Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 5 Articles
The construction and several control problems of a new hyperchaotic finance system are investigated in this paper. Firstly, a\nnew four-dimensional hyperchaotic finance system is introduced, based on which a new hyperchaos is then generated by setting\nparameters. And the qualitative analysis is numerically studied to confirm the dynamical processes, for example, the bifurcation\ndiagram, Poincar�´e sections, Lyapunov exponents, and phase portraits. Interestingly, the obtained results show that this new system\ncan display complex characteristics: chaotic, hyperchaotic, and quasiperiodic phenomena occur alternately versus parameters.\nSecondly, three single input adaptive controllers are designed to realize the control problems of such system: stabilization,\nsynchronization, and coexistence of antisynchronization and complete synchronization, respectively. It is noted that the designed\ncontrollers are simpler than the existing ones. Finally, numerical simulations are provided to demonstrate the validity and the\neffectiveness of the proposed theoretical results....
The approximate Prediction-Based Control method (aPBC) is the continuous-time version of the well-known Prediction-Based\nChaos Control method applied to stabilize periodic orbits of nonlinear dynamical systems. The method is based on estimating\nfuture states of the free system response of continuous-time systems using the solution from the Runge-Kutta implicit method\nin real time. Some aspects of aPBC are evaluated in the present work, particularly its robustness to low future states estimation\nprecision is exemplified....
This study presents the development and application of a fuzzy control system (FCS) for the control of the charge and\ndischarge process for a bank of batteries connected to a DC microgrid (DC-MG). The DC-MG runs on a maximum\npower of 1 kW with a 190V DC bus using two photovoltaic systems of 0.6kW each, a 1kW bidirectional DC-AC\nconverter to interconnect the DC-MG with the grid, a bank of 115 Ah to 120V lead-acid batteries, and a general\nmanagement system used to define the operating status of the FCS. This FCS uses a multiplexed fuzzy controller,\nnormalizing the controllerâ��s inputs and outputs in each operating status. The design of the fuzzy controller is based on a\nMamdani inference system with AND-type fuzzy rules. The input and output variables have two trapezoidal membership\nfunctions and three triangular membership functions. LabVIEW and the NI myRIO-1900 embedded design device were\nused to implement the FCS. Results show the stability of the DC bus of the microgrid when the bank of batteries is in the\ncharging and discharging process, with the bus stabilized in a range of 190 V�± 5%, thus demonstrating short response times\nto perturbations considering the microgridâ��s response dynamics....
This paper investigates the relationship between current, back electromotive force (back-EMF), and torque for permanent-magnet\nbrushless DC (PM BLDC) motors under advanced commutation control from the perspective of harmonics. Considering that\nthe phase current is the influencing factor of both torque and torque ripple, this paper firstly analyzes the effects of advanced\ncommutation on phase current and current harmonics. And then, based on the harmonics of the phase current and back-EMF, the\ntorque harmonic expressions are deduced. The expressions reveal the relationship of harmonic order between the torque, phase\ncurrent, and back-EMF and highlight the different contribution of individual torque harmonic to the total torque ripple. Finally,\nthe proposed harmonic analysis method is verified by the experiments with different speed and load conditions....
This paper addresses the fault-tolerant control of hypersonic flight vehicle. To estimate the unknown function in flight dynamics,\nneural networks are employed in controller design. Moreover, in order to compensate the actuator fault, an adaptive signal is\nintroduced in the controller design to estimate the unknown fault parameters. Simulation results demonstrate that the proposed\napproach could obtain satisfying performance....
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