Section 9.1 The 2DOF Structure for Stable Plants 9.1 The 2DOF Structure for Stable Plants 1DOF System The effect of the reference on the error was the same as that of the output disturbance on the system output: e(s)y(s) 1 r(s)-d(s)-1+G(s)C(s) Such a system has merely one degree of freedom.When the reference and the disturbance have similar dynamic characteristics (for example,both of them are steps),a 1DOF controller can simultaneously satisfy the requirement on tracking response and disturbance response in many cases 4口，+@，4定4定90C Zhang.W.D..CRC Press.2011 Version 1.0 3/95Section 9.1 The 2DOF Structure for Stable Plants 9.1 The 2DOF Structure for Stable Plants 1DOF System The effect of the reference on the error was the same as that of the output disturbance on the system output: e(s) r(s) = y(s) d(s) = 1 1 + G(s)C(s) Such a system has merely one degree of freedom. When the reference and the disturbance have similar dynamic characteristics (for example, both of them are steps),a 1DOF controller can simultaneously satisfy the requirement on tracking response and disturbance response in many cases Zhang, W.D., CRC Press, 2011 Version 1.0 3/95