Realization of causal current output-based optimal full/reduced-order observer and tracker for the linear sampled-data system with a direct transmission term

Realization of causal current output-based optimal full/reduced-order observer and tracker for the linear sampled-data system with a direct transmission term from input to output is proposed in this paper. First, a high-gain optimal linear quadratic analog tracker based on the reduced-order observer is proposed for the system model with a direct transmission term from input to output, so that it can effectively induce a high quality performance on state estimation and trajectory tracking design theoretically. Then, the prediction-based digital redesign method enables it to make the digitally controlled system to track the desired trajectory closely. However, there induces a causal problem on the realization of current output-based optimal full/reduced-order observer and tracker for the sampled-data system with a direct transmission term form input to measured output. To overcome this problem, a realization of the causal observer-based sampled-data tracker is newly proposed in this paper. An illustrative example is presented to demonstrate the effectiveness of the proposed method. Copyright (C) 2014 John Wiley & Sons, Ltd.