Nonlinear dynamical control systems
Nonlinear dynamical control systems
State and output feedback stabilization of multiple chained systems with discontinuous control
Systems & Control Letters
A discontinuous output feedback controller and velocity observer for nonlinear mechanical systems
Automatica (Journal of IFAC)
A constructive speed observer design for general Euler-Lagrange systems
Automatica (Journal of IFAC)
| Hi-index | 22.15 |
The problem of velocity estimation for general, n degrees-of-freedom, mechanical systems, is of great practical and theoretical interest. For unconstrained systems many partial solutions have been reported in the literature. However, even in this case, the basic question of whether it is possible to design a globally convergent speed observer remains open. In this paper, an affirmative answer to the question is given for general mechanical systems with knon-holonomic constraints, by proving the existence of a 3n-2k+1-dimensional globally exponentially convergent speed observer. An observer for unconstrained mechanical systems is obtained as a particular case of this general result. Instrumental for the construction of the speed observer is the use of the Immersion and Invariance technique, in which the observer design problem is recast as a problem of rendering attractive and invariant a manifold defined in the extended state-space of the plant and the observer.