Papers by Keyword: Control

Abstract: Information on the influence of the state of the production process of production and the uncertainty of the measurement on the decision on the product's suitability is given. It is shown on the example of brick production that the decision to accept a batch of bricks, taking into account the measurement uncertainty under unstable condition of the production process, may be erroneous. Three variants of the state of the production process for the production of 100-grade brick are considered. The first option - the average value of compressive strength does not coincide with the middle of the tolerance field, the production process is characterized as unstable, the second option - the average value of compressive strength does not coincide with the middle of the tolerance field, a greater value of the spread of the indicators compared with the first version and is characterized as an unstable process, the third option is the average value of the tensile strength, and compression coincides with the middle of the tolerance field, is characterized as a stable and reproducible process. It is established, that, if the production process is in a state of statistical controllability, i.e. stable, then taking into account the uncertainty of measurement, the brick grade remains 100. In an unstable process with an increase in the value of the standard uncertainty of type A, the controller's decision to identify the brand of brick 100 may be erroneous. Statistically stable and reproducible process makes it possible to increase the reliability of product quality control and to avoid mistakes in deciding on the rejection of products.

Abstract: The Modelling and control design of Two Wheel Vehicle represents an open and a challenging problem in terms of the complexity in these kind of vehicles. This article aims to represent a comparative analysis of two strategies of control which are modern controller LQR and Conventional Controller PID for the two wheeled vehicle. The main goal is to compare their performances in terms of the time specification and to determine the best control strategy. We begin our development with the implementation of the dynamic model of the two wheeled vehicle using Lagrange modeling with holonomic constraints. Further, the article deals with analyzing the eigenvalues of the linearized dynamic system at which the two wheeled vehicle lean and steer are stable. This research targets the development of the two controllers: PID and LQR. Those controllers are used to control both steer angle, and lean rate angle of two wheeled vehicle. The study includes as well a comparative assessment of those control strategies in terms of performance.

Abstract: A soft actuator is expected to be applied in the next generation of robotics. This study focuses on soft gel actuators hybridized with nanosheet liquid crystals. The resulting soft actuator has a highly hydrophilic property, and is suitable for underwater use. When the gel in water is heated to more than the transition temperature, the gel contracts; conversely, it swells when it is cooled. This gel actuator remarkably has an anisotropic contraction characteristic because the orientation of the nanosheets is uniformly arranged. However, little is known about its dynamic characteristics of the thermal contraction. As a basic analysis, this paper investigates the heating step response through experiments, and reveals the variation of the time constant against the dimensions.

Abstract: At present, the solution of not only the tactical tasks of the structure technical state preserving but also the strategic tasks of the erected and existing structures quality improving in order to develop the road and transport network in the development perspective lines is topical. The construction organization of the bridge structures is a complex process; it requires the performing work careful monitoring. The approach based on the information modeling used by construction participants, including the construction control service, is proposed in this paper. The article is devoted to the methodology that allows improving the document circulation procedure organization process efficiency and coordinating changes, due to the introduction of the information modeling technology, which influences on the building construction duration. The database is created to introduce the necessary data into the information model of the bridge structure, as well as the result parameters of the interaction with the model. The data on the practical implementation of the proposed approach on the example of the bridge construction object is presented; the analysis is made compared with the established process of construction production organization, and the advantages of the first one are fixed.

Abstract: The paper reviews the theory of technical evaluation of the containment and the experience of using the mobile geodetic diagnostic system at the nuclear power plant unit No. 4 of Rostov NPS. The paper considers the results of a regular built-in system designed to determine and evaluate the strain-stress state of containments during the acceptance in service, commissioning stage and operating period. A comparison with the results of the geodetic system obtained at the same stages of containment existence.

Abstract: Controlling chaotic dual-ring erbium-doped fiber laser and the produced dynamics are studied by modulating or shifting the laser loss while the control model is presented to pressure behavior of the laser to a periodic state or multi-periodic states by a periodic signal perturbing or shifting the loss. When the loss of one ring of the laser is modulated via a sinusoidal signal, chaotic behaviors of the dual-ring can be pressured in two single-periodic states while two rings emit cyclic pulses. It indicates that chaotic dual-ring erbium-doped fiber laser is effectively controlled. When another sinusoidal signal is taken to perform on the loss, the laser can be educe to present a period-2 or period-3 state. When the loss is shifted between two different levels, the dual-ring can be deduced to a period-4, a period-6 and other multi-periodic state. The results indicate that controlling chaotic dual-ring erbium-doped fiber laser can be realized via the chaos-control method.

Abstract: Amongst current aircraft research topics, morphing wing is of great interest for improving the aerodynamic performance. A morphing wing prototype has been designed for wind tunnel experiments. The rear part of the wing - corresponding to the retracted flap - is actuated via a hybrid actuation system using both low frequency camber control and a high frequency vibrating trailing edge. The camber is modified via surface embedded shape memory alloys. The trailing edge vibrates thanks to piezoelectric macro-fiber composites. The actuated camber, amplitude and frequency ranges are characterized. To accurately control the camber, six independent shape memory alloy wires are controlled through nested closed-loops. A significant reduction in power consumption is possible via this control strategy. The effects on flow via morphing have been measured during wind tunnel experiments. This low scale mock-up aims to demonstrate the hybrid morphing concept, according to actuator capabilities point of view as well as aerodynamic performance.

Abstract: The model of linear drive with redundant actuation and control system is designed to compare the energy efficiency of the different actuation type. The redundant actuation control system is optimized to increase the energy efficiency of the entire drive. Calculation with this model compares consumed electricity for each drive topology. The results can be used in the design of energy-efficient production machinery and equipment, which is the area of interest of so-called Ecodesign.

Abstract: The paper points out a novel design methodology for electromechanical linear axis. It is based on common process parameters and an automated iterative solution algorithm. For the first time ever, different types of electromechanical linear axes can be compared. Furthermore, an optimum solution aiming a low moment of inertia ratio is the result of the design process. Using the example of a machining center, simulation and experimental results are shown. The performance of the process-oriented design methodology relating to additional design objectives is shown in this context.

Abstract: In this research work, we consider the problem of sensor selection for the system controlling full penetration mode in electron beam welding. For this, we have investigated four signals from the backside of the workpiece: electron current in root plasma, ion current in root plasma, through-thickness electron current and penetrating bremsstrahlung X-ray. After having done the research we have estimated the advisability of two signals: one for cases if requirements for control precision are high and the other for other cases.