Reduced-Order Observer-Based LQR Controller Design for Rotary Inverted Pendulum

The Rotary Inverted Pendulum(RIP)is a widely used underactuated mechanical system in various applications such as bipedal robots and skyscraper stabilization where attitude control presents a significant challenge.Despite the implementation of various control strategies to maintain equilibrium,optimally tuning control gains to effectively mitigate uncertain nonlinearities in system dynamics remains elusive.Existing methods frequently rely on extensive experimental data or the designer’s expertise,presenting a notable drawback.This paper proposes a novel tracking control approach for RIP,utilizing a Linear Quadratic Regulator(LQR)in combination with a reduced-order observer.Initially,the RIP system is mathematically modeled using the Newton-Euler-Lagrange method.Subsequently,a composite controller is devised that integrates an LQR for generating nominal control signals and a reduced-order observer for reconstructing unmeasured states.This approach enhances the controller’s robustness by eliminating differential terms from the observer,thereby attenuating unknown disturbances.Thorough numerical simulations and experimental evaluations demonstrate the system’s capability to maintain balance below50Hz and achieve precise tracking below1.4 rad,validating the effectiveness of the proposed control scheme.

Using Visual MODFLOW Model to Assess the Efficiency of Subsurface Barrier Wall for Groundwater Flow Regulation and Reduction of Saline Intrution

Barrier walls effectively store water,regulate underground flows,improve exploitable reserves and prevent saltwater intrusion.The effectiveness of the underground barrier wall depends not only on the hydrogeological structure,the technical parameters of the wall but also on the layout scheme of the exploitation well system.The results showed that in natural conditions,the ground water level upstream of the barrier wall rose in the presence of a barrier wall.In wells located downstream of high barrier walls,the water level decreased.The amount of underground current flowing into the sea decreased,the annual average value of the whole region decreased was 316 m3/day and night.In presence of a wall,both the water level and the amount of evaporation increased.The average increase in evaporation volume during the calculation period of ten thousand days with walls was 4.114 m3/d.So in presence of a wall,the amount of water that can be exploited increases by the total amount of evaporation plus the decrease in discharge to the sea and is equal to 4,424 m3/d.In the exploitation condition,if the water level in the presence of wall is kept as low as in the absence of wall,the exploitation flow will increase to about 4,400 m3/day and night.From the calculated water level values when there is a wall and without a wall,we can see that if the exploitation flow in presence of a wall and in the absence of wall is the same,the water level drop at the calculated observation wells upstream of the wall will decrease from 0.21 m to 3.97 m.The condition of effective exploitation of the wall depends on the mining scheme.The exploitation scheme is reasonable,the exploitation flow of the wells does not exceed the allowable flow so as not to cause the drying of the aquifer at the location of the well.The upstream area of the wall reflects quite clearly as the Total dissolved solids content in observation wells upstream of the wall at the end of the calculation time is significantly reduced compared to that without the wall,ranging from 69 mg/L to 5,629 mg/L.In the presence of a wall,the water level of observation wells upstream of the wall is higher than that of without a wall from 0.10 m to 0.74 m.

Temperature-flow regulation rule in indirect connection heating system and its energy-saving contrast analysis

Primary and secondary networks are treated as a whole in indirect heating systems, and an advanced new temperature-flow regulation method is presented whose flow ratio is greater than 60% in a secondary network and 30% in a primary network when under a partial load. Through deducing and optimizing an exponential function flow regulation rule, the formulae of flow regulation and the supply and return water temperatures are obtained, and their relevant curves are plotted. After comparison, it is found that this control method has a huge energy conservation space, and it should therefore be generalized soon.

Hierarchical Task Planning for Power Line Flow Regulation

The complexity and uncertainty in power systems cause great challenges to controlling power grids.As a popular data-driven technique,deep reinforcement learning(DRL)attracts attention in the control of power grids.However,DRL has some inherent drawbacks in terms of data efficiency and explainability.This paper presents a novel hierarchical task planning(HTP)approach,bridging planning and DRL,to the task of power line flow regulation.First,we introduce a threelevel task hierarchy to model the task and model the sequence of task units on each level as a task planning-Markov decision processes(TP-MDPs).Second,we model the task as a sequential decision-making problem and introduce a higher planner and a lower planner in HTP to handle different levels of task units.In addition,we introduce a two-layer knowledge graph that can update dynamically during the planning procedure to assist HTP.Experimental results conducted on the IEEE 118-bus and IEEE 300-bus systems demonstrate our HTP approach outperforms proximal policy optimization,a state-of-the-art deep reinforcement learning(DRL)approach,improving efficiency by 26.16%and 6.86%on both systems.

Regulation effect of the grille spacing of a funnel-type grating water–sediment separation structure on the debris flow performance

The size of pores or the grille spacing of water–sediment separation structures directly affects their regulation effect on the debris flow performance.A suitable pore size or grille spacing can effectively improve the water–sediment separation ability of the structure.The new funnel-type grating water–sediment separation structure(FGWSS)combines vertical and horizontal structures and provides a satisfactory water–sediment separation effect.However,the regulation effect of the grille spacing of the structure on the debris flow performance has not been studied.The regulation effect of the structure grille spacing on the debris flow performance is studied through a flume test,and the optimal structure grille spacing is obtained.An empirical equation of the relationship between the relative grille spacing of the structure and the sediment separation rate is established.Finally,the influence of the water–sediment separation structure on the regulation effect of debris flows is examined from two aspects:external factors(properties of debris flows)and internal factors(structural factors).The experimental results show that the gradation characteristics of solid particles in debris flows constitute a key factor affecting the regulation effect of the structure on the debris flow performance.The optimum grille spacing of the FGWSS matches the particle size corresponding to the material distribution curves d85~d90 of the debris flow.The total separation rate of debris flow particles is related to the grille spacing of the structure and the content of coarse and fine particles in the debris flow.

Synchronized output regulation of switching networks based on synchronization observer

This paper studies the synchronized output regulation （SOR） problem of networked dynamic systems with switching topology that is uniformly connected and leader-rooted. In these networked systems, the tracked signal or the rejected disturbance is generated by the same exosystem, and however, the state of the exosystem is only available for leader nodes. First, a synchronization observer of the exosystem is proposed in this paper to overcome the difficulty caused by the unavailable state of the exosystem for follower nodes with directed switching information flow. It is shown that the observer state will synchronize to the state of the exosystem. Then, two feedback controllers based on decentralized dynamic error and state are presented to solve this SOR problem. Furthermore, the main idea in this paper will provide a promising way for realizing the multirobot systems＇ tracking and formation requirement. Numerical simulation results are presented to demonstrate the effectiveness of the theoretical results.

An output-based distributed observer and its application to the cooperative linear output regulation problem

In this paper, we first extend an existing stability result for a class of linear switched systems. This extended result will relax the existenceconditions of the output-based distributed observer for a leader system subject to jointly connected switching communication networks in the literature. As an application of this output-based distributed observer, we solve the cooperative output regulati on problem of a linear multi-age nt system subject to jointly connected switching communicatio n n etworks by composing a purely decentralized control law and the output-based distributed observer based on the certainty equivalence principle.

Caffeine and Pressure Flow Autoregulation

The benefits or detriments of caffeine on the human cardiovascular system have not been thoroughly studied and are still poorly understood. In a world where caffeinated beverages are evidently the adult drug of choice (e.g. coffee, energy drinks, soda, tea),?investigating its effects on our bodies is of great importance. In this study,?we examined the effects of caffeine, taken as a tablet, on pressure-flow autoregulation. Young adults between 18 and 21 years of age were the experimental subjects. They were instrumented to monitor systemic arterial blood pressure, peripheral blood flow, calculated peripheral vascular resistance, and the electrocardiogram during an autoregulatory maneuver in the absence and presence of caffeine. Caffeine-mediated vasoconstriction was observed as early as 15 minutes after its consumption. Sixty minutes post-caffeine, vasoconstriction was so prominent that autoregulation was abolished. This was reflected, in part, as a significant reduction in blood flow that accompanied a 3-fold increase in calculated peripheral resistance and a significant increase in systemic arterial pressure. Heart rate was unaffected by caffeine under our experimental conditions. We conclude that caffeine has the ability to inhibit significant cardiovascular properties including pressure-flow autoregulation. Even though more work is needed, the significant caffeine-mediated changes in flow, pressure and resistance during autoregulation could have serious consequences for the cardiovascular system specifically, and for one’s overall health in general.

Flow Regulation and Heat Transfer Characteristics in a Novel Turbine Shroud with Internal Asymmetric Throttle Chamber

Flow and heat transfer of a novel turbine shroud with throttle chamber under two kinds of orifice arrangements were numerically studied. The original shroud model composed of the impingement holes, film holes and jet channel. The two modified models have identical geometrical spacing except for the number and location of the orifices in the upper plate of the throttle chamber added in the jet channel. Different pressure values were set at the outlets of different row film holes simulating the mainstream favorable pressure gradient. The ratios of inlet total pressures of impingement holes to outlet static pressures of the third row film holes ranged from 1.6 to 3.6. The Nusselt number distributions were validated by the experimental data. The main target of this study was to quantify the impact of the throttle chamber on the flow regulation and internal heat transfer characteristics. The flow factor, relative mass flow rate, the Nusselt number and the heat transfer factors on the target walls were presented. It is found that the mass flow rate distributions in the film hole rows become more reasonable by the modification of location and number of the orifices on the throttle chamber. The throttle chamber decreases the heat transfer on the target walls.

Changes in Streamflow Regime Due to Anthropogenic Regulations in the Humid Tropical Western Ghats, Kerala State, India

Regulation of streamflow by a reservoir creates a flow regime much different from the preimpoundment period flow regime. Hydro-Electric Projects(HEPs) commissioned in the Western Ghat regions of the Kerala State, India during the last four decades caused considerable changes in the flow regimes of the rivers of the Kerala State in southwest India. In this paper, the Indicators of Hydrologic Alteration(IHA) approach proposed by Richter et al.(1996) is used to analyze flow regime changes in the Periyar and Muvattupuzha Rivers, due to the construction of the Idukki(1976), Idamalayar(1987) and Lower Periyar(1997) HEPs in the high ranges of the Western Ghats. Normal rainfall years(annual rainfall values within mean ± 0.75 standard deviation limits) are only considered in the analysis to focus on hydrologic alterations due to human activities. The mean hydrologic alteration in the Periyar River(deviation from the pre-development hydrologic indicator values) after commissioning of three HEPs is 35%. Inter-basin water transfer after power generation from the Idukki HEP resulted in a higher discharge in the adjacent Muvattupuzha River, leading to considerable changes in the hydroenvironment(mean hydrologic alterations varying between 57 to 63%). IHA parameters showing hydrologic alterations above the 67 th Percentile werefurther analyzed. For each of the pre-construction hydrologic parameters ± 1 standard deviation from the mean is set as the upper and lower management target limits. The values of each IHA parameter beyond these targets are considered as nonattainment. Considerable hydrologic alterations are observed, especially for low flows in both basins. Inter-basin transfer induced larger changes in flow parameters compared to intra-basin regulations. The study shows that under a proper water release and diversion scheme, the non-attainment of IHA parameters(values fall beyond the target limits) can be reduced. The findings of the study will be greatly beneficial to regional water management and restoration of an eco-environmental system in the humid tropical region.

Numerical Simulation of Oil and Gas Two-Phase Flow in Deep Condensate Gas Reservoirs in Bohai Buried Hills

The BZ19-6 gas field is characterized by high temperature and high pressure (HTHP), high condensate content, little difference between the formation pressure and dew point pressure, and large amount of reverse condensate liquid. During the early stage of depletion development, the production gas-oil ratio (GOR) and production capacity remain relatively stable, which is inconsistent with the conventional reverse condensate seepage law. In view of the static and dynamic conflict in development and production, indoor high-temperature and high-pressure PVT experiment was carried out to reveal the mist-like condensation phenomenon of fluids in the BZ19-6 formation. And the seepage characteristics of condensate gas reservoirs with various degrees of depletion under the condition of HTHP were analyzed based on production performance. The change rule of fluid phase state was analyzed in response to the characterization difficulties of the seepage mechanism. The fluid state was described using the miscible mechanism. And the interphase permeability interpolation coefficient was introduced based on interfacial tension. By doing so, the accurate characterization of the “single-phase flow of condensate gas-near-miscible mist-like quasi single-phase flow-oil-gas two-phase flow” during the development process was achieved. Then the accurate fitting of key indicators for oilfield development was completed, and the distribution law of formation pressure and the law of condensate oil precipitation under different reservoir conditions are obtained. Based on research results, the regulation strategy of variable flow rate production was developed. Currently, the work system has been optimized for 11 wells, achieving a “zero increase” in the GOS of the gas field and an annual oil increase of 22,000 cubic meters.

疏调气机法联合桂枝茯苓胶囊治疗子宫肌瘤的疗效及其对血清TGF-β_(1)、TSGF的影响

目的:探究疏调气机法联合桂枝茯苓胶囊治疗子宫肌瘤的疗效及其对血清转化生长因子β_(1)(transforming growth factor-β_(1),TGF-β_(1))、肿瘤特异性生长因子(tumor specific growth factor,TSGF)的影响。方法:将135例子宫肌瘤患者采用随机数字表法分为对照A组、对照B组和联合组,每组45例。3组均给予常规西药治疗,在此基础上,对照A组采用疏调气机法治疗,对照B组采用桂枝茯苓胶囊治疗,联合组采用疏调气机法联合桂枝茯苓胶囊治疗。比较3组疗效、不良反应发生率及治疗前后子宫肌瘤体积、子宫体积、子宫内膜厚度、中医证候积分、血清雌激素指标[雌二醇(estradiol,E_(2))、黄体生成素(luteinizing hormone,LH)、催乳素(prolactin,PRL)]、氧化应激指标[晚期氧化蛋白产物(advanced oxidation protein products,AOPP)、丙二醛(malonaldehyde,MDA)、超氧化物歧化酶(superoxide dismutase,SOD)]、TGF-β_(1)、TSGF水平。结果:联合组总有效率为97.78%(44/45),高于对照A组的84.44%(38/45)、对照B组的80.00%(36/45)(P<0.05);治疗后3组患者子宫肌瘤体积、子宫体积均小于治疗前,联合组小于对照A组、对照B组;子宫内膜厚度大于治疗前,联合组大于对照A组、对照B组(P<0.05);与本组治疗前比较,治疗后3组患者月经异常、下腹胀痛、面色晦暗积分均降低,联合组低于对照A组、对照B组(P<0.05);治疗后3组患者血清PRL、LH、E_(2)水平均低于治疗前,联合组低于对照A组、对照B组(P<0.05);治疗后3组患者血清SOD水平均高于治疗前,且联合组高于对照A组、对照B组,血清AOPP、MDA水平均低于治疗前,联合组低于对照A组、对照B组(P<0.05);与本组治疗前比较,治疗后3组患者血清TGF-β_(1)、TSGF水平均降低,联合组低于对照A组、对照B组(P<0.05);联合组不良反应发生率为13.33%(6/45),与对照A组的6.67%(3/45)、对照B组的8.89%(4/45)比较,差异无统计学意义(P>0.05)。结论:疏调气机法联合桂枝茯苓胶囊能提高子宫肌瘤临床疗效,下调血清TGF-β_(1)、TSGF水平,且具有一定安全性。

快掘面风流动态调控参数与压抽比对粉尘运移的影响及降尘分析

随着矿山快掘设备的逐渐引进,快掘面粉尘污染问题愈加严重。为有效减少快掘面生产过程中的粉尘污染,设计出风流动态调控降尘净化系统,通过调节风流的状态并设计了不同工况下的风流调控方案,以降低司机处粉尘浓度与粉尘的扩散距离。以陕西某矿快掘面为例,建立了风流—粉尘耦合场有限元模型,并对模型进行了井下验证;分析了风流动态调控降尘净化系统中出风口偏角、出风口缩放口径、出风口距端头距离及风量压抽比4个参数对风流与粉尘场的影响规律;设计正交试验分析了各参数与司机处粉尘浓度与粉尘扩散距离之间的关联性,确定了最佳调控净化方案。结果表明:各参数对司机处粉尘浓度与粉尘扩散距离影响程度的显著性排序由大到小依次为风量压抽比、出风口偏角、出风口距端头距离、出风口缩放口径。确定的最佳调控净化方案为出风口距离端头10 m、出风口偏角20°、出风口缩放口径1.0 m及风量压抽比1。设计搭建试验平台进行了准确性及净化效果测试验证,模拟值与试验值的平均误差小于8.91%,净化后司机处粉尘浓度由327.22 mg/m^(3)降低至156.47 mg/m^(3),降低了52.18%,粉尘扩散距离由39.74 m缩短至25.91 m,缩短了34.80%,有效改善了快掘面的空气环境。

双芯移相变压器在主动配电网电压和潮流调控中的应用分析

双芯移相变压器可以有效控制线路电压和潮流,优化潮流分布,提高电网电能质量。针对分布式电源的高比例接入造成的主动配电网电压波动和偏差问题,以及对潮流大小、方向和均衡度的影响,文章研究了双芯移相变压器的拓扑结构和工作原理;然后分析了串联变压器和励磁变压器的具体结构和作用,梳理了移相变压器分别应用于电压调节和潮流控制时的档位控制策略;最后基于MATLAB/Simulink建立了详细的仿真模型,研究了双芯移相变压器的电压调节效果,并对双线路并联、两路电源并联供电、多路电源并联供电三种应用场景下的潮流控制效果作了比较。仿真结果表明,双芯移相变压器可以在有限的档位内将线路电压控制在允许范围;与双线路并联、多路电源并联供电应用场景相比,两路电源并联供电时的潮流均衡效果最好,潮流偏差最小,本研究为双芯移相变压器的广泛应用提供了参考。

洪水期小浪底水库排沙影响因素及规律研究

小浪底水库排沙主要集中在汛前调水调沙期和汛期洪水期。2000—2022年汛前调水调沙期和汛期洪水期小浪底水库累计排沙分别为4.840亿t和21.546亿t,分别占水库运用以来排沙总量的18.3%、81.5%。研究表明,入库水量与回水长度是影响汛前调水调沙期小浪底水库排沙效果的主要因素;入库水量越大,回水长度越短,排沙效果越好。通过多元回归得到了汛前调水调沙期小浪底水库排沙量与影响因素的关系。汛期洪水期小浪底水库排沙主要影响因素为壅水指标和进出库流量比,通过研究量化了汛期洪水期排沙比与影响因素的关系。

基于自适应分布式滤波观测器的多智能体系统编队控制

本文考虑了全局指令系统输出信息受到信道扰动情况下线性多智能体系统的编队控制问题.首先,基于协作式输出调节理论框架对线性多智能体系统的编队控制问题进行数学建模.其次,针对受到信道扰动的全局指令系统输出信息,提出了一类基于受扰输出的自适应分布式滤波观测器,在降低网络信息交换量的同时消除扰动的影响.最后,设计了输出反馈确定等价控制律,解决了线性多智能体系统的分布式编队控制问题.给出了数值仿真结果检验控制性能.

国家高新区对提升区域综合竞争力的影响研究

为检验国家高新区对提升区域全面竞争力的实际影响效果,文章选用全国29个省份国家高新区2016—2021年的面板数据进行实证分析。结果显示,国家高新区在促进创新能力方面具有显著的正面作用,且对环境规制和要素流动性的影响在不同地域表现出明显的异质性:西部地区国家高新区在激发创新活力方面更显著,东部地区则在环境规制和要素流动性方面呈现多样化的表现;相较北部地区而言,南部地区国家高新区在提升创新能力方面成效更为显著。

环境规制与资本跨地区流动——来自新《环保法》实施的证据

本文利用2010—2020年中国上市工业企业的异地投资数据,实证检验了新《环保法》的实施对资本流动的影响。研究发现,新《环保法》的实施能够显著减少重污染企业异地投资的策略性行为,主要作用途径是加强外部资源约束和推动内部策略合规。进一步研究表明,新《环保法》的实施在减少污染转移的基础上,提高了重污染企业的创新效率和创新数量。本文在全面畅通国内大循环的战略背景下,为构建高质量的资本流动格局提供了政策启示。

全球数据监管竞争下我国个人信息出境标准合同研究

个人信息出境标准合同产生于全球数据跨境流动监管竞争加剧的时代,是一种重要的数据跨境监管工具,并为国际层面提供了具有可互操作性的数据跨境流动模式。通过梳理历史沿革、剖析制度现状可以发现,我国个人信息出境标准合同秉承着以数据安全为基础的数据自由流动的价值取向,是结合行政监管和企业自治的创新型数据监管工具,旨在保护合同外第三方受益人并监管数据出境全过程,以合同权利义务固定化数据监管标准。作为我国加入全球数据监管竞争的重要手段,个人信息出境标准合同制度在时代趋势下经历了从无到有的发展历程,各方面细节也在逐步完善,但在规范结构、条款规范和持续监管等方面尚存难题有待进一步研究和破解。我国应当从立法重心、结构重塑、监管内容等三个方面夯实制度基础以促进中国参与全球数据竞争。

高技术产业集聚对区域创新创业活跃度的影响

高技术产业集聚具有知识溢出效应、技术引领效应和创新驱动效应,对提高区域创新创业活跃度具有重要意义。基于2011—2021年中国278个地级及以上城市面板数据,选用双向固定效应模型研判高技术产业集聚对区域创新创业活跃度的影响及作用机制。研究结果显示:高技术产业集聚对区域创新创业活跃度的影响存在先增大后减小的倒“U”型特征。中介机制分析表明,高技术产业集聚能够通过缓解融资约束、加速人力资本流动和加强环境规制,对区域创新创业活跃度产生先增大后减小的非线性影响。异质性分析显示,高技术产业集聚对东部地区、沿海城市和资源型城市区域创新创业活跃度的影响效应较为显著。空间分析表明,高技术产业集聚对邻近区域创新创业活跃度的空间溢出效应表现为倒“U”型特征。基于此,政府部门及相关企业应营造高技术产业集聚新环境、完善要素配置新机制、定制差异化区域发展新方案,以促进区域创新创业活跃度提升。