Two types of zero-velocity-error servomechanisms

This paper describes two types of zero-velocity-error servomechanisms which exhibit high dynamic accuracy with a minimum bandwidth. The first type is a special integral control system. The second type contains a simple lag circuit in the feedback path. These systems are analyzed and discussed from both theoretical and practical design considerations. A method to aid in the determination of required bandwidth is introduced. A classification of possible zero-velocity-error systems and a method of deriving zero-forced-error systems are also presented.