Current Issue : October - December Volume : 2012 Issue Number : 4 Articles : 7 Articles
A consensus-based formation control for a class of networkedmultiple mobile robots is investigated with a virtual leader approach.\r\nA novel distributed control algorithm is designed based on the Lyapunov method and linear matrix inequality (LMI) technique\r\nfor time delay systems. A multiple Lyapunov Krasovskii functional candidate is proposed for investigating the sufficient conditions\r\nto linear control gain design for the system with constant time delays. Simulation results as well as experimental studies on Pioneer\r\n3 series mobile robots are shown to verify the effectiveness of the proposed approach....
This paper is concerned with robust stability of uncertain linear systems with interval time-varying delay. The time-varying delay\r\nis assumed to belong to an interval, which means that the derivative of the time-varying delay has an upper bound or a restriction.\r\nOn other occasions, if we do not take restriction on the derivative of the time-varying delay into consideration, it allows the\r\ndelay to be a fast time-varying function. The uncertainty under consideration includes a polytopic-type uncertainty and a linear\r\nfractional norm-bounded uncertainty. In order to obtain much less conservative results, a new Lyapunov-Krasovskii functional,\r\nwhich makes use of the information of both the lower and upper bounds of the interval time-varying delay, is proposed to derive\r\nsome new stability criteria. Numerical examples are given to demonstrate the effectiveness of the proposed stability criteria...
This paper presents development and control of a disc-typed one-wheel mobile robot, called GYROBO. Several models of the onewheel\r\nmobile robot are designed, developed, and controlled. The current version of GYROBOis successfully balanced and controlled\r\nto follow the straight line. GYROBO has three actuators to balance and move. Two actuators are used for balancing control by\r\nvirtue of gyro effect and one actuator for driving movements. Since the space is limited and weight balance is an important factor\r\nfor the successful balancing control, careful mechanical design is considered. To compensate for uncertainties in robot dynamics,\r\na neural network is added to the nonmodel-based PD-controlled system. The reference compensation technique (RCT) is used for\r\nthe neural network controller to help GYROBO to improve balancing and tracking performances. Experimental studies of a selfbalancing\r\ntask and a line tracking task are conducted to demonstrate the control performances of GYROBO....
This paper considers the problem of H8 observers design for a class of Lipschitz continuous nonlinear singular systems. The\r\nmethod is based on the parameterization of the solution of the generalized Sylvester equations obtained from the estimation\r\nerrors. Sufficient conditions for the existence of the observers which guarantee stability and the worst case observers error energy\r\nover all bounded energy disturbances is minimized are given. The approach also unifies the full-order, the reduced-order, and the\r\nminimal-order observers design. The solutions are obtained through linear matrix inequalities (LMIs) formulation. A numerical\r\nexample is given to illustrate our results....
Linear time-delay systems with transcendental characteristic equations have infinitely many eigenvalues which are generally hard to\r\ncompute completely. However, the spectrum of first-order linear time-delay systems can be analyzed with the Lambert function.\r\nThis paper studies the stability and state feedback stabilization of first-order linear time-delay system in detail via the Lambert\r\nfunction. The main issues concerned are the rightmost eigenvalue locations, stability robustness with respect to delay time, and\r\nthe response performance of the closed-loop system. Examples and simulations are presented to illustrate the analysis results....
A method is proposed for stabilization, using static state feedback, of systems subject to time-varying delays in both the states\r\nand their derivatives (i.e., neutral systems), in the presence of saturating actuators. Delay-dependent conditions are given to\r\ndetermine stabilizing state-feedback controllers with large domain of attraction, expressed as linear matrix inequalities, readily\r\nimplementable using available numerical tools and with tuning parameters that make possible to select the most adequate solution.\r\nThese conditions are derived by using a Lyapunov-Krasovskii functional on the vertices of the polytopic description of the actuator\r\nsaturations. Numerical examples demonstrate the effectiveness of the proposed technique....
We have investigated the synchronization and antisynchronization behaviour of two identical planar oscillation of a satellite in\r\nelliptic orbit evolving from different initial conditions using the active control technique based on the Lyapunov stability theory\r\nand the Routh-Hurwitz criteria. The designed controller, with our own choice of the coefficient matrix of the error dynamics that\r\nsatisfy the Lyapunov stability theory and the Routh-Hurwitz criteria, is found to be effective in the stabilization of the error states\r\nat the origin, thereby, achieving synchronization and antisynchronization between the states variables of two nonlinear dynamical\r\nsystems under consideration. The results are validated by numerical simulations using mathematica....
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