Analysis of a dc motor based velocity controller using disturbance observer

Abstract

Motion control incorporates a range of challenges when it comes to the control of mechanical systems. In rotary motion; position, velocity and acceleration control are the tasks required most often for robotics. The achievement of velocity control is one of the popular technical issues in motion control and industrial applications. The traditional approach for velocity control is PID based feedback controllers. PID controllers are not suitable for the applications subjected to higher external disturbances. This paper proposes a Disturbance Observer (DOB) based velocity controller. DOB together with the tuned PID controller can make the system robust. To validate the proposed method, stability analysis and experiments were carried out with and without DOB. The velocity responses of the experiments were analyzed for different modes of disturbances with different observer gains. The performance of the proposed controller shows enhanced results compared to the traditional velocity controllers.