针对已开发的精密直线气浮工作台,设计了腹底式被动结构的阻尼器以解决静压气浮导轨传动阻尼小,抗干扰能力差等问题.设计的阻尼器由固定于气浮滑套下端面的阻尼片以及处于阻尼片正下方的阻尼油槽和阻尼油组成.通过实验获取了阻尼器的阻尼系数,继而建立了气浮工作台机电控制模型.仿真分析了阻尼器对工作台气浮噪声和动态特性的影响规律:随着阻尼的增大,气浮工作台的稳定裕度和衰减噪声的能力增加,但动态响应速度降低.实验表明,实验结果与所推导的气浮工作台特性一致,且增加阻尼系数为293.78 N/m·s-1的阻尼器后,气浮工作台的定位噪声由60 nm(峰峰值)降为20 nm(峰峰值),位移灵敏度为20 nm,实验验证了采用此种结构的阻尼器可有效抑制精密气浮工作台定位噪声.%An abdominal and passive damper was developed and installed on an established precision air bearing stage to overcome the defects of an aerostatic guide such as less transmission damp and easier susceptibility. The damper is consisted of a damping disk fixed in the bottom of aerostatic guide and an oil groove directly under the disk. The damping coefficient was obtained by recommended experiments, and an electromechanical control model of the air bearing stage was established to describe the influence of the damper on the positioning noise and dynamic characteristic of the stage. Numerical simulation results indicate that the stability margin and noise suppression degree become much bigger with increasing damping coefficient, while the dynamic response speed of the stage gets worse. Experimental results show that, based on the developed system and the same control parameters, the damp characteristics obtained by experiments agree with the theoretical results, and the damper with damping coefficient 293. 78 N/m·s-1 suppresses the positioning noise of air bearing stage from 60 nm(pk-pk) to 20 nm(pk-pk). Furthermore, positioning resolution of the stage with damper is 20 nm. It proves that the developed damper can suppress the positioning noise of the air bearing stage effectively.
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