Adrian Ghionea

Bio: Adrian Ghionea is an academic researcher from Politehnica University of Bucharest. The author has contributed to research in topics: Machine tool & Predictive maintenance. The author has an hindex of 3, co-authored 19 publications receiving 55 citations. Previous affiliations of Adrian Ghionea include University of Bucharest.

Assisted Research of the Neural Network

Abstract: In the optimization of the trajectory or of the guidance of mobile robots one of the more important things is to assure one small difference between the output data of the system and the target This paper show how on-line will be possible to establish one convergence way to the target without any influences of the input data or initial conditions of the weights or biases The paper show the general components and the mathematical model of some more important neurons and one numerical simulation of the linear neural network In the paper was used the least mean square (LMS) error algorithm for adjusting the weights and biases and incremental training by different training rate, finally to obtain one minimum error to the target

Lathe Machining in the Era of Industry 4.0: Remanufactured Lathe with Integrated Measurement System for CNC Generation of the Rolling Surfaces for Railway Wheels

Abstract: Many projects and researches in the field of remanufacturing of specialized lathes are presented in the specialized literature. In the process of design for remanufacturing, a great number of solutions contain different aspects and data important to consider. The paper presents important stages of theoretical and applied research regarding the modernization of a conventional lathe with two working units by adaptation of four driving chains for CNC advance/positioning movements and improvements of translation couplings, adaptation of CNC equipment for driving and measuring simultaneous both wheels mounted on axle. The reducing of geometrical errors of the running profile is very important in reshaping the worn wheelsets. The lathe remanufacturing process involves the restoration of functional requirements and measurement of the geometric precision. The CNC capabilities of the remanufactured lathe require a database of parametric representation of profiles and rolling surfaces using CAD techniques according to international standards.

Establishing the State of Operation on Vibration Behavior of the Industrial Robot

Abstract: Diagnosis measurement of vibration and noise, should allow monitoring of equipment defects, through a system of preventive maintenance, predictive. Automatic diagnosis of machinery and equipment was made in order to ensure a higher reliability of these and how to obtain a more extended life cycle without the occurrence of defects. Vibrations are always measured in analog format (time domain) and must be transformed into the frequency domain. Therefore Fast Fourier Transform (FFT) method is used to evaluate vibration Almega AX-V6 robot. The application of preventive and predictive maintenance management supports enterprise, because it proves effective, the information you provide in making decisions.

Cad-cae methodology applied to analysis of a gear pump

Abstract: The use of modern CAD and FEM techniques in the con ception, simulation and manufacturing processes of industrial products has a large applic ation in the mechanical, automotive and aerospace i n- dustry domains. This paper presents important aspec ts of a practical methodology applied to design a gear pump using the CATIA software parametric abili ties followed by a FEM analysis of its assembly to identify the most stressed components. In the param etric design of the gear pump some of its construct ive and functional data, among them, the flow being the main parameter, were taken into account.

Cutting parameters and analysis by fea simulation of their influence on the re-profilation of the wheels of the railway wheelset

Abstract: Modern approaches on research projects in the field of lathes’ remanufacturing involve various simulation stages, like FEA and CAM, in order to obtain results and solutions with different aspects and data important to consider. These simulations may confirm data obtained through measurement, but also extrapolate values that can’t be measured directly on the machine-tool technological system. Usually, a mathematical and simulated models, with a low error percent, are the main key for the remanufacturing team. The newest trend in manufacturing technologies, the acclaimed Industry 4.0, relies on new design concepts and methods, data acquisition and exchange between systems, processing, visualization and automation. Modern simulation methods, system integration between simulated and measured data, augmented reality, etc., are important parts of the actual factories. More and more machine-tools without CNC capabilities are remanufactured in this new vision of Industry 4.0. This paper presents some phases in establishing the turning process parameters in profiling and re-profiling of the trains wheelsets. There are used specific instruments (a mathematical approach and 3D models for FEA simulation) in order to determine which system (tool holder – insert – process parameters) are better to be used on the remanufactured lathe. Key words: tread profile, wheelset, re-profilation, cutting parameters, FEA analysis.

Internal unsteady flow characteristics of centrifugal pump based on entropy generation rate and vibration energy

Abstract: The transient fluid exciting force induced by unsteady flow in the centrifugal pump is the only exciting force that cannot be effectively eliminated. In order to explore the vibration problem cause...

Proper Assisted Research Method Solving of the Robots Inverse Kinematics Problem

Abstract: Finding the better solution of the inverse kinematics problem, with the minimum of the trajectory errors, is very difficult because there are many variable parameters and many redundant solutions. The presented paper show the assisted solving of the inverse kinematics with the goal to minimize the final end-effector trajectory errors, by optimizing the distance between the and-effector final position and the target. All obtained results were been verified by applying the proper forward kinematics virtual LabVIEW instrumentation. The paper tries to answer at the inverse kinematics problem for one known mathematical trajectory and identifying the cinematic errors after the establishing and applying the proper assisted solving method using the Cycle Coordinate Descent Method coupled to the proper Neural Network Sigmoid Bipolar Hyperbolic Tangent (CCDM-SBHTNN). We were shown one complete study case to obtain one circle space trajectory using one arm type robot fixed on the ceiling. The presented method is general and can be used in all other robots types and in all other conventional and unconventional space curves.

Robot control device, robot, and robot system

Abstract: A robot control device controls the operation of a robot including a trunk that is rotatable around an axis, first and second robot arms that are provided at the trunk and rotatable with respect to the trunk, and first, second, and third inertial sensors. In an operation in which the second robot arm is brought into a stationary state and the first robot arm is rotated around the axis from the stationary state and moved to a target position, the robot control device makes B/A<0.27 satisfied when a maximum value of the amplitude of the angular velocity of the trunk around the axis before the first robot arm reaches the target position is defined as A, and a maximum value of the amplitude of the angular velocity of the trunk around the axis after the first robot arm has reached the target position first is defined as B.

The influence of gear micropump body asymmetry on stress distribution

Abstract: The paper presents the results of numerical calculations of stress distributions in the gear micropump body for applications in hydraulic systems, especially in the marine sector. The scope of the study was to determine the most favorable position of bushings and pumping unit in the gear pump body in terms of stress and displacement distribution in the pump housing. Fourteen cases of gear pump bushings and pumping unit locations were analyzed: starting from the symmetrical position relative to the central axis of the pump, up to a position shifted by 2.6 mm towards the suction channel of the pump. The analysis of the obtained calculation results has shown that the most favorable conditions for pump operation are met when the bushings are shifted by 2.2 mm towards the suction channel. In this case the maximal stress was equal to 109 MPa, while the highest displacement was about 15μm. Strength and stiffness criteria in the modernized pump body were satisfied.