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In this paper we propose a novel motion filtering approach that takes into consideration the existence of certain system constraints with respect to the amount of the corrective rotational and translational motions that can be applied on each video frame for stabilization. The interdependence between rotational and translational constraints is considered, and a modified Kalman filtering algorithm...
The presence of optical turbulence in video acquired by cameras viewing scenes at long distances can contribute significantly to degradation. This problem arises routinely, for example, in astronomy where objects of interest reside beyond the earth's atmosphere. Optical turbulence introduces time-varying perturbations in the images as well as blurring. In this paper, we introduce a method for suppressing...
Control design methods for the control of the reaction wheel pendulum using a single actuator are presented in this paper. The control algorithms are based on the energy of the system and its passivity properties.
The robustness of discrete iterative learning controller a-gainst initial state state error for discrete-time plant is investigated in this paper. When the initial state remains fixed for each iteration but is different from the desired one, it is shown that the output will converge to a trajectory which is the same as the desired one except the initial point for a traditional D-type discrete iterative...
The new approach of robust control systems synthesis, both linear, and nonlinear and non-stationary is offered. The control is carried out, providing the given phase constrains varied in acceptable limits, in view of constrains on its value and incompleteness of the information about functioning disturbances. The approach is based on introduction of auxiliary integral surfaces, on which the initial...
The combination of flatness-based trajectory planning and feedforward control with asymptotically stabilizing dynamic feedback control is considered for the tracking control of a distributed-parameter model of a piezoelectric stack actuator.
This paper addresses the problem of stabilization of linear systems subject to both model uncertainties, additive disturbance and input limits. A design technique, based both on the solution of a r-parameterized family of Riccati equations and the use of the S-procedure, is proposed to compute a piecewise linear state feedback control law. The links and tradeoffs between tolerance to the additive...
This paper presents the design, development and implementation of a Hybrid Adaptive Fuzzy Controller (HAFC) suitable for real-time industrial applications. The developed HAFC consists of a weighted combination of the Direct Adaptive Fuzzy Controller (DAFC) and Indirect Adaptive Fuzzy Controller (IAFC) and a gradually activated supervisory controller. The unique feature of the HAFC is that no mathematical...
In this paper the trajectory tracking control problem for a certain class of propagation processes modeled as Quasi-Linear Parameter Varying systems is considered. The propagation physical models are generally described by means of PDEs (partial differential equations). However in real world control problems the PDE models are usually converted into ODEs (ordinary differential equations) models adopting...
Nonlinear optimal control problems, in which state trajectories are permitted to be discontinuous at a finite number of times, and the jump times are choice variables, are analysed. Problems such as these arise in economics, lazer technique, and robototechnique. Necessary conditions for optimality, in the form of a Maximum Principle, for the impulse optimal control problems with general terminal and...
In many applications of motion control, problems associated with imprecisely measured or changing load (mass or moment of inertia) constitute a serious obstacle in the design of satisfactory controlling systems, more and more often compelling the introduction of various forms of uncertainties to engineering solutions. This paper deals with the time-optimal control for mechanical systems with uncertain...
Given paper presents practically a question statement on the possibility of unpredictable behaviour of the car. In the state space of the linearized model an untypical attractor is revealed which is similar to the Lorenz strange attractor generating an unregular trajectory behaviour. It is shown an opportunity of getting the complete conformity with the Lorenz system for which a strange attractor...
This paper presents the synthesis of a control law which guarantees asymptotic stability for a wheeled mobile robot under slip conditions subject to both constraints and system dynamics. This control law is obtained using Linear Matrix Inequalities. The improvements provided by the pro- posed adaptive control are compared with other control laws, dealing with slip effect, through simulation.
In this paper, an optimization-based iterative learning control approach is presented. Given a desired trajectory to be followed, the proposed learning algorithm improves the system performance from trial to trial by exploiting the experience gained from previous repetitions. Taking advantage of the a-priori knowledge about the systems dominating dynamics, a data-based update rule is derived which...
An optimal tracking controller design approach for non-linear non minimum-phase systems based on the concept of modified optimal control is presented. We extend the existing design strategy of modified optimal control to non-linear time-variant systems, since tracking a desired trajectory results in a time-variant non-linear system for the tracking error. We obtain an optimal control law which achieves...
This paper describes a hybrid control scheme to swing-up a pendulum mounted on a cart (cart-pole system) or on another pendulum (pendubot system). Switches between equilibria of the actuated link are used to swing-up the free link. It is argued that this hybrid design is robust and versatile, considerably simplifies the closed-loop analysis, and is well-suited for performance optimization.
This paper reports a complete formulation of a model predictive control strategy having guaranteed nominal asymptotic stability. The formulation includes a successive linearisation procedure to obtain a linear model from a non-linear plant model. It gives a complete state-space derivation including long-range prediction, trajectory tracking and modelling of both measured feedforward disturbances and...
By using robust control techniques, this paper proposes an adaptive control for rigid robots with the following important features: under a parameter-dependent PE (Persistent Excitation) condition, it gives a guaranteed transient performance of tracking a smooth desired trajectory while assuring the parameter estimation error to go to a residual set of the origin arbitrarily fast. Simulations are...
One of the most important problems in nonlinear H∞ control is how to solve its main equation i.e., HJI equation. We propose two new and efficient methods to solve this problem in state feedback set up, based on state dependent Riccati equation. Superiority of these suggested methods in comparison with some methods proposed before is shown through computer simulations.
This paper considers the impulsive-smooth behavior of a switched system interconnection described by the first-order kernel representation. The switched interconnection consists of past and future trajectories which are switched at a certain instant by an external switching mechanism. We derive necessary and sufficient conditions for the concatenability of the past and future behaviors both in the...
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