Analysis of systems with backlash and resolution

Abstract

A control system with backlash in the output gears and resolution in the error-sensing potentiometer is considered. Certain peculiarities in the equivalent describing function are observed. Stability analysis discloses a low-amplitude and low-frequency limit cycle in the system with backlash and resolution while it is found that a no limit cycle exists in the same system without taking potentiometer resolution into consideration. Thus the effect of resolution is to destabilize the system. Analysis by a describing function method and phase-plane study give the same results.