数控机床进给系统运动精度与能耗控制研究

Motion precision and energy consumption control forfeed system of CNC machine tools

针对数控机床进给系统运动精度及能耗控制存在的问题,提出了一种新的自适应滑模控制方法。首先,基于进给系统机械动力学模型和滑模控制理论,提出了一种自适应滑模趋近律,根据跟踪误差平方值对控制增益值进行了自适应更新;然后,利用Lyapunov理论证明了所提控制方法的稳定性;最后,通过实验的方式对所提方法的运动精度和能耗控制效果进行了验证,并在相同条件下将其与3类已有自适应控制方法进行了对比。研究结果表明:与已有其他自适应控制方法相比,在相同控制参数条件下,采用所提方法的进给系统X、Y轴的平均定位误差最多可分别降低16.4%及20.3%;在控制性能相近条件下,采用所提方法的进给系统X、Y轴控制能耗最多可分别降低1.92%及0.96%;此外,所提方法能够更为有效地抑制由于非连续控制产生的抖振现象。

Aiming at the problem of improving motion accuracy and energy consumption control for feed system of CNC machine tools,a new adaptive sliding mode control(ASMC)method was proposed.Based on the dynamics of feed system and sliding mode control(SMC)theory,an adaptive sliding mode reaching law was proposed.The control gain was updated adaptively according to square of the tracking error.Then,the stability of the proposed control method was proved by Lyapunov theory.Finally,the motion accuracy and energy consumption control effect of the proposed method were verified by experiments and comparing with three kinds of existing adaptive control methods.The results show that,comparing with other adaptive control methods,the average positioning errors of X and Y axes of the feed system can be at most reduced by 16.4%and 20.3%respectively under the same control parameters.And the energy consumption of X and Y axes of the feed system with the proposed method can be at most reduced by 1.92%and 0.96%respectively under the condition of similar control performances.In addition,the proposed method can suppress chattering caused by discontinuous control more effectively.