Preview Control of Hydrostatic Guideway for Ultraprecision CNC Machine Tools

摘要

An active preview control strategy is presented to suppress the vibration of hydrostatic guideway under dynamic machining force. A state space model of closed hydrostatic guideway system is built, and the predictability of machining force during cutting process is analyzed. Numerical simulation model of preview compensation control systems is established. The displacements of slide carriage are compared under the condition of no control, optimal control and active preview control. The variations of oil recess pressure are observed when using the two latter control methods. The results show that maximum displacement of slide carriage by using active preview control method reduces 73.3% compared to the optimal control method, and reduces 94.1% compared to the method without any control. Besides, the compliance of the oil recess pressure to machining force is improved by 23%. Finally, an experiment evaluating the displacement of slide carriage and variation of oil recess pressure is carried out and the numerical predictions agree with the experimental results. It is effective to control machining vibration of hydrostatic guideway by using active preview control strategy.