Adaptive set–point control of robotic manipulators with amplitude–limited control inputs

Zergeroğlu, Erkan; Dixon, Warren E.; Behal, Aman; Dawson, D.M.

doi:10.1017/s0263574799001988

Cited by 63 publications

(78 citation statements)

References 17 publications

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“…Property 2: The function in (24) denotes a normal projection algorithm, which ensures that the following inequality is satisfied (for further details, see [32]- [35]): (26) where , denote known, constant lower and upper bounds, respectively, of . After substituting the time derivative of (22) into (20), the closed-loop error system can be determined as (27) where denotes the parameter estimation error defined as (28) 2 Since the measurable regression matrix Y (1) contains only the reference trajectories x and _ x , the expression in (24) can be integrated by parts to prove that the adaptive estimate (t) can be generated using only measurements of e (t) (i.e., no r (t) measurements, and hence, no _ x(t) measurements are required).…”

Section: Closed-loop Error Systemmentioning

confidence: 99%

Global Adaptive Output Feedback Tracking Control of an Unmanned Aerial Vehicle

MacKunis

Wilcox

Kaiser

et al. 2010

IEEE Trans. Contr. Syst. Technol.

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Abstract-An output feedback (OFB) dynamic inversion control strategy is developed for an unmanned aerial vehicle (UAV) that achieves global asymptotic tracking of a reference model. The UAV is modeled as an uncertain linear time-invariant (LTI) system with an additive bounded nonvanishing nonlinear disturbance. A continuous tracking controller is designed to mitigate the nonlinear disturbance and inversion error, and an adaptive law is utilized to compensate for the parametric uncertainty. Global asymptotic tracking of the measurable output states is proven via a Lyapunovlike stability analysis, and high-fidelity simulation results are provided to illustrate the applicability and performance of the developed control law.Index Terms-Adaptive control, dynamic inversion (DI), Lyapunov methods, nonlinear control, robust control.

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Section: Closed-loop Error Systemmentioning

confidence: 99%

Global Adaptive Output Feedback Tracking Control of an Unmanned Aerial Vehicle

MacKunis

Wilcox

Kaiser

et al. 2010

IEEE Trans. Contr. Syst. Technol.

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“…In Loria (1997), a controller is proposed involving a gravity compensation term plus a saturating function through which the position errors pass. A velocity and position feedback method with adaptive gravity compensation is reported in Zergeroglu (2000) in which the velocity and position errors separately pass through two nonlinear saturating functions and the outputs are then added to an adaptive gravity compensation term. In Zavala (2006), a brief review of PD plus gravity compensation controllers is provided.…”

Section: Introductionmentioning

confidence: 99%

Teleoperation in the presence of varying time delays and sandwich linearity in actuators

2013

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In this paper, a novel control scheme is proposed to guarantee global asymptotic stability of bilateral teleoperation systems that are subjected to time-varying time delays in their communication channel and sandwich linearity in their actuators. This extends prior art concerning control of nonlinear bilateral teleoperation systems under time-varying time delays to the case where the local and the remote robots' control signals pass through saturation or similar nonlinearities that belong to a class of systems we name sandwich linear systems. Our proposed controller is similar to the proportional plus damping (P+D) controller with the difference that it takes into account the actuator saturation at the outset of control design and alters the proportional term by passing it through a nonlinear function; thus, we call the proposed method as nonlinear proportional plus damping (nP+D).The asymptotic stability of the closed-loop system is established using a LyapunovKrasovskii functional under conditions on the controller parameters, the actuator saturation characteristics, and the maximum values of the time-varying time delays. To show the effectiveness of the proposed method, it is simulated on a variable-delay teleoperation system comprising a pair of planar 2-DOF robots subjected to actuator saturation. Furthermore, the controller is experimentally validated on a pair of 3-DOF PHANToM Premium 1.5A robots, which have limited actuation capacity, that form a teleoperation system with a varying-delay communication channel.

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“…Solutions without considering velocity measurements and with gravity compensation are treated in (Loria et al, 1997). A full-state (position and velocity) feedback solution with adaptive gravity compensation is presented in (Zergeroglu et al, 2000). More recently, new schemes dealing with this regulation problem of robot manipulators with bounded inputs have been presented by Zavala & Santibañez (2006), Zavala & Santibañez (2007), Dixon (2007), Alvarez -Ramirez et al, (2003), and Alvarez- Ramirez et al, (2008).…”

Section: Introductionmentioning

confidence: 99%