Grigore Stamatescu

Prof. Grigore Stamatescu

Department of Automatic Control and Industrial Informatics, Faculty of Automatic Control and Computers, University Politehnica of Bucharest
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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3 February 2020 in Sensors
Verified
Journal Article
Open access
PDF file
Dan PopescuDan Popescu
Dan Popescu
FSFlorin Stoican
Florin Stoican
Grigore StamatescuGrigore Stamatescu
Grigore Stamatescu
LILoretta Ichim
Loretta Ichim
CDCristian Dragana
Cristian Dragana
The growing need for food worldwide requires the development of a high-performance, high-productivity, and sustainable agriculture, which implies the introduction of new technologies into monitoring activities related to control and decision-making. In this regard, this paper presents a hierarchical structure based on the collaboration between unmanned aerial vehicles (UAVs) and federated wireless sensor networks (WSNs) for crop monitoring in precision agriculture. The integration of UAVs with intelligent, ground WSNs, and IoT proved to be a robust and efficient solution for data collection, control, analysis, and decisions in such specialized applications. Key advantages lay in online data collection and relaying to a central monitoring point, while effectively managing network load and latency through optimized UAV trajectories and in situ data processing. Two important aspects of the collaboration were considered: designing the UAV trajectories for efficient data collection and implementing effective data processing algorithms (consensus and symbolic aggregate approximation) at the network level for the transmission of the relevant data. The experiments were carried out at a Romanian research institute where different crops and methods are developed. The results demonstrate that the collaborative UAV–WSN–IoT approach increases the performances in both precision agriculture and ecological agriculture.

28 October 2019 in Sensors
Verified
Journal Article
Open access
PDF file
Dan PopescuDan Popescu
Dan Popescu
FSFlorin Stoican
Florin Stoican
Grigore StamatescuGrigore Stamatescu
Grigore Stamatescu
OCOana Chenaru
Oana Chenaru
LILoretta Ichim
Loretta Ichim
Integrated systems based on wireless sensor networks (WSNs) and unmanned aerial vehicles (UAVs) with electric propulsion are emerging as state-of-the-art solutions for large scale monitoring. Main advances stemming both from complex system architectures as well as powerful embedded computing and communication platforms, advanced sensing and networking protocols have been leveraged to prove the viability of this concept. The design of suitable algorithms for data processing, communication and control across previously disparate domains has thus currently become an intensive area of interdisciplinary research. The paper was focused on the collaborative aspects of UAV–WSN systems and the reference papers were analyzed from this point of view, on each functional module. The paper offers a timely review of recent advances in this area of critical interest with focus on a comparative perspective across multiple recent theoretical and applied contributions. A systematic approach is carried out in order to structure a unitary from conceptual design towards key implementation aspects. Focus areas are identified and discussed such as distributed data processing algorithms, hierarchical multi-protocol networking aspects and high level WSN–constrained UAV-control. Application references are highlighted in various domains such as environmental, agriculture, emergency situations and homeland security. Finally, a research agenda is outlined to advance the field towards tangible economic and social impact.

30 November 2018 in Sensors
Verified
Journal Article
Open access
PDF file
Dan PopescuDan Popescu
Dan Popescu
CDCristian Dragana
Cristian Dragana
FSFlorin Stoican
Florin Stoican
LILoretta Ichim
Loretta Ichim
Grigore StamatescuGrigore Stamatescu
Grigore Stamatescu
Large-scale monitoring systems have seen rapid development in recent years. Wireless sensor networks (WSN), composed of thousands of sensing, computing and communication nodes, form the backbone of such systems. Integration with unmanned aerial vehicles (UAVs) leads to increased monitoring area and to better overall performance. This paper presents a hybrid UAV-WSN network which is self-configured to improve the acquisition of environmental data across large areas. A prime objective and novelty of the heterogeneous multi-agent scheme proposed here is the optimal generation of reference trajectories, parameterized after inter- and intra-line distances. The main contribution is the trajectory design, optimized to avoid interdicted regions, to pass near predefined way-points, with guaranteed communication time, and to minimize total path length. Mixed-integer description is employed into the associated constrained optimization problem. The second novelty is the sensor localization and clustering method for optimal ground coverage taking into account the communication information between UAV and a subset of ground sensors (i.e., the cluster heads). Results show improvements in both network and data collection efficiency metrics by implementing the proposed algorithms. These are initially evaluated by means of simulation and then validated on a realistic WSN-UAV test-bed, thus bringing significant practical value.

1 October 2017
Verified
Conference Paper
Closed access
CNCristina Nichiforov
Cristina Nichiforov
ISIulia Stamatescu
Iulia Stamatescu
IFIoana Fagarasan
Ioana Fagarasan
Grigore StamatescuGrigore Stamatescu
Grigore Stamatescu
Energy forecast is essential for a good planning of the electricity consumption as well as for the implementation of decision support systems which can lead the decision making process of energy system. Energy consumption time series prediction problems represent a difficult type of predictive modelling problem due to the existence of complex linear and non-linear patterns. This paper presents two approaches for energy consumption forecast: an autoregressive integrated moving average (ARIMA) model and a non-linear autoregressive neural network (NAR) model. The two models are deeply described and finally compared in order to evaluate their performance.

18 January 2017 in Energies
Verified
Journal Article
Open access
PDF file
Iulia StamatescuIulia Stamatescu
Iulia Stamatescu
NANicoleta Arghira
Nicoleta Arghira
Ioana FagarasanIoana Fagarasan
Ioana Fagarasan
Grigore StamatescuGrigore Stamatescu
Grigore Stamatescu
SISergiu Stelian Iliescu
Sergiu Stelian Iliescu
VCVasile Calofir
Vasile Calofir
This paper presents the development of a decision support system (DSS) for a low-voltage grid with renewable energy sources (photovoltaic panels and wind turbine) which aims at achieving energy balance in a pilot microgrid with less energy consumed from the network. The DSS is based on a procedural decision algorithm that is applied on a pilot microgrid, with energy produced from renewable energy sources, but it can be easily generalized for any microgrid. To underline the benefits of the developed DSS two case scenarios (a household and an office building with different energy consumptions) were analyzed. The results and throw added value of the paper is the description of an implemented microgrid, the development and testing of the decision support system on real measured data. Experimental results have demonstrated the validity of the approach in rule-based decision switching.

1 January 2014 in Procedia Engineering
Verified
Journal Article
Open access
Iulia StamatescuIulia Stamatescu
Iulia Stamatescu
IFIoana Făgărăşan
Ioana Făgărăşan
Grigore StamatescuGrigore Stamatescu
Grigore Stamatescu
NANicoleta Arghira
Nicoleta Arghira
SISergiu Stelian Iliescu
Sergiu Stelian Iliescu
The paper presents a solar-tracking method for control of photovoltaic panel movement in order to improve the conversion efficiency of the system. The designed algorithm is implemented on a solar-tracking experimental platform using a tri-positional control strategy. It makes use of measured values for radiation from appropriate sensors and assures command of the platform's two positioning motors. The solution was developed as a virtual instrument, using the graphical programming environment, LabVIEW. This allows for fast deployment, versatility and scalability