This article investigates the control problem for underactuated port-controlled Hamiltonian systems with multiple linearly parameterized additive disturbances including matched, unmatched, constant, and state-dependent components. The notion of algebraic solution of the matching equations is employed to design an extension of the interconnection and damping assignment passivity-based control methodology that does not rely on the solution of partial differential equations. The result is a dynamic state-feedback that includes a disturbance compensation term, where the unknown parameters are estimated adaptively. A simplified implementation of the proposed approach for underactuated mechanical systems is detailed. The effectiveness of the controller is demonstrated with numerical simulations for the magnetic-levitated-ball system and for the ball-on-beam system.
K E Y W O R D Sadaptive control, disturbance rejection, mechanical systems, passivity-based control, underactuated systems 1 This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
4112wileyonlinelibrary.com/journal/rnc Int J Robust Nonlinear Control. 2020;30:4112-4128.FRANCO et al.
4113A further aspect of energy shaping control that has been attracting increasing attention is robustness to disturbances, which are common to most practical application. Notable results in this area include the study of viscous friction within the controlled Lagrangians formulation, 12,13 and of continuous and smooth physical dissipation within the IDA-PBC framework, 14,15 while friction according to the Dahl model affecting the actuated part of the state was considered in Reference 16. Stability and robustness of disturbed PCH systems with dissipation were investigated in Reference 17. The robust energy shaping control of fully actuated mechanical systems with disturbances was presented in Reference 18, while disturbance attenuation for discrete-time systems was studied in Reference 19. More recently, integral IDA-PBC designs that rely on the classical solution of the PDE were proposed in References 20-22 for a class of underactuated mechanical systems with constant matched disturbances (ie, those affecting the actuated part of the state), and in Reference 23 for bounded matched disturbances. The result in Reference 21 was extended to unmatched constant disturbances in Reference 24, which, however, is only applicable to mechanical systems with constant inertia matrix. The case of nonconstant inertia matrix and variable but bounded disturbances was considered in Reference 25. In addition, the adaptive compensation of constant disturbances within energy shaping control was attempted in References 26,27: while the former still requires solving the PDE, the latter is confined to a limited class of mechanical systems. Besides energy shaping, a sliding mode control for a class of underactuated systems with dry friction was presented in Ref...