Pole placement method of controlling chaos in DC-DC buck converters

Based on the mechanism for the generation of chaos in a buck converter, a pole placement method is proposed and applied to controlling the chaos in a circuit. The control circuit is designed and tested. Numerical calculation and circuit implementation demonstrate the validity of this chaos control method.

Erratum to“A note on overshoot estimation in pole placements”

There is a mild flaw in the statement of Proposition 2.1 in the above paper （cf. [1] ）. We restate it as follows.

POLE PLACEMENT CONTROLLERS FOR LINEAR TIME-DELAY SYSTEMS WITH COMMENSURATE POINT DELAYS

This paper investigates the exact and approximate spectrum assignment properties associated with realizable output-feedback pole-placement type controllers for single-input single-output linear time-invariant time-delay systems with commensurate point delays. The controller synthesis problem is discussed through the solvability of a set of coupled diophantine equations of polynomials. An extra complexity is incorporated to the above design to cancel extra unsuitable dynamics being generated when solving the above diophantine equations. Thus, the complete controller tracks any arbitrary prefixed (either finite or delay-dependent) closed-loop spectrum. However, if the controller is simplified by deleting the above mentioned extra complexity, then the robust stability and approximated spectrum assignment are still achievable for a certain sufficiently small amount of delayed dynamics. Finally, the approximate spectrum assignment and robust stability problems are revisited under plant disturbances if the nominal controller is maintained. In the current approach, the finite spectrum assignment is only considered as a particular case to the designer's choice of a (delay-dependent) arbitrary spectrum assignment objective.

AN ALGEBRAIC METHOD FOR POLE PLACEMENT IN MULTIVARIABLE SYSTEMS

This paper considers the pole placement in multivariable systems involving known delays by using dynamic controllers subject to multirate sampling. The controller parameterizations are calculated from algebraic equations which are solved by using the Kronecker product of matrices. It is pointed out that the sampling periods can be selected in a convenient way for the solvability of such equations under rather weak conditions provided that the continuous plant is spectrally controllable. Some overview about the use of nonuniform sampling is also given in order to improve the system's performance.

An Improvement on Data-Driven Pole Placement for State Feedback Control and Model Identification

The recently proposed data-driven pole placement method is able to make use of measurement data to simultaneously identify a state space model and derive pole placement state feedback gain. It can achieve this precisely for systems that are linear time-invariant and for which noiseless measurement datasets are available. However, for nonlinear systems, and/or when the only noisy measurement datasets available contain noise, this approach is unable to yield satisfactory results. In this study, we investigated the effect on data-driven pole placement performance of introducing a prefilter to reduce the noise present in datasets. Using numerical simulations of a self-balancing robot, we demonstrated the important role that prefiltering can play in reducing the interference caused by noise.

Control strategy for pneumatic rotary position servo systems based on feed forward compensation pole-placement self-tuning method

The pneumatic rotary position system, in which an electro-pneumatic proportional flow valve controled a rotary cylinder, was studied, and its mathematical model was built. The model indicated that the controlled pneumatic system had disadvantages such as inherent non-linearity and variations of system parameters with working points. In order to improve the dynamic performance of the system, feed forward compensation self-tuning pole-placement strategy was adopted to place the poles of the system in a desired position in real time, and a recursive least square method with fixed forgetting factors was also used in the parameter estimation. Experimental results show that the steady state error of the pneumatic rotary position system is within 3% and the identified system parameters can be converged in 5 s. Under different loads, the controlled system has an excellent tracking performance and robustness of anti-disturbance.

CONTINUOUS-TIME GENERALIZED PREDICTIVECONTROL WITH POLE-PLACEMENT

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Enhancement of Ride Quality of Quarter Vehicle Model by Using Mixed H2/H with Pole-Placement

The aim of the present work is to illustrate the application of mixed H2/H∞ control theory with Pole-Placement in de- signing controller for semi-active suspension system. It is well known that the ride comfort is improved by reducing vehicle body acceleration generated by road disturbance. In order to study this phenomenon, Two Degrees of Freedom (DOF) in state space vehicle model was built in. However, the role of H is to minimize the disturbance effect on the output while H2 is used to improve the input of controller. Linear Matrix Inequality (LMI) technique is used to calculate the dynamic controller parameters. The simulation results show that the H2 and H techniques can effectively control the vibration of vehicle system where the reduction of suspension working space, dynamic tire load and body acceleration. Moreover, the simulation results show that the (RMS) of suspension working space was reduced by 44.5%, body acceleration and dynamic tire load are reduced by 18.5% and 20% respectively.

动力学系统在亏损时的反馈控制设计

通过引入反馈控制,使亏损系统动态特性得到优化。基于广义模态理论,利用系统矩阵结构特征,讨论亏损系统增益向量的计算方法,简化计算过程。通过分析二自由度飞机机翼运动学模型数据,验证该方法的有效性。

弹性驱动系统二自由度速度控制策略

针对二惯量弹性驱动系统,为了提高系统的稳定性,文章基于极点配置法对IP和PI速度控制系统进行参数设计,分析系统的阻尼特性。为改善系统快速性和稳定性,导入二自由度控制技术提高系统的设计自由度并增加一个前馈调节因子,分析其调节规律并给出一种设计方案。仿真分析表明,极点配置法结合二自由度控制可以保证速度控制系统快速性和稳定性的平衡,并且通过实验论证了设计的有效性。

Robust L_1 filtering with pole constraint in a disk via parameter-dependent Lyapunov functions

The problem of robust L 1 filtering with pole constraint in a disk for linear continuous polytopic uncertain systems is discussed. The attention is focused on design a linear asymptotically stable filter such that the filtering error system remains robustly stable, and has a L 1 performance constraint and pole constraint in a disk. The new robust L 1 performance criteria and regional pole placement condition are obtained via parameter-dependent Lyapunov functions method. Upon the proposed multiobjective performance criteria and by means of LMI technique, both full-order and reduced-order robust L 1 filter with suitable dynamic behavior can be obtained from the solution of convex optimization problems. Compared with earlier result in the quadratic framework, this approach turns out to be less conservative. The efficiency of the proposed technique is demonstrated by a numerical example.

LMI Approach to Robust H_∞/H_2 Controller Design with Regional Poles Constraint of a Pump-Motor System

The time domain guideposts requirements of a pump-motor system is transfered into a series of constraints which express the robust performance upper bound and regional poles limits of the closed loop system. Then the servo system control problem is transferred into the problem of robust performance optimizing under regional poles constrains described by linear matrix inequality （LMI）. These LMIs are easy to solve through the Matlab LMI-toolbox. Simulations indicate that the controller has excellent dynamic, static and disturbance rejection performance, and the control system is robust and has perfect H2 performance to the bounded external torque disturbance.

Robust L_2-L_∞ filtering with pole constraint in a disk via parameter-dependent Lyapunov functions

Addresses the design problems of robust L2-L∞ filters with pole constraint in a disk for uncertain continuous-time linear systems. The uncertain parameters are assumed to belong to convex bounded domains. The aim is to determine a stable linear filter such that the filtering error system possesses a prescribed L2-L∞ noise attenuation level and expected poles location. The filtering strategies are based on parameter-dependent Lyapunov stability results to derive new robust L2-L∞ performance criteria and the regional pole placement conditions. From the proposed multi-objective performance criteria, we derive sufficient conditions for the existence of robust L2-L∞ filters with pole constraint in a disk, and cast the filter design into a convex optimization problem subject to a set of linear matrix inequality constraints. This filtering method exhibits less conservativeness than previous results in the quadratic framework. The advantages of the filter design procedures are demonstrated by means of numerical examples.

Distributed Adaptive Output Consensus of Unknown Heterogeneous Non-Minimum Phase Multi-Agent Systems

This article addresses the leader-following output consensus problem of heterogeneous linear multi-agent systems with unknown agent parameters under directed graphs.The dynamics of followers are allowed to be non-minimum phase with unknown arbitrary individual relative degrees.This is contrary to many existing works on distributed adaptive control schemes where agent dynamics are required to be minimum phase and often of the same relative degree.A distributed adaptive pole placement control scheme is developed,which consists of a distributed observer and an adaptive pole placement control law.It is shown that under the proposed distributed adaptive control scheme,all signals in the closed-loop system are bounded and the outputs of all the followers track the output of the leader asymptotically.The effectiveness of the proposed scheme is demonstrated by one practical example and one numerical example.

基于极点配置方法的机器人柔性关节转速抑制策略研究

针对含有柔性关节的机械臂易出现转速波动的问题,在PI控制策略的基础上利用极点配置的方法优化控制器参数,进而通过提高输出转速精度的方式减弱机械臂的振动程度。首先,根据双惯量模型建立机械臂中柔性关节的动力学模型,进而通过动力学模型的数学表达式获得柔性关节的状态空间方程;其次,根据状态空间方程求得电机转速到电机电磁转矩的传递函数;第三,采用基于相同幅值的基于极点配置的PI控制策略优化控制器参数,并分析不同的极点参数对于系统动态特性的影响;最后,为了验证所提出控制策略的有效性,利用MATLAB对机械臂柔性关节伺服系统进行数值仿真实验,并搭建柔性关节的物理样机控制实验平台开展输出转角控制实验。数值仿真实验和物理样机控制实验表明:该文所提出的控制策略可通过适当选择极点参数使系统获得良好的动态特性,相比于传统的PI控制策略能够提高输出转速控制精度、抑制机械臂振动。

鸭式导弹自动驾驶仪开环截止频率的设计约束

极点配置方法在三回路驾驶仪设计中应用较广,针对开环截止频率这一关键参数的设计约束较为模糊。通过建立控制增益、闭环极点与系统开环截止频率的解析关系,将控制系统设计问题转化为开环截止频率的合理选择。结合鸭式布局导弹工程设计经验,分别讨论了舵机带宽、舵偏角速率、闭环零点和控制增益极性对开环截止频率选取的约束准则和工程应用修正,通过典型条件验证了该准则的适用性。

基于多主导极点法的时滞积分系统PID控制器设计

伺服与扰动抑制是时滞积分系统最基本的控制问题,对其进行控制难度较大。文中提出一种基于直接综合法和多主导极点配置法的微分先行PID(Proportional-Integral-Derivative)整定方法,这种方法通过比较串联滤波器与时滞积分被控对象组成的特征方程与实际期望的特征方程的系数,将三阶主导极点置于-1/λ处,并将二阶非主导极点置于-5/λ处(λ为调整参数),从而获得期望的特征方程。以实现期望的鲁棒性方式获得设计的控制器参数,通过选择不同的调优参数获取相应的Ms(Maximum sensitivity)值,在参数具有标称性的限定条件下拟合出关于Ms和调优参数的关系曲线,给出整定规则的解析形式。PIPTD(Pure Integral Plus Time Delay system)、DIPTD(Double Integral Plus Time Delay system)和FOPTDI(First-Order Plus Time Delay Integral System)系统的仿真结果表明,IAE(Integral Absolute Error)指标平均可降低35.79%,TV(Total Variation)指标平均可降低18.97%。

基于递归正位置反馈的三阶压电纳米定位台谐振控制

针对压电纳米定位台的低阻尼谐振振动,设计了一种基于递归结构的正位置反馈控制器(RPPF)的闭环控制方法。利用激励信号输入平台进行系统辨识并使用零极点对消方法简化三阶系统,对闭环特征方程使用费拉里法求解。针对控制器参数较多,极点配置不够准确等问题,利用飞蛾扑火算法对RPPF控制器进行参数配置。实验结果表明,与正位置反馈控制器(PPF)相比,递归正位置反馈控制器(RPPF)将三阶压电纳米定位台的闭环带宽从531 Hz提升到663 Hz,且50 Hz三角跟踪的最大绝对误差和均方根误差分别降低了30.12%和26.47%,具有更好的跟踪速度和精度。

高性能逆变器模拟控制器设计方法

分析表明如果设计方法欠佳,PID控制器不能发挥优良调节能力,使逆变器单环控制系统性能不很理想。该文提出一种基于极点配置的逆变器瞬时电压PID控制器设计方法,使PID控制逆变器动态响应快速、非线性负载情况下输出电压THD低,稳态精度高,系统鲁棒性强。在理论上,从状态空间的角度阐述了此方法使PID控制逆变器系统性能优良的本质。仿真与实验结果有效地验证了理论分析。逆变器瞬时电压PID控制与电压电流双环控制相比,在电路结构、成本等方面更具优越性。

一种高性能的单相逆变器多环控制方案

提出了一种高性能的单相逆变器控制策略。该方案在电压电流双闭环控制基础上增加了外层的重复控制器。在实现输出电压解耦和扰动电流补偿后,电压外环采用比例积分环节,电流内环采用比例环节的控制器。理论分析证明在这种双环结构下,可以实现任意配置闭环极点,因而使逆变器达到了很快的响应速度及较好的稳态精度。位于内层的双环瞬时控制器改善了系统的动态特性,位于外层的重复控制器提高了稳态精度及抗非线性负载扰动的能力,两种控制器各司其职,互为补充,为单相逆变器波形控制提供了一种接近完美的控制方案。最后在一台基于DSPTMS320F240的单相PWM逆变器实验装置上验证了该控制方案的正确性。