4 research outputs found
A Hybrid Controller for Stability Robustness, Performance Robustness, and Disturbance Attenuation of a Maglev System
Devices using magnetic levitation (maglev) offer the potential for friction-free, high-speed, and high-precision operation. Applications include frictionless bearings, high-speed ground transportation systems, wafer distribution systems, high-precision positioning stages, and vibration isolation tables. Maglev systems rely on feedback controllers to maintain stable levitation. Designing such feedback controllers is challenging since mathematically the electromagnetic force is nonlinear and there is no local minimum point on the levitating force function. As a result, maglev systems are open-loop unstable. Additionally, maglev systems experience disturbances and system parameter variations (uncertainties) during operation. A successful controller design for maglev system guarantees stability during levitating despite system nonlinearity, and desirable system performance despite disturbances and system uncertainties. This research investigates five controllers that can achieve stable levitation: PD, PID, lead, model reference control, and LQR/LQG. It proposes an acceleration feedback controller (AFC) design that attenuates disturbance on a maglev system with a PD controller. This research proposes three robust controllers, QFT, Hinf , and QFT/Hinf , followed by a novel AFC-enhanced QFT/Hinf (AQH) controller. The AQH controller allows system robustness and disturbance attenuation to be achieved in one controller design. The controller designs are validated through simulations and experiments. In this research, the disturbances are represented by force disturbances on the levitated object, and the system uncertainties are represented by parameter variations. The experiments are conducted on a 1 DOF maglev testbed, with system performance including stability, disturbance rejection, and robustness being evaluated. Experiments show that the tested controllers can maintain stable levitation. Disturbance attenuation is achieved with the AFC. The robust controllers, QFT, Hinf , QFT/ Hinf, and AQH successfully guarantee system robustness. In addition, AQH controller provides the maglev system with a disturbance attenuation feature. The contributions of this research are the design and implementation of the acceleration feedback controller, the QFT/ Hinf , and the AQH controller. Disturbance attenuation and system robustness are achieved with these controllers. The controllers developed in this research are applicable to similar maglev systems
Engineering Dynamics and Life Sciences
From Preface:
This is the fourteenth time when the conference “Dynamical Systems: Theory
and Applications” gathers a numerous group of outstanding scientists and engineers, who
deal with widely understood problems of theoretical and applied dynamics.
Organization of the conference would not have been possible without a great effort of
the staff of the Department of Automation, Biomechanics and Mechatronics. The patronage
over the conference has been taken by the Committee of Mechanics of the Polish Academy
of Sciences and Ministry of Science and Higher Education of Poland.
It is a great pleasure that our invitation has been accepted by recording in the history
of our conference number of people, including good colleagues and friends as well as a large
group of researchers and scientists, who decided to participate in the conference for the
first time. With proud and satisfaction we welcomed over 180 persons from 31 countries all
over the world. They decided to share the results of their research and many years
experiences in a discipline of dynamical systems by submitting many very interesting
papers.
This year, the DSTA Conference Proceedings were split into three volumes entitled
“Dynamical Systems” with respective subtitles: Vibration, Control and Stability of Dynamical
Systems; Mathematical and Numerical Aspects of Dynamical System Analysis and
Engineering Dynamics and Life Sciences. Additionally, there will be also published two
volumes of Springer Proceedings in Mathematics and Statistics entitled “Dynamical Systems
in Theoretical Perspective” and “Dynamical Systems in Applications”