Novel algorithms for the synchronization control of nonlinear systems

Abstract

SummaryWe show how the design of repetitive learning controls, which typically require perfect knowledge of the period T characterizing the periodic reference signals to be tracked, can be generalized, through the design of novel recursive add‐on period identifiers, to face sufficiently small period uncertainties in synchronization problems. Exponential period identification is achieved so that the asymptotic convergence properties guaranteed by the classical learning controls are preserved. Simulation results concerning multi‐link robot synchronization tasks are included. Copyright © 2015 John Wiley & Sons, Ltd.

A learning control algorithm for periodic robot synchronization: Experimental results

“…Encouraging robustness aspects are confirmed in a scenario in which uncertainties characterize both the slave robot dynamics and the varying period of the "periodic" position signal provided by the master. Notice that, even though the work of Tomei and Verrelli 7 has solved a more general control theory problem (see the references therein), the error dynamics coming from the robotic application of the repetitive learning control proposed in this paper do not, however, belong to the class of nonlinear systems there analyzed, 7 with a consequent modification of the analytical arguments involved in the stability proof turning to be necessary and constituting a definite theoretical improvement.…”

“…The same control problem becomes, however, more difficult to be solved as soon as the information about the period T is not completely a priori available. This is the case of visual servoing or master-slave synchronization problems 6 (see the related discussions in the works of Tomei and Verrelli 7 and Verrelli, 8 as well as in the works of Andry et al 9 and Drake et al 10 ).…”

“…The aim of this brief, which is to be intended as the application-oriented extending sequel to our recent theoretical paper, 7 is to show that the robot synchronization problem can be solved by a feedback control that is easily implementable in practice. The research direction outlined in the work of Tomei and Verrelli,7 ie, concerning the experimental validation of algorithms of this type, is thus successfully explored. Encouraging robustness aspects are confirmed in a scenario in which uncertainties characterize both the slave robot dynamics and the varying period of the "periodic" position signal provided by the master.…”