多个线性时滞系统的关联稳定与协调控制

研究线性时滞系统的时滞无关关联稳定性和协调控制问题.利用双线性矩阵不等式(BMI),给出了两个系统关联稳定和协调镇定的充分条件,将关联和协调控制器的设计问题转化为具有BMI约束的非凸优化问题,并给出了求解这类问题的交替算法.最后,通过一个数值例子来说明本文结果的有效性.研究结果表明,不稳定的时滞系统可以通过设计关联或协调控制构成稳定的组合系统.     

基于BMI方法的线性系统的关联稳定与协调控制

本文研究了线性大系统的关联稳定与协调控制问题. 基于双线性矩阵不等式, 给出了两个子系统关联稳定与协调镇定的充分与必要条件. 结论表明, 即使子系统不稳定, 组成的大系统也易能被协调镇定, 而不需要假定子系统的稳定. 其次, 协调控制器的设计问题转化为 BMI 约束下的优化问题, 为求解此问题, 提出了优化交替算法, 并给出了此算法收敛性的简单证明. 最后, 数值算例表明了优化算法的有效性.     

Lurie控制系统的关联绝对稳定性—双线性矩阵不等式方法

研究任意两个相互独立的Lurie控制系统能否通过关联或协调控制组成绝对稳定大系统的问题,给出两个Lurie控制系统可关联绝对稳定的充分条件,并给出了计算关联矩阵的双线性矩阵不等式方法.研究结果表明:两个非绝对稳定的系统可以通过关联或协调控制来实现关联大系统的绝对稳定性,取消了大系统稳定性分析中对关联的不合理限制.文末给出了本文结果的数值例子.     

Lurie控制系统的关联绝对稳定性一双线性矩阵不等式方法

研究任意两个相互独立的Lurie控制系统能否通过关联或协调控制组成绝对稳定大系统的问题，给出两个Lurie控制系统可关联绝对稳定的充分条件，并给出了计算关联矩阵的双线性矩阵不等式方法．研究结果表明：两个非绝对稳定的系统可以通过关联或协调控制来实现关联大系统的绝对稳定性，取消了大系统稳定性分析中对关联的不合理限制．文末给出了本文结果的数值例子．     

多输入／多输出实时计算机协调施力控制系统的设计与实现

本文给出了电液伺服系统三点实时协调控制加载的一种设计方法.这种具有条件输出反馈补偿器的系统在协调结构上是比较简单的.该协调控制器是用于变后掠机机翼的升力加载控制系统之中.通过5000次重复试验表明,本文所提出的方法是可行的,试验结果是优良的.本方法对静止和运动加载式实时计算机力控制系统的设计具有实用价值.     

带时滞的双时间尺度系统反馈镇定

研究带时滞的双时间尺度系统的反馈镇定问题,首先,给出子系统稳定的一个充分条件.然后,利用两个子系统稳定性得到带时滞的双时间尺度系统稳定的一个充分条件,最后,利用线性反馈分析得到两个子系统的稳定设计,从而使得整个系统稳定.给出一个数值例子验证了可行性和有效性.     

一种基于行为效用理论的多移动机器人编队协调方法

本文提出了一种基于行为效用理论的多移动机器人编队协调方法，用于解决多移动机器人编队初始化问题，实现自治的多移动机器人按特定的空间结构进行编队以完成特定的任务．我们对编队问题协调控制策略和算法进行了研究，给出了行为效用方程及两个衡量值，并针对编队问题的协调控制过程中目标点重复决策问题及偏远目标的选择问题进行了探讨并给出了相应的改进协调方案，计算机仿真试验验证了本文所提方法的有效性和可行性．     

基于Petri网的事件协调控制方法研究

事件的协调控制是离散事件系统中一项重要的研究内容,同时包含资源约束和事件约束的混杂约束更是系统设计的难点问题。以DES系统的加权Petri网模型为基础,以DES中变迁库所混杂约束的转换问题为研究对象,将事件协调约束转换为Petri网系统的结构约束,使得库所变迁混合约束问题转化为单一的库所约束问题。首先,提出基于Petri网的事件协调控制方法的设计算法,通过研究变迁约束转换为库所约束的规则与方法,将DES变迁库所混杂约束问题转换为单一的库所约束问题,从库所约束的角度来分析事件协调控制。其次,在3种不同系数约束的变迁≤约束表达式下,利用Petri网结构的特性,将变迁间的协调控制约束转换为系统的库所≤约束,并给出具体的算法步骤。最后,给出基于Petri网的事件协调控制方法的技术难点,剖析进一步分析和研究的主要问题。     

一类关联非线性系统的全局镇定

研究一类线性部分为传递函数,且带有不确定非线性部分的两个相互独立的输出反馈非线性系统关联后的反馈镇定问题.结合Lurie型直接控制系统,给出系统输出全局稳定的充分条件,最后对一个数值例子作仿真,说明了本文方法的有效性.     

汽车转向/防抱死制动系统的非线性鲁棒协调控制

针对汽车转向系统和防抱死制动系统的协调控制问题,提出一种新的非线性鲁棒协调控制系统.该控制结构由转向控制器和制动控制器组成.为了改善整个系统的鲁棒性和协调性,根据汽车转向和制动非线性综合模型,基于Hamilton函数方法设计了汽车非线性鲁棒协调控制器.该控制器通过预置状态反馈完成系统的耗散Hamilton函数实现.设计了适用于复杂工况的制动力分配策略.仿真结果验证了所设计控制算法的稳定性和有效性.     

Special decentralized control problems in discrete-time interconnected systems composed of two subsystems

In this paper, some special decentralized control problems are addressed for discrete-time interconnected systems. First it is pointed out that some subsystems must be unstable to ensure stability of the overall system in some special cases. Then a special kind of decentralized control problem is studied. This kind of problem can be viewed as harmonic control among independent subsystems. Research results show that two unstable systems can generate a stable system through some effective cooperations. In addition, a decentralized controller design method based on linear matrix inequality is also given by using parameter-dependent Lyapunov function method developed for the study of robust stability. A special linear star coupled dynamical network is also considered. The central subsystem must be unstable to stabilize the whole network under a special coupling. Several examples are given to illustrate the results.     

一类组合类摆系统的双态性

The property of dichotomy of interconnected second-order pendulum-like systems with multiple equilibria is investigated. This interconnection can be viewed as harmonic control of independent subsystems. Linear interconnections and a class of input and output interconnections are considered in this paper. The effects of input and output interconnections are shown through a permutation matrix. Frequency domain and linear matrix inequality (LMI) conditions of dichotomy of interconnected pendulum-like systems are derived. It is shown that global properties of two coupled systems can be changed significantly through interconnections. Examples are given to illustrate the results.     

Composite disturbance-observer-based control and terminal sliding mode control for uncertain structural systems

A new type of composite control scheme of disturbance-observer-based control and terminal sliding mode control (TSMC) is proposed for uncertain structural systems. The disturbance are supposed to include two parts. One is generated by an exogenous system, which can represent the harmonic signals with modelling perturbations in structural system. The other part is external excitation in H ₂-norm context. The disturbance observers based on regional pole placement and D-stability theory are presented, which can be designed separately from the controller design. By integrating the disturbance observer with TSMC law, the disturbance with the exogenous system can be estimated and compensated, and external excitation can be attenuated in finite time. Finally, simulations for a four-degree-of-freedom building model excited by 1940 El Centro earthquake excitation are given to demonstrate the effectiveness of the approach and compare the proposed results with the previous schemes with accuracy.     

Composite disturbance-observer-based control and terminal sliding mode control for non-linear systems with disturbances

A novel type of control scheme combining the disturbance-observer-based control (DOBC) with terminal sliding mode (TSM) control is proposed for a class of multiple-input–multiple-output (MIMO) continuous non-linear systems subject to disturbances. The disturbances are supposed to include two parts. One in the input channel is generated by an exogenous system with uncertainty, which can represent the harmonic signals with modelling perturbations. The other is supposed to have the bounded H ₂ norm. The disturbance observers based on regional pole placement and D-stability theory are presented, which can be constructed separately from the controller design. By integrating DOBC with TSM control laws, the disturbances can be rejected and attenuated, simultaneously, and the desired dynamic performances can be guaranteed for non-linear systems in finite time with known and unknown non-linear dynamics, respectively. Two simulation examples for a flight control system and a hard disk drive actuator are given respectively to demonstrate the effectiveness of the proposed control schemes compared with the previous schemes.     

基于辅助变压器的逆变控制技术研究

在六阶梯波逆变器中采用谐波注入法能够减少输出波形的谐波。本文对带有辅助变压器的六阶梯波逆变器的开关控制技术进行了研究，给出了辅助变压器的变比和开关元件导通角与逆变器输出谐波之间的函数关系．通过对该函数关系的分析，求出了使逆变器输出谐波最小时的最佳变比和开关元件的最佳导通角，并给出了实现该控制方法的逻辑电路框图和仿真实验结果。     

Properties of pseudo-harmonic systems

The concept of pseudo-harmonic systems is introduced under the model of general systems given by Lin (1987). The concept can be thought as an abstract of some problems in optimization theory and is a generalization of harmonic systems introduced by Ma and Lin (1987 a). Some elementary properties of pseudo-harmonic systems and three basic principles are given, a few questions are posed, and a few tests of applications of the results are discussed.     

Stability and performance of current harmonic controllers for multiphase PMSMs

Multiphase electric machines can provide significant benefits over conventional three-phase machines. A drawback to multiphase machines is that they are known to have problems with stator current harmonics. The harmonics can be eliminated by various current harmonic control methods. However, there appears to be no clear agreement on the most suitable method for multiphase machines. This paper aims to compare different current harmonic controllers in terms of stability and performance under model uncertainty. A detailed theoretical analysis of the harmonic controllers is given by taking a modern multi-input multi-output approach based on a structured singular value analysis. Further, the performance of the harmonic controllers is studied with experimental results from a dual three-phase permanent magnet synchronous machine. The analysis and results of this paper show how to design robust high-performance current harmonic controllers for multiphase machines.     

时滞反馈力作用下含有分数阶阻尼的随机系统的响应与分叉研究

分析了时滞反馈力作用下含有分数阶阻尼的随机系统,并讨论了该系统的稳态响应及随机分叉.首先,通过对含有时滞项的近似处理以及基于广义谐和函数的随机平均法得到了该系统的稳态响应.然后使用算例对方法的有效性进行了验证,其中主要研究了时滞反馈作用力和分数阶阻尼对系统稳态响应的影响,结果表明上述两者的变化会影响系统的稳态响应并引发随机分叉现象.     

Real-time particle swarm optimization based current harmonic cancellation

As a powerful optimization algorithm, particle swarm optimization (PSO) has been widely applied to power system researches. However, most existing applications of PSO can only be implemented offline. The difficulties of online implementation mainly come from the unavoidable lengthy simulation time to evaluate a candidate solution. Recently, PSO was implemented online that can identify parameters in a motor control systems. In this paper, the real-time PSO (RT-PSO) based identification technique is applied to cancel current harmonics in power systems. By transforming the identification problem to optimization problem, RT-PSO can simultaneously identify four parameters associated with fundamental current from measurement. In this way, there is no need to identify the fundamental frequency separately or construct fundamental signal from identified harmonic information. The identification algorithm can be applied to three-phases independently, even for unbalanced system or single-phase system. The identified fundamental signal is then used as the reference for current harmonics cancellation. The RT-PSO based harmonic cancellation is realized with an active filter and used to compensate harmonic current created by a nonlinear load. Simulation results demonstrate that the RT-PSO algorithm can provide accurate identification of the fundamental current which in turn will result in good harmonic cancellation performance. As a capable online optimization technique, RT-PSO can be extensively applied to many optimization and control problems.     

对称规则SPWM的谐波分析及DSP实现

给出了一种基于DSP芯片TMS320F240的对称规则SPWM信号生成法，较为详尽地分析了SPWM信号的谐波成分、总谐波失真度及其和载波比的关系。由于只需知道采样时刻，就可确定该采样周期内脉冲信号的开关点，因此SPWM特别适合在线计算。对生成的SPWM信号进行Fourier分析，结果表明，正弦波经过该方式调制以后．输出信号中不含有直流成分；当载波比为偶数时，输出信号中不含偶次谐波；提高载波比有利于滤除高次谐波。根据以上特点，将SPWM应用到某型制冷机减振电机的驱动上，对实测的电压和电流信号进行分析，其结果与理论分析相吻合。与采用模拟信号驱动的方式进行了比较，最后给出了实验结果。