8 results on '"Dinca, Liviu"'
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2. Solar UAVs—More Aerodynamic Efficiency or More Electrical Power?
- Author
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Dinca, Liviu, Corcau, Jenica-Ileana, and Voinea, Daniel-Gabriel
- Subjects
- *
SOLAR energy , *SOLAR cells , *DRONE aircraft , *CLEAN energy , *ENERGY shortages , *SURFACE area , *SOLAR cell efficiency - Abstract
Solar UAVs (unmanned aerial vehicles) have experienced important development in recent years. The use of solar free energy is not neglected in the present energy crisis, with the intention to move toward green energies. However, an important problem arises concerning the limited amount of solar energy available on board UAVs. Until now, high-aerodynamic-efficiency configurations have been used. These configurations use high-aspect-ratio wings. However, high-aspect-ratio wings have some disadvantages regarding their excessive elasticity and weak bending resistance in the housing section. Additionally, the aircraft maneuverability is reduced. In this work, a study is proposed on a solar UAV configuration that sacrifices high aerodynamic efficiency for a higher surface area available for solar cells. In this manner, the amount of energy available on board the UAV is increased, and the UAV structure becomes more rigid and robust. The presented UAV fits better with more complex evolutions, is more maneuverable and the wingspan is much reduced. This UAV is more compact, can maneuver better in the take-off and landing phases, and the necessary storage space is considerably reduced. This paper highlights the performances that can be achieved using this kind of UAV and explores whether these performances are enough for some applications. Using an on-board energy balance, the possible performances of this new configuration is studied. As this is a preliminary study, the precision level is not very high, but it offers an image concerning the possibilities of this new configuration. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Numerical Simulation for Redundant Electro-Hydrostatic Servo-Actuators under Certain Special Conditions.
- Author
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Dinca, Liviu, Bogateanu, Radu, Corcau, Jenica-Ileana, Dumitrache, Alexandru, and Suatean, Bogdan
- Subjects
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COMPUTER simulation , *LEAD time (Supply chain management) , *TRANSPORT planes , *HYDROSTATIC extrusion - Abstract
This work presents some numerical simulations, performed using AMESim software, for a system composed by two redundant servo-actuators. Certain operating conditions are taken into account for these two electro-hydrostatic servo-actuators, which are coupled to the command surface (aileron) of a transport aircraft. We first considered the situation of slight asymmetries in the construction of the servo-actuators, then a situation in which one servo-actuator fails at maximum flight speed, and then at a medium flight speed, and finally we considered the effect of gusts upon the system. Small differences in the construction of the servo-actuators were taken into consideration by modifying each of the pump displacements, one by +2% and one by −2%, from the nominal value. It is possible that many other asymmetries exist in the construction of servo-actuators, such as different liquid leakages in the cylinders or pumps, small differences in the controller coefficients, and so on. These differences should be taken into account in future works. Our results provide evidence that, under some operation situations of redundant servo-actuators, significant overstresses can appear in one servo-actuator, leading to a decrease in the time for which the system operates correctly. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
4. CANARD UAV IMPROVEMENT USING VECTORED THRUST.
- Author
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DINCA, Liviu, CORCAU, Jenica-Ileana, and CUMPAN, Dionis
- Subjects
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THRUST , *DISTANCES , *VERTICALLY rising aircraft - Abstract
This paper presents a study concerning a canard UAV improvement using vectored thrust. There are taken into account the take-off and landing behavior. Vectored thrust can extent the attack angle range for a canard UAV, and so, one can decrease the take-off and landing speeds and also the take-off and landing distances. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. Fuzzy Energy Management for Hybrid Fuel Cell/Battery Systems for More Electric Aircraft.
- Author
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Corcau, Jenica-Ileana, Dinca, Liviu, Grigorie, Teodor Lucian, and Tudosie, Alexandru-Nicolae
- Subjects
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FUEL cells , *AIRPLANES , *LITHIUM-ion batteries , *DC-to-DC converters , *ELECTRIC current converters - Abstract
In this paper is presented the simulation and analysis of a Fuzzy Energy Management for Hybrid Fuel cell/Battery Systems used for More Electric Aircraft. The fuel cell hybrid system contains of fuel cell, lithium-ion batteries along with associated dc to dc boost converters. In this configuration the battery has a dc to dc converter, because it is an active in the system. The energy management scheme includes the rule based fuzzy logic strategy. This scheme has a faster response to load change and is more robust to measurement imprecisions. Simulation will be provided using Matlab/Simulink based models. Simulation results are given to show the overall system performance. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. FUZZY LOGIC CONTROL FOR A DC TO DC BUCK CONVERTER.
- Author
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CORCAU, Jenica-Ileana and DINCA, Liviu
- Subjects
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DC-to-DC converters , *FUZZY control systems , *FUZZY logic , *CLOSED loop systems , *COMPUTER simulation , *MATHEMATICAL models - Abstract
In this paper one presents a model and an analysis of a dc-to-dc Buck converter, in closed loop, from 24V to 12 V with a power of 500 W. Model is implemented in MATLAB/SIMULINK toolbox SIMPOWERSYS. Control system is a fuzzy logic one, Mamdani type, and using P.I. configuration. One opted for a fuzzy controller due to its flexibility in its configuration and tuning process, and also because it doesn’t need to know a mathematical model for the Buck converter. Fuzzy controller is composed of two sub-controllers in parallel, one for the proportional component and a second for integrative component. One proposes this configuration because fewer inference rules are necessary and also the tuning process is easily accomplished compared to a fuzzy controller with two inputs. Implemented model is validated by numerical simulations and the results are realistic and confirm the possibility to use this type of controller. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
7. TEMPERATURE EFFECTS ESTIMATION AND COMPENSATION IN A MINIATURE THREE-AXIAL ACCELEROMETER BY USING FUZZY LOGIC TECHNIQUES.
- Author
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Grigorie, Teodor Lucian, Gresita, Constantin Irinel, Corcau, Jenica Ileana, Dinca, Liviu, and Stancu, Catalin Nicusor
- Subjects
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FUZZY logic , *ACCELEROMETERS , *MINIATURE craft , *NONLINEAR analysis , *NEURAL circuitry - Abstract
The paper presents a way to obtain an intelligent miniaturized three-axial accelerometric sensor, based on the on-line estimation and compensation of the sensor errors generated by the environmental temperature variation. Taking into account that this error's value is a strongly nonlinear complex function of the values of environmental temperature and of the acceleration exciting the sensor, its correction may not be done off-line and it requires the presence of an additional temperature sensor. The proposed identification methodology for the error model is based on a neuro-fuzzy procedure which process off-line the numerical values obtained from the accelerometer experimental testing for different values of acceleration applied to its axes of sensitivity and for different values of operating temperature. In the sections of the paper are shown the results of the experimental testing of the accelerometer on all the three sensitivity axes, the identification of the error models on each axis by using fuzzy logic techniques combined with adaptive neural-network techniques, and the validation of the obtained models with experimental values. After the training of the neuro-fuzzy developed models for all of the three detection channels was obtained a reduction by almost two orders of magnitude of the acceleration absolute maximum error due to environmental temperature variation. [ABSTRACT FROM AUTHOR]
- Published
- 2016
8. A FUZZY LOGIC CONTROL STRUCTURE OF A MEMS ACCELEROMETER.
- Author
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Grigorie, Teodor Lucian, Negrea, Petre, Corcau, Jenica Ileana, Dinca, Liviu, and Grigorie, Otilia
- Subjects
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FUZZY systems , *ARCHITECTURAL designs , *FUZZY logic , *FUZZY arithmetic , *ACCELEROMETERS - Abstract
A way to improve the transient regime of a miniature accelerometer by using a smart control structure to close its loop is here presented. The control structure is developed by using the fuzzy logic techniques and it replaces an electronic block on the feedback path of the closed loop, block that, in the classical architecture, assured the system damping and, in the same time, played the role of elastic link of the accelerometer proof mass. The paper exposes gradually the operating principle of the miniature accelerometer, its mathematical modeling, the results obtained for classical closed loop architecture, the design procedure for the smart closed-loop control structure, and the results of the smart architecture. Finally, a comparative numerical study between the classical and the proposed accelerometer architectures is made [ABSTRACT FROM AUTHOR]
- Published
- 2013
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