Coefficient plane synthesis of zero velocity lag servomechanisms

The basic coefficient plane technique is extended to cover the synthesis of zero velocity lag servomechanisms, thus offering the facility of a rapid and exact design philosophy for this class of feedback control systems. An important application of the technique to the direct evaluation of sensitivity of system performance to changes in load dynamics is discussed in detail. Because certain standard compensation methods result in a high, rather than infinite, velocity constant, a brief study has been made to determine the allowable drift of the system zero such that the performance criteria of interest are not significantly affected. For the type of servo-mechanism studied, it is concluded that the order of drift met in practice when using these compensation methods is not normally sufficient to invalidate the use of the coefficient plane technique at the synthesis stage.