【作者】 上官霞南；

【导师】 杨嘉祥；

【作者基本信息】 哈尔滨理工大学 ， 电力电子与电力传动， 2007， 硕士

【摘要】 混合磁悬浮球是一种典型的机电一体化系统,其中的控制器是磁悬浮控制系统至关重要的一环。因此,本论文以混合磁悬浮球系统的控制器为主,对混合磁悬浮球控制系统进行了研究。在分析混合磁悬浮球系统构成及工作原理的基础上,开发了一套单自由度混合磁悬浮球实验装置,并以此系统为研究对象,针对系统具有大气隙和非线性特点,利用奇异摄动法导出了控制系统模型。在分析PID控制器参数对控制系统性能影响的基础上,提出了采用变参数PID控制器对混合磁悬浮球进行控制,并给出了控制器参数的整定原则。在MATLAB的SIMULINK环境下用S-function编写变参数PID控制器的参数变化模块和混合磁悬浮球的非线性模型,并进行了动态仿真。由于混合磁悬浮球系统为非线性,而传统PID控制器通常不能有效克服被控对象模型参数的大范围变化及其非线性因素的影响,所以,本文首先设计了基本模糊控制器,并用MATLAB进行了仿真研究。为了改善系统的稳态性能,之后又提出采用Fuzzy-PID双模控制器,在大偏差范围内采用模糊控制,小偏差范围内采用传统PID控制,并进行了混合磁悬浮球起浮特性的仿真,仿真结果表明这种控制策略有利于使磁悬浮球在大范围内稳定起浮。在这一系统中,切换点的选择成为影响系统性能的关键。过早切换会使超调量增大,甚至造成积分饱和现象,使系统失稳;过迟切换,如果模糊控制器有较大的静差,则有可能根本无法进入PID控制。文中对切换点的选择进行了分析和仿真研究。最后,本文还对另一种模糊PID控制即参数自调整模糊PID控制进行了分析和仿真研究,仿真表明,参数自调整模糊PID控制能明显改善混合磁悬浮球起浮的动态性能。更多还原

【Abstract】 The hybrid magnetic levitation ball is one of typical mechatronics systems, among which the performance of the controller is very important. So this thesis focuses on the controller of the hybrid magnetic levitation ball system and research for its control system.On the basis of analyzing of the hybrid magnetic levitation ball system’s composing and working principle, a set of single axis hybrid magnetic levitation ball experimental device is developed, Considering that the hybrid magnetic levitation ball is a big gap and nonlinear magnetic suspension system, the model of the control system is given, where the singular perturbation method is used.On the basis of analyzing of how the parameters of the PID controller affect the performance of the control system, a variable parameters PID controller applied to the hybrid magnetic levitation ball system is presented. The parameters turning principle of this controller are proposed. The control system is simulated with the SIMULINK of MATLAB; the parameters turning module and the nonlinear model of the hybrid magnetic levitation ball are realized by S-function.The hybrid magnetic levitation ball is a nonlinear system, however, classical PID controller often can’t overcome efficiently the effects of great changes of model parameters and nonlinear factors. So in this thesis the basic fuzzy controller is designed and the computer simulation on MATLAB is implemented. To improve the steady performance of the system, a Fuzzy-PID double model controller is applied to the hybrid magnetic levitation ball system; applying fuzzy control in a large error range; applying classical PID control in a small error range. The simulation results show that this kind of control strategy can make the hybrid magnetic levitation ball stabilize in a large range. How to choose the threshold is the key to design the Fuzzy-PID controller. Too early switch can not present the advantage of fuzzy controller and even lead to integral saturation; while too late switch can not turn into PID control because of the static state error of fuzzy-PID control. The choice principle of the threshold is analyzed and simulated.At last, parameter self-tuning Fuzzy-PID control is researched and simulation results indicate that the dynamic performance of the hybrid magnetic levitation ball system is improved.更多还原