摘要：Abstract: The problem of velocity estimation in a mechanical system has been paid a lot of attention for the past several years. In this paper we propose a finite-time observer for a class of non-linear systems containing the Lagrangian systems with disturbances. The discontinuous observer design, proposed here, does not need bounded trajectories in the system, as opposed to what is considered in the literature. To deal with the quadratic term in the velocity, a transformation of states is introduced. Dissipative properties are used for observer design and this is reduced to the solution of some matrix inequalities.
