Nonlinear Passive Elements Research Articles

МОДЕЛЮВАННЯ ОПТОЕЛЕКТРОННОГО НАВАНТАЖЕННЯ, ЯКЕ ЖИВИТЬСЯ ВІД ФОТОЕЛЕМЕНТА ТА АКУМУЛЯТОРА

Метою даної роботи є побудова еквівалентних електричних схем оптоелектронного навантаження, яке живиться від фотоелемента та акумулятора. В роботі показано необхідність створення таких еквівалентних електричних схем, а саме при підключенні світлодіодів та напівпровідникових лазерів до сонячних фотоелементів, в якості джерела електричної енергії, та при використанні акумуляторів електроенергії. Показано, що еквівалентні електричні схеми витікають з фізичних явищ в напівпровідникових пристроях і рівнянь, які описують явища перетворення електричної енергії в світлову. Викладено різні еквівалентні схеми оптоелектронного навантаження. Показано, як просту так і найбільш узагальнену еквівалентні електричні схеми. Зокрема, показано еквівалентну схему акумулятора і спрощені схеми фотоелемента та оптоелектронного випромінювача світла, де в якості навантаження виступає світлодіод. Зазначено, що розвитком даної моделі є більш узагальнена еквівалентна електрична схема, де в якості оптоелектронного навантаження виступає напівпровідниковий інжекційний лазер. Розписані їх параметри та викладені рівняння для струмів та напруг. Також показано існування пасивних паразитних елементів в таких електричних схемах. Також показано, що в якості схеми заміщення фотоелемента, в спрощеній моделі, використано ідеальне джерело напруги та резистор з конденсатором. В подальшому, в узагальненій моделі, для більш широкого моделювання роботи фотоелемента, в якості схеми заміщення було використано ідеальне джерело струму та нелінійні пасивні елементи. Тобто, в результаті, було отримано узагальнену еквівалентну електричну схему акумулятора, підключеного до фотоелемента та оптоелектронного навантаження. Побудовано рівняння для струмів та напруг в отриманої схеми заміщення. Зроблено висновок. Бібл. 7, рис. 5.

A study on non-linear behavior of memristor emulator using multisim

A Memristor (memory resistor) is a two terminal non-linear passive element used to relate magnetic flux with respect to electric charge. A Memristor opposes the flow of electric current across a device like a resistor but also remember the last charge that was flowing through it. Memristor is a fourth passive circuit element after inductor ‘L’ resistor ‘R’, and capacitor ‘C. The voltage and current relationship in a memristor is a multivariable function therefore analyzing the circuit is a difficult task. This paper depicts the designing of a memristor model emulator using multisim and studied about its linear and non-linear characteristics.

Scale-free networks as an epiphenomenon of memory

Many realistic networks are scale free, with small characteristic path lengths, high clustering, and power law in their degree distribution. They can be obtained by dynamical networks in which a preferential attachment process takes place. However, this mechanism is non-local, in the sense that it requires knowledge of the whole graph in order for the graph to be updated. Instead, if preferential attachment and realistic networks occur in physical systems, these features need to emerge from a local model. In this paper, we propose a local model and show that a possible ingredient (which is often underrated) for obtaining scale-free networks with local rules is memory. Such a model can be realised in solid-state circuits, using non-linear passive elements with memory such as memristors, and thus can be tested experimentally.

Generation of chaotic microwave pulses with the help of passive synchronization of spin wave self-modulation frequencies in self-oscillatory ring systems

Passive synchronization (PS) of spin wave self-modulation frequencies of a chaotic microwave signal has been observed for the first time in a self-oscillatory ring system involving a nonlinear passive element with saturable absorption. The development of PS led to the generation of a periodic train of chaotic microwave pulses with an off/duty ratio exceeding 20. It is established that the repetition period of chaotic microwave pulses can be controlled by changing gain in the ring system.

Sky-hook control of nonlinear quarter car model traversing rough road matching performance of LQR control

The control of the stationary random response of a two degree of freedom (dof) quarter car vehicle model with nonlinear passive elements traversing a homogenous rough road with sky-hook damper control strategy is considered. The sky-hook damper control strategy is realized through a feedback control scheme. The parameters of the sky-hook damper are optimally determined by equating the control force of the feedback system to that obtained by linear quadratic regulator (LQR) control in a mean square equivalence sense. The nonlinear suspension is of hysteretic type and modeled by the Bouc–Wen model. The equivalent linearization method is used to linearize the system and the stochastic optimal control LQR theory is applied to the equivalent linear system. Results show the enhanced performance of feedback control based on sky-hook to levels of performance of LQR control which are also verified by Monte Carlo simulation.

STOCHASTIC OPTIMAL ACTIVE CONTROL OF A 2-DOF QUARTER CAR MODEL WITH NON-LINEAR PASSIVE SUSPENSION ELEMENTS

Active control of the time varying response to a stationary random excitation of a two-degree-of-freedom vehicle model with non-linear passive suspension elements is considered in this paper. The method of equivalent linearization is used to derive the equivalent linear model and the optimal control laws are obtained by using stochastic optimal control theory based on full state information. Velocity squared damping and hysteresis type of stiffness non-linearities are considered. The performance of active suspensions with non-linear passive elements is found to be superior to the corresponding passive suspension systems. As a check on the accuracy of the equivalent linearization technique, a Monte Carlo simulation has also been performed. The results are compared with the results obtained from linearized vehicle model and good agreement between the results has been observed.

Active control of non-stationary response of a two-degree of freedom vehicle model with nonlinear suspension

Active control of non-stationary response of a two-degree of freedom vehicle model with nonlinear passive suspension elements is considered in this paper. The method of equivalent linearization is used to derive an equivalent linear model and optimal control laws are obtained by using stochastic optimal control theory based on full state information. Velocity squared quadratic damping and hysteretic type of stiffness nonlinearities are considered. The effect of the nonlinearities on the active system performance is studied. The performance of active suspensions with nonlinear passive elements is found to be superior to the corresponding passive suspension systems.

Active Control of Non-stationary Response of Vehicles with Nonlinear Suspensions

SUMMARY Active control of non-stationary response of a single degree of freedom vehicle model with nonlinear passive suspension elements is considered in this paper. The method of equivalent linearization is used to derive the equivalent linear model and the optimal control laws are obtained by using stochastic optimal control theory based on full state information. Velocity squared quadratic damping and hysteresis type of stiffness nonlinearities are considered. The effect of the nonlinearities on the active system performance is studied. The performance of active suspensions with nonlinear passive elements is found to be superior to the corresponding passive suspension systems.