Contact Force Estimation for an Elastic Beam Using Optimal High-Gain Disturbance Observer

This contribution presents a contact force estimation approach based on an optimal high-gain disturbance observer for an elastic beam using noisy measurements. The reconstruction of contact forces as an example for unknown input estimation represents a class of typical mechanical engineering problems related to the estimation of unknown effects for disturbance rejection or accommodation or fault diagnosis and isolation. The high-gain disturbance observers applied here is able to estimate estimate unknown external inputs together with system states. But choosing observer gains is a difficult task because of the influence of measurement noise. The important advantage of the proposed approach in comparison with classical high-gain disturbance observer is the self adjustment of the observer gains according to the actual estimation situation. Estimation results based on real measurements from known high-gain disturbance observer and the proposed optimal one are compared. It can be shown that the proposed algorithm allows optimized disturbance observer gains calculation, being able to be situatively adapted.