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In this paper, a general design approach is proposed to derive the feedforward control law in feedback-feedforward control systems. This design approach is based on the concept of `control equilibrium point'. In this design approach, the feedback controller generates the transient control command and the feedforward controller generates the steady state one. Using the proposed feedforward controller,...
Avionics system has many uncertainties at runtime, software self-evolution was proposed for changing behaviors of runtime software systems. Software cybernetics makes better use of the interplay between control theory and software engineering. In this paper, we present a cybernetics approach called Self-Evolving Control (SEC) after analysis the software evolution and software cybernetics. This approach...
In this paper, a design approach is proposed for feedforward-feedback control systems. As the basis of the proposed design approach, steady state control command is defined as the control command which maintains the desired situation of the system. Steady state control law is derived form system's mathematical model and employed as feedforward controller. Using such a feedforward controller, for a...
With ever increased needs for an improved product quality, production efficiency, and cost in today's globalized world market, advanced process control should not only realize the accuracy of each control loops, but also has the ability to achieve an optimization control of production indices that are closely related to the improved product quality, enhanced production efficiency and reduced consumption...
A robotic manipulation system for automated selection and transfer of individual living cells of interest to analysis locations is presented. The system is the first in a series of operational components comprising an integrated system for the analysis of cell expression and metabolism at the single cell level. In our approach, we begin with a commonly used cell transfer technique, which uses glass...
This paper presents an adaptive fuzzy controller for the robust backstepping control of a class of uncertain nonlinear systems in pure-feedback form. The proposed approach incorporates the Nussbaum gain function (NGF) and the dynamic surface control (DSC) into the existing adaptive fuzzy control scheme. The major features of the proposed method are that: 1) the two problems, control directions and...
Numerous physical processes are modeled by partial differential equations and are often instrumented with boundary actuators and sensors. A major new effort has been underway in recent years to develop constructive designs of boundary control laws for unstable PDE systems. This development draws upon the ideas of "backstepping" synthesis for nonlinear ODEs from the 1990s and is an infinite-dimensional,...
Networked control systems (NCS) are an active area of research within control and estimation. Networked control systems have many advantages by comparison with the traditional ones. The fault detection problem is studied in this paper for a class of linear networked control systems (NCS) with communication delays. Aim is to generate residual signals which, in the fault free case, are supposed to be...
We consider the adaptive control problem for a class of SISO unknown nonlinear systems in the presence of additive input disturbances, with guaranteed prescribed performance. By prescribed performance we mean that the tracking error should converge to an arbitrarily predefined small residual set, with convergence rate no less than a prespecified value, exhibiting a maximum overshoot less than a sufficiently...
Adaptive Optics is a technique that uses the measurements of a wave front sensor to flatten distorted wave fronts with a deformable mirror in a feedback loop in order to provide diffraction limited performance with ground-based telescopes. In order to achieve the highest possible Strehl, a measure of performance, the measurement and the control of the most important atmospheric modes (tip and tilt)...
Robust output-feedback simplified adaptive control model following with uncertainties and disturbances is considered. Sufficient conditions for closed-loop stability, model following performance and prescribed Hinfin disturbance attenuation level are introduced, under an almost-strictly-positive-realness requirement on the plant. A numerical example, taken from the field of flight control, demonstrates...
This contribution deals with design of controllers for integrating processes with time delay. In contrast to many other methods, the proposed method is not based on the time delay approximation. A control structure combining standard 1DOF and 2DOF control structures is considered. The control design is performed in the RMS ring of retarded quasipolynomial (RQ) meromorphic functions - an algebraic...
This paper deals with the position and attitude control of a Vega-type space launcher. The first part of the paper develops a general model of the launcher that takes into account the gravity, air density and mass variation. It also derives a linear model with uncertainty for the dominant dynamics, taking the nonlinear characteristics of the system as parametric uncertainty. The second part introduces...
Stability is the first demand of the feedback control design. The parametrization of all stabilizing controllers is standard theory. The stabilizing controller has some free parameters which can be used for further optimization. Linear Quadratic (LQ) control and Dead Beat control are standard algorithms for optimal control of discrete time models of real systems. The dead beat control results in very...
A new approach for the design of robust static output feedback controller for a class of discrete-time Lipschitz nonlinear systems with time-varying uncertainties is proposed based on linear matrix inequalities. The controller has also a guaranteed disturbance attenuation level (Hinfin performance). Thanks to the linearity of the proposed LMIs in both the admissible Lipschitz constant of the system...
The paper proposes a method for feedback stability evaluation for discrete-time, linear time-varying control systems. It is assumed that the time-varying system can be described by linear matrices operators, equivalent to general discrete-time, time-varying state space model with nonzero input-output delay. The main used tools are Bode diagrams approximated for time-varying systems, using power spectral...
In this paper, we use level set methods to numerically generate the minimum-time optimal velocity profiles for a vehicle with given acceleration limits driving along a specified path. The proposed approach solves the Hamilton-Jacobi-Bellman (HJB) equation associated with the given optimal control problem by computing the level sets of the value function. Once the optimal cost is found, the optimal...
This paper deals with the observer design for nonlinear time delay systems. The approach is to represent the observer error system as the feedback interconnection of a linear system and a time varying nonlinearity. The proposed result developed for designing the observer is in term of linear matrix inequalities (LMI) that guarantees the global uniform asymptotic stability of the error dynamic system...
The Archimedes wave swing (AWS) is a a fully- submerged wave energy converter (WEC), that is to say, a device that converts the kinetic energy of sea waves into electricity. A first prototype of the AWS has already been built and tested. This paper presents simulation results of the performance of several control strategies applied to this device, including PID control, reactive control, phase and...
This paper deals with intelligent controller design using artificial neural networks (ANN) in the role of feedback controllers. Neural controllers are built up and trained as inverse neural process models. Their performance and robustness are, gradually, improved and augmented by introducing, first, an adaptive simple integrator and, then, a controller with fuzzy integrator part. The proposed ANN...
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