Search results for "Control theory"
showing 10 items of 1333 documents
Event-Triggered Nonlinear Control of OWC Ocean Wave Energy Plant
2018
This paper presents event-triggered nonlinear controllers for oscillating water column (OWC) ocean wave energy plant. The study is based on event-triggered backstepping controller (ET-BSC) and event-triggered sliding mode controller (ET-SMC) to control the rotational speed of an OWC turbine coupled to a generator. The designed controllers are capable to avoid the stalling of the Wells turbine so as to maximize its output power. The aim of event-triggered control is to minimize the control updates, thus providing efficient utilization of resources without compromising the OWC performance. In this regard, aperiodic sampling has been applied using an event-triggering rule derived from Lyapunov…
Stabilization of a Class of Stochastic Nonlinear Systems
2013
This paper addresses two control schemes for stochastic nonlinear systems. Firstly, an adaptive controller is designed for a class of motion equations. Then, a robust finite-time control scheme is proposed to stabilize a class of nonlinear stochastic systems. The stability of the closed-loop systems is established based on stochastic Lyapunov stability theorems. Links between these two methods are given. The efficiency of the control schemes is evaluated using numerical simulations.
Dynamic Output-Feedback Passivity Control for Fuzzy Systems under Variable Sampling
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/767093 Open Access This paper concerns the problem of dynamic output-feedback control for a class of nonlinear systems with nonuniform uncertain sampling via Takagi-Sugeno (T-S) fuzzy control approach. The sampling is not required to be periodic, and the state variables are not required to be measurable. A new type fuzzy dynamic output-feedback sampled-data controller is constructed, and a novel time-dependent Lyapunov-Krasovskii functional is chosen for fuzzy systems under variable sampling. By using Lyapunov stability theory, a sufficie…
Impulsive control on the synchronization for a class of chaotic Systems
2014
In this paper, the impulsive control problem on the synchronization for a class of chaotic systems is discussed. Based on Lyapunov stability theory, the new impulsive synchronization strategy is presented to realize the chaos synchronization and possesses the wider scope of application. Finally the numerical simulation examples are given to demonstrate the effectiveness of our theoretical results.
H<inf>&#x221E;</inf> controller design for the synchronization of a hyper-chaotic system
2013
In this paper, the robust control on the synchronization of a hyper-chaotic system is investigated. Based on Lyapunov stability theory and linear matrix inequality techniques, the multi-dimensional and the single-dimensional robust H∞ synchronization controllers are constructed for the possible application in practical engineering. Some numerical simulations are provided to demonstrate the effectiveness of the presented controllers.
Simulation of PLL with impulse signals in MATLAB: Limitations, hidden oscillations, and pull-in range
2015
The limitations of PLL simulation are demonstrated on an example of phase-locked loop with triangular phase detector characteristic. It is shown that simulation in MatLab may not reveal periodic oscillations (e.g. such as hidden oscillations) and thus may lead to unreliable conclusions on the width of pull-in range.
Using the modern CNC controllers capabilities for estimating the machining forces during the milling process
2017
Machining forces can nowadays be measured by using 3D dynamometers, which are usually very expensive devices and hardly available for most of the CNC machine-tools users. On the other hand, modern CNC controllers have nowadays the ability to display and save many outputs within the machining process, such as the currents or even the torques at the shaft's level for the feed motors on each axis. These outputs can be used for estimating the machining forces, but it is to be noticed that the above-mentioned currents and torques are proportional with the overall resistant forces, which includes not only technological forces, but also friction, inertial and pre-tensioning forces. This paper pres…
The Shaping of Flux Density at the Air Gap of Small DC Motors with Different Permanent-Magnet Poles
1995
Design, operation and reliability of permanent-magnet DC micromotors are highly dependent of the magnet employed, i.e. of its demagnetization curve, type of magnetization (either radial or tangential), size and position within the micromotor as well as of its shape.
The Inactivation Principle: Mathematical Solutions Minimizing the Absolute Work and Biological Implications for the Planning of Arm Movements
2008
An important question in the literature focusing on motor control is to determine which laws drive biological limb movements. This question has prompted numerous investigations analyzing arm movements in both humans and monkeys. Many theories assume that among all possible movements the one actually performed satisfies an optimality criterion. In the framework of optimal control theory, a first approach is to choose a cost function and test whether the proposed model fits with experimental data. A second approach (generally considered as the more difficult) is to infer the cost function from behavioral data. The cost proposed here includes a term called the absolute work of forces, reflecti…
Relations Between Autonomous Motivation and Leisure-Time Physical Activity Participation: The Mediating Role of Self-Regulation Techniques
2016
This study tested the predictive validity of a multitheory process model in which the effect of autonomous motivation from self-determination theory on physical activity participation is mediated by the adoption of self-regulatory techniques based on control theory. Finnish adolescents (N = 411, aged 17–19) completed a prospective survey including validated measures of the predictors and physical activity, at baseline and after one month (N = 177). A subsample used an accelerometer to objectively measure physical activity and further validate the physical activity self-report assessment tool (n = 44). Autonomous motivation statistically significantly predicted action planning, coping planni…