基于解耦控制的同步传动技术的应用研究

对龙门移动式镗铣床同步传动不一致性问题进行研究,用两台直线电机作为龙门柱纵向进给的传动机构,分析了扰动与输出之间存在的耦合,设计出一种解耦控制器,并用龙门框架不平行时所产生的应力变化进行补偿。仿真结果表明,系统性能良好,并能快速实现同步运行。     

H∞ ALMOST DISTURBANCE DECOUPLING FOR MIMO BILINEAR SYSTEMS

The H_∞ almost disturbance decoupling problem is considered. In this paper, a nonlinear design is proposed to find a state feedback controller for bilinear systems. The closed‐loop system is internally stable and achieves disturbance attenuation in nonlinear H_∞ sense. We defined a special form of Lyapunov function, which is constructed in terms of one or a set of positive definite constant matrices. If, except of the origin of system, the corresponding polynomial of the positive definite matrix (or several polynomials relevant to the positive definite constant matrices) has (have) no zero on a given subset of state space, then we can construct a controller to solve our problem. It is found that the controller structure could be complicated, but is feasible in computation and may require optimization technique to search the solution. We consider both SIMO and MIMO cases with illustrated examples.     

Disturbance decoupling of switched linear systems

In this paper, we consider disturbance decoupling problems for switched linear systems. We will provide necessary and sufficient conditions for three different versions of disturbance decoupling, which differ based on which signals are considered to be the disturbance. In the first version, the exogenous input is considered as the disturbance, in the second, the switching signal and in the third both of them are considered as disturbances. All three versions of disturbance decoupling have direct counterparts for linear parameter-varying (LPV) systems, while the latter instance of the problem is relevant for disturbance decoupling of piecewise linear systems, as we will show. The solutions of the three disturbance decoupling problems will be based on geometric control theory for switched linear systems and will entail both mode-dependent and mode-independent static state feedback.     

A practical robust nonlinear controller for maglev levitation system

In order to explore the precise dynamic response of the maglev train and verify the validity of proposed controller, a maglev guideway-electromagnet-air spring-cabin coupled model is developed in the first step. Based on the coupled model, the stresses of the modules are analyzed, and it is pointed out that the inherent nonlinearity, the inner coupling, misalignments between the sensors and actuators, and external disturbances are the main issues that should be considered for the maglev engineering. Furthermore, a feedback linearization controller based on the mathematical model of a maglev module is derived, in which the nonlinearity, coupling and misalignments are taken into account. Then, to attenuate the effect of external disturbances, a disturbance observer is proposed and the dynamics of the estimation error is analyzed using the input-to-state stability theory. It shows that the error is negligible under a low-frequency disturbance. However, at the high-frequency range, the error is unacceptable and the disturbances can not be compensated in time, which lead to over designed fluctuations of levitation gap, even a clash between the upper surface of electromagnet and lower surface of guideway. To solve this problem, a novel nonlinear acceleration feedback is put forward to enhancing the attenuation ability of fast varying disturbances. Finally, numerical comparisons show that the proposed controller outperforms the traditional feedback linearization controller and maintains good robustness under disturbances.     

再入飞行器横侧向耦合多变量姿态控制技术研究

结合多变量控制理论和定量反馈理论(QFT),设计了飞行器的横侧向耦合多变量姿态控制系统。通过飞行器的飞行仿真表明,多变量控制系统可以在存在较大不确定性的情况下,确保对横侧向指令进行精确跟踪,具有较强的鲁棒性。针对高速再入飞行器的弱气动条件下偏航控制不理想的问题,充分利用飞行器的多变量特性,利用副翼对偏航的耦合影响,用以协调控制偏航通道的姿态角。仿真结果表明,该方法达到了优化偏航通道控制的目的。     

洁净室温湿度控制算法研究

通常洁净室温湿度系统具有大时滞、时变及耦合性,难以建立精确数学模型.本文针对某洁净制药车间的温湿度控制,采用了前馈补偿器,模糊PID控制与改进型Smith预估补偿算法相结合的控制方案,提高温湿度实时控制性能.仿真结果表明,该方案解决了温湿度系统耦合问题,提高了温湿度控制精度,获得较好的控制效果.     

基于单神经元的永磁同步电机解耦控制

针对永磁同步电机(PMSM)磁场定向控制为代表的传统解耦策略难以实现高性能控制的问题,本文利用神经网络不依赖对象模型的特点以及出色的学习能力,提出了一种基于单神经元的永磁同步电机解耦控制策略.在传统磁场定向控制模型的基础上,构建了基于单神经元的永磁同步电机解耦控制系统,进行了仿真,并搭建以数字信号处理器为核心的电机控制实验平台上进行实验论证.结果表明,基于单神经元解耦的永磁同步电机控制系统具有快速响应能力,并且几乎达到无静差、无超调,实现了PMSM的高性能控制.     

基于未建模动态补偿的一类MIMO非线性系统的自适应广义预测解耦切换控制

针对一类不确定的多输入多输出(MIMO)离散时间零动态不稳定非线性系统, 提出了一种基于未建模动态补偿的非线性广义预测解耦切换控制方法. 该控制方法要求系统的未建模动态满足线性增长条件, 放宽了未建模动态全局有界的限制. 建立了所提的自适应控制方法的稳定性和收敛性分析. 而且, 在设计广义预测解耦控制器时, 把“一一映射”与ANFIS的训练相结合来估计系统的未建模动态, 保证了ANFIS的万能逼近特性. 最后, 仿真结果验 证了所提方法的优越性.     

基于ARM的免疫原理解耦算法的研究

为满足复杂工业过程控制对鲁棒性的要求,将采用免疫神经元PID控制解耦算法进行试验,验证改进算法的优化性能.该控制系统的硬件设计采用嵌入式系统(ARM)方式,用于环境试验箱进行试验,软件采用C语言的编程规则进行设计,解耦算法的实现采用了神经元控制结构和免疫反馈原理二者相结合.通过实验表明,这种新的控制解耦算法学习速度快,动态响应时间短,实现了参数的在线优化,提高了系统的鲁棒性.     

高压饱和气体制备系统饱和室多变量控制研究

高压饱和气体制备系统的饱和室出口压力、流量和温度调节系统是一个相互耦合的三输入三输出系统。针对以上特点采用部分解耦控制策略,压力—流量调节子系统采用静态解耦的专家控制方式,温度调节子系统采用串级模糊PID控制方式。通过仿真试验证明这种控制策略能够获得良好的控制效果。