增益调节下具随机干扰压电致动器的模型参考自适应控制

    Model Reference Adaptive Control of Piezoelectric Actuators with Stochastic Disturbances under Gain Adjustment

    • 摘要: 压电致动器具有位移分辨率高的特点,在精密定位系统中作为致动器得到广泛应用。然而,由于压电致动器受到迟滞非线性、蠕变以及随机干扰等因素的影响,使得输出的稳定性和定位精度难以实现。本文提出了一种基于可调增益的模型参考自适应控制方法,用于控制具有外部扰动和随机干扰压电致动器的输出。该方法通过引入Lyapunov函数和自适应更新律,建立了计算自适应调节增益的随机非线性闭环控制系统。本文所提出的自适应控制方案,在压电致动器输出的依概率有界性和输出与参考模型输出之间跟踪误差的均方收敛性方面具有创新性。此外,本文提出的方法仅要求了解不确定扰动及随机噪声强度的有界性。仿真结果验证了自适应增益调节器设计的有效性和优越性。

       

      Abstract: Piezoelectric actuators have the characteristic of high displacement resolution and are widely used as actuators in precision positioning systems. However, due to the effects of hysteresis nonlinearity, creep, and stochastic disturbance on piezoelectric actuators, the stability and positioning accuracy of the output are difficult to achieve. In this research, a new model reference adaptive control method is proposed for controlling the output displacement of piezoelectric actuators with external and stochastic disturbances. This method establishes a stochastic nonlinear closed-loop control system with computational adaptive gain adjustment by introducing Lyapunov function and adaptive update law. The proposed adaptive structure is innovative in terms of the probability boundedness of the output of the piezoelectric actuator and the mean square convergence of the tracking error between the output and the reference model output. In addition, the proposed method only requires an understanding of the boundedness of uncertain disturbances and stochastic noise intensity. The simulation results demonstrate the effectiveness and superiority of the designed adaptive gain regulator.

       

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