Search results for "Control Engineering"
showing 10 items of 435 documents
Analysis of Torque Developed in Axial Flux, Single-Phase Brushless DC Motor With Salient-Pole Stator
2004
An analysis of the torque developed by a single-phase disc brushless permanent magnet motor with salient-pole stator is presented. The machine represents a new family of brushless disc motors with the starting torque issue appearing to be most challenging. To produce a starting torque, the permanent magnets on one of the rotor discs are distributed nonuniformly. However, this significantly distorts a shape of the cogging torque versus rotational angle characteristic which, in turn, affects a waveform of the overall torque. A three-dimensional (3-D) finite-element model is used for the purpose of determining of angular variations of the torque developed by the motor. To find how the torque v…
Hidden Oscillations In The Closed-Loop Aircraft-Pilot System And Their Prevention* *This work was supported by Russian Science Foundation (project 14…
2016
Abstract The paper is devoted to studying and prevention of a special kind of oscillations-the Pilot Involved Oscillations (PIOs) which may appear in man-machine closed-loop dynamical systems. The PIO of categories II and III are defined as essentially non-linear unintended steady fluctuations of the piloted aircraft, generated due to pilot efforts to control the aircraft with a high precision. The main non-linear factor leading to the PIO is, generally, rate limitations of the aircraft control surfaces, resulting in a delay in the response of the aircraft to pilot commands. In many cases, these oscillations indicate presence of hidden, rather than self-excited attractors in the aircraft-pi…
Researches Regarding Optimising the Contouring Precision of CNC Laser Cutting Machines
2014
This paper presents some experimental researches regarding the manufacturing accuracy of a profiling machine together with an approach to eliminate the positioning and contouring errors. A mathematical model based on transfer functions is used as starting approach in order to tune the feed drives of the machine. The accuracy of the profiling machine is tested before and after the tuning process, in order to validate the proposed approach. There are unfolded both positioning tests along one axis and contouring tests on two axes.
Method for improving the contouring accuracy for CNC profiling machines at the shop floor level
2009
Computer Numerically Controlled (CNC) laser cutting machines are capable of producing high-quality precise parts. However, as cutting speeds is increased, in order to achieve higher productivity, the accuracy of the parts is affected. In order to improve the contouring accuracy of these machines, a simple straight-forward joint simulation and experimental strategy is proposed. The position controllers within the feed drives are considered the key factor in improving the dynamic behavior and consequently the contouring accuracy of a CNC laser cutting machine at the shop floor level.
Approaches to evaluate the virtual instrumentation measurement uncertainties
2002
This paper deals with the metrological characterization of virtual instruments. After a brief description of the features, the components and the working principle of the virtual instruments and the various uncertainty sources are analyzed. Then, two methods to evaluate the uncertainty of the measurement results are presented: a numerical method simulating the physical process of the A/D conversion, and an approximated theoretical method applying the "uncertainty propagation law" of the "guide to the expression of uncertainty in measurement." With both methods, the combined standard uncertainty of the measurement result is obtained, starting from the standard uncertainty generated by each s…
Experimental validation of a quaternion-based attitude estimation with direct input to a quadcopter control system
2013
This paper presents a method to calculate the attitude quaternion of a quadcopter with few calculations. The quaternion calculation is based on accelerometers and gyroscopes from an Inertial Measurement Unit (IMU). The quaternion from the accelerometer is calculated as the shortest rotation arc from the gravity vector in the navigation frame. The quaternion from the gyroscope is calculated based on equations of the quaternion derivative. A complementary filter is combining the two quaternions with a componentwise comparison. The attitude estimation is calculated without any trigonometric functions. The quaternion is directly used as an input to the attitude controller. The attitude controll…
Numerical procedures and their practical application in PV modules analyses. Part I: air mass
2019
Abstract The subject of the article is aspects of PV modules and cells measurement, with the use of natural sunlight. A light source is an important element during calibration and measurements of solar cells and modules. All designers of artificial light sources try to recreate natural light using so called measurement tables. The correctly performed measurement, i.e. meeting all the appropriate atmospheric conditions, guarantees obtaining the result with the use of a reference spectrum. The article has two main aims. The first aim of the article is to answer the question asked earlier - if the sunlight spectrum registered in appropriate conditions is so good that it serves as the reference…
Mathematical Control of Complex Systems 2013
2014
Mathematical control of complex systems have already become an ideal research area for control engineers, mathematicians, computer scientists, and biologists to understand, manage, analyze, and interpret functional information/dynamical behaviours from real-world complex dynamical systems, such as communication systems, process control, environmental systems, intelligent manufacturing systems, transportation systems, and structural systems. This special issue aims to bring together the latest/innovative knowledge and advances in mathematics for handling complex systems. Topics include, but are not limited to the following: control systems theory (behavioural systems, networked control syste…
A fully-automated procedure for measuring the electrical parameters of an induction motor drive with rotor at standstill
2003
The paper presents an automatic procedure to measure at standstill the electrical parameters of an induction motor fed by a PWM voltage source inverter. The proposed procedure executes automatically three tests using only the available PWM inverter control technique to obtain the required motor supply voltages. It allows the measurement of all the T-form circuit electrical parameters starting from the nameplate data as data-entry. It uses only a current sensor and no voltage sensor and process on line the collected data samples with a fast and easy to implement recursive least squares algorithm. Effectiveness of the automated procedure has been proved both by simulation and experimental tes…
Effects of reversible lane implementation, a case study simulation
2019
In a modern society, transport is a necessity for carrying out certain activities that human communities are involved in. This need for mobility is on a continuous rise and can be characterized by the possibility of moving from one point to another, using different means of transport, in order to facilitate the performed activities. The purpose of this research is to design and evaluate the implementation of a system of reversible lanes using simulation. As methodology, it starts from an analysis of data collected from real traffic condition through implementation and simulation with the Synchro application. The analysis proposes solutions to decongest traffic through the implementation of …