Reduction of Forced Error in Closed-Loop Systems

This paper illustrates a method for reducing the forced-dynamic error in servomechanisms by design based on error coefficients. After a brief review of the dependence of the forced dynamic error upon error coefficients, the relationship between error coefficients and the parameters of a servomechanism is derived. This relationship is then used to show how closed-loop systems can be modified to obtain favorable error coefficients that reduce the forced-dynamic error. The method has been tested by simulation, and photographs of simulator response show how the effect of additional integrations can be achieved by error-coefficient adjustment.