无人车稳定性DP优化协调控制方法仿真

为了提高无人车驾驶的稳定性,提出基于DP优化的无人车稳定性协调控制方法。设计无人车动力学模型,确保无人车自身稳定性的同时,实现车辆行驶过程路径的快速与高精度跟踪。利用五次多项式方程描述无人车的换道轨迹曲线,建立换道约束条件,在满足约束条件的前提下,获得最优换道路线。采用DP优化算法解决车辆行驶过程中频繁换挡的问题,实现无人车稳定性协调控制,提高无人车行驶过程中的稳定性和安全性。实验结果表明,所提方法可以提高无人车路径跟踪精度,保证车辆驾驶的稳定性和安全性。

轴承钢中夹杂物调控的冶金技术现状及智能化展望

随着我国高铁、航空航天、风电等重大装备的应用与建设,对轴承钢提出了高品质、长寿命和高可靠性的要求。通过介绍国内外高性能轴承钢中夹杂物调控现状,分析国内特殊钢企业在夹杂物调控领域的水平与差距,提出高性能轴承钢中夹杂物智能化调控的技术展望。通过非铝脱氧钢中夹杂物调控、低氧稀土钢中夹杂物调控、镁对钢中夹杂物调控和热处理对钢中夹杂物调控生产出高性能轴承钢,为国内相关特殊钢企业提供研发思路和参考。

后危机时代中国金融稳定与调控研究

美国次贷危机引致的全球性金融危机给世界经济发展态势带来了巨大冲击，欧债危机余音未尽。后危机时代中国金融领域的发展同时面临着机遇和挑战。在这样的背景之下，研究后危机时代中国金融事业的稳定状况与金融调控的相关理论无疑就获得了日渐增强的现实意义。

电力系统低频振荡的协调控制

区域间低频振荡的可能性和危害性日益增加,严重威胁着电网的安全稳定,为此,阐述电力系统稳定器(power system stabilizer,PSS)各环节抑制低频振荡的原理。建立电力系统模型,以系统模型为基础对发电机励磁系统与电力系统的低频振荡之间的关系进行分析,利用相位补偿法对PSS进行参数设计;利用MATLAB程序对2区4机电力系统进行单机分别配置PSS参数;利用改进的粒子群算法配置PSS参数进行协调控制。通过仿真计算,验证了利用改进的粒子群算法协调配置PSS参数对抑制系统低频振荡的效果比单机分别配置更好。

Stable Control of Influence Factor during Two-phase Anaerobic Digestion for Agricultural Organic Waste

Two-phase anaerobic digestion process is influenced by acid control for hydrogen production, reaction temperature, substrate detention time, sludge activity, and granular formation. Al of these technological parameters are directly related to success or failure of the system operation and treatment effect.

低氧诱导因子及其抑制剂研究进展

低氧(hypoxia)是生物体内常见的生理和病理现象,也是常见的实体肿瘤微环境。人和其他哺乳动物体内存在一系列应对缺氧胁迫的调节机制,而低氧诱导因子(hypoxia-inducible factors,HIFs)是这些调节机制中的关键调控因子,是一类参与细胞缺氧应答反应的转录因子家族。大量研究表明,HIFs与生物体的生长、发育、血管生成、红细胞生成、细胞代谢和自噬以及肿瘤的发生、发展、转移侵袭、放化疗抗性和癌症患者的不良预后等密切相关。因此,进一步加强HIFs及其抑制剂的相关研究对于肿瘤的认识与治疗具有重要意义。从HIFs的蛋白质结构、稳定性调控、转录激活调控及其靶向抑制剂的研究进展等方面进行综述,以期为靶向HIFs的肿瘤治疗提供新线索,为新型HIFs抑制剂的研究与开发提供参考。

Alkalinity stabilization behavior of bauxite residue:Ca-driving regulation characteristics of gypsum

Alkaline anions,include CO3^2–,HCO3^–,Al(OH)4^–,OH^–,continuously released from bauxite residue(BR),will cause a potential disastrous impact on surrounding environment.The composition variation of alkaline anions,alkaline phase transformation pathway,and micro-morphological transition characteristics during the gypsum addition were investigated in an attempt to understand alkalinity stabilization behavior.Results demonstrated that alkaline anions stabilization degree in leachates can reach approximately 96.29%,whilst pH and alkalinity were reduced from 10.47 to 8.15,47.39 mmol/L to 2 mmol/L,respectively.During the alkalinity stabilization,chemical regulation behavior plays significant role in driving the co-precipitation reaction among the critical alkaline anions(CO3^2–,HCO3^–,Al(OH)4^–,OH^–),with calcium carbonate(CaCO3))being the most prevalent among the transformed alkaline phases.In addition,XRD and SEM-EDX analyses of the solid phase revealed that physical immobilization behavior would also influence the stability of soluble alkali and chemical bonded alkali due to released Ca^2+from gypsum which aggregated the clay particles and stabilized them into coarse particles with a blocky structure.These findings will be beneficial for effectively regulating strong alkalinity of BR.

Pre-evaluation on stability of proposed expressway embankment with existing geothermal regulation measures in permafrost regions

Embankment stability is the primary problem for the expressway construction in permafrost regions.The proposed Qinghai-Tibet Expressway(QTE)is planned to construct along the Qinghai-Tibet Project Corridor.Confronted with harsh environmental condition and intense heat exchange between earth and atmosphere,it is necessary to predict and evaluate the stability of the proposed QTE.In this study,the factors affecting the embankment stability are analyzed firstly.And then,a scheme for the stability evaluation of the embankment is established.Finally,the evaluation scheme is used for the pre-evaluation of the stability for the proposed QTE with different geothermal regulation measures(GRMs).The results indicate that the influencing factors include climatic environment,permafrost property,engineering condition and geological condition,and among them,engineering condition and permafrost property are the main influence factors for embankment stability.The stability of the proposed QTE varies greatly in the different geomorphological regions.The application effect and contribution to embankment stability of the existing GRMs are different,and using GRMs cannot completely overcome the influence of various factors on expressway stability.In the construction process,different GRMs should be adopted depending on the geomorphological environment where the embankment is located to ensure the embankment stability.

Stability analysis and stabilization of wireless networked control systems based on deadband control scheduling

The stability analysis and stabilization problems of the wireless networked control systems(WNCSs) with signal transmission deadbands were considered. The deadbands were respectively set up at the sensor to the controller and the controller to the actor sides in the WNCS, which were used to reduce data transmission, furthermore, to decrease the network collision and node energy consumption. Under the consideration of time-varying delays and signal transmission deadbands, the model for the WNCS was presented. A novel Lyapunov functional which took full advantages of the network factors was exploited. Meanwhile, new stability analysis and stabilization conditions for the WNCS were proposed, which described the relationship of the delay bounds, the transmission deadband bounds and the system stability. Two examples were used to demonstrate the effectiveness of the proposed methods. The results show that the proposed approach can guarantee asymptotical stability of the system and reduce the data transmission effectively.

Coordinated and uncoordinated design of LFO damping controllers with IPFC and PSS using ICA and SFLA

A single machine-infinite-bus(SMIB) system including the interline power flow controllers(IPFCs) and the power system stabilizer(PSS) controller is addressed. The linearized system model is considered for investigating the interactions among IPFC and PSS controllers. To improve the stability of whole system again different disturbances, a lead-lag controller is considered to produce supplementary signal. The proposed supplementary controller is implemented to improve the damping of the power system low frequency oscillations(LFOs). Imperialist optimization algorithm(ICA) and shuffled frog leaping algorithm(SFLA) are implemented to search for optimal supplementary controllers and PSS parameters. Moreover, singular value decomposition(SVD) method is utilized to select the most effective damping control signal of IPFC lead-lag controllers. To evaluate the system performance, different operating conditions are considered. Reponses of system in five modes including uncoordinated and coordinated modes of IPFC and PSS using ICA and SFLA are studied and compared. Considering the results, response of system without controller shows the highest overshoot and the longest settling time for rotor angel at the different operating conditions. In this mode of system, rotor speed has the highest overshoot. Rotor angel in the system with only PSS includes lower overshoot and oscillation than system without controller. When PSS is only implemented, rotor speed deviation has the longest settling time. Rotor speed deviation in the uncoordinated mode of IPFC and PSS shows lower overshoot than system with only PSS and without controller. It is noticeable that in this mode, rotor angel has higher overshoot than system with only PSS. The superiority of the suggested ICA-based coordinated controllers is obvious compared with SFLA-based coordinated controllers and other system modes. Responses of coordinated PSS and IPFC SFLA-based supplementary controllers include higher peak amplitude and longer settling time compared with coordinated IPFC and PSS ICA-based controllers. This comparison shows that overshoots, undershoots and the settling times are reduced considerably in coordinated mode of IPFC based controller and PSS using ICA. Analysis of the system performance shows that the proposed method has excellent response to different faults in power system.

基于工业物联网的生产数据采集及控制研究

为对工业生产过程进行准确的数据采集和控制,提出一种基于物联网的生产数据采集及控制系统。其中,基于物联网技术进行系统的构建,基于模糊PID控制进行生产环境的温度调控,基于扩展卡尔曼滤波进行生产材料的含水率的检测。实验结果表明,与传统的PID控制相比,设计的基于模糊PID控制的温度调控模块能够进行效果更好的温度控制,能够更快达到目标温度值;设计的基于扩展卡尔曼滤波算法的含水率检测方法能够进行准确的含水率检测。综上,构建的生产数据采集及控制系统性能良好,能够应用于实际的工业生产场景,数据采集与控制效果良好,具有一定的实际工程应用价值。

New parameter tuning method of washout filter-aided controller for dynamic behavior adjustment

Stabilizing unstable operating points is an effective way to enhance process benefits and safety, which motivates the development for a variety of advanced control strategies. The washout filter-aided controller(WFC), originally used for electric power system and aircraft, has been introduced to adjust the dynamic behavior of chemical process. However, the parameter tuning method faces two major limitations: the dimension of operating variables must be equal to or greater than that of state variables and only one positive real eigenvalue exists in the open loop system. To overcome the two limitations, this paper proposes a new parameter tuning method, so that the WFC is applicable in most chemical processes. By solving a constrained optimization problem, the controller parameters are determined under the constraint that the reassignment of the eigenvalues of the unstable desired operating point can satisfy the stability condition. Thus parts of the equilibrium manifold including the desired operating point are stabilized without affecting the shape of the equilibrium manifold. Finally, the effectiveness of the WFC improved by the proposed parameter tuning method is illustrated through a case study for propanediol anaerobic fermentation.

Coordinated Design of Thyristors Controlled Braking Resistors and Power System Stabilizer for Damping

This paper presents a new concept for damping electro-mechanical oscillations in large turbo generator. The proposed concept is based on coordination between Power System Stabilizer （PSS） and Thyristor Controlled Braking Resistor （TCBR）. This coordination will enhance the stability of the inertial and torsional oscillatory modes. The study is performed on system-I of the second IEEE benchmark for simulation of Sub-Synchronous Oscillations, using eigenvalue analysis and verified by detailed digital simulation. A dynamic fundamental frequency model for TCBR is developed. The pole placement technique is used to design the control system of TCBR and PSS. The shaft torque＇s following a disturbance is computed and analyzed. The obtained results indicate that substantial damping is achieved by the proposed coordination.

高分子固液复合界面与液体黏附调控

受猪笼草口缘区润滑效应启发,将低表面能液体注入高分子微纳米多孔结构中可构筑高分子固液复合界面.与超疏水固体界面相比,固液复合界面展现出独特的浸润性和黏附性.界面黏附是高分子复合材料重要的性质之一,实现界面黏附的精准调控对促进这类材料的发展和应用具有至关重要的作用.本文重点从稳定性调控、方向性调控以及原位可逆调控3个方面综述提升固液复合界面黏附可控性的工作,通过在表面微米结构中组装纳米层状及异质纳米层状结构,提高界面黏附的稳定性;使用界面薄层定向冷冻干燥法、激光刻蚀法以及复型法等方法,构筑具有取向结构的高分子固液复合界面,实现界面黏附的方向性调控;通过在界面中引入快速响应的智能基元,设计智能响应高分子固液复合界面,实现界面黏附的原位可逆调控.最后,概述了这类材料目前存在的问题并展望了其未来发展的方向.

Interference RNA induction and drug target validation

The ability to knockdown the expression of an endogenous gene by RNAi has emerged as a powerful strategy for the rapid identification of specific gene functions. Vector-based constitutive expression of shRNA can result in stable and efficient knockdown of target genes. However, constitutive expression of shRNA imposes major limitations when analyzing the fimction of genes whose expression is vital for the survival of an organism. Inducible RNAi systems can circumvent this limitation by enabling the inhibition of expression of an essential gene only when the inducing agent is present, and the level of knockdown of the essential gene can be controlled and adjusted by the concentration of inducing agent. In this review, we briefly summarize the recent development of various inducible RNAi systems and their potential applications in drug target validation.

Barrier stabilizing mediators in regulation of microvascular endothelial permeability

Increase of microvascular permeability is one of the most important pathological events in the pathogenesis of trauma and burn injury. Massive leakage of fluid from vascular space leads to lose of blood plasma and decrease of effective circulatory blood volume, result- ing in formation of severe tissue edema, hypotension or even shock, especially in severe burn injury. Fluid resusci- tation has been the only valid approach to sustain patient＇s blood volume for a long time, due to the lack of overall and profound understanding of the mechanisms of vascular hyperpermeability response. There is an emerging concept in recent years that some so-called barrier stabilizing media- tors play a positive role in preventing the increase ofvascu-lar permeability. These mediators may be released in re- sponse to proinflammatory mediators and serve to restore endothelial barrier function. Some of these stabilizing mediators are important even in quiescent state because they preserve basal vascular permeability at low levels. This review introduces some of these mediators and reveals their underlying signaling mechanisms during endothelial barrier enhancing process.

GLOBAL ASYMPTOTIC REGULATION CONTROL FOR NONLINEAR SYSTEMS WITH iISS INVERSE DYNAMICS

This paper investigates a global asymptotic regulation control problem for a class of nonlinear systems with dynamic uncertainties.The requirement of a priori knowledge of control directions is removed and the inverse dynamics satisfy the weaker integral input-to-state stable condition.By application of the changing supply rates and the Nussbaum-type gain techniques,a partial state-feedback regulator is constructed.The main results demonstrate that the designed controller ensures the system state converges to the origin whereas the other signals of the closed-loop system are bounded. Simulation results are illustrated to show the effectiveness of the proposed approach.