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A vision-based enhanced PID control algorithm for the gap-flying-through problem using a low-cost multirotor platform is the main topic of this paper. We designed an image processing program to detect the target rectangle gap in each video frame captured by onboard camera of the drone. During the process, some manipulation such as dilate and erode are implemented to reduce the noise. To control the...
This paper deals with the control of a two-degree-of-freedom, laboratory-scale helicopter-like system (termed the toycopter), where the aerodynamic force is manipulated using the propeller speed. This system can be shown not to be flat and thus classical linearization techniques cannot be applied. However, a low-order flat system can be obtained by (i) using a high-gain feedback with suitable proportional...
A systematic procedure for planning sensor movements in a specified spatial domain in such a way as to maximize the accuracy of parameter estimation of a given distributed system is proposed. The global design criterion is the expectation of a general local design criterion defined on the Fisher information matrix, given a-priori distribution of the parameters to be identified. The approach converts...
Switched linear systems exhibit a continuous state evolving along the continuous flow of time according to linear time invariant differential equations. Furthermore, a discrete interface to the environment is provided, acting on input signals by switching between a finite number of differential equations and generating output signals when the continuous state crosses certain boundaries. We suggest...
The determination of the reachable states for a class of infinite-dimensional nonlinear systems with control constraints is investigated. The main results reduce this problem to the determination of the reachable states, by means of admissible controls, for the approximate linear systems. The approach is developed using a state space system framework and is based on the application of a result from...
Neural networks can be used as continuous-time models of nonlinear dynamic systems. Based on the neural plant model, various nonlinear control design methodologies may be applied. In this study, direct inverse control and input-output-linearization are used for trajectory tracking of a batch reactor. Given the same approximate neural model, input-output-linearization proves to be superior to direct...
The aim of this paper is to provide a methodology for the design of practical continuous high gain event-based observers for nonlinear systems with an almost everywhere injective r-observability map. As opposed to other high gain approaches, injectivity is allowed to be lost for a nonempty set of bad input points. An example with simulations illustrates the procedure.
The solution to constrained linear model predictive control (MPC) problems can be pre-computed off-line in an explicit form as a piecewise affine (PWA) state feedback law defined on polyhedral regions of the state space. Even though real-time optimization is avoided, implementation of the PWA state-feedback law may still require a significant amount of computation due to the problem of determining...
We introduce in this paper the Random Exchange Diffusion Bernoulli Filter (RndEx-BF), which enables joint target detection and tracking by a network of collaborative sensors. RndEx-BF is a fully distributed algorithm that, unlike consensus-based solutions, does not require iterative internode communication between sensor measurements. Internode communication cost is further reduced by a novel hybrid...
The particle Gibbs algorithm can be used for Bayesian parameter estimation in Markovian state space models. Sometimes the resulting Markov chains mix slowly when the component particle filter suffers from degeneracy. This effect can be somewhat alleviated using backward simulation. In this paper we show how a simple modification to this scheme, which we refer to as refreshed backward simulation, can...
Particle filtering - perhaps more properly named Sequential Monte Carlo - approaches have a strong potential for signal and image processing applications. A problem of great practical significance in this field, which remains largely unsolved as of today, is the estimation of fixed model parameters based on the output of sequential simulations. In this contribution, we investigate maximum likelihood...
This paper investigates intra-adaptive wavelets for video coding with frame-adaptive motion-compensated lifted wavelet transforms. With motion-compensated lifted wavelets, the temporal wavelet decomposition operates along motion trajectories. However, valid trajectories for efficient multi-scale filtering have a finite duration in time. This is due to well known effects like occlusions or inaccurate...
A problem for radiation of time accelerating electromagnetic pulses is considered in paraxial approximation. It is shown that the pulse envelope moves in the times-patial coordinates on the surface of a cylinder, the parabolic one for the pulse in the form of Airy function and for the hyperbolic one for Gaussian. Each of the pulse propagates in time with deceleration along the dominant propagation...
We tackle the problem of controlling a mechanical system by means of a robust discrete-time linear predictive control which is the discrete time version of the Robust Generalized Proportional Integral Control. It is assumed that the model uncertainties and external disturbances are bounded and bandlimited, so that they can be modeled by means of a polynomial approximation which needs to be rejected...
LgV controllers are well known continuous-time Lyapunov design tools. The object of this work is to discuss their sampled-data versions. Piecewise constant controllers are described in order to provide asymptotic stability and damping at the sampling instants. These sampled-data controllers are tested on a synchronous machine model and their performances are compared through simulations to those obtained...
A novel method for embedding and detecting a chaotic watermark in the digital spatial image domain, based on segmenting the image and locating regions that are robust to several image manipulations, is presented in this paper. Each selected region is approximated by an ellipse. The watermark is embedded on its bounding rectangle. This representation proves robust under geometric attacks. The controlled...
POCP is a new Matlab package running jointly with GloptiPoly 3 and, optionally, YALMIP. It is aimed at nonlinear optimal control problems for which all the problem data are polynomial, and provides an approximation of the optimal value as well as some control policy. Thanks to a user-friendly interface, POCP reformulates such control problems as generalized problems of moments, in turn converted by...
Controlled invariant terminal constraints fail to enforce strong feasibility in a rich class of MPC problems, for example when employing move-blocking. In previous work, controlled invariant feasibility was proposed for the purpose of formulating strongly feasible move-blocking MPC problems. In this paper, first, a maximum controlled invariant feasible set condition is derived. Based on this condition...
A fast receding horizon scheme for trajectory optimization under input constraints is presented and applied to a laboratory helicopter with three degrees-of-freedom (3DOF). The approach utilizes saturation functions to transform the underlying input-constrained optimal control problem into an unconstrained one. The numerical solution of the optimality conditions is based on the classical gradient...
We consider the problem of reaching a target without leaving a prescribed constraint set for a dynamical system described by a controlled differential equation and a controlled reset function. First, we characterize the set of initial conditions from which the objective can be reached. Then, we characterize the optimal reaching time function. Our approach is based on set-valued analysis and viability...
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