The Toeplitz-Observability Smooth Variable Structure Filter

The smooth variable structure filter (SVSF) is a recently proposed method that is used for estimation purposes, such as fault detection [1]–[2]. The SVSF demonstrates good results and robustness when it is applied to linear and nonlinear systems that are fully measured. However, the results differ when some of the states are not measured. In this case, the SVSF is combined with the Luenberger method, which has some limitations. In this paper, a novel form of the SVSF is derived using the Observability and Toeplitz matrices. The benefits of the proposed method are demonstrated by using a computer simulation that involves an electro-hydrostatic actuator proposed in [3]–[5].