Răzvan Şolea

Dr. Răzvan Şolea

"Dunarea de Jos" University of Galati, Galaţi, Romania
orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

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

Representative Publications

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18 January 2007 in Integrated Computer-Aided Engineering
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Journal Article
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Răzvan ŞoleaRăzvan Şolea
Răzvan Şolea
UNUrbano J. Nunes
Urbano J. Nunes
Fully automatic driving is emerging as the approach to dramatically improve efficiency (throughput per unit of space) while at the same time leading to the goal of zero accidents. This approach, based on fully automated vehicles, might improve the ef

25 October 2022 in Sensors
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Journal Article
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Minca EugeniaMinca Eugenia
Minca Eugenia
Adrian FilipescuAdrian Filipescu
Adrian Filipescu
DCDaniela Cristina CERNEGA
Daniela Cristina CERNEGA
Răzvan ŞoleaRăzvan Şolea
Răzvan Şolea
Adriana FilipescuAdriana Filipescu
Adriana Filipescu
GSGeorgian Simion
Georgian Simion
A digital twin for a multifunctional technology for flexible manufacturing on an assembly, disassembly, and repair mechatronics line (A/D/RML), assisted by a complex autonomous system (CAS), is presented in the paper. The hardware architecture consists of the A/D/RML and a six-workstation (WS) mechatronics line (ML) connected to a flexible cell (FC) and equipped with a six-degree of freedom (DOF) industrial robotic manipulator (IRM). The CAS has in its structure two driving wheels and one free wheel (2DW/1FW)-wheeled mobile robot (WMR) equipped with a 7-DOF robotic manipulator (RM). On the end effector of the RM, a mobile visual servoing system (eye-in-hand MVSS) is mounted. The multifunctionality is provided by the three actions, assembly, disassembly, and repair, while the flexibility is due to the assembly of different products. After disassembly or repair, CAS picks up the disassembled components and transports them to the appropriate storage depots for reuse. Disassembling or repairing starts after assembling, and the final assembled product fails the quality test. The virtual world that serves as the digital counterpart consists of tasks assignment, planning and synchronization of A/D/RML with integrated robotic systems, IRM, and CAS. Additionally, the virtual world includes hybrid modeling with synchronized hybrid Petri nets (SHPN), simulation of the SHPN models, modeling of the MVSS, and simulation of the trajectory-tracking sliding-mode control (TTSMC) of the CAS. The real world, as counterpart of the digital twin, consists of communication, synchronization, and control of A/D/RML and CAS. In addition, the real world includes control of the MVSS, the inverse kinematic control (IKC) of the RM and graphic user interface (GUI) for monitoring and real-time control of the whole system. The “Digital twin” approach has been designed to meet all the requirements and attributes of Industry 4.0 and beyond towards Industry 5.0, the target being a closer collaboration between the human operator and the production line.

15 June 2022 in Inventions
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Journal Article
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Dan IonescuDan Ionescu
Dan Ionescu
Adrian FilipescuAdrian Filipescu
Adrian Filipescu
GSGeorgian Simion
Georgian Simion
Minca EugeniaMinca Eugenia
Minca Eugenia
DCDaniela Cristina CERNEGA
Daniela Cristina CERNEGA
Adriana FilipescuAdriana Filipescu
Adriana Filipescu
This paper aims to describe modeling and control in what concerns advanced manufacturing technology running on a flexible assembly, disassembly and repair on a mechatronic line (A/D/RML) assisted by an Autonomous Robotic System (ARS), two robotic manipulators (RM) and visual servoing system (VSS). The A/D/RML consists of a six workstations (WS) mechatronics line (ML) connected to a flexible cell (FC) equipped with a 6-DOF ABB industrial robotic manipulator (IRM) and an ARS used for manipulation and transport. A hybrid communication and control based on programmable logic controller (PLC) architecture is used, which consists of two interconnected systems that feature both distributed and centralized topology, with specific tasks for all the manufacturing stages. Profinet communication link is used to interconnect and control FC and A/D/RML. The paper also discusses how to synchronize data between different field equipment used in the industry and the control systems. Synchronization signals between the master PLC and ARS is performed by means of Modbus TCP protocol and OPC UA. The structure of the ARS consists of a wheeled mobile robot (WMR) with two driving wheels and one free wheel (2DW/1FW) equipped with a 7-DOF RM. Trajectory tracking sliding-mode control (TTSMC) is used to control WMR. The end effector of the ARS RM is equipped with a mobile eye-in-hand VSS technology for the precise positioning of RM to pick and place the workparts in the desired location. Technology operates synchronously with signals from sensors and from the VSS HD camera. If the workpiece does not pass the quality test, the process handles it by transporting back from the end storage unit to the flexible cell where it will be considered for reprocessing, repair or disassembling with the recovery of the dismantled parts. The recovered or replaced components are taken over by the ARS from disassembling location and transported back to the dedicated storage warehouses to be reused in the further assembly processes.

1 October 2019
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Conference Paper
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Răzvan ŞoleaRăzvan Şolea
Răzvan Şolea
AMAlexandru Margarit
Alexandru Margarit
DCDaniela Cernega
Daniela Cernega
ASAdrian Serbencu
Adrian Serbencu
This paper presents an efficient method to implement head gesture recognition to be the base of a framework for the physically disabled people. Currently, the most common way to control an powered wheelchair is to use a joystick. However, there are some individuals unable to operate joystick-driven powered wheelchairs due to sever physical disabilities. This paper proposes a novel head pose control algorithm to assist disabled patients (persons who cannot move their hands or legs but are able to make head movement). It this paper an interface that enables an powered wheelchair to be operated by gestures, such as head movements, is presented. The control system translates the position of the users head into speed and directional control of the wheelchair. The proposed algorithm was implemented/tested in real-time on the powered wheelchair.

24 January 2025 in Energies
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Marian GaiceanuMarian Gaiceanu
Marian Gaiceanu
SESilviu Epure
Silviu Epure
Răzvan ŞoleaRăzvan Şolea
Răzvan Şolea
RBRazvan Buhosu
Razvan Buhosu
This work contributes to both Romania’s and the European Union’s energy policies by highlighting the research results obtained within the Dunarea de Jos University of Galati, but also through the technological transfer of this knowledge to the industry. In order to improve the power quality of the nonlinear loads connected to the electrical grid, a three-phase shunt active power filter prototype based on the Harmonic Component Separation Method with a Low-Pass Filter was used. The active power filter is connected at the Point of Common Coupling to compensate for individual loads or even all of them simultaneously. Therefore, active power filters can be used to compensate for the power factor and reduce the harmonic distortion of power supplies, or for processes subsequently connected to additional nonlinear loads, thus improving the energy efficiency. The shunt active power filter prototype is composed of the power side (three-phase insulated gate bipolar transistor bridge, DC link capacitor precharge system, inductive filter) and the control side (gate drive circuits, control subsystems, signal acquisition system). The filter control strategy is based on the principle of separating harmonic components with a low-pass filter, implemented by the authors on the industrial prototype. In this paper, the main technical features of the industrial shunt active power filter prototype are specified. The authors of this paper involved three cascaded control loops: the DC link voltage control loop, the shunt active power filter current control loop and the phase-locked loop. Both simulation and experimental results for the shunt-type active power filter prototype were obtained. By analyzing the obtained waveforms of the power supply source in two cases (with and without an active power filter), a decrease in the total harmonic distortion was demonstrated, both the voltage harmonic distortion factor THDu and the current harmonic distortion factor THDi in the case of the active power filter connection. By using the Field-Programmed Gate Array processing platform, the powerful computational speed features were exploited to implement the active shunt power filter control on an experimental test bench. Conducting source current harmonics mitigation increased the efficiency of the power system by decreasing the respective harmonic Joule losses. The energy-saving feature led to the increased added value of the parallel active power filter. Through the performed laboratory tests, the authors demonstrated the feasibility of the proposed control solution for the industrial prototype. In accordance with the European Union’s Research and Technological Development Policy, the development of an innovation ecosystem was taken into consideration. The unified and efficient integration of all the specific actors (enterprises, research institutes, universities and entrepreneurs) in innovation was achieved.

1 January 2009
Verified
Book Chapter
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Răzvan ŞoleaRăzvan Şolea
Răzvan Şolea
DCDaniela Cernega
Daniela Cernega