Model orbit output feedback tracking of underactuated mechanical systems with actuator dynamics

ABSTRACT

Robust periodic motion generation is developed for a class of mechanical systems with actuator dynamics. The virtual constraint (VC) approach is first refined under incomplete state measurements and it is then extended to the case where the actuator dynamics are brought into play for avoiding limitations in the system performance. The extended VC approach is subsequently coupled to the nonlinear ${\mathcal{H}}_{\mathrm{\infty }}$ synthesis to yield the robust output feedback periodic motion generation for mechanical systems of underactuation degree one, driven by electrical motors with their own dynamics. The effectiveness of the proposed synthesis is supported in the numerical study made for a cart-pendulum testbed.

KEYWORDS:

• Robust control
• mechanical systems
• orbital stabilisation
• disturbance attenuation
• actuator dynamics

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Leonardo Herrera http://orcid.org/0000-0001-8989-0617

Yury Orlov http://orcid.org/0000-0001-9114-0436

Notes

1 The existence of such solutions is well-known (Orlov & Aguilar, 2014) to ensure the local controllability and observability of the error system in question.