It is a difficult to accurately estimate the rotor position in a surface permanent magnet synchronous motor (SPMSM). especially for low speed conditions because the back electromotive force (EMF) is almost zero. In this paper. an improved sliding mode observer (SMO) with a continuous sliding mode switching function (which could reduce the chattering effect) is proposed to estimate the... https://danddcollectiblers.shop/product-category/chip/