Output-feedback adaptive control for the global regulation of robot manipulators with bounded inputs (original) (raw)
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A generalized global adaptive tracking control scheme for robot manipulators with bounded inputs
International Journal of Adaptive Control and Signal Processing, 2014
In this work, a generalized adaptive scheme for the global motion control of robot manipulators with constrained inputs is proposed. It gives rise to various families of bounded adaptive controllers defined through a general class of saturation functions. Compared with adaptive tracking control algorithms previously developed in a bounded-input context, the proposed adaptive approach guarantees the motion control objective for any initial condition, avoiding discontinuities throughout the scheme, preventing the inputs to reach their natural saturation bounds, and permitting innovation on the saturating structure through its generalized form, giving a wide range of possibilities for performance improvement. Experimental results corroborate the efficiency of the proposed scheme.
A generalized scheme for the global adaptive regulation of robot manipulators with bounded inputs
Robotica, 2013
SUMMARYIn this work, a generalized adaptive control scheme for the global position stabilization of robot manipulators with bounded inputs is proposed. It gives rise to various families of bounded controllers with adaptive gravity compensation. Compared with the adaptive approaches previously developed in a bounded-input context, the proposed scheme guarantees the adaptive regulation objective: globally, avoiding discontinuities in the control expression as well as in the adaptation auxiliary dynamics, preventing the inputs to reach their natural saturation bounds, and imposing no saturation-avoidance restriction on the control gains. Experimental results corroborate the efficiency of the proposed adaptive scheme.
2011
Two important practical aspects of robot manipulators control are the difficulty of obtaining accurate velocity measurements and the uncertainty of parameters of the dynamical model. To deal with these problems, several adaptive output feedback tracking controllers have been proposed. In this paper, it is proved that, as long as the regression matrix is persistenly exciting, uniform global asymptotical stability can be achieved through an adaptive output feedback controller.
Scrutiny of Nonlinear Adaptive Output Feedback Control for Robotic Manipulators
Springer International Publishing, 2014
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Global trajectory tracking through output feedback for robot manipulators with bounded inputs
Asian Journal of Control, 2011
In this work, a globally stabilizing output feedback scheme for the trajectory tracking of robot manipulators with bounded inputs is proposed. It achieves the motion control objective avoiding input saturation and excluding velocity measurements. Moreover, it is not defined using a specific sigmoidal function, but any one on a set of saturation functions. Consequently, the proposed scheme actually constitutes a family of globally stabilizing output feedback bounded controllers. Furthermore, the bound of such saturation functions is explicitly considered in their definition. Hence, the control gains are not tied to satisfy any saturation-avoidance inequality and may consequently take any positive value, which may be considered beneficial for performance adjustment/improvement purposes. Further, a class of desired trajectories that may be globally tracked avoiding input saturation and excluding velocity measurements is completely characterized. Global asymptotic stabilization of the closed-loop system solutions towards the prespecified desired trajectory is proved through a strict Lyapunov function. The efficiency of the proposed scheme is corroborated through experimental results.
Global adaptive output feedback tracking control of robot manipulators
2000
Abstract This paper presents a solution to the problem of global, output feedback, tracking control of uncertain robot manipulators, specifically, a desired compensation adaptation law plus a nonlinear feedback term coupled to a dynamic nonlinear filter is designed to produce global asymptotic link position tracking while compensating for parametric uncertainty and requiring only link position measurements
IET Control Theory & Applications, 2015
An output-feedback proportional-integral-derivative-type control scheme for the global position stabilisation of robot manipulators with bounded inputs is proposed. It guarantees the global regulation objective avoiding input saturation by releasing the feedback not only from the exact knowledge of the system structure and parameter values, but also from velocity measurements. With respect to previous approaches of the kind, the proposed scheme remains simple while increasing design/performance-adjustment flexibility. For instance, it does not impose the use of a specific sigmoidal function to achieve the required boundedness but involves a generalised type of saturation functions. More importantly, it is characterised by a very simple control-gain tuning criterion, the simplest hitherto obtained in the considered analytical context. Experimental tests on a 2-degree-of-freedom direct-drive manipulator corroborate the efficiency of the developed scheme.
On global output feedback tracking control of robot manipulators
2000
We revisit the global output feedback (OFB) tracking control problem for rigid-link robot manipulators subject to parametric uncertainty. Motivated by misunderstandings in the literature concerning our previous result, we propose a new global OFB adaptive controller which, in contrast to our previous work, eliminates the need for a post-stability analysis transformation to derive a velocity-independent control strategy. The structure of the new controller along with a new Lyapunov function are used to illustrate global asymptotic link position tracking. Experimental results are included to demonstrate the controller performance
An adaptive output feedback controller for robot arms: stability and experiments
Automatica, 2001
An adaptive output feedback controller for robot arms is developed in this paper. A nonlinear observer based on desired joint velocities and bounded joint position error is used to estimate joint velocities. Experimental results validate the ewectiveness of the proposed adaptive output feedback controller.