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- Creator:
- Patil, Hrishikesh
- Description:
- MEMS (Micro-electro-mechanical systems) gyroscopes are widely used as an inertial measurement unit in different industrial applications. MEMS are the device that combines mechanical and electrical components on a small silicon wafer with components sized in the range of a micro meter. Amongst all the gyroscopes available, vibratory gyroscopes are most simple in construction and are widely used. In vibratory rate gyroscope, sensitivity is achieved by reducing frequency mismatch and this is mostly done by selecting the common beam topology. However, due to the common beam, mechanical coupling effect is introduced, which might affect the overall stability of the device. Thus, this is a challenging part for a designer to achieve higher sensitivity, while maintaining stability. In this thesis a new 2-DOF vibratory rate gyroscope is proposed that has two independent axis of vibration with a mechanical coupling measure. Design includes selection of structural parameter, as well as driving and sensing topology. The structural design parameters of drive and sense beams are carefully selected so as to achieve maximum sensitivity, while reducing the overall coupling between the drive and sense mechanism. The design showed improved decoupling and sensing sensitivity. From the simulation, the displacement sensitivity is in the range of 3nm/(°/sec) and capacitance change is in the range of femto Farad. Furthermore, the angular rate table and capacitance results are provided in this paper to verify device performance.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
- Creator:
- Alsemaan, Mohammad
- Description:
- Solar energy is probably the most abundant renewable energy which is of great importance to fundamentally solve the energy crisis problem if can be harvested extensively and efficiently. This dissertation reviews the solar energy conversion systems and focuses on analyzing and developing high efficiency single-stage three-phase solar inverter system. Firstly, the recently developed material for solar cell is reviewed, and the solar model is derived, as well as solar string model. Based on the output put characteristic of solar string, the current state-of-art MPPT technologies are discussed and the P&O method is adopted for simplification purpose. Then the system design of solar inverter is fully is performed. The hardware design provides the detail design guidelines for most key components and provide suggested component in the market for prototype construction. The latest GaN device is adopted to improve efficiency and six-channel compact driving chip is used to reduce converter size. After that, the control loop design for three-phase inverter is detailed, with current loop and voltage loop illustrated respectively. Finally, the simulation results for control loop design and MPPT control are provide to verify the feasibility of the previous design. Based on the structure of selected system and new semiconductor device adopted, potential high efficiency solar conversion system can be expected.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
- Creator:
- Mohamed, Wurod Qasim
- Description:
- Advanced wireless communication systems are expected to support high data rates and reliable transmission. A key technology that achieves the required high spectral efficiency is the application of Multiple-Input Multiple-Output-Orthogonal Frequency Division Multiplexing techniques. MIMO systems use multiple transmit antennas to send a signal to the multiple receive antennas exploiting multipath propagation. The OFDM technique is applied to combat the frequency-selective fading environments and to increase the data rates The essential techniques used by MIMO to improve the performance of the wireless communication systems are spatial multiplexing and space time coding. In this thesis, I investigate and develop a signal detection and decoding technique called parallel processing decoding algorithm. The technique uses BPSK and QPSK modulations in Rayleigh flat fading environments and frequency-selective fading channels. Using a parallel decoding algorithm, the receiver can extract all received symbols independently and simultaneously. This technique increases processing speed and prevents error propagation at the receiver, present in other decoding techniques. The key advantages of parallel both a higher channel capacity and a better signal to noise ratio, are achieved. Also, it was seen that the bit error probability, BER, of the proposed decoding method decreases dramatically with increasing the difference between receive and transmit antennas number.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
4. Investigation on the Use of Graph Signal Processing for an Intelligent Taxis Transportation System
- Creator:
- Al-attabi, Ali Khalaf Nawar
- Description:
- This thesis demonstrates the benefits of using Graph Signal Processing (GSP) techniques for an intelligent taxis transportation system. Graph Signal Processing, an application arising to handle multiple source signals on a graph, has developed into an active field of research during the last several years due to its ability to analyze enormous datasets or dynamic data that usually pose a challenge to researchers. One of the most significant operations of Graph Signal Processing that arises in many areas is noise reduction. This thesis introduces a possible method of using Graph Signal Processing and its operations to analyze signals in a network of taxi stand locations. Two examples are given using real data of taxis' and stands' locations in San Francisco where the number of taxis around these stands is the detected signal. The results showed the effectiveness of using Graph Fourier Transform to detect the anomalies in the signals which represent unusual transportation activities or driver distributions within the taxi network. Signal denoising is addressed by using four techniques which are often based on the signal filtering methods. The first technique used the low pass filter, followed by a harmonic decline filter, and then standard and modified Kalman filters, including the case for uncertain observation or process noise between the standard and adaptive Kalman filters. The results are compared with the other filters.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
- Creator:
- Strobel, Ryan
- Description:
- In some special cases, locations of wireless devices within buildings must be determined with reasonable accuracy. Consider the World Trade Center disaster on 9/11/2001. First Responders were spread throughout the World Trade Center without an effective means of command and control. Leaders had no way of knowing where individuals were and, hence, where to direct help. GPS is the most common method used to determine location, but GPS is largely ineffective within buildings due to multipath and obstructed line of site (OLOS) conditions. Another method for location determination uses time of arrival (TOA) measurements on communication signals transmitted from known locations. Three or more TOA measurements allow the receiver’s location to be estimated (trilateration). This method works best in flat, open environments; however, performance depreciates in OLOS environments such as inside buildings. In OLOS environments, signals propagate through multipath. This thesis investigates the location of wireless devices within building. The TOA error caused by multipath and OLOS conditions is modeled as a random variable with a probability distribution that is a weighted sum of a combination of Gaussian and exponential functions. Kalman filtering techniques are then used to mitigate the effects of TOA error and estimate the true location of the receiver. The results show that the position of a wireless device within a building can be accurately estimated.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
- Creator:
- Mhawesh, Mustafa Azzam Naji
- Description:
- This thesis builds on a recently developed Failure Recovery Synthesis (FRS) technique for robotic manipulators, which is mounted on a movable platform to achieve an originally specified task after an arm joint failure. The FRS locks in place the failed arm joint and determines a new position for the base of the arm and a new grasping location for the end-effector. This work aims towards improving the trajectory planning technique of the FRS in order to generate optimal reaching motions in case of an arm joint failure. Aiming towards improving the robotic trajectory planning technique in the FRS, the work adopts previous results from experimental observations on human elbow constrained reaching movements. The assumption that the end-effector of an elbow locked anthropomorphic robotic manipulator is in contact with a specific surface during the entire movement allows us to describe the contact conditions by using higher order kinematic constraints such as velocities, accelerations, and jerks. By adopting contact specifications at initial and final task locations, kinematic synthesis and path planning techniques enable us to generate an entire end-effector trajectory connecting the two locations. The proposed method was validated by comparing its outcome to an actual human elbow-constrained reaching motion profile. The results show a smooth trajectory that closely follows the human hand path.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
- Creator:
- Sultan, Gazi
- Description:
- Even though the term digital modulation signifies modulating an analog time-continuous carrier-wave based on digital binary data, the signal processing is still carried out by analog signal-processing blocks. in this thesis, a novel Direct Digital Frequency Synthesizer (DDFS), targeted for CMOS implementation as an alternative to traditional PLL used for digital modulation, has been proposed. the novel DDFS integrates a discrete-sinewave generation-logic, based on the quarter-wave symmetry of a sinusoidal wave. It provides spurious improvement comparable to that of a DDFS incorporating a full-wave sine-LUT. the proposed DDFS architecture allows one to design distinctive modulator circuits for BPSK, DBPSK, QPSK, π/4-DQPSK, BFSK, and MFSK modulation schemes. Such modulators perform most of the signal-processing in the digital domain, without having to rely on multiple frequency-generators and other analog processing blocks which are used in traditional digital modulation schemes. in other words, the thesis aims to show how the proposed DDFS structure can be exploited to implement digital modulators. the thesis makes a successful attempt to render the digital modulation process as “all-digital” or “truly-digital” as possible without having to rely much on analog parts. Thus, the work presented here can be considered as an approach to transforming or embedding the digital modulators on to a single chip. Furthermore, at the end of the thesis, a novel architecture for a frequency-hopping π/4-DQPSK spread-spectrum transmitter has been modeled.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
- Creator:
- Al-sharqi, Mutasem
- Description:
- Wireless Power Transfer (WPT) is a field of science where energy can be transferred between two points (such as from a power source to an electrical load or consuming device) to charge electronic devices wirelessly. Examples of such electronic devices are cellphones, portable computers (laptops), integrated circuits, light emitting diodes, and electric vehicles. WPT can avoid the disadvantages of the traditional charging systems such as the need to plug electronic devices continuously to the power outlet, power failure due short circuits, and dangerous battery materials. The advantages of WPT in comparison to the wired system include reducing the copper material, which is necessary to make cables, transmit power to isolated areas (deserts, mountains, and islands) where wired transmission is very difficult to implement, and the reduction of expenses. Wireless transmission is beneficial in cases where using cables or attached wires can be dangerous or unavailable. This thesis focuses on finding solutions to problems that the WPT systems face, finding a valid distance range for Friis’ equation, choosing the best power distribution, and improving the overall WPT system. MATLAB® program was used to calculate the predicted results for far-field WPT. By looking at the results, it is safe to conclude that the directed WPT is much more convenient in terms of transmitting covered distance and the Beam Efficiency compared to the isotropic WPT.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
- Creator:
- Mangukiya, Yamik
- Description:
- Nearly 1 in 50 are affected by paralysis, which restrains the free movements of human body parts. Paralyzed individuals require support systems that can aid motion and enhance body parts in order to do common Activities of Daily Living (ADL). the most commonly used assistive systems are prosthetic and orthotic devices. Prosthetics are artificial extensions used to replace the missing body parts or supplement the paralyzed body parts. Orthotic devices are external mechanical structures that support non-functional body parts, which are actuated by motors. This study presents an orthotic robotic arm that can help in retraining flexion and extension movements of the forearm of the person affected by stroke. an Orthotic Robotic Arm (ORA) is a rigid brace, which has two Degrees of Freedom (DoF) and is used to restore the function of the forearm by enabling individuals with paralysis to self-initiate and control movement of their partially paralyzed forearm using muscle signals. a series of experimental trials (n = 5) were conducted using two subjects and an 80% accuracy was achieved. Preliminary results suggest that the ORA has the potential to improve the mobility of hand movements of paralyzed individuals.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering
- Creator:
- Deng, Ping
- Description:
- This paper brings forth a smart automatic lighting system (SALS) by expatiating on designing theories together with implementation approaches. This system was designed to realize the goal of cutting down the amounts of electricity usage in people’s daily life. The main enhancement deals with controlling lights that depend on current light intensity inside room and human existence for the purpose of gaining the optimal efficiency of power saving. In respect of automatic control technology, this paper segregates the central control unit into five modules: automatic control module, PIR detection module, lighting intensity detection module, modes switching module, and LCD 1602 display module. System takes AT89S51, a typical 51-type microcontroller as its controlling core. AT89S51 performs the function of turning on/off the lighting unit by receiving the signals from PIR sensor as well as lighting intensity sensor. This paper covers the hardware design together with its corresponding software application on each module, including electronic circuits and software codes. On simulation modeling stage, I have put to use software of Proteus and Keil C51 for realizing all of the fundamental actions of this system on screen. This testing processing aims at making sure that all design structures and circuits are correct and reasonable.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Electrical Engineering