65 research outputs found
Active Queue Management of TCP Flows with Self-scheduled Linear Parameter Varying Controllers
No full textControl-theoretic approaches to Active Queue Management (AQM) are typically based on linearizations of fluid flow models around design conditions. These conditions depend on the Round Trip Time (RTT), and the AQM performance is known to degrade if RTT values during actual operation depart substantially from design values. To overcome this difficulty a self-scheduled LPV controller for AQM is considered in this paper, where the controller is modified in real-time based on RTT. Simulations show that the self-scheduled LPV controller has good performance for both constant and time-varying RTTs, and outperforms two other common control-theoretic approaches to AQM
Reduced order modeling, nonlinear analysis and control methods for flow control problems
No full textModeling, control and evaluation of fluid flow systems using adaptation based linear parameter varying models
No full textRobust Autopilot Design Based on a Disturbance/Uncertainty/Coupling Estimator
No full textAutopilot failures have caused fatal results for both military and civilian applications, leading to loss of life and property. Major contributing factors are disturbances (e.g., winds), uncertainties (e.g., unmodeled dynamics and parameter variations), and couplings (e.g., a bank maneuver affecting pitch attitude). In this brief, a novel disturbance/uncertainty/coupling estimator structure is introduced for identifying and canceling these effects as a whole. A controller scheme based on the design is implemented with explicit bounds for robust stability and robust performance. Validity of the proposed approach is illustrated under high winds, strong couplings, and large parameter variations
Constructing linear parameter varying models through adaptation for the control of a class of nonlinear systems
No full textIn this paper a novel method is proposed for constructing linear parameter varying (LPV) system models through adaptation. For a class of nonlinear systems, an LPV model is built using its linear part, and its coefficients are considered as time-varying parameters. The variation in time is controlled by an adaptation scheme with the goal of keeping the trajectories of the LPV system close to those of the original nonlinear system. Using the LPV model as a surrogate, a dynamical controller is built by utilizing self-scheduling methods for LPV systems, and it is shown that this controller will indeed stabilize the original nonlinear system
Moving Object Tracking using Simulated Motion Data
No full textThis paper presents the development of missile motion tracking using computer simulation and analyzes the results. In order to investigate the missile motion, simulated data and missile model is implemented in numerical computing package MATLAB/Simulink. To analyze the motion, object detection, corrections of the calculations using Kalman filter and velocity estimation of detected object steps are implemented on simulated data. The generated results are compared and shown at the end of the paper
LQG/LTR Position Control of an BLDC Motor with Experimental Validation
No full textIn this paper, position control of a BLDC motor is studied. This position control is LQG/LTR control algorithm. In addition, a system identification approach is used to obtain the nominal plant of BLDC Motor. As a consequence, proposed controller is employed for an experiment. It is done by a real-time target machine
Frequency constrained control of oscillations in flow problems
No full textIn this paper we investigate the control of flow problems where the control objective is to reduce the oscillation amplitude while keeping the frequency of oscillation between predefined limits at all times. Starting from a simple model representing the oscillatory mode dynamics of the governing equations, the conditions that the control parameters must satisfy in order to achieve the desired objective are derived in detail. The results obtained are illustrated on a physical application example, namely cavity flow control, where it is seen that the controller is successful in achieving the control goal
Analysis and Nonlinear Control of Galerkin Models Using Averaging and Center Manifold Theory
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