基于区间二型模糊摩擦补偿的鲁棒自适应控制

Robust Adaptive Control Based on Interval Type-2 Fuzzy Friction Compensation

针对不确定机械系统中普遍存在的摩擦力,由于其非线性和不确定性,传统基于摩擦模型的补偿控制方法难以达到满意的系统性能要求.本文提出基于自适应区间二型(Type-2)模糊逻辑系统对系统摩擦进行补偿建模,并在该摩擦补偿方法的基础上设计出鲁棒自适应控制器,保证系统输出精度,且对摩擦环境的变化具有较强自适应性.区间二型模糊逻辑系统相对于传统一型模糊逻辑系统具有较强的处理不确定性问题的能力,在本文中使用自适应区间二型模糊逻辑系统不断逼近摩擦力,根据李雅普诺夫稳定性理论求出自适应律并证明系统跟踪误差的有界性.在不同摩擦环境下的仿真结果验证了本文所提摩擦建模方法与控制策略的有效性与实用性.

Due to the nonlinearity and uncertainty of friction in uncertain mechanical systems,it is difficult to establish an accurate friction model.The traditional compensation control method based on friction model is difficult to meet the requirements of system performance.The adaptive interval Type-2 fuzzy logic system is proposed to model system friction,then the robust adaptive controller is designed on the basis of the friction compensation method,which ensures the output precision of the system and has strong adaptability to variational environment.Interval Type-2 fuzzy logic system has stronger ability to deal with the uncertainty problem than the traditional Type-1 fuzzy logic system,so the adaptive interval Type-2 fuzzy logic system is used to approximate friction.The adaptive law is derived and the boundedness of the tracking error is proved based on the Lyapunov stability theory.The effectiveness and practicability of the friction modeling method and control strategy are verified by simulations under different friction environments.