直流位置伺服系统的二自由度分数阶控制

为提高直流位置伺服系统的控制性能，提出了一种2自由度（two degree-of-freedom，2DOF）分数阶控制方法．通过设计一种2DOF控制结构，实现了系统的跟随和抗扰特性的解耦控制；将内模控制（internal model control，IMC）与分数阶控制相结合，选用分数阶滤波器，推导出了跟随控制器和抗扰控制器设计方法；根据控制性能的要求，利用系统截止频率和最大灵敏度指标，实现了2DOF控制器参数的解析整定．仿真实验结果表明，2DOF分数阶控制方法具有良好的位置跟随特性和抗干扰能力．

Two-degrees-of-freedom Fractional Control Method for DC Position Servo System

To improve the control performance in DC-position servo systems, we propose a two-degrees-of-freedom (2DOF) fractional-order control method. By designing a 2DOF control structure, we achieve decoupling control of the system's set-point tracking and disturbance rejection responses. Then, we develop a design method for the set-point tracking and disturbance rejection controllers by choosing a fractional-order filter by combining internal model control (IMC) and fractional control. Based on the control performance requirements, we use the system's cut-off frequency and maximum sensitivity index to analytically tune the parameters of the 2DOF controller. Simulation and experimental results show that the fractional-order 2DOF controller has good set-point tracking characteristics and disturbance rejection capability.