On the linear Active Rejection Control of Thomson´s Jumping Ring

The problem of tracking a smooth time-varying reference trajectory for Thomson´s ring is addressed from the perspective of Active Disturbance Rejection Control (ADRC). The tracking controller is designed on the basis of the tangent linearization model of the nonlinear system around a constant equilibrium point. The large height deviations, outside the region of validity of the approximate linearization, trigger the effect of unknown nonlinearities and exogenous perturbations. These disturbances are properly on-line estimated and canceled with the help of a linear extended observer-linear controller based output feedback control scheme. Experimental results are presented which validate the effectiveness of the proposed control scheme.