578 research outputs found
Observer-based adaptive sliding mode fault-tolerant control for the underactuated space robot with joint actuator gain faults
summary:An adaptive sliding mode fault-tolerant controller based on fault observer is proposed for the space robots with joint actuator gain faults. Firstly, the dynamic model of the underactuated space robot is deduced combining conservation law of linear momentum with Lagrange method. Then, the dynamic model of the manipulator joints is obtained by using the mathematical operation of the block matrices, hence the measurement of the angular acceleration of the base attitude can be omitted. Subsequently, a fault observer which can accurately estimate the gain faults is designed, and the estimated results are fed back to the adaptive sliding mode fault-tolerant controller. It is proved that the proposed control algorithm can guarantee the global asymptotic stability of the closed-loop system through the Lyapunov theorem. The simulation results authenticate the effectiveness and feasibility of the control strategy and observation scheme
New developments in mathematical control and information for fuzzy systems
Hamid Reza Karimi, Mohammed Chadli and Peng Sh
Adaptive Approximation-Based Control for Nonlinear Systems: A Unified Solution with Accurate and Inaccurate Measurements
A unified solution to adaptive approximation-based control for nonlinear
systems with accurate and inaccurate state measurement is synthesized in this
study. Starting from the standard adaptive approximation-based controller with
accurate state measurement, its corresponding physical interpretation,
stability conclusion, and learning ability are rigorously addressed when facing
additive measurement inaccuracy, and explicit answers are obtained in the
framework of both controller matching and system matching. Finally, it proves
that, with a certain condition, the standard adaptive approximation-based
controller works as a unified solution for the cases with accurate and
inaccurate measurement, and the solution can be extended to the nonlinear
system control problems with extra unknown dynamics or faults in actuator
and/or process dynamics. A single-link robot arm example is used for the
simulation demonstration of the unified solution
Supervision of Nonlinear Networked Control Systems Under Network Constraints
International audienceThe remote supervision for a class of nonlinear systems in the presence of additive disturbances and measurement noises is considered in this paper. The communication network may introduce time delays while exchanging data among sites connected to the network medium (i.e., the data acquisition site and the remote plant site). Two different approaches are presented in this paper. The first one uses a conventional estimator-based predictor when the uncertainties are supposed to be known. In the case of unknown but bounded uncertainties by known bounds, an interval estimation-based predictor evaluating the set of admissible values for the state is investigated. The state prediction techniques are used to compensate the effect of network-induced delays. Simulation results are introduced to illustrate the efficiency of the proposed techniques
Anti‐windup controller design for singularly perturbed systems subject to actuator saturation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166157/1/cth2bf00153.pd
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