电液位置伺服系统的抖振消弱滑模控制

Chattering Reduction Sliding Mode Control for Electro-Hydraulic Position Servo System

比例滑模策略保留了线性控制的某些优点,但抖振的存在不仅会降低控制精度,甚至会激发系统的未建模动态或引起机械谐振,严重制约了比例滑模控制在电液位置系统中的应用。为避免抖振对系统精度与稳定性的影响,提出采用模糊模型,根据切换函数及其导数的状态自调整比例滑模切换增益,以柔化控制信号。试验结果表明,通过模糊理论实现增益自调整,能有效降低抖振,既实现了高精度控制,又保留了滑模策略抗参数摄动及抗扰动能力强的特点。

The proportion sliding mode strategy retains the linear control advantages,but the presence of buffeting will reduce the control precision,even stimulate the system unmodeled dynamics or cause mechanical resonance.These deficiencies seriously restrict the application of the proportion of sliding mode control in electro-hydraulic position system.In order to avoid chattering influence on the system accuracy and stability,self-tuning sliding mode switching gain is designed to soften the control signal,according to the switch function and its derivative of the fuzzy model.The results show that the system achieves the gain self-adjusting by fuzzy theory,reduces the buffeting,implements high-precision control,and retains characteristics both of the anti-parameter perturbations and anti-disturbance ability.