Search results for "control theory"
showing 10 items of 1333 documents
Identification and Experimental Validation of an Induction Motor Thermal Model for Improved Drivetrain Design
2017
The ability of an electric powertrain to perform according to mechanical specifications is equally important as assessing its thermal protection limits, which are affected by its electrical and thermal properties. Although rated parameters (such as power, torque, etc.) are easily accessible in catalogs of equipment producers, more specific properties like mass/length of copper winding, heat dissipation factor, etc., are not available to customers. Therefore, an effective selection of drivetrain components is limited due to the lack of sufficient data and the need to consult critical design decisions with suppliers. To overcome this limitation, we propose a method to estimate the temperature…
Supplementary frequency regulation in non-synchronous AC system connected via MTDC
2019
Abstract In smart grid power system operation, frequency regulation is one of the most critical tasks towards power balance in the grid. This paper presents the schemes for improvement in operation of secondary loop of turbine-generator unit for frequency regulation in non-synchronous AC areas connected via multi-terminal direct current (MTDC) network. Two schemes have been discussed; (i) voltage droop based lead/lag compensator and (ii) DC power modulation at converter terminal depending upon frequency deviation from each AC area. In the first scheme, droop design based on lead/lag compensator using DC voltage deviation is introduced as supplementary signal at turbine-generator unit in eac…
Aircraft wing rock oscillations suppression by simple adaptive control
2020
Abstract Roll angular motion of the modern aircraft operating in non-linear flight modes with a high angle of attack often demonstrates the limit cycle oscillations, which is commonly known as the wing rock phenomenon. Wing rock dynamics are represented by a substantially non-linear model, with parameters varying over a wide range, depending on the flight conditions (altitude, Mach number, payload mass, etc.) and angle of attack. A perspective approach of the wing rock suppression lies in the adaptation methods. In the present paper an application of the simple adaptive control approach with the Implicit Reference Model (IRM) is proposed and numerically studied. The IRM adaptive controller …
Localization from inertial data and sporadic position measurements
2020
International audience; A novel estimation strategy for inertial navigation in indoor/outdoor environments is proposed with a specific attention to the sporadic nature of the non-periodic measurements. After introducing the inertial navigation model, we introduce an observer providing an asymptotic estimate of the plant state. We use a hybrid dynamical systems representation for our results, in order to provide an effective, and elegant theoretical framework. The estimation error dynamics with the proposed observer shows a peculiar cascaded interconnection of three subsystems (allowing for intuitive gain tuning), with perturbations occurring either on the jump or on the flow dynamics (depen…
A new phase locked loop strategy for power quality instruments synchronisation
2006
Power quality instrumentation requires the accurate fundamental frequency estimation and the signal synchronization, even in presence of disturbances. In the paper the authors present an innovative synchronization technique, based on a single phase software PLL. To evaluate how the synchronization technique is adversely affected by the application of stationary and transient disturbing influences, appropriate testing conditions have been developed, taking into account the requirements of the in-force standards. In the paper the proposed technique is described and PLL performances in presence of stationary and transient disturbances are presented
Positioning system for assembly and manufacturing tasks
2019
The paper presents a two-axis positioning system using asynchronous motors as actuation devices. Theuse of asynchronous motors reduces the overall cost of the system, while providing actuating torques superior to the ones provided by stepping motors. The system is controlled by mean of a programmable logic controller (PLC) and two voltage-frequency inverters fitted with motion control cards. In contrasts to a stepping motor system, which works in open loop mode, the proposed system uses closed loop control on each axis. The motion loop is closed by means of an incremental encoder.
A limited feedback scheme based on spatially correlated channels for coordinated multipoint systems
2012
High spectral efficiency can be achieved in the downlink of multi-antenna coordinated multi-point systems provided that the multiuser interference is appropriately managed at the transmitter side. For this sake, downlink channel information needs to be sent back by the users, thus reducing the rate available at the uplink channel. The amount and type of feedback information required has been extensively studied and many limited feedback schemes have been proposed lately. A common pattern to all of them is that achieving low rates of feedback information is possible at the cost of increasing complexity at the user side and, sometimes, assuming that some statistics of the channel are known. I…
Expert control of DO in the aerobic reactor of an activated sludge process
2001
Abstract An expert control structure is proposed for the control of dissolved oxygen (DO) in a Nitrification Denitrification Biological Excess Phosphorus Removal (NDBEPR) plant to account for the several processes that are influenced by the DO concentration in the aerator. In the scheme a supervisory fuzzy controller determines the set point of an inner DO control loop where an Adaptive Robust Generic Model Control (ARGMC) controller is used. The fuzzy supervisory control has a hierarchical structure. Off-line measurements of biological parameters of influent and effluent streams can be used to periodically update the set points of the fuzzy controllers. The complete control scheme has been…
Robust l2-gain control for 2D nonlinear stochastic systems with time-varying delays and actuator saturation
2013
Abstract This paper is concerned with the problems of stability analysis and l2-gain control for a class of two-dimensional (2D) nonlinear stochastic systems with time-varying delays and actuator saturation. Firstly, a convex hull representation is used to describe the saturation behavior, and a sufficient condition for the existence of mean-square exponential stability of the considered system is derived. Then, a state feedback controller which guarantees the resulting closed-loop system to be mean-square exponentially stable with l2-gain performance is proposed, and an optimization procedure to maximize the estimation of domain of attraction is also given. All the obtained results are for…
New Approach of Controlling Cardiac Alternans
2018
The alternans of the cardiac action potential duration is a pathological rhythm. It is considered to be relating to the onset of ventricular fibrillation and sudden cardiac death. It is well known that, the predictive control is among the control methods that use the chaos to stabilize the unstable fixed point. Firstly, we show that alternans (or period-2 orbit) can be suppressed temporally by the predictive control of the periodic state of the system. Secondly, we determine an estimation of the size of a restricted attraction's basin of the unstable equilibrium point representing the unstable regular rhythm stabilized by the control. This result allows the application of predictive control…