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Linear vapor compressors are becoming more widely utilized in refrigeration applications due to their high efficiency as compared with traditional rotary devices. The nature of the free piston in a linear compressor allows the system resonant frequency to vary with the force of gas compression. In order to ensure efficient operation of the compressor the motor must be excited in such a way as to ensure...
The magnetic levitation (MagLev) system control is one of the most complex problems due to open-loop instability, nonlinear dynamics and uncertain parameters. The 3rd order differential model of MagLev is linearized by using input-output linearization. The control law is designed using feedback linearization (FL) augmented by uncertainty estimates. The states and uncertainties are estimated using...
In this paper we propose a novel solution to the labeled multi-target tracking problem. The method presented is specially effective in scenarios where the targets have once moved in close proximity. When this is the case, disregarding the labeling uncertainty present in a solution (after the targets split) may lead to a wrong decision by the end user. We take a closer look at the main cause of the...
We consider a target tracking problem where, in addition to the usual sensor measurements, accurate observations with uncertain timestamps are available. Such observations could, e.g., come from traces left by a target or from witnesses of an event, and have the potential in some scenarios to improve the accuracy of an estimate significantly. The Bayesian solution to the smoothing problem for one...
The paper presents a study on the impact of uncertainty on the dynamic response of electric power systems. Three sources of uncertainty are considered, namely, (i) uncertainty in the values of the parameters of physical devices; (ii) uncertainty in the models of dynamic devices; and (iii) variations of the parameters and the numerical scheme to integrate the differential algebraic equations that describe...
We propose a new method for controlling rigid robot manipulators guaranteeing that a user-defined tracking performance is ultimately met while facing uncertain system dynamics and input disturbance. Our control approach is based on the passivity-based control technique and eliminates the limitations of existing methods (e.g. impractical tuning to avoid chattering and difficult estimation of uncertainty...
In recent papers, we have shown that a Lebesgue-Stieltjes optimal control theory forms the foundations for unscented optimal control. In this paper, we further our results by incorporating uncertain mixed state-control constraints in the problem formulation. We show that the integrated Hamiltonian minimization condition resembles a semi-infinite type mathematical programming problem. The resulting...
For most teleoperation tasks, it is desired that the telerobot manipulator follows timely and precisely the reference motion set at the master side. However, the conventional control approach may not guarantee the desired performance when there are dynamic uncertainties, especially when there is a notable variation of the telerobot's payload. In this paper, a neural learning based compensation mechanism...
Aerodynamic uncertainty can lead to large variations in the dynamics of fixed-wing unmanned aerial vehicles. Thus, waypoint navigation is normally done using a feedback controller. In some environments navigation can be done in the open-loop provided that the control is desensitized to the uncertainty. In this paper, unscented optimal control is used to design such open-loop controls for guiding a...
We provide a new adaptive controller for curve tracking in the plane under unknown curvature. We prove a global asymptotic stability theorem that ensures tracking of the curve and convergence of the curvature estimate to the unknown curvature. Our curvature identification result is an improvement over the known adaptive curve tracking results, which do not ensure parameter identification, or which...
A method is presented for synthesizing output estimators for a class of continuous time, uncertain, linear parameter-varying (LPV) systems. The uncertain system is described as an interconnection of a nominal LPV system and a block structured perturbation. The nominal LPV system is “gridded” over the space of parameters, with the state matrices being arbitrary functions of the parameters. The input/output...
In this paper, a method of unmatched disturbance compensating integral sliding model predictive control for constrained linear discrete-time systems with bounded disturbances is presented. The basic idea is to shape a discrete-time integral sliding mode control into an optimal constrained control problem with model predictive control. By choosing another projection matrix in the integral sliding surface,...
In this paper, a new distributed adaptive control for a class of multiagent systems with model uncertainties is proposed to track the desired trajectory specified by an informed agent. It is assumed that there also exist parametric uncertainties and unknown dynamics with the informed agent. Linearly parameterized approximators are employed to estimate these unknowns and only part of agents needs to...
In this work, we present a new distributed adaptive iterative learning control (AILC) scheme for a class of high-order nonlinear multi-agent systems (MAS) under alignment condition with both parametric and nonparametric system uncertainties, where the actuators may be faulty and the control input gain functions are not fully known. Nonparametric uncertainties such as norm-bounded nonlinear uncertainties...
The derivation and implementation of the natural switching surfaces (NSS) considering parametric uncertainties for a flyback converter operating at boundary conduction mode (BCM) is the main focus of this paper. The NSS presents many benefits for the control of non-linear systems; for example fast transient response under load-changing conditions. However, the performance considerable worsens when...
For the purpose of probe soft landing on small bodies safely, this paper focuses on improving convergence speed, decrease the chattering and process uncertainties and perturbations from the trajectory tracking control system. This paper presents improved Terminal sliding mode control based on active disturbance reject, which changes terminal sliding mode surface to the sliding mode hyper-surface and...
The certainty-equivalence super-twisting controller (CESTA) combines approaches from variable structure and adaptive control. In this paper, an improved variant of this algorithm is presented that resorts to a recently introduced Lyapunov function for the super twisting algorithm, establishing a novel continuous adaptation law. These controllers are beneficial for systems that are affected by structured...
This paper addresses the formation control problem of a multi-agent system (MAS) under the leader-follower scheme. Thus, the followers must to keep a desired relative distance with respect to the leader trajectory against known and constant communication delay. Thus, in order to ensured the coordinated behavior and formation control against parametric uncertainties and external disturbances, a decentralized...
In this paper, we propose a method to analyze the amount of operation reserves procured in a system based on two stages. The first stage is a detailed hourly unit commitment and the second stage is a simulation model with a shorter time period. The method is applied to the Spanish hydrothermal system and several cases are analyzed to determine the impact of the time period in the use of the operation...
This paper proposes a disturbance observer (DOB)-based adaptive non-homogeneous higher order sliding mode control (HOSMC) scheme. Given a large initial tracking error, the proposed HOSMC provides fast convergence rate by using non-homogeneous finite time stabilization. In addition, a disturbance observer based adaptive control method is employed to identify bounded uncertainties. To solve the overestimation...
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