Robust DC servosystem design based on the parameterization of two degrees of freedom control systems

The authors propose a general robust servosystem design method based on the two-degrees-of-freedom (TDOF) controllers. With this approach, it is possible to specify the command input response to an arbitrary reference model while keeping a strong robustness to system variations and a high suppression performance with respect to disturbances. These can be designed independently of the command input response. The TDOF method is generalized to unstable plants, and two types of practical parameterizations for the TDOF controller are proposed in order to design the speed and position servosystems, respectively. Their excellent control performances have been confirmed by experimental results. The application of one of the proposed servocontrollers to the motion control of robotic manipulators is described