Position Based Static Friction Estimation for DC Motors Using Disturbance Observer

Estimation of friction is not considered necessary in motion control systems when the precision is not a major concern. Effects of the frictional components could be ignored for small friction: motor torque ratio DC motors. Friction estimation is required to increase the precision of the motion control system. Available research illustrates a way of average value estimation for static friction and viscous friction for a full rotation. As far as practical scenario is concerned, frictional components are having a rotor wide variation. Proposed method attempts to estimate the rotor wide static friction variation for a small DC motor. Disturbance Observer has been used for static frictional torque measurements. Rotor wide static friction variation is shown in the results and it illustrates mechanical health of the system.