基于专家知识的自校正控制器

本文讨论了参数自校正问题，提出了基于专家知识和智能推理的自校正控制器的设计方法，并给出了工程实践例证。

离散系统输出反馈强正实控制器综合

基于正实引理使用线性矩阵不等式（ＬＭＩ）方法讨论了离散系统一般强正实控制问题的解，给出了任意阶输出反馈强正实控制器的存在条件．证明了给定离散系统可输出反馈强正实当且仅当三个ＬＭＩ存在一个合适解，可低阶输出反馈强正实当且仅当带秩约束条件的三个ＬＭＩ存在一个合适解．

正线性时滞系统的L_1(l_1)-增益性能分析及正控制器设计

讨论连续(离散)时间正线性时滞系统的L_1(l_1)-增益性能分析及正控制器设计问题.由于正系统的非负特性,自然地可利用L_1(l_1)-增益来估计系统的性能.首先,给出了正线性时滞系统渐近内稳定且满足给定的L_1(l_1)-增益指标的充要条件.然后,基于上述条件,针对单输入系统,利用奇异值分解(SVD)方法给出了正L_1(l_1)-控制器存在的充要条件,此条件可表示为非线性规划(NLP)问题.并将所给的方法推广到多输入情形,得到了具有特殊形式的L_1(l_1)-控制器的存在条件.最后,给出数值算例来验证理论结果的有效性.

降阶正实控制器设计

基于线性矩阵不等式 (LMI)方法 ,考虑了连续和离散对象的降阶正实控制器设计问题 .通过一阶对象的分析表明 ,广义对象阶是最小阶正实控制器阶的可达上界 ,因此降阶正实控制器的存在性依赖于具体对象参数 .给出了一个新的降阶正实控制器阶的上界 ,该上界蕴涵了已有结果 .上界的估计是构造性的 ,可以给出这种降阶正实控制器的设计算法 .文中给出了简单的算例 。

广义系统输出反馈严格正实控制器设计

研究连续广义系统的正实控制问题。目的是设计静态输出反馈和动态输出反馈严格正实控制器使得闭环系统容许且扩展严格正实。基于广义系统严格正实引理,利用线性矩阵不等式和广义代数Riccati不等式,给出了广义系统静态输出反馈和动态输出反馈严格正实控制器存在的充要条件及设计方法。对动态输出反馈情形,给出了一个数值算例说明控制器设计方法的有效性及可行性。

线性系统严格正实控制器设计的LMI方法

基于LMI方法运用严格正实引理讨论了一类线性系统严格正实控制器的问题 ,给出了输出反馈严格正实控制器的存在条件和设计方法 .

在线推理式自校正模糊控制器的原理及应用

介绍了一种自校正模糊控制器.该控制器在保证对系统的实时控制的基础上,采用在线式推理方式,通过引入调整因子,依据具体情况相应改变推理规则,通过模糊推理,最后将各部分结果相加,得到综合结果.还给出了该控制器在焊接自动控制中的具体应用事例.通过仿真,将自校正模糊控制器与简单模糊控制器做了比较.实践表明该控制器具有较好的适应性.

TI推出新型正高压热插拔控制器

日前，德州仪器(TI)宣布推出采用可编程电源与电流限制功能的热插拔电源管理器，以支持9～80V的正压系统。该款10引脚的3毫米×5毫米新型控制器充分利用了TI新的0．7微米硅绝缘体模拟工艺(silicon—on—insulator analog process)，以确保提供全面的MOSFET安全工作区(SOA)保护，从而简化了高压系统设计。

带有多个状态滞后的连续系统正实控制

针对以往研究的连续系统中没有同时考虑多个状态滞后和执行器故障的情况,对带有多个状态滞后的连续系统进行了研究.通过理论分析得出了这类系统渐近稳定且扩展严格正实的充分条件.在此基础上,对这类系统存在不确定性和执行器故障的情况进行了研究.结果表明,所设计的正实控制器能够保证闭环系统对容许不确定性及执行器故障都是渐近稳定和扩展严格正实的.同时,通过实例分析,说明所提出的正实控制器设计方法可行且有效.

一种基于阀值开关与双环控制的新型锁相环

级联DSC算法被广泛地应用于提取电网电压正序基波分量,但是该算法存在延时时间内无法工作的问题。针对该问题,设计了级联DSC与正序相序谐振控制器协同控制的方案来分离电压基波分量。为应对不同的电网故障,提出了一种阀值开关技术,将电网故障进行分类,并选取相对应的控制结构来进行优化控制。基于所提方法在Matlab/Simulink中搭建了相应的锁相环模型,仿真结果表明在电网故障及存在谐波污染的条件下,所提的新型锁相环方法能够快速、准确地锁定电网电压相位,并且削弱了故障对锁相环输出频率的影响。

Trigonometric Regularization and Continuation Method Based Time-Optimal Control of Hypersonic Vehicles

Aiming at the time-optimal control problem of hypersonic vehicles(HSV)in ascending stage,a trigonometric regularization method(TRM)is introduced based on the indirect method of optimal control.This method avoids analyzing the switching function and distinguishing between singular control and bang-bang control,where the singular control problem is more complicated.While in bang-bang control,the costate variables are unsmooth due to the control jumping,resulting in difficulty in solving the two-point boundary value problem(TPBVP)induced by the indirect method.Aiming at the easy divergence when solving the TPBVP,the continuation method is introduced.This method uses the solution of the simplified problem as the initial value of the iteration.Then through solving a series of TPBVP,it approximates to the solution of the original complex problem.The calculation results show that through the above two methods,the time-optimal control problem of HSV in ascending stage under the complex model can be solved conveniently.

Controlling Chaos in a Semiconductor Laser via Weak Optical Positive Feedback and Modulating Amplitude

Numerical analysis of weak optical positive feedback （OPF） controlling chaos is studied in a semiconductor laser. The physical model of controlling chaos produced via modulating the current of semiconductor laser is presented under the condition of OPF. We find the physical mechanism that the nonlinear gain coefficient and linewidth enhance- ment factor of the laser are affected by OPF so that the dynamical behaviour of the system can be efficiently controlled. Chaos is controlled into a single-periodic state, a dual-periodic state, a tri-periodic state, a quadr-periodic state, a pentaperiodic state, and the laser emitting powers are increased by OPF in simulations. Lastly, another chaos-control method with modulating the amplitude of the feedback light is presented and numerically simulated to control chaotic laser into multi-periodic states.

IMC based robust PID controller tuning for disturbance rejection

It is well-known that the IMC-PID controller tuning gives fast and improved set point response but slow disturbance rejection. A modification has been proposed in IMC-PID tuning rule for the improved disturbance rejection. For the modified IMC-PID tuning rule, a method has been developed to obtain the IMC-PID setting in closed-loop mode without acquiring detailed information of the process. The proposed method is based on the closed-loop step set point experiment using a proportional only controller with gain K_(c0). It is the direct approach to find the PID controller setting similar to classical Ziegler-Nichols closed-loop method. Based on simulations of a wide range of first-order with delay processes, a simple correlation has been derived to obtain the modified IMC-PID controller settings from closed-loop experiment. In this method, controller gain is a function of the overshoot obtained in the closed loop set point experiment. The integral and derivative time is mainly a function of the time to reach the first peak(overshoot). Simulation has been conducted for the broad class of processes and the controllers were tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison. The PID controller settings obtained in the proposed tuning method show better performance and robustness with other two-step tuning methods for the broad class of processes. It has also been applied to temperature control loop in distillation column model. The result has been compared to the open loop tuning method where it gives robust and fast response.

Digitally Controlled Boost PFC Converters Operating with Large Scale Load Fluctuations

When boost power factor correction(PFC) circuit works with large scale load fluctuations, it is easy to cause a higher total harmonic distortion and a lower power factor because of traditional controllers and inductor current mode. To solve this problem, this paper proposes a PFC control system, which can operate with load fluctuations up to 1 000 W by using duty cycle feed-forward control theory to achieve smooth switching mode. The duty cycles in the next period of the control system are pre-estimated in the current cycle, which enhances the speeds of AD samplers and switching frequency, and reduces the cost and volume of the equipment to some extent. Introductions of system decoupling and feed-forward of input-voltage greatly improve the system performance. Both theoretical simulation and experimental results prove the advantage of the proposed scheme.

Modeling and motion control simulation of tendon based parallel manipulator translation mechanism for sensor based high value waste processing

A novel sorting system based on one degree of freedom (DOF) tendon based parallel manipulator (TBPM) for high value waste processing was presented and designed. In order to control the motion of loads, nonlinear state feed forward control algorithm in the tendon length coordinate was used. Considering the system redundancy and actuation behavior, algorithms of optimal tension distribution and forward kinematics were designed. Then, the simulation experiments of motion control were implemented. The results demonstrate that the proposed TBPM translation system performs robust capacities. It can transfer the loads 1 m away within 1.5 s. With further optimization, the translation duration can be further reduced to be about 1 s and the optimized translation is followed with 43.59 m/s2 maximum acceleration. The translation errors at the aim position remain below 0.4 mm.

Accurate Reactive Power Controller and Power Factor Correction Using Fuzzy Logic

This paper presents the use of fuzzy logic technique to control the reactive power of load and hence improve the source power factor. A shunt compensator is proposed, which consists of a voltage controlled reactor by full-wave thyristor bridge in parallel with a capacitor. The proposed voltage control technique composed of two independent fuzzy controllers, primary and secondary. The PFC （primary fuzzy controller） is designed based on linearization method to introduce to the network the nearest value of reactive power （VAR） required to correct the power factor. The SFC （secondary fuzzy controller） is designed to achieve accurate compensation for the required VAR to achieve the pre-set power factor value. Simulations for 15 different practical study cases are presented to evaluate the performance of the controller, and the results show how the designed controller is fast and accurate. Harmonics analyses are carried out up to the 13th harmonic to determine the requirement of harmonics filter.

Automatic Correcting Control Method of RMG Based on Changeable Transducer Connection Form

By analyzing causes, damages and popular solutions for gnawing rail phenomenon of Rail-Mounted Gantry （shorted for RMG）, this article puts forward a kind of automatic correcting control system, the system can change between two transducer connection forms, and as a result, can prevent or decrease gnawing rail problem to a great extent. We present principles of correcting obliquity, sideward displacement of gantry frame and principles of malfunction diagnosis and some important schematic diagrams. The most significant feature of our system is that we can change transducers＇ connection form to respective or cross driving mode according to the extent of obliquity and sideward displacement of gantry frame, which make full use of both modes＇ advantages. As a result, the system not only can minish gnawing rail phenomenon, diagnose causes of gnawing rail and give an corresponding alarm, but also, in cross connection driving mode, has an unique capacity of preventing gnawing rail phenomenon utilizing its own characteristics under cross connection mode and gantry frame＇s rigidity.

On-Line Adaptive Repetitive Controller for Power Factor Correction Systems

When the fundamental frequency is shifting, it is hard for traditional repetitive controller to work at the resonant frequencies. In this paper, a novel adaptive repetitive controller for power factor correction systems is proposed to suppress the current harmonics. Through the controller, the shifting sampling times of the repetitive controller in a fundamental period can be obtained. Mathematical analysis, simulations and physical experiments have validated the effectiveness of the adaptive repetitive controller.

Stable analysis on speed-adaptive observer in regenerating mode

Speed-adaptive full-order flux observer is the most promising flux estimator among all the sensorless control method.However,conventional speed-adaptive flux observer becomes unstable during regenerating operation at low speed since induction motor is an observable system except dc excitation.Thus,the instability problem is caused by inappropriate designing of observer.Based on the eigenvalues of extended observer,this paper interprets unstable situation,that the eigenvalues of extended ob-server have a positive real part.Therefore,the observer cannot converge.Against the two different solutions for unstable prob-lem-positive real maintaining and current error augment,the proposed method based on the eigenvalue could unify these two solutions,which gives the complete stability condition for speed-adaptive full-order observer.It does a lot help in observer de-signing.The observer configured by this proposed method was verified in the torque controlling of 20 kW induction motor.According to the experiment result,with appropriate designing of observer,the unstable situation during regeneration mode could be completely overcome.