The state presumption using the error presumptive observer loosen the restriction range by the sliding mode observer

When all states cannot be observed from the output of a system, some states are presumed by using an observer. But, a correct state presumption is difficult for an actual system by the influence of a disturbance and a parameter variation. The VSS observer and the unknown input observer have been proposed as an observer corresponding to the disturbance and the parameter variation. First, in this paper, the sliding mode observer using the duality improved VSS observer's problem not having robustness enough by an interference of the two power for working the power of optimal regulator and VSS control simultaneously is proposed. And, it notes that VSS observer and a sliding mode observer have a strong robustness only when some conditions are fulfilled. But, these conditions have large restriction to an output matrix. As the result, these observers have a limit in applying to a real system. Then, secondly, the method of the state presumption using the error presumptive observer loosen the restriction range by the sliding mode observer is proposed. Finally, it is shown that the proposed observer is validated for loosen the restriction range by the simulation