风能高效利用提供理论依据和技术参考。

Feasibility of Using Two versus Three Rapid Tests for HIV Diagnosis in India: Analysis of Public Health Program Data

Under India’s National AIDS Control Program (NACP), WHO recommended strategy of using three rapid tests is adopted for diagnosis of HIV in an asymptomatic individual. Since the NACP has a stringent kit evaluation procedure and due to the availability of newer third generation Rapid Diagnostic Tests (RDTs) it may be possible to adapt two test strategy for HIV diagnosis instead of the recommended three test strategy. The authors reviewed programmatic data on HIV testing to explore whether use of two rapid tests for HIV diagnosis as against three tests could be a feasible approach without compromising the quality and readability of testing. Data on the HIV diagnosis performed on serum specimens collected for the period of one year (2011-12) from 82 Integrated Testing and Counselling Centers (ICTCs) or Prevention of Parent to Child Transmission Centers (PPTCTs) associated with State reference Laboratories (SRLs) was analysed. Out of 654258 results that were analysed 25168 (3.84%) specimens were positives. It was observed that both two and three test algorithms provided similar results for majority (>99%) of the HIV positive specimens. Discordance was observed in labelling of specimen with inconclusive status (N = 21), however the true status of these samples could not be obtained. The analysis indicated that the use of two test algorithm will have programmatic benefits in terms of reduced financial burden to the programme and ease of procurement, shipment and storage before and after distribution without comprising the quality of the testing. The prospective study would confirm this observation.

欠驱动航天器模糊自适应增强耦合姿态控制

在快速轨道机动期间,针对固体推进作用下推力偏心、安装误差等因素带来的姿态强干扰问题,提出了一种基于推力矢量控制技术的航天器姿态欠驱动智能控制方法。首先,建立了航天器姿态误差动力学模型,并分析推力矢量控制输入的欠驱动特性。然后,考虑强干扰不确定性和滚转通道耦合弱的问题,设计了基于增强耦合策略与自适应模糊观测器的欠驱动智能控制律,结合模糊逻辑函数逼近强干扰不确定项并引入控制律中,实现航天器的姿态欠驱动智能控制,通过Lyapunov理论证明了系统的稳定性。最后,通过与分层滑模控制方法进行对比仿真,验证了所设计的方法能够使得三轴姿态稳定时间缩短14%,滚转通道耦合弱产生的静差被有效消除,为快速轨道机动期间的强干扰抑制技术提供基础。

Rapid Quantification of Chinese Medicine Zuo Jin Pill via RRLC

A rapid method based on rapid resolution liquid chromatography（RRLC） coupled with a diode array detector（DAD） was developed for the simultaneous determination of six major constituents（magnoflorine,jatrorrhizine,coptisine,palmatine,berberine and evodiamine） in traditional Chinese medicine（TCM） Zuo Jin Pill（ZJP）.The satisfactory chromatographic separation was carried on an Eclipse Plus C18 column（1.8 μm i.d.,150 mm×4.6 mm） by linear gradient elution with a mobile phase of acetonitrile-acetate buffer.All the calibration curves show good linearity（r2 0.9998）.The detection limits and quantification limits ranged in 1.4―12 ng and 4.8―30 ng,respectively.The intra-and inter-day precisions were less than 0.63% with accuracies 98.60%―100.78%,and the recoveries were from 99.45% to 100.46%.Furthermore,hierarchical cluster analysis（HCA） was used to evaluate the variation of the herbal prescription.The results demonstrate that this analytical method is simple,sensitive and reliable for rapidly analyzing six major bioactive compounds in ZJPs and is helpful to comprehensively evaluating the quality of this TCM.

可重构功率电路的电力电子实验教学平台设计

为了便于开展电力电子领域多种功率电路分析、控制与特性测试教学,设计了一个可重构功率电路的电力电子实验教学平台,包括功率电路的可重构组件、电压电流采集模块、国产快速原型控制器、上位机以及示波器。基于该实验教学平台可以构建多种拓扑功率电路,并在Matlab/Simulink软件中开发控制算法以自动生成实验控制程序。

矿井灾变时期气囊密闭技术的研究与优化

为探究气囊密闭工艺在矿井发生灾变过程中的密闭工艺效果,以唐山开滦实验巷道为工程条件,运用Fluent数值软件,结合快速气囊密技术,研究了不同火灾发展阶段下灾区爆炸危险气体的变动特性以及运移规律,分析了快速气囊密闭的工艺效果,并针对现有工艺进行了进一步的优化和设计。结果表明:灾区内上隅角CH_(4)浓度最高,气囊密闭具有封堵速度快、气密性好的特性,能在5 min内完成巷道的完全封堵,漏风率控制在5%以内,同时快速气囊密闭使得通风量急剧减少,CH_(4)积聚速度变快,氧气扩散较慢,未形成爆炸危险区域。利用PLC控制方式和远程遥控手段优化现有气囊密闭工艺,实现了远程控制。

基于快速原型化的小型涡喷发动机起动过程控制

为快速验证小型涡喷发动机起动过程控制规律,基于快速原型化技术搭建了半物理试验平台。设计了快速原型试验系统整体架构,对控制系统的软硬件设计和智能节点的工作原理进行了说明,使用Speedgoat Mobile实时目标机作为电子控制器,以STM32为核心设计智能节点,选用Modbus协议对信号进行编码,实现电子控制器和智能节点之间的数据通信。针对小型涡喷发动机的起动过程设计了一种控制规律,利用自动代码生成技术生成电子控制器可执行程序,部署到实时目标机中,完成了起动过程控制规律的试验验证。仿真结果表明,电子控制器和智能节点通信正常,工作可靠稳定,起动过程平稳迅速、不熄火、不超温、不超转,提出的快速原型化控制技术能够有效地缩短开发周期,具有良好的工程实用价值。

区域水库群防汛安全风险快速评估及预警

近年来极端气候事件频发,给人类自身安全和整个社会经济带来深刻影响,对区域防洪响应提出了更高层次的要求,区域水库群防汛安全风险快速评估方法需求日益增加。本文在传统风险分析评估的基础上,引入瑞利信号衰落模拟风险信号的传播,通过风险概率联合分布描述水库风险关联性,分析了区域水库群防汛风险分布影响,初步建立了定量的区域水库群风险率计算模式,并将其应用于“22·6”北江特大洪水过程,分析了韶关地区的区域水库风险情况,结果表明,区域风险分布符合实际,模型简单且计算效率较高,实现了对区域水库群防汛安全风险快速评估及预警,同时可为今后防御流域洪水及水旱灾害防御工作提供参考借鉴,以提高区域水库群应对极端气候条件下洪涝灾害的能力。

主动悬置次级通道模型验证及减振性能测试

以电磁作动器式主动液阻悬置为研究对象,建立机-电-磁-液多物理场耦合的力学及数学模型,并推导次级通道传递特性,旨在分析和评估其在抑制车辆振动方面的性能。采用基于电压控制形式的次级通道传递特性的窄带复数滤波最小均方N-C-FxLMS(narrowband complex filtered-x least mean square)算法对系统进行仿真,并且基于dSPACE半实物仿真平台和inova振动试验台进行试验验证。仿真结果表明,在25~200 Hz的频段内,所提出的控制策略能够显著改善系统的减振性能。试验结果表明,主动控制能将传递至车身端的振动减小17 dB~27 dB,验证了模型的准确性和控制策略的有效性,为主动悬置系统的设计和优化提供了有价值的理论依据和试验支持。

基于转动惯量存储与释放的风电场快速功率调控策略

随着风电场大规模并网,电网等效惯量和调频能力下降,在故障情况下风电场难以提供电网所需的功率支撑,迫切需要提高风电场功率调节能力。针对当前风电场功率调节缓慢、无法灵活调节输出功率的问题,提出一种基于转动惯量存储与释放的双馈风机快速功率调节方法和风电场功率调节指令优化分配方案。利用换流器响应快速的特点,根据转速动态调节风机电磁转矩,控制风机存储或释放转动惯量,快速改变风机输出功率。在功率调节指令的分配中,考虑风速波动性以及风机惯量存储与释放的特性,以风电场功率调节与指令偏差最小化为目标对功率指令进行优化分配,降低风速波动对快速功率调节的负面影响。在Matlab-Simulink中建立风电场仿真模型进行验证,结果表明所提策略能够实现风机30 ms内的功率响应,有效抑制风速波动对风电场快速功率调节的影响,提升风电场频率调节的能力。

快速康复技术配合损伤控制外科技术在多发伤患者中的运用效果及影响因素分析

目的分析快速康复技术配合损伤控制在多发伤患者康复中的临床效果及其并发症发生情况,并探讨影响并发症发生的因素。方法收集昆明医科大学附属红河医院2020年10月至2022年11月间的108例多发伤患者临床资料,分为A组(55例)和B组(53例)。A组采用快速康复措施+损伤控制,B组采用常规康复措施+损伤控制。比较2组临床疗效、并发症发生情况及相关影响因素。结果A组在凝血功能、乳酸、体温恢复时间及术中出血量方面明显优于B组(P<0.05),而手术时间则较长(P<0.05)。A组术后ISS评分及Mb、CK、HMGB1水平均低于B组(P<0.05)。A组并发症发生率(7例)低于B组(20例)(P<0.05)。Logistic回归分析显示,治疗康复措施是影响术后并发症的主要因素。结论快速康复技术配合损伤控制治疗多发伤患者具有较好的临床效果,可明显降低术后并发症发生率,其中良好的康复治疗方式是减少并发症的关键。