Characteristic analysis of feedback control system with simplified disturbance compensator

In this paper, simplified disturbance compensator is proposed. It is the low order form of disturbance observer, and based on not acceleration but velocity. Disturbance observer is a powerful strategy to realize a robust acceleration control. However, it requires acceleration information and it is obtained by differentiation of velocity or second differentiation of position in general case, so there exits a tradeoff between the observer design and the noise sensitivity. The simplified disturbance compensator is more insensitive than observer because it is based on velocity and does not require the time differentiation. Additionally, it provides the performance of position control and load suppression equivalent to disturbance observer. Availability of the proposed method is confirmed by simulation and experimental results.