Sequential Inverse Optimal Control of Discrete-Time Systems

This paper presents a novel sequential inverse optimal control(SIOC)method for discrete-time systems,which calculates the unknown weight vectors of the cost function in real time using the input and output of an optimally controlled discrete-time system.The proposed method overcomes the limitations of previous approaches by eliminating the need for the invertible Jacobian assumption.It calculates the possible-solution spaces and their intersections sequentially until the dimension of the intersection space decreases to one.The remaining one-dimensional vector of the possible-solution space’s intersection represents the SIOC solution.The paper presents clear conditions for convergence and addresses the issue of noisy data by clarifying the conditions for the singular values of the matrices that relate to the possible-solution space.The effectiveness of the proposed method is demonstrated through simulation results.

On the Sequential Control of ITER Poloidal Field Converters for Reactive Power Reduction

Sequential control applied to the International Thermonuclear Experimental Re- actor （ITER） poloidal field converter system for the purpose of reactive power reduction is the subject of this investigation. Due to the inherent characteristics of thyristor-based phase-controlled converter, the poloidal field converter system consumes a huge amount of reactive power from the grid, which subsequently results in a voltage drop at the 66 kV busbar if no measure is taken. The installation of a static var compensator rated for 750 MVar at the 66 kV busbax is an essential way to compensate reactive power to the grid, which is the most effective measure to solve the problem. However, sequential control of the multi-series converters provides an additional method to improve the natural power factor and thus alleviate the pressure of reactive power demand of the converter system without any additional cost. In the present paper, by comparing with the symmetrical control technique, the advantage of sequential control in reactive power consumption is highlighted. Simulation results based on SIMULINK are found in agreement with the theoretical analysis.

Recent developments on applications of sequential loop closing and diagonal dominance control schemes to industrial multivariable system

With a focus on an industrial multivariable system, two subsystems including the flow and the level outputs are analysed and controlled, which have applicability in both real and academic environments. In such a case, at first, each subsystem is distinctively represented by its model, since the outcomes point out that the chosen models have the same behavior as corresponding ones. Then, the industrial multivariable system and its presentation are achieved in line with the integration of these subsystems, since the interaction between them can not actually be ignored. To analyze the interaction presented, the Gershgorin bands need to be acquired, where the results are used to modify the system parameters to appropriate values. Subsequently, in the view of modeling results, the control concept in two different techniques including sequential loop closing control(SLCC) scheme and diagonal dominance control(DDC) schemes is proposed to implement on the system through the Profibus network, as long as the OPC(OLE for process control) server is utilized to communicate between the control schemes presented and the multivariable system. The real test scenarios are carried out and the corresponding outcomes in their present forms are acquired. In the same way, the proposed control schemes results are compared with each other, where the real consequences verify the validity of them in the field of the presented industrial multivariable system control.

A Non-Scan Testable Design of Sequential Circuits by Improving Controllability

As a method for testing a sequential circuit efficiently, a scan design is usually used. But, since this design has some drawbacks, a non-scan testable design should be discussed. The testable design can be implemented by enhancing controllability and observability. This paper discusses a non-scan testable design for a sequential circuit by only focusing the improvement of controllability. The proposed design modifies a circuit so that all the FFs can be directly controlled by primary input lines in a test mode. Experimental results show that we can get a good testability using this method.

SEQUENTIAL QUADRATIC PROGRAMMING METHODS FOR OPTIMAL CONTROL PROBLEMS WITH STATE CONSTRAINTS

A kind of direct methods is presented for the solution of optimal control problems with state constraints. These methods are sequential quadratic programming methods. At every iteration a quadratic programming which is obtained by quadratic approximation to Lagrangian function and linear approximations to constraints is solved to get a search direction for a merit function. The merit function is formulated by augmenting the Lagrangian function with a penalty term. A line search is carried out along the search direction to determine a step length such that the merit function is decreased. The methods presented in this paper include continuous sequential quadratic programming methods and discreate sequential quadratic programming methods.

EVALUATION OF GEOCHEMICAL QUALITY CONTROLIN DETERMINATION OF Mn IN SOILS USING A SEQUENTIAL CHEMICAL EXTRACTION

Sequential chemical extraction procedure has been widely used to partition particulate trace metals into various fractions and to describe the distribution and the statue of trace metals in geo environment. One sequential chemical extraction procedure was employed here to partition various fractions of Mn in soils. The experiment was designed with quality controlling concept in order to show sampling and analytical error. Experimental results obtained on duplicate analysis of all soil samples demonstrated that the precision was less than 10%(at 95%confidence level). The accuracy was estimated by comparing the accepted total concentration of Mn in standard reference materials (SRMs) with the measured sum of the individual fractions. The recovery of Mn from SRM1 and SRM2 was 94.1%and 98.4%, respectively. The detection limit, accuracy and precision of the sequential chemical extraction procedure were discussed in detailed. All the results suggest that the trueness of the analytical method is satisfactory.

Application of fiberoptic bronchscopy in patients with acute exacerbations of chronic obstructive pulmonary disease during sequential weaning of invasive-noninvasive mechanical ventilation

BACKGROUND:Early withdrawal of invasive mechanical ventilation(IMV) followed by noninvasive MV(NIMV) is a new strategy for changing modes of treatment in patients with acute exacerbations of chronic obstructive pulmonary disease(AECOPD) with acute respiratory failure(ARF).Using pulmonary infection control window(PIC window) as the switch point for transferring from invasive to noninvasive MV,the time for early extubation can be more accurately judged,and therapy efficacy can be improved.This study aimed to prospectively investigate the clinical effectiveness of fiberoptic bronchscopy(FOB) in patients with AECOPD during sequential weaning of invasive-noninvasive MV.METHODS:Since July 2006 to January 2011,106 AECOPD patients with ARF were treated with comprehensive medication and IMV after hospitalization.Patients were randomly divided into two groups according to whether fiberoptic bronchoscope is used(group A,n=54) or not(group B,n=52) during sequential weaning from invasive to noninvasive MV.In group A,for sputum suction and bronchoalveolar lavage(BAL),a fiberoptic bronchoscope was put into the airway from the outside of an endotracheal tube,which was accompanied with uninterrupted use of a ventilator.After achieving PIC window,patients of both groups changed to NIMV mode,and weaned from ventilation.The following listed indices were used to compare between the groups after treatment:1) the occurrence time of PIC,the duration of MV,the length of ICU stay,the success rate of weaning from MV for the first time,the rate of reventilatJon and the occurrence rate of ventilator-associated pneumonia(VAP);2) the convenience and safety of FOB manipulation.The results were compared using Student's f test and the Chi-square test.RESULTS:The occurrence time of PIC was(5.01 ±1.49) d,(5.87±1.87) d in groups A and B,respectively(P<0.05);the duration of MV was(6.98±1.84) d,(8.69±2.41) d in groups A and B,respectively(P<0.01);the length of ICU stay was(9.25±1.84) d,(11.10±2.63) d in groups A and B,respectively(P<0.01);the success rate of weaning for the first time was 96.30%,76.92%in groups A and B,respectively(P<0.01);the rate of reventilation was 5.56%,19.23%in groups A and B,respectively(P<0.05);and the occurrence rate of VAP was 3.70%,23.07%in groups A and B,respectively(P<0.01).Moreover,it was easy and safe to manipulate FOB,and no side effect was observed.CONCLUSIONS:The application of FOB in patients with AECOPD during sequential weaning of invasive-noninvasive MV is effective in ICU.It can decrease the duration of MV and the length of ICU stay,increase the success rate from weaning MV for the first time,reduce the rate of reventilation and the occurrence rate of VAP.In addition,such a method is convenient and safe in patients of this kind.

On the Stable Sequential Kuhn-Tucker Theorem and Its Applications

The Kuhn-Tucker theorem in nondifferential form is a well-known classical optimality criterion for a convex programming problems which is true for a convex problem in the case when a Kuhn-Tucker vector exists. It is natural to extract two features connected with the classical theorem. The first of them consists in its possible “impracticability” (the Kuhn-Tucker vector does not exist). The second feature is connected with possible “instability” of the classical theorem with respect to the errors in the initial data. The article deals with the so-called regularized Kuhn-Tucker theorem in nondifferential sequential form which contains its classical analogue. A proof of the regularized theorem is based on the dual regularization method. This theorem is an assertion without regularity assumptions in terms of minimizing sequences about possibility of approximation of the solution of the convex programming problem by minimizers of its regular Lagrangian, that are constructively generated by means of the dual regularization method. The major distinctive property of the regularized Kuhn-Tucker theorem consists that it is free from two lacks of its classical analogue specified above. The last circumstance opens possibilities of its application for solving various ill-posed problems of optimization, optimal control, inverse problems.

Meta-analysis and Trial Sequential Analysis of Compound Qingdai Capsule in the Treatment of Psoriasis

[Objectives]To analyze the efficacy of Compound Qingdai Capsule in the treatment of psoriasis and conduct a systematic evaluation.[Methods]The clinical total effective rate,PASI index score,IL-17 level,IL-23 level,TNF-level,and adverse reactions were analyzed.TSA 0.9 software was used to conduct sequential analysis of the total effective rate,and subgroup analysis was performed according to the average age of the experimental group.[Results]Single application of Compound Qingdai Capsule or in combination with other methods in the treatment of psoriasis was superior to non-Compound Qingdai Capsule group,and the side effects were less than non-Compound Qingdai Capsule group;the n≥40 year-old group had certain heterogeneity,suggesting that the difference was statistically significant,and the effective rate was higher than that of the control group.The funnel plot showed that the graph was asymmetrical,and there may be publication bias or the possibility of low-quality literature.The TSA results indicated that the actual sample size was far lower than the expected sample size,and the cumulative Z value did not reach the TSA cut-off value and more trials need to be included to confirm the efficacy.[Conclusions]Compound Qingdai Capsule has a clear curative effect on psoriasis,and its safety is high.This study can provide relevant evidence for the effectiveness of Chinese patent drugs(CPD)in treating psoriasis.

机力通风冷却塔风机自寻优群控方法研究

机力通风冷却塔以占地面积小的显著优点,在中小型基建工程中得到广泛应用。为提升中小型基建工程外冷系统的节能性和可靠性、改进传统多风机控制方法,创新性地提出了一种基于累计运行时间的机力通风冷却塔风机自寻优群控方法。将多风机整体化控制改进为顺序化联动控制,可有效降低风机启动门槛出力、消除整体化控制固有缺陷,满足非线性、时变性、大滞后系统控制的节能、可靠需求。经工程验证:该方法是一种契合纯变频电机配置冷却塔系统的多风机控制方法。该方法风机出力柔和、控制线性度好、系统易镇定、稳态偏差小;能够通过累计运行时间参数比对,实现风机自动交互运行,运行可靠性高。该方法的提出与实际应用可对配置机力通风冷却塔的中小型基建工程的安全节能运行提供借鉴。

噻吗洛尔滴眼液在急性房角关闭危象序贯治疗中的疗效

目的观察噻吗洛尔滴眼液在急性房角关闭危象序贯治疗中的疗效。方法前瞻性随机双盲病例对照研究。连续纳入2021年4月至2023年10月河北大学附属医院诊断为急性房角关闭危象(acute angle-closure crisis,AACC)的患者,收集其病例资料并以随机数字表法分为应用噻吗洛尔组(A组)与安慰剂组(B组)。所有患者序贯应用药物治疗、前房穿刺、激光周边虹膜成形术,以治疗后2 h、4 h、6 h为治疗节点,记录并统计在各个节点2组患者的眼压下降值、AACC得到控制的眼数及所需时间。结果在序贯治疗后2 h、4 h、6 h的3个节点,A组的眼压下降值分别为(13.87±13.85)mmHg(1 mmHg=0.133 kPa)、(28.42±12.87)mmHg、(35.69±8.51)mmHg,AACC得到控制的眼数分别为23眼(29.87%)、51眼(66.23%)、71眼(92.20%);B组的眼压下降值分别为(15.88±14.95)mmHg、(28.17±13.63)mmHg、(33.90±13.59)mmHg,AACC得到控制的眼数分别为30眼(36.59%)、58眼(70.73%)、75眼(91.46%);治疗有效的患者中,AACC控制的时间A组为(3.29±1.31)h,B组为(3.38±1.34)h。2组患者在序贯治疗各个节点的眼压下降值、AACC缓解的眼数及病情缓解所需时间差异均无统计学意义(P>0.05)。结论在AACC的序贯治疗过程中,噻吗洛尔滴眼液对于提高治疗成功率无明显帮助。

面向并联环流最小化的垂直式矩阵型重力储能系统多机协调控制

重力储能利用高度落差对固体重物储能介质进行升降,实现储能系统的充放电。和抽水蓄能相比,由于其具有不依赖水资源、选址灵活等特点,应用前景广泛。为提高重力储能系统的充放电运行效率,研究了面向多机并联功率环流最小化的垂直式矩阵型重力储能系统多机协调控制问题。首先,基于PSCAD/EMTDC构建垂直式矩阵型重力储能系统模型,分析了其充放电特性;其次,通过对重力储能系统多机并联运行时产生的机组间功率环流机理及抑制问题进行分析,提出了基于重力储能系统双层控制架构的多个机组间协调控制方法,该控制方法可在快速满足电网侧功率充放电需求的同时,实现并联运行机组间的功率环流最小化,提高了重力储能系统的充放电运行效率,最后,仿真结果验证了上述多机协调控制策略的有效性。

无粘结环锚预应力衬砌张拉工艺足尺模型试验研究

针对预应力衬砌张拉过程中易出现应力集中而导致张拉裂缝的现象,通过开展洞外地面足尺模型试验,提出了分级分步张拉顺序和质量控制指标。首先根据钢绞线摩阻测试计算出摩擦系数,随后应用上述张拉顺序和质量控制方法进行自动张拉,并采用磁通量传感器和混凝土应变计分别对钢绞线和内衬混凝土的应力变化开展实测。现场张拉试验结果表明:①钢绞线沿程预应力损失约16.3%,采用的双层钢绞线在实践中可保证较高的有效预应力;②对锚具槽进行分级分步张拉,可使内衬混凝土获得较均匀的封闭环向压应力环,平均压应力达-10.9 MPa;③提出的3项控制指标可进行量化管理,结合自动张拉技术可有效地保证张拉质量。

构网型变流器多环控制阻抗建模与稳定性分析

构网型变流器的控制方式按照是否存在电压电流控制双环可以分为只含有功率控制环的单环控制和含有功率控制环和电压电流控制双环的多环控制。两种控制方式并网运行特性在不同频段有较大区别。该文首先建立考虑电压电流解耦控制双环的构网型变流器多环控制序阻抗模型,对比分析两种控制方式对变流器输出阻抗的影响;其次针对加入电压电流控制双环造成的低频相位裕度不足问题,提出引入虚拟阻抗方法提高变流器并网稳定性;最后利用仿真与实验验证了稳定性分析的准确性。

Solution sequential deposited organic photovoltaics:From morphology control to large-area modules

Organic optoelectronic materials enable cutting-edge,low-cost organic photodiodes,including organic solar cells(OSCs)for energy conversion and organic photodetectors(OPDs)for image sensors.The bulk heterojunction(BHJ)structure,derived by blending donor and acceptor materials in a single solution,has dominated in the construction of active layer,but its morphological evolution during film formation poses a great challenge for obtaining an ideal nanoscale morphology to maximize exciton dissociation and minimize nongeminate recom-bination.Solution sequential deposition(SSD)can deliver favorable p–i–n vertical component distribution with abundant donor/acceptor interfaces and relatively neat donor and acceptor phases near electrodes,making it highly promising for excellent device performance and long-term stability.Focusing on the p–i–n structure,this review provides a systematic retrospect on regulating this morphology in SSD by summarizing solvent selection and additive strategies.These methods have been successfully implemented to achieve well-defined morphology in ternary OSCs,all-polymer solar cells,and OPDs.To provide a practical perspective,comparative studies of device stability with BHJ and SSD film are also discussed,and we review influential progress in blade-coating techniques and large-area modules to shed light on industrial production.Finally,challenging issues are out-lined for further research toward eventual commercialization.

基于空变数据的相控贝叶斯-序贯高斯模拟方法

传统的地质统计学估计和模拟方法在整合测井和地震数据时,笼统地采用静态空间的数据,而未考虑样点与待模拟点空间沉积的变化以及岩相变化对样点取值影响的问题,尤其是储层空间非均质性强、井分布不均匀时。基于贝叶斯序贯高斯算法,针对碎屑岩储层,研究了一种基于空间变化数据的相控模拟方法。首先,定义一个随待模拟点位置变化而动态变化的空间三维球体模型,将空间数据的选择从静态的一维柱体拓展到该球体。然后,在考虑物源方向的情况下,采用变差函数工具对三维球体模型内的数据进行筛选。同时,利用沉积相进行约束,进一步提高样点取值的精确性。最后,采用反距离加权算法确定样点的权重。川西坳陷东坡实际工区资料的应用表明,基于空变数据的相控贝叶斯序贯高斯模拟方法,平面上河道模拟展布形态与地震属性一致性较好,剖面上河道清晰连续,分辨率也得到提升,盲井模拟结果与测井数据吻合率达到92%,验证了方法的准确性。对比不同硬件配置的应用结果表明,该方法适应于不同性能的硬件条件,验证了方法的实用性。

基于专家知识库的一键顺控系统镜像调试技术研究与应用

针对智能变电站一键顺控系统现场调试工作量大、耗时长、效率低的问题,提出一种基于专家知识库的一键顺控系统镜像调试方法。基于“五防”规则建立基本单元模型,生成各类典型间隔设备的操作规则函数,实现专家知识库的构建。通过解析智能变电站的系统规格描述(system specification description,SSD)文件构建一次设备拓扑连接表,基于设备状态的推理算法结合设备操作规则函数,实现操作票专家知识库的自动生成。搭建基于专家知识库的一键顺控系统镜像调试平台,通过智能电子设备(intelligent electronic device,IED)镜像仿真和一次设备潮流仿真测试方法,对一键顺控系统进行全面测试。将现场作业工序迁移至镜像调试平台中完成,实现一键顺控系统镜像调试成果在变电站的“即插即用”。测试结果表明,平台的应用可以大幅提高现场一键顺控系统的调试效率、质量和安全性。

限制负载角的永磁同步电机序列模型预测控制

针对永磁同步电机模型预测控制中增加负载角限制函数可以避免电机失步但会导致模型预测控制权重系数调节更加繁琐的问题,提出了一种可限制负载角的永磁同步电机无权重系数模型预测控制。该方法基于字典法实现模型预测控制,对目标函数进行分层序列优化,实现无权重系数下的多目标优化。为验证该方法的有效性,进行了仿真和实验研究。结果表明,本方法可以实现负载角限制且动静态性能与传统方法一致,与传统方法相比,转矩与磁链的稳态误差相近,约为0.3N·m和0.005V·s,但省去了权重系数的调整,减少了计算负担。

基于三角模糊数序贯博弈的电网安全研究

智能电网系统面临着复杂性、多样性的网络安全风险。针对电网工艺漏洞攻防双方在博弈分析中无法对信息属性损失作出准确判断的问题,提出了一种三角模糊数序贯博弈模型。以序贯博弈树方法进行智能电网攻防博弈,构建出攻击者和防御者的最优策略,实现对智能电网的工控安全防护。通过对智能电网攻击者和防御者构建序贯博弈模型,得到攻防博弈效用。提出运用三角模糊数和概率分布向量的方法来构建非模糊化损失,得到攻防双方清晰化的系统损失值。对三角模糊数序贯博弈算法和贝叶斯序贯算法进行比较,得到智能电网均衡路径中的攻击者和防御者的最优策略,以保障智能电网网络安全运行和防护。该研究为智能电网以及典型工控系统网络安全博弈提供参考。

基于人工智能识别的特高压站顺控验收系统设计

在特高压变电站的运维工作中,传统的操作流程存在数据量庞大、核实效率低以及准确率低的问题。基于人工智能识别的特高压站顺控验收系统利用人工智能技术,通过整合标准操作流程库和实际操作数据,实现操作流程的智能识别、匹配和验证。通过学习和优化,系统可以不断提升核实算法和模型的准确性,以适应不断变化的操作流程需求。该系统的智能识别能有效减少人为错误的发生,为电力行业的数字化转型和智能化运维提供有力支持。