CNC机床伺服系统中模糊自整定PID控制研究

在CNC机床伺服进给系统中,控制对象的位置、速度具有不确定性和非线性,很难去建立精确的数学模型,而常规PID控制器的参数无法随着被控对象参数的变化而及时调整。模糊控制降低了对被控对象数学模型的要求,只需把经验知识转化为控制策略,进而使模型难以确定的复杂系统得以有效的控制,模糊PID控制器结合了常规PID控制和模糊控制的优点,将其应用于CNC机床伺服进给系统中,在MATLAB环境下进行仿真分析,结果表明,模糊自整定PID控制器具有更好鲁棒性,改善了伺服进给系统的动态性能。

Research on fuzzy auto-tuning PID control of CNC servo system

In servo feed system of CNC machine tools,the position and velocity of controlled object have the characteristics of randomness and nonlinearity,which is difficult to establish accurate mathematical models.However,the parameters of conventional PID controller can’t be adjusted immediately with the parameters changing of the controlled object.Yet the fuzzy control reduces the request of mathematical model for controlled object by only transforming the experience to control strategy,and the complex system will be controlled effectively.Therefore fuzzy PID controller,combining the advantages of conventional PID control and fuzzy control,is applied in servo feed system of CNC machine tools,and simulated and analyzed in MATLAB,which result shows that the fuzzy auto-tuning PID controller improves the dynamic performance of the servo feed system with its better robustness.