Kalman filter-based disturbance observer and its applications to sensorless force control

Force estimation plays a very important role in many application areas. The disturbance observer is significantly becoming the preferred approach since it offers distinct advantages of improving the robustness of force control and the accuracy of force estimation. However, one of the main disadvantages is the limitation from white Gaussian noise. This paper proposes an improved design methodology for the disturbance observer. The main contribution of the work described in this paper is the design of disturbance observers combined with a Kalman filter with a multisensor system. From the experimental results, white Gaussian noise was reduced and fast response in contact motion was achieved. The effectiveness of the proposed disturbance observer has been confirmed through comparisons with conventional methods in 1-d.o.f. linear motor systems.