A Constructive Globally Convergent Adaptive Speed Observer For Port‐Hamiltonian Mechanical Systems with Non‐Holonomic Constraints

Abstract

This paper presents an adaptive speed observer for general port-Hamiltonian mechanical systems with non-holonomic constraints in the presence of unknown friction forces and constant disturbances. Unlike the observers recently reported in the literature, which have been designed either under the assumptions of no friction and the absence of disturbances or for a specific class of mechanical systems with the requirement of an explicit solution of certain Partial Differential Equations (PDEs) that cannot be derived a priori, this observer proposes a design that obviates the solution of PDEs and ensures global convergence for general mechanical systems with k-non-holonomic constraints. The observer is totally constructive and given by explicit expressions. The simulation results testify to the effectiveness and the robust features of the developed observer.

Output feedback tracking control for nonholonomic wheeled mobile manipulator systems with full-output constraints

“…Besides, the differential calculation causes an inevitable delay of speed signal acquisition and be sensitive to noise. 18,19 Therefore, considering the high cost of high-precision speed sensor and possible failure, the velocity observer and output feedback control are developed to avoid the difficulty of speed information acquisition. There are two common ways to realize output feedback, one is to build an observercontroller design scheme, which has been successfully applied in robot, manipulator, spacecraft 20 and so on.…”