2024-03-29T09:05:46Z
https://eej.aut.ac.ir/?_action=export&rf=summon&issue=34
AUT Journal of Electrical Engineering
2588-2910
2588-2910
2011
43
1
A Hierarchical SLAM/GPS/INS Sensor Fusion with WLFP for Flying Robo-SAR's Navigation
S.M.
Mirzababaei
M.K.
Akbariii
In this paper, we present the results of a hierarchical SLAM/GPS/INS/WLFP sensor fusion to be used in navigation system devices. Due to low quality of the inertial sensors, even a short-term GPS failure can lower the integrated navigation performance significantly. In addition, in GPS denied environments, most navigation systems need a separate assisting resource, in order to increase the availability and reliability of the device. When the GPS service/information is available, the integrated SLAM system arranges for a landmark-based map using a GPS/INS feature. But in case of inaccessibility of GPS information, the latest formerly produced map plays an important role in decreasing the INS errors. In addition, a Wireless Fingerprinting (WLFP) mechanism helps us limit the errors in the system. The results of the proposed method decreases the average estimation precision on the order of 2.6m, without any performance degradation and in different experiments, which is the maximum sustainable error (below 2.66m) for flyer landing on the base. The mentioned method could be used in computer networks to schedule the services too.
Inertial Navigation System
GPS
Car Navigation
Unmanned Autonomous Vehicle
Wireless Fingerprint
2011
04
01
1
10
https://eej.aut.ac.ir/article_83_426bffd5d72349cb1f5fd1533231b25f.pdf
AUT Journal of Electrical Engineering
2588-2910
2588-2910
2011
43
1
Robust Control of Encoderless Synchronous Reluctance Motor Drives Based on Adaptive Backstepping and Input-Output Feedback Linearization Techniques
Jafar
Soltanii
Hossein
Abootorabi Zarchi
In this paper, the design and implementation of adaptive speed controller for a sensorless synchronous reluctance motor (SynRM) drive system is proposed. A combination of well-known adaptive input-output feedback linearization (AIOFL) and adaptive backstepping (ABS) techniques are used for speed tracking control of SynRM. The AIOFL controller is capable of estimating motor two-axis inductances (Ld, Lq), simultaneously. The overall stability of the proposed control and Persistency of Excitation (PE) condition are proved based on Lyapunov theory. In the proposed control drive system, the maximum torque control (MTC) scheme and constant current in inductive axis control (CCIAC) are applied to generate the motor d and q axis reference currents which are needed for the AIOFL controller. In addition, an ABS speed controller is designed to compensate for the machine parameter uncertainties and load torque disturbances. Another contribution of this paper is to estimate the rotor speed and position in very low speed by using 1) a simple technique for eliminating the voltage sensors, 2) a simple method for online estimation of the stator resistance, and 3) modeling the voltage drop of the inverter power switches. Finally, the validity and capability of the proposed method are verified through simulation and experimental studies.
Synchronous Reluctance Motor
Adaptive Backstepping and Input-Output Feedback Linearization
Encoderless
2011
04
01
11
23
https://eej.aut.ac.ir/article_84_b82364e3371e5d098ed89b7789d8e134.pdf
AUT Journal of Electrical Engineering
2588-2910
2588-2910
2011
43
1
A Novel Reconfiguration Mixed with Distributed Generation Planning via Considering Voltage Stability Margin
M. H.
Hemmatpour
M.
Mohammadian
M.
Rashidinejad
In recent years, in Iran and other countries the power systems are going to move toward creating a competition structure for selling and buying electrical energy. These changes and the numerous advantages of DGs have made more incentives to use these kinds of generators than before. Therefore, it is necessary to study all aspects of DGs, such as size selection and optimal placement and impact of them on Distribution System (DS) reconfiguration. So, the problem of optimum reconfiguration and optimal location of DGs (DGs Planning) in DS is a task which must be solved in an optimal manner. This paper presents a novel approach for optimum reconfiguration and optimal location of DGs in distribution networks based on a hieratical two-stage optimization problem to improve power system voltage stability margin and reduce active power losses. Hence, a toolbox has been developed to recognize loadability limit of distribution power systems based on Lagrangian optimization method. Finally, the simulations are carried out on 33, 69 bus IEEE distribution systems and demonstrate the validity of the proposed method.
Distribution System (DS)
Distributed Generations (DGs)
Graph Theory (GT)
Harmony Search (HS)
Hierarchical Optimization
Loadability limit
Matroid Theory
Reconfiguration
Voltage Stability (VS)
2011
04
01
23
34
https://eej.aut.ac.ir/article_85_0caa4957937a94ddcf995e24f42e5389.pdf
AUT Journal of Electrical Engineering
2588-2910
2588-2910
2011
43
1
A Low Power Low Voltage Rail to Rail Constant gm Differential Amplifier with 150 dB CMRR and Enhanced Frequency Performance
Leila
Safari
Seyed Javad
Azhari
This paper proposes a low voltage (±0.55V supply voltage) low power (44.65µW) high common mode rejection ratio (CMRR) differential amplifier (d.a.) with rail to rail input common mode range (ICMR), constant transconductance (gm) and enhanced frequency performance. Its high performance is obtained using a simple negative averaging method so that it cancels out the common mode input signals at the same input terminals while preserving high frequency operation. The principle of operation, small signal analysis and the formula of its most important parameters are explained and derived. Simulation results with HSPICE using TSMC 0.18µm CMOS are presented showing rail to rail operation, CMRR of 150dB, voltage gain of 31.6dB, gain bandwidth of 95.8 MHz and input referred noise of 100.64nv/√Hz. Compared to conventional amplifier ones those are 94.4dB , 3.4dB, 1.62 times and 1.72 times better, respectively. The CMRR corner case simulation results are also provided showing from 52.1dB to 74.6dB improvement over conventional one.
High CMRR Differential Amplifier
Low Voltage
low power
Rail to Rail
Quasi Floating Gate
2011
04
01
35
44
https://eej.aut.ac.ir/article_86_1ad880a24eba6ebfa3a9a8d9f3014a17.pdf
AUT Journal of Electrical Engineering
2588-2910
2588-2910
2011
43
1
A Novel ±0.5V Ultra High Current Drive and Output Voltage Headroom Current Output Stage with Very High Output Impedance
Hassan
Faraji Baghtash
Ahmad
Ayatollahiii
Khalil
Monfaredi
A novel ultra-high compliance, low power, very accurate and high output impedance current output stage (COS) with extremely high output current drive capability is proposed in this paper. The principle of operation of this unique structure is discussed, its most important formulas are derived and its outstanding performance is verified by HSPICE simulation in TSMC 0.18µm CMOS, BSIM3, and Level49 technology. This deliberately composed structure utilizes a well combination (for a mutual auto control action) of negative and positive feedbacks to achieve ever demanded merits such as very low power of 150µW, ultra high ratio of 3000 for output current over the bias current (which is selected to be 0.5µA) at low THD of -20dB and very high output impedance of 5GΩ with power supplies of ±0.5V when operating at class AB mode. Simulation results with ±0.5V power supply shows an absolute output voltage dynamic range of 0.9V which interestingly provides the highest yet reported output voltage compliance for Current mode building blocks implemented by regular CMOS technology. Full process, voltage, and temperature variation (PVT) analysis of the circuit is also investigated in order to approve the well robustness of the structure. The transient stepwise response is also done to verify the proposed COS stability.
Ultra-low voltage
Ultra-high compliance
Current output stage
Current amplifier
Class AB
High current capability
High output impedance
Low THD
2011
04
01
45
53
https://eej.aut.ac.ir/article_87_309d734118352dbc15fd418685446246.pdf
AUT Journal of Electrical Engineering
2588-2910
2588-2910
2011
43
1
Design and Construction of a Novel Tactile Sensor for Measuring Contact-Force, Based on Piezoelectric Effect
N.
Nasserii
S.
Najarian
A.
Tavakoli Golpaygani
G.
Darb Emamieh
In this paper, design and construction of a tactile sensor for measuring contact-force is presented. Mechanism of measuring contact-force in this tactile sensor is based on impedance changing of piezoelectric crystal and voltage of different points in circuit as a result of applying force on the crystal. By considering a specific point in the circuit and recording the changes of its voltage, magnitude of applied force can be estimated. Structure of the sensor consists of a disk-shaped piezoelectric crystal that its diameter is 2 cm, its thickness is 2 mm and its resonance frequency is 135 kHz. This crystal is placed in a metal chamber. A spring is on the crystal on which a moving part is installed for applying force. One of the characteristics of the sensor is that its size and shape can be easily tailored to the different applications. By miniaturizing this sensor and using biocompatible materials, it is applicable in different fields of medicine such as minimally invasive surgery (MIS).
TACTLE SENSOR
Contact Force
Piezoelectric
2011
04
01
55
60
https://eej.aut.ac.ir/article_88_48e7a2e4415ff29141a4ed0200514111.pdf
AUT Journal of Electrical Engineering
2588-2910
2588-2910
2011
43
1
Analysis of the Frequency Effects on Design and Back-Iron Characteristics of Double-Layer Secondary Single-Sided Linear Induction Motors
A.
Shirii
A.
Shoulaieii
Input frequency is one of the important variables in design and performance analysis of single-sided linear induction motors (SLIMs). Changing the frequency changes both the dimension of the SLIM in design process and the performance of the designed motor. The frequency influences the induced eddy currents in the secondary sheet as well as saturation level of the secondary back-iron. In this paper, the effect of the input frequency on the dimensions of the SLIM is investigated in the design process. Then, the frequency effects on the magnetic characteristics of the secondary back-iron as well as the SLIM performance are analyzed for a designed motor. Finally, the analytical results are confirmed by 2D time-stepping finite element method.
Input frequency
secondary back-iron saturation
EFFICIENCY
power factor
normal force
output thrust
2011
04
01
61
68
https://eej.aut.ac.ir/article_90_9d72c806e69b43cffc1e7df29edfbb4b.pdf