Lucian Stefanita GRIGORE

Dr. Lucian Stefanita GRIGORE

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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 April 2020 in Processes
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Journal Article
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LGLucian Stefanita GRIGORE
Lucian Stefanita GRIGORE
IPIustin Priescu
Iustin Priescu
DJDaniela Joita
Daniela Joita
Ionica OncioiuIonica Oncioiu
Ionica Oncioiu
Today, industrial robots are used in dangerous environments in all sectors, including the sustainable energy sector. Sensors and processors collect and transmit information and data from users as a result of the application of robot control systems and sensory feedback. This paper proposes that the estimation of a collaborative robot system’s performance can be achieved by evaluating the mobility of robots. Scenarios have been determined in which an autonomous system has been used for intervention in crisis situations due to fire. The experimental model consists of three autonomous vehicles, two of which are ground vehicles and the other is an aerial vehicle. The conclusion of the research described in this paper highlights the fact that the integration of robotic systems made up of autonomous vehicles working in unstructured environments is difficult and at present there is no unitary analytical model.

21 April 2021 in Applied Sciences
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LGLucian Stefanita GRIGORE
Lucian Stefanita GRIGORE
Ionica OncioiuIonica Oncioiu
Ionica Oncioiu
IPIustin Priescu
Iustin Priescu
DJDaniela Joița
Daniela Joița
Today, terrestrial robots are used in a multitude of fields and for performing multiple missions. This paper introduces the novel development of a family of crawling terrestrial robots capable of changing very quickly depending on the missions they have to perform. The principle of novelty is the use of a load-bearing platform consisting of two independent propulsion systems. The operational platform, which handles the actual mission, is attached (plug and play) between the two crawler propulsion systems. The source of inspiration is the fact that there are a multitude of intervention robots in emergency situations, each independent of the other. In addition to these costs, there are also problems with the specialization of a very large number of staff. The present study focused on the realization of a simplified, modular model of the kinematics and dynamics of the crawler robot, so that it can be easily integrated, by adding or removing the calculation modules, into the software used. The designed model was integrated on a company controller, which allowed us to compare the results obtained by simulation with those obtained experimentally. We appreciate that the analyzed Explosive Ordnance Disposal (EOD) robot solution represents a premise for the development of a family of EOD robots that use the same carrier platform and to which a multitude of operational platforms should be attached, depending on the missions to be performed.

30 August 2023 in Mathematics
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OAOctavian Alexa
Octavian Alexa
CTCiobotaru Ticusor
Ciobotaru Ticusor
LGLucian Stefanita GRIGORE
Lucian Stefanita GRIGORE
Teodor Lucian GrigorieTeodor Lucian Grigorie
Teodor Lucian Grigorie
ASAmado George Stefan
Amado George Stefan
CVCristina Vlădescu
Cristina Vlădescu
This paper presents mathematical models to estimate the kinematics and dynamics of wheeled and tracked robots. The models account for the physical–mechanical characteristics of the ground, the influence of the center of gravity displacement on the cornering moment of resistance, and the influence of the interaction of the crawler with the roadway. The results of the models are characterized by defining computational relationships for a robot’s equations of motion, longitudinal forces, transverse forces, and resistive turning moments generated via longitudinal forces and transverse forces.

1 January 2015 in Procedia Economics and Finance
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INIonel Nuţă
Ionel Nuţă
OOOctavian Orban
Octavian Orban
LGLucian Stefanita GRIGORE
Lucian Stefanita GRIGORE
The last time we witness extreme natural phenomena, plus technological accidents, weather situations, global warming, asymmetric non -classical actions of unknown nature, with influences immediate or direct or indirect, over the life of each human individual and the human society as a whole. All of these are causes emergency generators that produce large numbers of casualties and material damage scale. Prevention and emergency management is increasingly becoming an integral part of policy and strategy development, security and stability at all levels and in all areas of interest. In both fields the primary role plays the man who has to travel on site, analyse, and make decisions of life and death for solving emergencies. Unfortunately, no matter how well prepared it has its limits. The key to solving this problem lies in intelligent action coordinated between man and machine. Thus, there is need to undertake a technological bridge between people, machines and methods of intervention in emergencies. Therefore, research efforts in recent years have been focused mainly on the satisfaction of human needs replacement staff for the execution of high-risk missions in difficult environments with controlled accelerated progress in the field of mechatronics, optoelectronics, electronics computing power and allowed the market providing specialized technologies required to achieve this goal. One solution is the development of families of robots specialized for prevention and intervention, capable of movement in critical areas before the emergency to be unleashed and out of control, to save life and property or to obtain a detailed view transmitting data and information necessary human an effective response

30 September 2020 in Materiale Plastice
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Journal Article
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LGLucian Stefanita GRIGORE
Lucian Stefanita GRIGORE
ASAmado-George Stefan
Amado-George Stefan
OOOctavian Orban
Octavian Orban
The development of 3D printing technologies has gained considerable momentum. Almost every technical-scientific field uses this technology. The technology of 3D printing thermoplastic materials (or fusible filaments - FFF), is based on the realization of the parts by depositing successive layers of extruded filament at temperatures corresponding to the viscous aggregation state. One of the research activities of the CERAS research center is the realization of collaborative drone systems, drones capable of moving in each of the three unstructured environments: aerial, terrestrial aquatic / underwater. This paper presents a study on the choice of the type of thermoplastic material, for making the structural elements (chassis) of an underwater Rover. The need for this study arose from the fact that the design and construction of underwater vehicles is generally demanding. The materials must be characterized by resistance to compression / stretching / shearing, as in underwater environments the existence of currents, pressures (with increasing depth of immersion). Also, the materials must be chemically neutral, because in aquatic environments we can find various chemicals spilled in water (intentional or not) and finally salinity.

15 March 2023 in Drones
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ATAndra TOFAN-NEGRU
Andra TOFAN-NEGRU
ASAmado George Stefan
Amado George Stefan
LGLucian Stefanita GRIGORE
Lucian Stefanita GRIGORE
Ionica OncioiuIonica Oncioiu
Ionica Oncioiu
The aim of the paper is to validate the analytical–numerical analysis method regarding the operating regime of the propellers of a quadcopter. The research aims to mark the flow areas whose numerical results differ from the experimental ones and to investigate the possible reasons for the discrepancies between the values. The paper presents the determination of the air velocity produced by the rotational movement of a quadcopter propeller for a stationary position of the drive motor. The velocities were determined both experimentally at various points located below the propeller plane using hot-wire anemometric probes and numerically using a time-lapse simulation with a rotating sliding table. The numerical simulations carried out consisted of the determination of the time variation of the velocity distribution developed by the propeller in the rotational movement for the different operating (power) cycles of the engine. In addition, a technique that utilizes reverse engineering to determine the propeller profile, the anemometric probe calibration, and the average velocity values measured at various points below the propeller plane for engine operating regimes that range from 60 to 90% are also presented.