柔性臂振动的双目三维检测和主动控制

针对柔性臂的振动问题,设计并搭建了一套基于双目视觉检测,以伺服电机驱动控制的柔性臂实验平台进行研究。根据电机的运行状态将柔性臂振动分为定点振动和旋转振动,通过双目视觉对柔性臂上的特征点进行三维重建,进而获取柔性臂的定点和旋转振动信号。对振动信号进行模态分析获取柔性臂的振动特性,并据此设计基于蚁群优化参数的PD控制器抑制柔性臂的弯曲振动,然后与常规PD控制效果进行比较。实验结果表明,基于蚁群优化参数的PD控制能够在较短时间内有效抑制柔性臂的定点振动,相较于常规PD控制抑振效果有明显改善,并且旋转振动的抑制效果也很显著,以此验证了蚁群PD控制算法在快速抑振上的有效性。     

基于状态反馈附加阻尼控制的柔性直流电网抑制低频振荡

为了提升交直流互联系统的动态稳定性,研究了利用多端柔性直流输电系统阻尼交流系统低频振荡的方法。分析了柔性直流电网接入后系统的振荡模态,研究了直流电网对交流系统稳定性的影响,并基于全维状态空间反馈设计了柔性直流系统的附加阻尼控制器。系统振荡时该附加阻尼控制器能够输出附加控制量,调节各换流站的有功功率,从而抑制系统的振荡。以含有四端柔性直流电网的新英格兰10机系统为例进行了仿真研究,仿真结果表明,引入了该控制器的柔性直流电网能够很好地抑制原系统的低频振荡,改善系统的动态性能。     

采用时滞广域测量信号的区间低频振荡阻尼控制器设计

针对电力系统区间低频振荡问题,基于广域测量系统和柔性交流输电系统技术,提出了一种采用时滞广域测量信号的电力系统阻尼控制器设计方法。该方法结合时滞依赖状态反馈鲁棒控制和状态观测理论,实现了广域电力系统的时滞输出反馈鲁棒控制。以四机两区域电力系统为例,设计了晶闸管可控串联补偿(TCSC)附加阻尼控制器。小信号分析和时域仿真结果都表明:所设计的控制器能显著抑制区间低频振荡,并且具有时滞不敏感性和运行条件鲁棒性。     

基于反推控制和模态估计的永磁同步电机驱动柔性涡簧储能控制方法

涡卷弹簧是新型机械弹性储能系统的储能介质,作为典型的机械弹性元件,在储能过程中表现出较大柔性,使得常规PI控制器难以让系统在正常运行范围内保持较好的动态性能。首先,将涡卷弹簧等效为Euler-Bernoulli梁,基于Lagrange方程建立描述涡卷弹簧振动模态且能用于控制算法的动力学模型;然后,将非线性反推控制引入系统控制中,提出一种基于反推控制的永磁同步电机直接驱动柔性负载的储能运行和振动抑制相统一的控制方法,建立包括模态振动抑制的速度控制器和电流控制器,并从理论上证明了控制器的稳定性;同时针对涡卷弹簧模态的未知性,设计一种带遗传因子最小二乘算法的涡卷弹簧振动模态估计方法。实验结果表明,与传统PI控制相比,提出的控制方法在有效抑制涡簧振动的同时实现了系统平稳储能,由此验证了该方法的正确性与有效性。     

基于动态转矩反馈的机械臂柔性系统振动抑制

针对机械臂关节伺服系统由于谐波减速器、齿皮带等柔性环节的存在使系统发生机械振动现象,建立了考虑刚度系数变化和大减速比的数学模型,分析机械谐振产生机理,提出了一种动态转矩反馈的控制策略,由扰动观测器实时观测动态转矩构成动转矩闭环。为进一步抑制振动现象,增强系统鲁棒性和抗扰能力,研究了随动态转矩实时调整的转速变增益PI控制方法。仿真表明,采用动态转矩反馈的转速变增益PI控制策略能够很好地抑制机械振动且有较强的抗扰能力和动态响应性能。     

磁悬浮系统振动抑制方法综述

磁悬浮系统是无接触、非线性、多变量耦合、易受干扰的机电系统，悬浮对象容易产生振动，导致磁悬浮系统的动态性能降低和运行不稳定，解决磁悬浮系统振动问题是实现其高性能运动的前提之一。基于国内外磁悬浮系统振动抑制的研究现状，论文分析磁悬浮系统振动的产生原因，给出磁悬浮系统的动力学模型，分别探讨磁悬浮列车、磁悬浮轴承和磁悬浮电机的振动抑制方法，并仿真分析磁悬浮高速电机的振动抑制，为磁悬浮系统的高精度位置控制提供基础。     

随机激励条件下转子系统的主动振动控制

针对随机激励下线性转子系统的振动主动控制,给出了随机激励下受控柔性转子系统的状态空间模型,基于线性二次型高斯控制理论,提出了转子系统在白噪声和有色噪声激励下振动的最优控制策略。以一个柔性转子轴承系统为例,用数值方法研究了El.Centro地震激励作用下随机最优策略对转子-轴承系统的振动主动控制,并讨论了性能指标中不同权函数对控制效果的影响。结果表明:文中所提出的随机最优控制策略能有效地抑制转子系统的振动,控制效果随着与转子系统位移和速度相关的权矩阵的增大而变好,随着与控制相关的权矩阵的增大而变差。这对于旋转机械系统随机最优控制中权矩阵的选择具有一定的参考价值。     

基于MEMS传感器的船载天线振动监测系统研究

针对传统结构振动监测系统存在设计复杂、体积大、功耗高等问题,设计一种基于MEMS传感器的船载测控系统天线结构振动监测系统,提出了一种多节点、远距离结构振动监测系统设计方案,并结合振动传感器选型、振动监测系统软件设计和硬件设计三方面进行了研究。该系统可完成对振动信号的实时采集与分析,并已成功应用到船载测控系统天线振动信号检测中,满足系统指标要求,为船载测控系统天线进行故障诊断和维修奠定基础。     

基于负载位置反馈的永磁同步电机驱动柔性负载谐振抑制方法

柔性负载广泛存在于电气传动系统中。根据柔性的成因,伺服系统中柔性负载主要分为柔性关节和柔性连杆两类系统。针对这两类典型的柔性负载系统,首先引用已有的研究成果对其建立了一致的动力学模型。然后将PI调节器应用于系统控制中,由于自由度有限,谐振抑制效果并不理想。因而,控制系统中需要引入状态反馈。针对谐振抑制的需要,通过增加一个额外的位置传感器对末段位置进行测量,然后将其反馈至控制系统中。针对负载位置反馈策略,分析了其系统性能与参数关系,并采用三种策略对其进行了极点配置。仿真和实验验证了所提出的基于负载位置反馈及其参数整定方法的有效性。     

H∞扭振抑制控制器在热连轧机组上的应用

针对冶金热连轧机交流调速主传动系统存在的机电扭转振荡现象以及热连轧机传动控制系统的数学模型和外部干扰存在不确定性,基于H∞控制的干扰抑制和鲁棒性,本文采用H∞扭振抑制控制器来抑制热连轧机组的轧机扭振问题.并在传统的PI控制策略基础上,设计出有效抑制轧机振动的补偿器.同时对控制器的结构进行了改进,以将补偿器引入实际系统.该系统仿真结果表明该控制器具有较好的轧机振动抑制性能,从而验证了该振动抑制策略的可行性和正确性,并且易于工程实现.     

Two-degree-of-freedom robust speed controller for high-performancerolling mill drives

A scheme is presented for the speed control of rolling mill drives. The proposed speed controller is based on a two-degree-of-freedom (TDF) structure and uses an observer-based state feedback compensator for the major control loop. The control method yields a robust system with respect to system uncertainties and modeling errors and is very effective for vibration suppression. Experimental verification was carried out on a prototype rolling mill minimodel system. The experimental drive system has a three-mass-model structure (motor-gear-load) connected by low stiffness shafts. The mechanical resonances and the inertia ratios between the motor, gear, and load are comparable to those of an actual rolling mill system (resonant frequencies are at 17.4 Hz and 51.3 Hz). The proposed scheme was compared to the conventional PI controller and the performance of each scheme is presented. A high closed loop speed bandwidth was obtained with the proposed TDF speed controller     

Manoeuvring and vibration reduction of a flexible spacecraft integrating optimal sliding mode controller and distributed piezoelectric sensors/actuators

This investigation is to apply optimal sliding mode (OSM) control theory and distributed piezoelectric sensor/actuator technology to vibration control of a flexible spacecraft. An approximate analytical dynamic model of a slewing flexible spacecraft with surface‐bonded piezoelectric sensors/actuators is developed using Hamilton's principle with discretization by assumed model method. To satisfy pointing requirements and simultaneously suppress vibration, two separate control loops are adopted. The first uses the piezoceramics as sensors and actuators to actively suppress certain flexible modes by designing a positive position feedback (PPF) compensators that add damping to the flexible structures in certain critical modes in the inner feedback loop; then a second feedback loop is designed using OSM control to slew the spacecraft. The OSM controller minimizes the expected value of a quadratic objective function consisting of only the states with the constraints that the error states always remain on the intersection of sliding surfaces. The advantage in this method is that the vibration reduction and attitude control are achieved separately in the two separate feedback loops, allowing the pointing requirements and simultaneous vibrations suppression to be satisfied independently of one another. An additional attraction of the design method is that the selection of PPF gain is determined by introducing a cost function to be minimized by the feedback gains which are subject to the stability criterion at the same time, such that the feedback gains are selected in a more systematical way to avoid the arbitrary selecting of feedback gains. The proposed control strategy has been implemented on a flexible spacecraft, which is a hub with a cantilever flexible beam appendage and can undergo a single axis rotation. Both analytical and numerical results are presented to show the theoretical and practical merits of this approach. Copyright © 2006 John Wiley & Sons, Ltd.     

挠性航天器姿态机动和振动抑制的自适应控制

针对挠性航天器姿态机动控制中存在的参数不确定性、外部干扰、挠性附件振动及挠性模态不易直接测量的问题,提出一种具有干扰抑制的自适应输出反馈机动控制器设计方法.设计中无需忽略挠性附件和中心刚体的耦合,利用挠性附件固有物理特性构造一种结构简单的开环模态观测器,然后用以此获得的模态估计信息及可测量的姿态四元数和角速度信息,基于...     

Basic consideration of vibration suppression and disturbancerejection control of multi-inertia system using SFLAC (state feedbackand load acceleration control)

SFLAC (state feedback and load acceleration control) is proposed for vibration suppression and disturbance rejection control of a multi-inertia system. A multi-inertia system is the model of a steel rolling mill, a flexible arm, a large-scale space structure, etc., and its control will be an important problem in the future of motion control. The main idea of SFLAC is to control the load acceleration which can be estimated by the state observer including the disturbance estimation. A simple PI speed controller and SFLAC based on the reduction models using two and three inertia moments are designed. The effectiveness of SFLAC is demonstrated showing some simulation results     

Speed control system and design of resonant system with disturbance observer

In industrial motor drive systems such as industrial plants and industrial robots, a torsional vibration often is generated because of the elastic elements in torque transmission. This vibration makes it difficult to achieve quick responses of speed and may result in damage to the plant. Such systems simply are modeled as a two mass system. The shaft torque feedback system with the disturbance observer, which is called “resonance ratio control,” is proposed to suppress the vibration for the two-mass system. In this paper, the design of controller gains in the shaft torque feedback system is examined considering not only the control performance such as the vibration suppression and dynamic responses, but also the robust stability against the noise and the model uncertainties. This paper shows the validity of the control system and the examinations by several experiments.     

Active vibration control of a motor system by using H∞ control theory

This paper considers the vibration control of a motor system which has a motor and a load connected with a flexible shaft. However, this system often generates a shaft torsional vibration. Traditional methods of treating this problem to adjust the PID controller so that the closed-loop frequency response is slower than that of the vibration mode. On the other hand, one method has already been proposed in which the vibration is suppressed by a disturbance observer. This paper proposes a new approach based on H_∞ control theory. For comparison, a PI control system based on classical control theory also is constructed. The results of several experiments show that compared with the PI control system, the H_∞ control system is effective in suppressing the vibration. Further, the H_∞ controller obtained in the study consists of a PI controller and a series compensator that functions as an active vibration controller.     

基于ESO-backstepping的多机电力系统非线性鲁棒励磁解耦控制

通过构造扩张状态观测器(extended state observer,ESO)对发电机励磁系统模型误差和不确定外扰进行动态补偿,并运用反步法对补偿后的模型设计非线性解耦控制律。由于该方法对系统模型的非线性部分有选择地利用ESO进行动态补偿,既避免了运用反步法设计时自适应参数的引入,又能充分利用系统的特性,减轻ESO的估计负担,有效地兼顾了控制器鲁棒性及控制精度这两方面的要求。仿真表明：该方法鲁棒性强,参数易于选取,与比例–积分–微分(proportion-integration- differentiation,PID)+电力系统稳定(power system stabilizer,PSS)控制器励磁控制器相比较,具有更为优秀的动态品质,方法简单有效。     

单元机组协调系统的非线性内模控制

协调系统的性能直接影响单元机组运行的安全性和经济性。为了克服非线性环节以及能量供需之间关联耦合作用对协调系统控制品质的影响，本文将反馈线性化方法与多变量内模控制结构结合，针对一个通用的非线性协调系统模型，设计出非线性内模协调控制器。文中分析了多变量非线性内模控制结构的鲁棒稳定性及动态性能。在不同负荷下的仿真试验表明，所设计的控制系统具有良好的解耦效果和抗干扰能力。     

Vibration control of flexible arm by multiple observer structure

This paper describes vibration control of a flexible arm by multiple‐observer structure using the accelerations of the arm. In general, a flexible arm has several oscillation modes. In the model of a flexible arm described as a two‐mass resonant system, the reaction torque feedback makes the flexible arm system stable. In the N‐mass resonant system, it is known that the reaction torque feedback makes all oscillation modes, only the reaction torque feedback is not enough to make the system stable. Resonance ratio control with the arm disturbance observer has been proposed. The arm disturbance observer is able to suppress the disturbance applied to the tip, but it is not sufficient for the disturbance applied to other points on the arm. The aim is to make the control system robust to arm inertia variation and disturbance. This paper proposes vibration control of flexible arm by acceleration feedback, and disturbance rejection by multiple‐observer structure using the acceleration of the arm. The validity of the proposed method is shown by simulations and experiments. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(2): 68–75, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20175