Design of active disturbance rejection internal model control strategy for SISO system with time delay process

A novel control scheme of active disturbance rejection internal model control(ADRIMC) is proposed to improve the anti-interference ability and robustness for the dead-time process. The active anti-interference concept is introduced into the internal model control(IMC) by analyzing the relationship between IMC and disturbance observer control(DOB). Further, a design process of disturbance filter is presented to realize the active anti-interference ability for ADRIMC scheme. The disturbance filter is used to estimate an equivalent disturbance consisting of both external disturbances and internal disturbances caused by model mismatches.Simulation results demonstrate that the proposed method possesses a good disturbance rejection performance, though losing some partial dynamic performance. In other words, the proposed method shows a tradeoff between the dynamic performance and the system robust.

Meta-analysis of the efficacy and safety of Huanglian Wendan Decoction alone or combined with western medicine in treating insomnia caused by phlegm-heat internal disturbance

Objective To evaluate the efficacy and safety of Huanglian Wendan Decoction(黄连温胆汤,HLWDD)alone or combined with western medicine in treating insomnia caused by phlegm-heat internal disturbance in recent 10 years.Methods The randomized controlled trials of HLWDD alone or combined with western medicine in treating insomnia caused by phlegm-heat internal disturbance from January 1,2012 to April 1,2022 were searched in China National Knowledge Infrastructure(CNKI),China Science and Technology Journal Database(VIP),Wanfang Database,China BioMedical Literature Database(CBM),PubMed,Web of Science,Embase,and Cochrane Library databases.After being screening,the included literature was analyzed to evaluate the effective rate,Pittsburgh Sleep Quality Index(PSQI)score,traditional Chinese medicine(TCM)syndrome score,and adverse reactions of HLWDD on insomnia caused by phlegm-heat internal disturbance.The subgroup analyzed the effect of HLWDD after different treatment courses,and compared the therapeutic effects of HLWDD alone and HLWDD combined with western medicine.Results Twenty-seven randomized controlled trials were finally included,with a total of 2395 patients.The results of the meta-analysis showed that the curative effect of HLWDD alone or combined with the western medicine group was better than that of the western medicine group[RR=1.14,95%CI(1.06,1.22),P=0.000].The PSQI score[SMD=-0.31,95%CI(-0.42,-0.20),P=0.000],TCM syndrome score[SMD=-0.40,95%CI(-0.67,-0.12),P=0.005],and adverse reaction rate[RR=0.21,95%CI(0.15,0.29),P=0.000]of HLWDD alone or combined with western medicine group were significantly reduced compared with the western medicine group.The subgroup’s analysis showed that the curative effect of HLWDD alone or combined with western medicine group of 4 weeks treatment course was better than that of the western medicine group[RR=1.14,95%CI(1.03,1.26),P<0.05].The TCM syndrome score of HLWDD alone or combined with the western medicine group of 4 weeks treatment course decreased more obviously than that of the western medicine group[SMD=-0.60,95%CI(-0.96,-0.25),P<0.05].There were no significant differences between HLWDD alone or combined with western medicine group and western medicine group with different treatment courses based on PSQI score and adverse reaction rate.Based on the effective rate,the comparison between the HLWDD alone group and the western medicine group[RR=1.09,95%CI(1.00,-1.20)P<0.05],and between the HLWDD combined with western medicine group and the western medicine group[RR=1.15,95%CI(1.03,1.29),P<0.05]was the same.PSQI score[SMD=-0.44,95%CI(-0.59,-0.30),P<0.05]and TCM syndrome score[SMD=-1.10,95%CI(-1.59,-0.61),P<0.05]of HLWDD combined with western medicine group were significantly lower than those of the western medicine group.There were no significant differences of adverse reaction rate between HLWDD alone group[RR=0.08,95%CI(0.04,0.17),P<0.05]and HLWDD combined with western medicine group[RR=0.36,95%CI(0.24,0.53),P<0.05].Conclusion HLWDD alone or combined with western medicine is an effective treatment for insomnia caused by phlegm-heat internal disturbance,which has a high effective rate,significantly reduced PSQI score and TCM syndrome score,and favorable safety.The best course of treatment is 4 weeks.

Multi-loop Internal Model Controller Design Based on a Dynamic PLS Framework

In this paper,a multi-loop internal model control(IMC) scheme in conjunction with feed-forward strategy based on the dynamic partial least squares(DyPLS) framework is proposed.Unlike the traditional methods to decouple multi-input multi-output(MIMO) systems,the DyPLS framework automatically decomposes the MIMO process into a multi-loop system in the PLS subspace in the modeling stage.The dynamic filters with identical structure are used to build the dynamic PLS model,which retains the orthogonality among the latent variables.To address the model mismatch problem,an off-line least squares method is applied to obtain a set of optimal filter parameters in each latent space.Without losing the merits of model-based control,a simple and easy-tuned IMC structure is readily carried over to the dynamic PLS control framework.In addition,by projecting the measurable disturbance into the latent subspace,a multi-loop feed-forward control is yielded to achieve better performance for disturbance rejection.Simulation results of a distillation column are used to further demonstrate this new strategy outperforms conventional control schemes in servo behavior and disturbance rejection.

Vehicle Active Steering Control Research Based on Two-DOF Robust Internal Model Control

Because of vehicle＇s external disturbances and model uncertainties,robust control algorithms have obtained popularity in vehicle stability control.The robust control usually gives up performance in order to guarantee the robustness of the control algorithm,therefore an improved robust internal model control（IMC） algorithm blending model tracking and internal model control is put forward for active steering system in order to reach high performance of yaw rate tracking with certain robustness.The proposed algorithm inherits the good model tracking ability of the IMC control and guarantees robustness to model uncertainties.In order to separate the design process of model tracking from the robustness design process,the improved 2 degree of freedom（DOF） robust internal model controller structure is given from the standard Youla parameterization.Simulations of double lane change maneuver and those of crosswind disturbances are conducted for evaluating the robust control algorithm,on the basis of a nonlinear vehicle simulation model with a magic tyre model.Results show that the established 2-DOF robust IMC method has better model tracking ability and a guaranteed level of robustness and robust performance,which can enhance the vehicle stability and handling,regardless of variations of the vehicle model parameters and the external crosswind interferences.Contradiction between performance and robustness of active steering control algorithm is solved and higher control performance with certain robustness to model uncertainties is obtained.

Improvement of precision for pendulous integrating gyro accelerometer via adaptive internal model control

An adaptive internal mode control is proposed to eliminate effectively periodic disturbance with uncertain frequency caused by input error angle of PIGA （Pendulous Integrating Gyro Accelerometer）. An adaptive algorithm with periodic disturbance frequency identification on line is applied and the internal model controller parameters are adjusted to eliminate disturbance. Then the convergence of this algorithm and the stability of the system are proved by the averaging method. Simulation results verify the proposed scheme can eliminate periodic disturbance and improve the test precision for PIGA effectively.

Control Design for Harmonic Disturbance Rejection for Robot Manipulators with Bounded Inputs

Currently most of control methods are of one degree of freedom（1-DOF） control structure for the robot systems which are affected by unmeasurable harmonic disturbances,at the same time in order to obtain perfect disturbance attenuation level,the controller gain must be increased.In practice,however,for robotic actuators,there are physical constraints that limit the amplitude of the available torques.This paper considers the problem of tracking control under input constraints for robot manipulators which are affected by unmeasurable harmonic disturbances.A new control scheme is proposed for the problem,which is composed of a parameter-dependent nonlinear observer and a tracking controller.The parameter-dependent nonlinear observer,designed based on the internal model principle,can achieve an estimation and compensation of a class of harmonic disturbances with unknown frequencies.The tracking controller,designed via adaptive control techniques,can make the systems asymptotically track the desired trajectories.In the control design,the continuous piecewise differentiable increasing function is used to limit control input amplitude,such that the control input saturation is avoided.The Lyapunov stability of closed loop systems is analyzed.To validate proposed control scheme,simulation results are provided for a two link horizontal robot manipulator.The simulation results show that the proposed control scheme ensures asymptotic tracking in presence of an uncertain external disturbance acting on the system.An important feature of the methodology consists of the fact that the designed controller is of 2-DOF control structure,namely,it has the ability to overcome the conflict between controller gain and robustness against external disturbances in the traditional 1 -DOF control structure framework.

ALMOST DISTURBANCE DECOUPLING FOR A CLASS OF MINIMUM-PHASE HIGHER-ORDER CASCADE NONLINEAR SYSTEMS

The problem of almost disturbance decoupling (ADD) with internal stability is discussed, for a class of high_order cascade nonlinear systems having zero dynamics. Using adding power integrator techniques, the ADD problems via a smooth static state feedback is solved.

Design of an Attitude and Disturbance Rejection Controller for Spacecraft

According to the Rodrigues parameter and the internal model principle,an adaptive state feedback control law is proposed for a rigid spacecraft with inertia uncertainty and exotic disturbances generated by an unknown nonlinear exosystem.The uncertainty of parameters is treated by an adaptive control law.And a new internal model is proposed to estimate the exotic disturbances.By using the Lyapunov analysis method,the control law is designed to ensure that the system's state variables asymptotically converge to stable,and the disturbances can be completely rejected.Finally,numerical simulations are included to demonstrate the performance of the presented controller.

Internal and external disturbances aware motion planning and control for quadrotors

Resilient motion planning and control,without prior knowledge of disturbances,are crucial to ensure the safe and robust flight of quadrotors.The development of a motion planning and control architecture for quadrotors,considering both internal and external disturbances(i.e.,motor damages and suspended payloads),is addressed.Firstly,the authors introduce the use of exponential functions to formulate trajectory planning.This choice is driven by its ability to predict thrust responses with minimal computational overhead.Additionally,a reachability analysis is incorporated for error dynamics resulting from multiple disturbances.This analysis sits at the interface between the planner and controller,contributing to the generation of more robust and safe spatial–temporal trajectories.Lastly,the authors employ a cascade controller,with the assistance of internal and external loop observers,to further enhance resilience and compensate the disturbances.The authors’benchmark experiments demonstrate the effectiveness of the proposed strategy in enhancing flight safety,particularly when confronted with motor damages and payload disturbances.

Global Disturbance Rejection of Switched Nonlinear Systems with Switched Internal Model

This paper investigates the problem of global disturbance rejection for a class of switched nonlinear systems where the solvability of the disturbance rejection problem for subsystems is not assumed. The disturbances are assumed to be sinusoidal with completely unknown frequencies, phases and amplitudes. First, as an extension of the classic concept of internal model for non-switched systems, a switched internal model is proposed. Second, in order to solve the problem under study, an adaptive control method is established on the basis of the multiple Lyapunov functions method. Also,adaptive state-feedback controllers of subsystems are designed and incorporated with a switching law to asymptotically reject the unknown disturbances. Finally, an example is provided to demonstrate the effectiveness of the proposed design method.

Attitude Regulation of Flexible Spacecrafts with Unknown Control Directions and Input Disturbances

In this paper,the authors address the attitude regulation problem of uncertain flexible spacecraft with unknown control directions and input disturbances.The major challenges of the problem include the concurrence of the unknown actuation sign and the unknown parameters in both the plant and the external disturbances,along with the impact of vibrations from flexible appendages.To overcome these challenges,the authors transform the conventional mathematical model of a flexible spacecraft to a multivariable strict-feedback normal form and adopt a systematic approach within the framework of nonlinear output regulation.To solve the attitude regulation and disturbance rejection problem,the authors introduce a nonlinear internal model candidate to convert the problem into a stabilization problem for an augmented system.Then,a Nussbaum function-based stabilizer is designed to handle unknown control directions and complete the design.Simulation results are provided to show the effectiveness of the proposed controller.

基于DeST的超低能耗建筑负荷特性研究

为实现节能减排,进一步降低建筑的能耗,通过DeST软件对严寒地区SJZU超低能耗示范中心建筑的负荷进行模拟计算,对比超低能耗建筑和不同节能水平的建筑负荷特性,分析新风量和内扰对建筑负荷的影响规律,利用数学分析方法研究内扰因素对建筑负荷的显著性。结果表明:典型超低能耗建筑的全年最大热负荷为14.74 kW,全年最大冷负荷为13.23 kW;全年累计负荷较不同节能水平下的节能建筑显著降低;人均新风量增加5 m^(3)/(h·人),全年累计热负荷平均增幅为4.73%,而全年累计冷负荷几乎不变;超低能耗建筑全年累计负荷的影响最显著的内扰因素是人员密度。

强扰煤岩体蠕变过程中跨尺度非连续结构演化研究进展

【目的和方法】巷道围岩时效变形破坏、蠕变型冲击地压等灾害是深井面临的重大威胁,加之深部采动与结构变化的影响,亟需研究强扰煤岩体蠕变过程中跨尺度非连续结构演化规律,系统回顾煤岩体力学性质的尺度效应、非连续结构与多物理场效应,以及煤岩体长时稳定性、蠕变演化规律与力学模型。【结果和结论】强调不同尺度(细观-宏观-工程尺度)、不同尺寸(REV范围内)煤岩变形破裂过程中非连续结构(包括裂隙和矿物)与物理力学性质存在密切的关联特征。指出煤岩体跨尺度非连续结构导致应力场非均匀分布,造成力学各向异性、尺度效应及尺寸效应,进而出现非协调宏观破裂现象。透明解析与推演煤岩变形破裂过程中跨尺度非连续结构与多物理场演化规律,是认识煤岩灾变内禀机制的关键。明确指出现有蠕变实验与蠕变模型在煤岩表面变形及破裂方面具有优势,但无法预测煤岩内部变形与非连续结构;为此提出了全尺寸CT扫描重构、数字体图像相关(DVC)、跨尺度等效岩体-等效晶质建模(SRM-GBM)相结合的破解方法。对扰动煤岩体蠕变前沿问题进行了讨论,阐明了非连续结构与应力引起内部变形损伤诱发蠕变这一新观点,指出非连续结构和应力是煤岩非协调蠕变的主控因素,最后建立了强扰煤岩体蠕变过程中跨尺度非连续结构与多物理场演化的精细化建模及透明解析新方法。研究成果为相关矿山灾害的发生机理、预警与防控提供理论基础。

基于延迟补偿的永磁同步电机并行自抗扰控制

为了解决永磁同步电机在多工况下转速易受到内外扰动的影响,提出一种基于延迟补偿的并行线性自抗扰控制策略。针对永磁同步电机可能受到信号处理、逆变器响应等因素从而引入的外部时滞效应的问题,引入Smith预估器与自抗扰控制相结合,使控制系统更加精确、快速地响应内部参数变化和外部扰动。同时,针对线性自抗扰控制器(LADRC)在有限带宽内其抗扰性能较差的问题,设计了并行线性自抗扰控制器,在保持其带宽不变与参数易于整定的同时,有效提高其抗扰动能力。最后,对自抗扰控制器的稳定性进行了分析,并在此基础上进行了参数设计与扰动性能分析。仿真与实验结果表明,所提算法相比LADRC在电机受到速度阶跃、负载扰动与内部参数变化时,在调整时间上分别提升了52.5%、49.5%与42.4%,从而验证了该控制策略能有效增强永磁同步电机在多工况下抗内外扰动与速度跟踪能力。

直流伺服电机新型位置-速度控制策略

针对由直流电机位置伺服系统自身参数不确定以及外部扰动影响,导致系统响应速度、控制精度降低的问题,提出了一种新型位置-速度双环控制策略。速度控制器采用模糊内模PID(proportional-integral-differential)控制,利用模糊原理实现对内模PID控制器参数,即滤波时间常数λ的在线智能整定;位置控制器采用基于自抗扰的非奇异快速终端滑模控制(non-singular fast terminal sliding mode control,NFTSMC),利用线性扩张状态观测器对系统总体的内外干扰进行估计,并以反馈形式进行补偿,同时采用NFTSMC对系统的状态变量进行跟踪,以提高系统的跟踪性能和抗干扰性;最后使用仿真与实验方法验证了新型双闭环控制策略对直流电机位置伺服系统具有良好的控制性能。

将息疗法结合柴胡加龙骨牡蛎汤治疗老年肝郁兼痰热内扰型不寐患者临床观察

目的探究将息疗法结合柴胡加龙骨牡蛎汤用于老年肝郁兼痰热内扰型不寐患者的临床效果。方法采用随机数字表法将2022年3月—2023年3月荆门市中医医院收治的120例肝郁兼痰热内扰型不寐患者分为观察组和对照组,各60例。对照组予右佐匹克隆片治疗,观察组在对照组的基础上予柴胡加龙骨牡蛎汤联合将息疗法治疗,比较两组睡眠质量、睡眠指标,临床效果及不良反应。结果治疗后,两组匹兹堡睡眠质量指数量表(PSQI)评分均显著降低,且观察组显著低于对照组(P<0.05);两组睡眠效率(SE)、慢波睡眠(SWS)时间均显著优于治疗前,觉醒时间(AT)均短于治疗前,且观察组SE、SWS时间显著优于对照组,AT显著短于对照组(P<0.05)。观察组治疗总有效率为91.67%(55/60),显著高于对照组的80.00%(48/60)(P<0.05);且观察组不良反应总发生率为10.00%(6/60),显著低于对照组的46.67%(28/60)(P<0.05)。结论老年肝郁兼痰热内扰型不寐患者采用将息疗法联合柴胡加龙骨牡蛎汤治疗,能够有效提高睡眠质量,改善SWS时间、SE、AT指标,效果显著,且具有较高安全性。

基于内模控制和改进自抗扰控制的 主汽温串级控制系统

超超临界机组主汽温系统本身是一类典型的大时滞、多扰动、非线性的热力系统,并且在深度调峰工况下,锅炉燃烧稳定性下降、水动力不足、辐射/对流换热特性迁移,传统的PID串级控制难以满足新形势下的控制需求。该文提出一种基于内模控制和改进自抗扰控制的主汽温串级控制系统。首先,针对内回路非线性、回滞特性,改进并应用非线性自抗扰控制器;其次,针对外回路的大迟延、大惯性特性,采用内模控制进行超前预测和调节,增强外回路对于设定值的跟踪能力和系统的鲁棒性。仿真结果表明:相较于传统的PID串级控制,该方法对于主汽温控制对象有更好的跟踪、抗扰能力以及更强的鲁棒性。在某1000 MW机组实际应用表明,该方法可以适应现场复杂多变的环境,在满足电厂“两个细则”考核要求的同时,有效改善主汽温控制特性,汽温稳态偏差控制在±2℃,变负荷时偏差≤±5℃,具有良好的工程应用前景。

新型忆阻耦合异质神经元的放电模式和预定义时间混沌同步

首先提出一种新型局部有源忆阻器,并分析该忆阻器的频率特性、局部有源性及非易失性.然后将新型局部有源忆阻器引入二维Hindmarsh-Rose神经元和二维FitzHugh-Nagumo神经元,构建新型忆阻耦合异质神经元模型.在数值仿真中,通过改变耦合强度,发现该模型具有周期尖峰放电模式、混沌尖峰放电模式、周期簇发放电模式及随机簇发放电模式.最后基于Lyapunov稳定性理论和预定义时间稳定性理论,提出一种新型预定义时间同步策略,并将该策略应用于新型忆阻耦合异质神经元的混沌同步中.结果表明,与有限时间同步策略、固定时间同步策略和传统预定义时间同步策略相比,新型预定义时间同步策略的实际收敛时间最小.研究新型忆阻耦合异质神经元的放电模式和混沌同步有助于探索大脑的神经功能,并在神经信号处理及保密通信领域中具有重要意义.

酸枣仁汤及右佐匹克隆对“肝血不足、虚热内扰”失眠患者睡眠质量及HAMA、HAMD评分的影响

目的:研究酸枣仁汤及右佐匹克隆对“肝血不足、虚热内扰”失眠患者睡眠质量及汉密尔顿焦虑量表(HAMA)、汉密尔顿抑郁量表(HAMD)评分的影响。方法:选择2022年5—12月在南安市康复院接受治疗的“肝血不足、虚热内扰”失眠患者138例作为观察对象,按随机数字表法分为观察组及对照组,各69例。对照组予以右佐匹克隆治疗,观察组在对照组基础上予以酸枣仁汤治疗,两组均治疗1个月。对比两组疗效、匹兹堡睡眠质量指数(PSQI)和失眠严重程度(SPIEGEL量表)评分、HAMA和HAMD评分,以及不良反应发生情况和睡眠满意度。结果:观察组总有效率为98.55%,较对照组的86.96%高(P<0.05)。治疗后两组PSQI、SPIEGEL量表评分均较治疗前更低,且观察组均较对照组更低(P<0.05)。治疗后两组HAMA和HAMD评分均较治疗前更低,且观察组均较对照组更低(P<0.05)。观察组不良反应总发生率为8.70%,与对照组的11.59%比较,差异无统计学意义(P>0.05)。观察组患者睡眠满意度为98.55%,较对照组的85.51%明显更高(P<0.05)。结论:酸枣仁汤联合右佐匹克隆对“肝血不足、虚热内扰”失眠患者的疗效较好,可改善其睡眠质量、睡眠满意度及HAMA、HAMD评分,安全性较高。

国医大师熊继柏从痰热论治失眠症临证经验

历代医家对失眠症认识虽有不同,但总以阴阳失调、脏腑失衡为主要病机。国医大师熊继柏认为,本病总以痰热内扰为核心病机,临证多从痰论之,强调痰、湿、热在疾病发生、发展及治疗中的关键作用。由于现代人生活节奏快,长时间心情紧张,易致肝气郁结,思虑气结,久郁而伤心脾,脾虚湿蕴,聚而生痰,郁而化热;或因过食肥甘厚味,导致体内痰湿内生,久积则化热,故痰、湿、热郁结,扰心动神而导致失眠。熊老以黄连温胆汤随症加减,取得满意疗效。