1,725 research outputs found
Discrete Robust Control of Robot Manipulators using an Uncertainty and Disturbance Estimator
This article presents the design of a robust observer based on the
discrete-time formulation of Uncertainty and Disturbance Estimator (UDE), a
well-known robust control technique, for the purpose of controlling robot
manipulators. The design results in a complete closed-loop, robust,
controller--observer structure. The observer incorporates the estimate of the
overall uncertainty associated with the plant, in order to mimic its dynamics,
and the control law is generated using an auxiliary error instead of state
tracking error. A detailed qualitative and quantitative stability analysis is
provided, and simulations are performed on the two-link robot manipulator
system. Further, a comparative study with well-known control strategies for
robot manipulators is presented. The results demonstrate the efficacy of the
proposed technique, with better tracking performance and lower control energy
compared to other strategies.Comment: 20 pages, 7 figures, 1 tabl
Optimized state feedback regulation of 3DOF helicopter system via extremum seeking
In this paper, an optimized state feedback regulation of a 3 degree of freedom (DOF) helicopter is designed via extremum seeking (ES) technique. Multi-parameter ES is applied to optimize the tracking performance via tuning State Vector Feedback with Integration of the Control Error (SVFBICE).
Discrete multivariable version of ES is developed to minimize a cost function that measures the performance of the controller. The cost function is a function of the error between the actual and desired axis positions. The controller parameters are updated online as the optimization takes place. This method significantly decreases the time in obtaining optimal controller parameters. Simulations were conducted for the online optimization under both fixed and varying operating conditions. The results demonstrate the usefulness of using ES for preserving the maximum attainable performance
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