On Generation of Virtual Outputs via Signal Injection: Application to Observer Design for Electromechanical Systems
For researchers working on observer design for electromechanical systems, this paper offers an improved filter with guaranteed convergence, though it is an incremental improvement over existing methods.
The paper proposes a new filter with guaranteed convergence for reconstructing virtual outputs via signal injection, outperforming classical designs. Simulations and experiments on a 1-dof magnetic levitation system demonstrate its effectiveness.
Probing signal injection is a well-established technique to extract additional information from a weakly (or non) observable dynamical system. Using averaging theory, a framework to analyse such schemes for general nonlinear systems has been recently proposed in [Combes et. al., 2016], where it is shown that the signal injection may be used to generate a new high frequency component of the systems output that can be used for state observation or controller design. A key step for the success of this technique is the implementation of a filter to reconstruct this virtual output from the measurement of the overall systems output. The main contribution of this paper is to propose a new filter with guaranteed convergence properties that outperforms the classical designs. The method is applied to a general class of electromechanical systems, and its performance is assessed via simulations and experiments on the benchmark example of a 1-dof magnetic levitation system.