直线电机悬浮平台系统的二型模糊滑模控制

发布时间：2018-01-12 22:05

本文关键词：直线电机悬浮平台系统的二型模糊滑模控制　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文以二自由度(Two Degrees of Freedom,2-DOF)的直线电机悬浮平台系统为研究对象。考虑悬浮系统要求在两个2-DOF方向上的独立控制,以及系统对强鲁棒性和高精度的要求,传统控制策略无法实现系统的高性能要求。本文根据滑模控制的非线性控制特点,设计具有解耦效果的滑模控制器,并结合区间二型模糊系统(Interval Type-2 Fuzzy Logic System,IT2-FLS)、分数阶微积分等理论和方法,针对悬浮系统的变量间存在的非线性耦合以及不确定性因素扰动的问题进行控制策略研究,主要研究内容如下:在对悬浮平台系统的数学模型分析的基础上,考虑悬浮系统运行中受负载阻力扰动、参数变化等不确定因素的影响,设计滑模控制器以提高系统的鲁棒性。同时利用滑模控制自身可以解耦特性,不加入单独的解耦控制器,对双输入双输出的悬浮系统的输入与输出之间的耦合进行解耦。将系统看成两个单输入单输出(SISO)的子系统并分别设计滑模面,利用控制层次化的思想,根据Lyapunov理论设计滑模控制律使两个子系统的状态量分别收敛到各自滑模面,达到解耦的目的,使系统可以在2-DOF的方向实现高精度定位。采用区间二型模糊控制器取代滑模控制的切换项,降低由于抖振造成系统性能下降的影响。仿真结果表明,设计的解耦区间二型模糊滑模控制器实现了输入与输出状态量之间的解耦,区间二型模糊系统相对普通一型模糊系统在处理不确定性问题上,具有更好的表现,该控制策略实现了系统对自身参数变化以及突加负载阻力引起的扰动具有较好的抑制作用,保证系统强鲁棒性的同时,也有效地削弱了系统的抖振。考虑分数阶微积分具有柔化信号的特性以及其它优点,结合滑模控制可以进一步提高系统性能,设计了区间二型模糊分数阶滑模控制。在对系统设计解耦的过程中,设计分数阶滑模面以及分数阶趋近律。并采用一个区间二型模糊控制器替换滑模控制切换项中的增益与不连续的符号函数的乘积。仿真结果表明,区间二型模糊分数阶滑模控制比区间二型模糊整数阶滑模具有更好地控制性能,系统对负载和参数变化扰动具有更强的鲁棒性。
[Abstract]:This paper deals with two Degrees of Freedom with two degrees of freedom. Considering the independent control of the suspension system in two 2-DOF directions and the requirement of strong robustness and high precision of the system, the linear motor suspension platform system based on 2-DOF is studied. The traditional control strategy can not meet the high performance requirements of the system. According to the nonlinear control characteristics of sliding mode control, a sliding mode controller with decoupling effect is designed in this paper. The theory and method of interval Type-2 Fuzzy Logic system IT2-FLSU, fractional calculus and so on are combined. The control strategy for the nonlinear coupling between variables and the disturbance of uncertain factors is studied. The main contents are as follows: on the basis of the mathematical model analysis of the suspended platform system. The sliding mode controller is designed to improve the robustness of the suspension system by considering the uncertain factors such as load resistance disturbance and parameter change in the operation of the suspension system. At the same time, the sliding mode control itself can be decoupled. No separate decoupling controller is added. Decoupling the coupling between input and output of double input and double output suspension system, the system is regarded as two subsystems of single input and single output SISO, and the sliding mode surface is designed respectively. According to the theory of Lyapunov, the sliding mode control law is designed to make the state of the two subsystems converge to the respective sliding mode surface, so that the decoupling can be achieved. The system can achieve high precision positioning in the direction of 2-DOF. The switching term of sliding mode control is replaced by interval 2 fuzzy controller to reduce the effect of buffeting on the performance of the system. The simulation results show that. The decoupling interval type 2 fuzzy sliding mode controller realizes the decoupling between the input and output state variables. The interval type 2 fuzzy system has better performance in dealing with the uncertainty than the common type 1 fuzzy system. The control strategy can restrain the disturbance caused by the change of the system parameters and the load resistance, and ensure the strong robustness of the system at the same time. Considering that fractional calculus has the characteristics of soft signal and other advantages, combined with sliding mode control, the system performance can be further improved. The interval 2 fuzzy fractional sliding mode control is designed in the process of decoupling the design of the system. The fractional sliding mode surface and fractional approach law are designed, and a fuzzy controller of interval type 2 is used to replace the product of the gain in the switching term of sliding mode control and the discontinuous symbol function. The simulation results show that. Interval 2 fuzzy fractional sliding mode control has better control performance than interval 2 fuzzy integral order sliding mode, and the system is more robust to disturbance of load and parameter variation.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM359.4;TP273

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