离散伺服定位系统的复合非线性控制  

Composite nonlinear control for discrete-time positioning servo systems

作　　者：程国扬[1] 彭可茂[2] 王惠[1] 

机构地区：[1]福州大学电气工程与自动化学院,福建福州350108 [2]新加坡国立大学Temasek实验室,新加坡117508

出　　处：《电机与控制学报》2010年第1期95-101,共7页Electric Machines and Control

基　　金：教育部留学回国人员科研启动基金(LXKQ0804)

摘　　要：针对带有扰动和执行器幅值受限的伺服系统,提出一种离散时间复合非线性控制方案,用于实现快速和准确的定点跟踪。此控制方案是在复合非线性反馈控制的框架中嵌入一个扰动估计与补偿机制。其中,复合非线性反馈控制律包含线性和非线性反馈两部分,分别实现快速响应和抑制超调,从而提高瞬态性能;采用一个降阶观测器对系统中的不可量测状态和未知常值扰动进行估计,并用于补偿,从而消除稳态误差。对该控制方案下的闭环系统稳定性进行理论分析。将提出的控制方案应用于一个双积分模型的伺服系统,进行仿真研究,并与一种采用积分控制来消除扰动的复合非线性反馈控制方案进行比较。结果表明所提出的控制方案在定点跟踪任务中具有更好的性能鲁棒性。A discrete-time composite nonlinear control scheme is proposed to achieve fast and accurate set-point tracking for servo systems subject to disturbances and actuator saturation. The control scheme incorporated a mechnism of disturbance estimation cum compensation into the framework of composite nonlinear feedback （CNF） control. The CNF control law consisted of a linear feedback part for achieving fast response and a nonlinear feedback part for suppressing the overshoot, so as to improve the transient performance. A reduced-order observer was adopted to estimate the unmeasurable state variables and unknown constant disturbance, and then used for compensation to remove the steady state error. Closed-loop stability with the proposed control scheme was analyzed theoretically. The control scheme was applied to a servo system modeled by a double integrator. Simulations were carried out, and a comparison was made with a previous CNF scheme, which resorted to integral control for rejecting disturbance. The results confirm that the proposed control scheme has a better performance robustness in set-point tracking tasks.

关 键 词：伺服系统 非线性 扰动 状态观测器 补偿 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]