Discrete-Time Super-Twisting Observer With Implicit Euler Method

This brief proposes a new discrete-time realization of the super-twisting algorithm based observer. While keeping the property of chattering suppression, the estimation precision of the proposed realization scheme is consistent with the continuous-time super-twisting algorithm (STA), that is, in the absence of noises, the estimation errors satisfy the standard asymptotical accuracy level, i.e., vertical bar e(1)vertical bar similar to mu(1)h(2) and vertical bar e(2)vertical bar similar to mu(2)h with sampling time h and two positive constants mu(1) and mu(2). Comparing to the conventional explicit Euler method, the proposed scheme is more exact in the term of smaller constants mu(1) and mu(2). The superiority of the proposed scheme is demonstrated through an example of typical buck converter circuit system.