The super-twisting second-order sliding-mode algorithm is modified in order to design a velocity observer for uncertain mechanical systems. The finite time convergence of the observer is proved. Thus, the observer can be designed independently of the controller. A discrete version of the observer is considered and the corresponding accuracy is estimated.
['Jorge Davila', 'Leonid Fridman', 'Arie Levant']
Second-order sliding-mode observer for mechanical systems