基于预设性能转台伺服系统的参数估计和自适应控制

针对含参数未知和非线性摩擦动态的转台伺服系统，提出了一种基于预设性能函数的参数估计和自适应控制方法.利用一种连续的摩擦模型表示转台伺服系统的摩擦动态，引入高阶神经网络对其进行逼近.通过构造一种滤波辅助变量获取参数估计误差信息，并将估计误差信息作为参数自适应律的遗漏因子，保证估计值能够快速收敛到真实值.为了提高转台伺服系统的瞬态响应和稳态性能，利用预设性能函数将原始系统的跟踪误差转换为一个新的误差动态，在此基础上设计自适应控制器，实现对期望轨迹的精确跟踪.仿真结果验证了本文所提算法的有效性. 

Adaptive Parameter Estimate and Control Based on Prescribed Performance for the Turntable Servo Mechanism

In this paper, a parameter estimate and adaptive control method was proposed based on prescribed performance function(PPF) for the turntable servo mechanisms with unknown parameters and nonlinearity friction dynamics. A continuous friction model was employed to capture the friction dynamics of the turntable servo mechanism, and high-order neural network(HONN) was adopted to approximate the nonlinearity friction dynamics. An auxiliary filter variable was designed to drive the information of the parameter estimation, which was used as a new leakage term of parameter update law to make the estimation values achieve to true values. To improve the transient behavior and steady-state performance of the turntable servo mechanism, the PPF was adopted to translate the error system of the original system into a new error system. Simulation results validate the effectiveness of the proposed control scheme.