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This paper deals with computer simulation of nonlinear control systems specified in the form of so-called generalized transfer functions. It briefly summarizes the underlying theoretical concepts, discusses the basics of their software implementation in Maple computer algebra system and presents special-purpose tools developed for simulation of generalized transfer functions in the MATLAB/Simulink...
STATic synchronous COMpensator (STATCOM) can be integrated into electric transmission systems to provide reactive power compensation and grid voltage support for achieving high-efficient and reliable Flexible AC Transmission Systems (FACTS). An emerging solution for STATCOM with modular structure and multilevel voltage output, named as modular multilevel STATCOM (mmSTATCOM) shows its great advantages...
The dynamic response of photovoltaic (PV) power converters plays a critical role to perform fast Maximum Power Point Tracking (MPPT). Among different options, linear controllers are a very popular choice to control power converters due to their design simplicity and basic implementation. However, the simplicity of the controller comes with a sacrifice in the speed and performance given the extremely...
Generally speaking, it is relatively difficult to getting the General analytical solution for solving System State Equation of nonlinear system. In this paper, it will introduce a new way that using the direct integration solution of State equation of nonlinear control systems to solve the general state equation of nonlinear control systems. Based on MATLAB software, it realizes and verifies the algorithm...
This paper deals with a robust stabilization problem of discrete model-reference control systems on integer grid coordinates. At present, all feedback control systems are realized using discretized signals. However, the analysis and design of discrete-time and discrete-value (point-to-point) control systems has not been established. In this paper, the robust stability of that type of discretized control...
An algebraic framework for discrete-time nonlinear control systems is introduced, based on the forward and backward shifts of the vector fields, dual to that based on differential 1-forms. As an application, the accessibility criterion of a control system in terms of vector fields is given and compared to those obtained under more restrictive assumptions.
The problem of disturbance decoupling of discrete-time nonlinear control systems by dynamic measurement feedback is addressed in this paper. New input-output linearization conditions are derived to provide weaker sufficient conditions for disturbance decoupling problem than existing ones. Additionally, it is shown that these conditions are necessary if one assumes the certain form of the dynamic feedback.
This paper explores the role of symmetries and reduction in nonlinear control and optimal control systems. We formulate symmetries in nonlinear control systems and then link it to symmetries in optimal control of such systems. We apply Poisson reduction to the Pontryagin maximum principle to reduce the optimal control system. Affine and kinematic optimal control systems are of particular interest:...
The paper addresses the problem of transforming the discrete-time single-input single-output nonlinear state equations into the extended observer form, which, besides the input and output, also depends on a finite number of their past values. The simple necessary and sufficient conditions for the existence of the extended coordinate change and the output transformation, allowing to solve the problem,...
The paper focuses on unification of the study of continuous- and discrete-time nonlinear control systems using the mathematical tools of pseudo-linear algebra. The realization problem is studied through the language of differential forms. Necessary and sufficient conditions are given for the existence of the state space realization of the nonlinear input-output equation defined in terms of the pseudo-linear...
Fuzzy logic controller (FLC) is an attractive alternative to existing classical or modern controllers for designing the challenging Non-linear control systems. It does not require any system modeling or complex mathematical equations governing the relationship between inputs and outputs. Fuzzy rules are very easy to learn and use, even by non-experts. It typically takes only a few rules to describe...
Performance of planned shipboard distribution/generation systems can be affected by power fluctuations and inappropriate control strategies. A measure of observability of such systems will allow one to quantify their operational performance. This paper attempts to account for observability of these systems through the incorporation of nonlinear dynamics of converters and electromechanical behavior...
Fuzzy logic controller (FLC) is an attractive alternative to existing classical or modern controllers for designing the challenging Non-linear control systems. However conventional FLC (CFLC) performance is greatly dependent on its inference rules. In most cases, the more rules being applied to a FLC, the accuracy of the control action is enhanced at the expense of longer computational time. As a...
As the SRD system is multivariable, highly coupled and nonlinear, it is difficult to get a satisfied result by the conventional control. In this paper, the adaptive fuzzy PID controller is designed as the speed regulator, by using the Simulink toolbox of the Matlab, the result shows that the controller can reduce the overshoot, improve the accuracy and possess good robustness.
Rotational inverted pendulum (RIP) is widely used as a benchmark system in evaluating various control strategies, as it is an ideal test bed that represents under-actuated plants. Although a proportional-integral-derivative (PID) controller is popular and relatively simple in structure, its use in balancing the RIP is usually not recommended due to the difficulties in finding the suitable PID controller...
We present a Nonlinear Model Predictive Control (NMPC) algorithm for real-time control of large-scale river networks in delta areas. The algorithm consists of an iterative, finite-horizon optimization of the system over a short-term control horizon. The underlying set of nonlinear internal process models represents relevant physical phenomena such as flow routing in the river network, and the dynamics...
This work deals with the optimal control problem which has been proposed to solve using the discrete augmented lagrangian based non-linear programming approach. It is shown that this technique guarantee a satisfactory performance in the face of both optimality by minimizing the energy and maximizing the output. Later on, the optimization has been more effective by using PSO-GA-Based Optimization to...
A nonlinear two loop quaternion based state dependent Ricatti equation (QSDRE) control and an LQR control based on linearized system equations are designed to improve the pointing performance of a large Earth Observation camera carried by a spacecraft with deployed solar panels. The system is modeled as eight bodies, a spacecraft, a high resolution camera, four solar panels, two in each side, and...
We investigate a special case of switched system which are described by a set of nonlinear control systems with nonlinearity of sector type. Using Lyapunov function method we obtain the estimations of switched system solution at the final time moment depending of initial state of solution. The subsystems can be stable or unstable. We investigate using Lyapunov function of Lurje-Postnikov type [5],...
The objective of this work is to demonstrate the use of acceleration feedback to improve the performance of a maglev system, especially in disturbance attenuation. In the single degree-of-freedom (DOF) system studied here, acceleration feedback has the effect of virtually increasing inertia, damping and stiffness. It is shown that it can be used to increase disturbance rejection without sacrificing...
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