516 research outputs found
Nonlinear Model Predictive Control for Constrained Output Path Following
We consider the tracking of geometric paths in output spaces of nonlinear
systems subject to input and state constraints without pre-specified timing
requirements. Such problems are commonly referred to as constrained output
path-following problems. Specifically, we propose a predictive control approach
to constrained path-following problems with and without velocity assignments
and provide sufficient convergence conditions based on terminal regions and end
penalties. Furthermore, we analyze the geometric nature of constrained output
path-following problems and thereby provide insight into the computation of
suitable terminal control laws and terminal regions. We draw upon an example
from robotics to illustrate our findings.Comment: 12 pages, 4 figure
Distributed Neurodynamics-Based Backstepping Optimal Control for Robust Constrained Consensus of Underactuated Underwater Vehicles Fleet
Robust constrained formation tracking control of underactuated underwater
vehicles (UUVs) fleet in three-dimensional space is a challenging but practical
problem. To address this problem, this paper develops a novel consensus based
optimal coordination protocol and a robust controller, which adopts a
hierarchical architecture. On the top layer, the spherical coordinate transform
is introduced to tackle the nonholonomic constraint, and then a distributed
optimal motion coordination strategy is developed. As a result, the optimal
formation tracking of UUVs fleet can be achieved, and the constraints are
fulfilled. To realize the generated optimal commands better and, meanwhile,
deal with the underactuation, at the lower-level control loop a neurodynamics
based robust backstepping controller is designed, and in particular, the issue
of "explosion of terms" appearing in conventional backstepping based
controllers is avoided and control activities are improved. The stability of
the overall UUVs formation system is established to ensure that all the states
of the UUVs are uniformly ultimately bounded in the presence of unknown
disturbances. Finally, extensive simulation comparisons are made to illustrate
the superiority and effectiveness of the derived optimal formation tracking
protocol.Comment: This paper is accepted by IEEE Transactions on Cybernetic
Adaptive neural network control of underactuated surface vessels with guaranteed transient performance: Theory and experimental results
In this paper, an adaptive trajectory trackingcontrol algorithm for underactuated unmanned surfacevessels (USVs) with guaranteed transient performance isproposed. To meet the realistic dynamical model of USVs,we consider that the mass and damping matrices are notdiagonal and the input saturation problem. Neural Networks(NNs) are employed to approximate the unknown externaldisturbances and uncertain hydrodynamics of USVs. Moreover,both full state feedback control and output feedbackcontrol are presented, and the unmeasurable velocities ofthe output feedback controller are estimated via a highgainobserver. Unlike the conventional control methods,we employ the error transformation function to guaranteethe transient tracking performance. Both simulation andexperimental results are carried out to validate the superiorperformance via comparing with traditional potential integral(PI) control approaches
Nonlinear Trajectory Tracking Control for Marine Vessels with Additive Uncertainties
The paper presents a nonlinear control law for a marine vessel to track a reference trajectory. In the wake of theresults obtained in [19], an integrative approach is incorporated in the linear algebra methodology in order toreduce the effect of the uncertainty in the tracking error. This new approach does not increase the complexityof the design methodology. In addition, the zero convergence of tracking error under polynomial uncertaintiesis demonstrated. Simulation results under environmental disturbance and model mismatches are presentedand discussed.Fil: Serrano, Mario Emanuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; ArgentinaFil: Godoy Bordes, Sebastian Alejandro. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de Automática; ArgentinaFil: Gandolfo, Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de Automática; ArgentinaFil: Mut, Vicente Antonio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de Automática; ArgentinaFil: Scaglia, Gustavo Juan Eduardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de IngenierĂa QuĂmica; Argentin
Ship Course Keeping Using Different Sliding Mode Controllers
This study addresses three sliding mode heading controllers for dealing with uncertain wave disturbances. A nonlinear steering model is derived, and the feedback linearization method is chosen to simplify the nonlinear system in this study. The adaptive method and disturbance observer technique are proposed for course keeping and ensuring robust performance of the time varying wave moment and actuator dynamics. Finally, the simulation results on a navy ship illustrate the effectiveness of the presented control algorithms for course keeping
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