检索结果-南通市图书馆

Real-time Feed-forward Force Compensation for active magnetic bearings System Based on H∞ Controller

Chinese Journal of Mechanical Engineering 2011年第1期24卷 58-66页

作者： GAO Hui XU Longxiang College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

There are two kinds of unbalance vibrations—force vibration and displacement vibration due to the existence of unbalance excitation in active magnetic bearings（AMB） system. And two unbalance compensation methods—closed-loop feedback and open loop feed-forward are presented to reduce the force vibration. The transfer function order of the control system directly influencing the system stability will be increased when the closed-loop method is adopted, which makes the real-time compensation not easily achieved. While the open loop method would not increase the primary transfer function order, it provides conditions for real-time compensation. But the real-time compensation signals are not easy to be obtained in the open loop method. To implement real-time force compensation, a new method is proposed to reduce the force vibration caused by the rotor unbalance on the basis of AMB active control. The method realizes real-time and on-line force auto-compensation based on H∞ controller and one novel feed-forward compensation controller, which makes the rotor rotate around its inertia axis. The time-variable feed-forward compensatory signal is provided by a modified adaptive variable step-size least mean square（VSLMS） algorithm. And the relevant least mean square（LMS） algorithm parameters are used to solve the H∞ controller weighting functions. The simulation of the new method to compensate some frequency-variable and sinusoidal signals is completed by MATLAB programming, and real-time compensation is implemented in the actual AMB experimental system. The simulation and experiment results show that the compensation scheme can improve the robust stability and the anti-interference ability of the whole AMB system by using H∞ controller to achieve close-loop control, and then real-time force unbalance compensation is implemented. The proposed research provides a new control strategy containing real-time algorithm and H∞ controller for the force compensation of AMB system. And

关键词： active magnetic bearings H∞ robust controller sensitivity and complementary sensitivity VSLMS algorithm feed-forward compensation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unbalance Vibratory Displacement Compensation for active magnetic bearings

引用

Chinese Journal of Mechanical Engineering 2013年第1期26卷 95-103页

作者： GAO Hui XU Longxiang ZHU Yili College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

As the dynamic stiffness of radial magnetic bearings is not big enough, when the rotor spins at high speed, unbalance displacement vibration phenomenon will be produced. The most effective way for reducing the displacement vibration is to enhance the radial magnetic bearing stiffness through increasing the control currents, but the suitable control currents are not easy to be provided, especially, to be provided in real time. To implement real time unbalance displacement vibration compensation, through analyzing active magnetic bearings （AMB） mathematical model, the existence of radial displacement runout is demonstrated. To restrain the runout, a new control scheme-adaptive iterative learning control （A1LC） is proposed in view of rotor frequency periodic uncertainties during the startup process. The previous error signal is added into AILC learning law to enhance the convergence speed, and an impacting factor/3 influenced by the rotor rotating frequency is introduced as learning output coefficient to improve the rotor control effects, As a feed-forward compensation controller, AILC can provide one tmknown and perfect compensatory signal to make the rotor rotate around its geometric axis through power amplifier and radial magnetic bearings. To improve AMB closed-loop control system robust stability, one kind of incomplete differential PID feedback controller is adopted. The correctness of the AILC algorithm is validated by the simulation of AMB mathematical model adding AILC compensation algorithm through MATLAB soft. And the compensation for fixed rotational frequency is implemented in the actual AMB system. The simulation and experiment results show that the compensation scheme based on AILC algorithm as feed-forward compensation and PID algorithm as close-loop control can realize AMB system displacement minimum compensation at one fixed frequency, and improve the stability of the control system. The proposed research provides a new adaptive iterative/earning cont

关键词： active magnetic bearings unbalance displacement compensation mathematical model adaptive iterative learning control

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nonlinear optimal control of rotating flexible shaft in active magnetic bearings

引用

Science China(Technological Sciences) 2011年第5期54卷 1084-1094页

作者： G. S. TOMBUL S. P. BANKS Department of Automatic Control & Systems Engineering The University of Sheffield

The optimal control of nonlinear systems has been studied for years by many researchers. However, the application of optimal control problem to nonlinear non-affine systems needs more attention. In this paper we propose an optimal control design technique for a class of nonlinear and control non-affine equations. The dynamic equations of a flexible shaft supported by a pair of active magnetic bearings (AMBs) are used as the nonlinear control non-affine equations. Mathematical model for the flexible beam is chosen to be the well known Timoshenko beam model, which takes rotary inertia and shear deformations into account, and it is assumed that the shaft is supported by two frictionless bearings at the ends. The effective control of such systems is extremely important for very high angular velocity shafts which are a feature of many modern machines. The control must be able to cope with unbalanced masses and hence be very robust. We shall approach the problem by discretising the Timoshenko beam model and using standard difference formulae to develop a finite-dimensional model of the system. Then we use a recently developed technique for controlling nonlinear systems by reducing the problem to a sequence of linear time-varying (LTV) systems. An optimal control designed for each approximating linear, time-varying system and recent results show that this method will converge uniformly on compact time intervals to the optimal solution.

关键词： approximation technique nonlinear optimal control timoshenko beam active magnetic bearings

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

active magnetic bearings Control

Active Magnetic Bearings Control

引用

第二十九届中国控制会议

作者： Jozef RITONJA Botjan POLAJZER Drago DOLINAR Bojan GRAR Peter CAFUTA University of Maribor Faculty of Electrical Engineering and Computer Science

In the paper a decentralized control for active magnetic bearings is *** the numerical evaluation of dif-ferent control algorithms a mathematical model of the controlled plant is *** this reason basic characteristics and fundamental operation principle of magnetic levitation as well mathematical model of the rigid shaft are *** control systems for magnetic levitations are *** majority of industrial applications of active magnetic bearings were still based on conventional PID control *** control system design is presented as rule based *** sensitivity of control system on supplementary dynamics,parameter variations and measurement noise is *** active magnetic bearing laboratory system is *** obtained simulation and experimental results are compared.

关键词： active magnetic bearings Mathematical Model Control PID Controller

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Failure Mechanism of Three-level Power Amplifier for active magnetic bearings

Failure Mechanism of Three-level Power Amplifier for Active ...

引用

第二十九届中国控制会议

作者： ZHOU Dan,ZHU Changsheng College of Electrical Engineering,Zhejiang University,Hangzhou Zhejiang 310027,P.R.China

The switching power amplifiers with high efficiency are often required in active magnetic bearings,but they have some problems due to the switching *** fact,the control current in the switching power amplifiers is superimposed with a considerable number of higher *** three-level PWM modulation was proposed to obtain smaller current ripples or lower ***,three-level PWM modulation was found to be failure under some conditions and the failure had seriously affected its *** failure mode and failure mechanism are in detail studied in this ***,the methods for reducing such failure in the three-level switching power amplifiers are suggested.

关键词： active magnetic bearings Failure Mechanism Power Amplifier Three-level

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Characteristic model based all-coefficient adaptive control of an AMB suspended energy storage flywheel test rig

引用

Science China(Information Sciences) 2018年第11期61卷 113-127页

作者： Xujun LYU Long DI Zongli LIN Yefa HU Huachun WU School of Mechanical and Electronic Engineering Wuhan University of Technology Hubei Provincial Engineering Technology Research Center for magnetic Suspension ASML-HMI 1762 Automation Pkwy 4. Charles L.Brown Department of Electrical and Computer Engineering University of Virginia

Feedback control of active magnetic bearing(AMB) suspended energy storage flywheel systems is critical in the operation of the systems and has been well studied. Both the classical proportional-integralderivative(PID) control design method and modern control theory, such as H∞ control and μ-synthesis,have been explored. PID control is easy to implement but is not effective in handling complex rotordynamics. Modern control design methods usually require a plant model and an accurate characterization of the uncertainties. In each case, few experimental validation results on the closed-loop performance are available because of the costs and the technical challenges associated with the construction of experimental test *** this paper, we apply the characteristic model based all-coefficient adaptive control(ACAC) design method for the stabilization of an AMB suspended flywheel test rig we recently constructed. Both simulation and experimental results demonstrate strong closed-loop performance in spite of the simplicity of the control design and implementation.

关键词： adaptive control characteristic modeling energy storage flywheels active magnetic bearings

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Design of high performance linear feedback laws for operation that extends into the nonlinear region of AMB systems

引用

Control Theory and Technology 2017年第4期15卷 301-315页

作者： Lyu, Xujun Hu, Yefa Wu, Huachun Lin, Zongli School of Mechanical and Electronic Engineering Wuhan University of Technology Wuhan Hubei China Hubei Maglev Engineering Technology Research Center Wuhan Hubei China Charles L. Brown Department of Electrical and Computer Engineering University of Virginia Charlottesville U.S.A.

Existing active magnetic bearings （AMBs） operate in the linear region of the magnetic material flux density, which limits the utilization of the bearing capacity. In order to increase the utilization of the bearing capacity and enhance the performance of the AMB system, this paper develops a method for designing high performance linear feedback laws. The resulting feedback laws allow the AMB to operate in its nonlinear region and hence improve the closed-loop performance. We first establish an approximate nonlinear AMB current force response model, and place this nonlinear curve inside a sector formed by two piecewise linear lines. Based on the linear line segments in these two piecewise linear lines, we determine the maximum disturbance that can be tolerated by solving an optimization problem with linear matrix inequality （LMI） constraints. For a given level of disturbance under the maximum tolerable disturbance, we formulate and solve the problem of designing the linear feedback that achieves the highest level of disturbance rejection as another LMI problem. Both g2 disturbances and g disturbances are considered. Finally, we illustrate our design by both simulation and experimental results.

关键词： active magnetic bearings actuator nonlinearities disturbance rejection constrained control

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Control of a flexible rotor active magnetic bearing test rig: a characteristic model based all-coefficient adaptive control approach

引用

Control Theory and Technology 2014年第1期12卷 1-12页

作者： Long DI Zongli LIN Charles L. Brown Department of Electrical and Computer Engineering University of VirginiaP.O. Box 400743 Charlottesville VA 22904-4743 U.S.A.

active magnetic bearings （AMBs） have found a wide range of applications in high-speed rotating machinery industry. The instability and nonlinearity of AMBs make controller designs difficult, and when AMBs are coupled with a flexible rotor, the resulting complex dynamics make the problems of stabilization and disturbance rejection, which are critical for a stable and smooth operation of the rotor AMB system, even more difficult. Proportional-integral-derivative （PID） control dominates the current AMB applications in the field. Even though PID controllers are easy to implement, there are critical performance limitations associated with them that prevent the more advanced applications of AMBs, which usually require stronger robustness and performance offered by modern control methods such as H-infinity control and if-synthesis. However, these advanced control designs rely heavily on the relatively accurate plant models and uncertainty characterizations, which are sometimes difficult to obtain. In this paper, we explore and report on the use of the characteristic model based all-coefficient adaptive control method to stabilize a flexible rotor AMB test rig. In spite of the simple structure of such a characteristic model based all-coefficient adaptive controller, both simulation and experimental results show its strong performance.

关键词： active magnetic bearings Adaptive control Characteristic modeling Flexible rotor Robustness

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

RESEARCH ON CONTROL OF FLYWHEEL SUSPENDED BY active magnetic BEARING SYSTEM WITH SIGNIFICANT GYROSCOPIC EFFECTS

引用

Chinese Journal of Mechanical Engineering 2004年第1期17卷 63-66页

作者： ZhangKai ZhaoLei ZhaoHongbin DepartmentofPhysicalEngineering TsinghuaUniversityBeijing100084China

Traditional PID controllers are no longer suitable formagnetic-bearing-supported high-speed flywheels with significant gyroscopic effects. Becausegyroscopic effects greatly influence the stability of the flywheel rotor, especially at highrotational speeds. Velocity cross feedback and displacement cross feedback are used to overcomeharmful effects of nutation and precession modes, and stabilize the rotor at high rotational *** analysis is given to show their effects. A control platform based on RTLinut and a PCis built to control the active magnetic bearing (AMB) system, and relevant results are *** velocity cross feedback and displacement cross feedback in a closed loop control system, theflywheel successfully runs at over 20000 r/min.

关键词： active magnetic bearings Flywheel Displacement cross feedback Velocitycross feedback Gyroscopic effects

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fuzzy-Immune PID Control for AMB Systems

引用

Wuhan University Journal of Natural Sciences 2006年第3期11卷 637-641页

作者： SU Yixin LI Xuan ZHOU Zude CHEN Youping ZHANG Danhong School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 Hubei China School of Automation Wuhan University of Technology Wuhan 430070 Hubei China

In order to improve the dynamic performance of active magnetic hearing systems with highly nonlinear and naturally unstable dynamics, a new nonlinear fuzzy-immune proportional integral-derivative （PID） controller is proposed by combining the immune feedback law with linear PID con trol. This controller consists of a PID controller and a basic immune proportional controller in cascaded connection, the nonlinear function of the immune proportional controller is realized by using fuzzy reasoning. Simulation results demon strate that the active magnetic bearing system with the proposed controller has better dynamic performance and disturbance rejection ability than using the linear PID controller.

关键词： active magnetic bearings fuzzy reasoning artificial immune fuzzy-immune PID

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：