Search results for "scheduling"
showing 10 items of 275 documents
LPV models: Identification for gain scheduling control
2001
In this paper the use of discrete-time Linear Parameter Varying (LPV) models for the gain scheduling control and identification methods for non-linear or time-varying system is considered. We report an overview on the existing literature on LPV systems for gain scheduling control and identification. Moreover, assuming that inputs, outputs and the scheduling parameters are measured, and a form of the functional dependence of the coefficients on the parameters is known, we show how the identification problem can be reduced to a linear regression so that a Least Mean Square and Recursive Least Square identification algorithm can be reformulated. Our methodology is applied for the identificatio…
Integrated Approach to Part Scheduling and Inspection Policies for a Job Shop Manufacturing System
2007
The quality of a product greatly depends on the quality of its components. This requires that manufacturing specifications have to be met in the manufacturing environment and as a consequence inspection stations are present in many manufacturing systems and inspection policies must be adopted. One problem, which has been widely investigated, concerns the detection of the inspection points in the hypothesis that the action to be taken is known when a defective part is detected. If different jobs are to be produced, then operation scheduling becomes yet another complex problem needing to be solved. And while the problem of scheduling has received a great amount of attention from researchers, …
An execution, monitoring and replanning approach for optimal energy management in microgrids
2011
abstract This work develops a new approach for optimal energy management of electrical distribution ‘smart-grids’. Optimality aims at improving sustainability through the minimization of carbon emissions and atreducing production costs and maximizing quality. Input data are the forecasted loads and productionsfrom renewable generation units, output data are a set of control actions for the actuators. Theconsidered electrical distribution system includes storage units that must be considered over a 24 h timeinterval, to consider an entire charge and discharge cycle. The objectives for the optimal management ofdistributed (renewables and not) generation are technical, economical and environme…
Multimedia applications in industrial networks: integration of image processing in profibus
2003
This paper analyzes the transmission of images through Profibus for applications concerned with the processing of images integrated in control systems, by means of a detailed study of two real cases with different bandwidth requirements. We analyze the special features of an artificial vision system making use of Profibus as a transport system, the scheduling of the traffic in order to guarantee the delivery of the images and the control traffic before their deadlines, the protocol used, and the compression techniques usable in this kind of system, which enable us to reduce the necessary bandwidth for the applications without degrading the operation of the image processing application. We p…
Nonlinear Control of a Pneumatic Muscle Actuator System
2001
Abstract The performance of a Pneumatic Muscle Actuator under three tracking control strategies is compared: robust backstepping, sliding-mode and gain scheduling. Robustness is assured for the three controllers in the presence of model uncertainties and external perturbations. Exponential stability is proved for the sliding-mode tracking controller, ultimate boundedness for the backstepping tracking controller and exponential stability for constant or slowly-varying reference signals for the gain scheduling controller. Computer simulations show a good performance for the tracking of a sine wave by the first two controllers, although the sliding-mode strategy yields a high-frequency switchi…
Effect of Channel-Quality Indicator Delay on HSDPA Performance
2007
This paper evaluates the effect of the channel estimation inaccuracy on the performance of an HSDPA system. This study provides some results from system level simulations that have been conducted over a very complete dynamic simulator which models an HSDPA system full compliant with specifications. This emulator allows performing multi-user transmission and link adaptation with a limited modulation and coding scheme (MCS) selection based on the channel quality indicator (CQI) modes. Many factors such as the user equipment (UE) speed, the employed scheduling algorithm or the traffic load have been considered in the assessment. Moreover the intrinsic constraints of a WCDMA system like HSDPA h…
A Model-Based Control Strategy for Wind Turbines with Asynchronous Generator
2007
In this paper a model based control methodology is described with reference to a wind turbine for production of alternative energy. The mathematical model of a 600 kW wind turbine is taken into account assuming a well defined profile of the rotor blades. A set of reference angular speeds of the asynchronous generator and a set of reference pitch angles of the blade wind turbine are obtained in order to maximize the extracted wind power and to reach equilibrium conditions between the wind-generated torque and the electric torque of the generator. Finally a PID model based controller is designed and then tested by means of simulation experiments.
LPV Predictive Control of the Stall and Surge for Jet Engine 1
2001
Abstract Predictive control of constrained LPV systems is applied to the model of the stall and surge control for jet engine compressors. The objective of the used technique is to optimize nominal performance while guaranteeing robust stability and constraint satisfaction. This is achieved by exploiting invariant sets and a receding horizon optimization procedure which provides on-line a non-linear correction to a gain-scheduled linear feedback designed off-line. A comparison with a contractive gain-scheduling control technique is also shown.
LPV Model Identification For The Stall And Surge Control of a Jet Engine
2001
Abstract The problem of identifying discrete-time Linear Parameter Varying (LPV) models of non-linear or time-varying systems for gain scheduling control is considered assuming that inputs, outputs and the scheduling parameters are measured, and a form of the functional dependence of the coefficients on the parameters is known. The identification procedure is applied to the controlled model of compressors for jet engines. The model is controlled in order to avoid rotating stall and surge. Aim of the present paper is to identify the LPV model based on the nonlinear model of compressors in order to design a robust gain scheduling predictive controller.
Load Optimization in Endurance Sports by Means of Antagonistic Dynamical Models
2012
Abstract Prediction of performance dynamics as well as planning and control of corresponding optimal load profiles are difficult tasks in endurance sports. The reason is that fatigue and recovery are effective with delays. I. e. a small overload in the start phase can cause a collapse long time later. Such interaction between load and performance can be modelled by means of antagonistic models like PerPot and then can help to optimize performance together with avoiding overload. Based on a lot of positive results extensions of PerPot have been developed, which are now able to determine the individual anaerobe threshold (IAT) by simulation, giving heart rate oriented load scheduling a new qu…