Abstract Active object recognition provides a mechanism for selecting informative viewpoints to complete recognition tasks as quickly and accurately as possible. One can manipulate the position of the camera or the object of interest to obtain more useful information. This approach can improve the computational efficiency of the recognition task by only processing viewpoints selected based on the amount of relevant information they contain. Active object recognition methods are based around h...
Abstract The Microsoft Kinect sensor is a low cost RGB-D sensor. In this dissertation, its calibration is fully investigated and then these parameters are compared to the parameters given by Microsoft and OpenNI. The parameters found were found to be di_erent to those given by Microsoft and OpenNI therefore, every Kinect should be fully calibrated. The transformation from the raw data to a point cloud is also investigated. Then, the Hough transform is presented in its 2-dimensional form. The ...
Abstract A 3-phase Z-source inverter has been researched, designed, simulated, built and tested. The purpose of the inverter is to deliver 3-phase 400 VAC from a DC supply that can vary over a range of 20 to 70 Vdc. This is done with a Zsource inverter topology which is a single conversion method with no additional DC to DC boost converter. A novel DSP control algorithm allows the inverter to achieve the following: · Run Space Vector Pulse Width Modulation (SV-PWM) for maximum DC bus voltag...
Abstract The characterization and classification of liquids through instrumentation is essential in many industries. As such, measuring the characteristics of liquids is not just useful as a control parameter within an industrial process; such measurements can also be used to classify the liquid. Such a sensor is especially practical if it can be connected in-line with the liquid to be measured, thus minimally influencing flow. A piezoceramic tube was studied in an attempt to produce a senso...
Abstract All real systems experience input saturation. Since the first proportional controller was implemented, systems have been susceptible to saturation. The introduction of the proportional-integral (PI) controller complicates matters further, since it reduces the steady state error to zero for zero-order setpoint tracking. This encompasses a fair portion of the implemented control strategies in the world. It is clear that saturation, by limiting the input state for the process, limits t...
Abstract Fractal image compression is a comparatively new technique which has gained considerable attention in the popular technical press, and inore recently in the research literature. The most significant advantages claimed are high reconstruction quality at low coding rates, rapid decoding, and "resolution independence" in the sense that an encoded image may be decoded at a higher resolution than the original. While many of the claims published in the popular technical press are cle...
Abstract Spread Spectrum systems are found in many flavours, used in many applications and have existed since the early days of radio communications. The properties of spread spectrum do however place restrictions on the design, and often make the implementation expensive and complex. When using spread spectrum to provide a basic communications infrastructure, many factors need to be considered. These indude supplying the appropriate technology at the right cost. To achieve this a trade-off ...
Abstract This thesis deals with the damping of electromechanical oscillations using Power System Stabilizers (PSS). The thesis focuses on three problems associated with the damping of these oscillations, namely the determination of the optimal locations of the PSS, the determination of the best control structure of the PSS and the design of robust PSS. We develop two new methods for determining the optimal locations of the PSS. These two methods are based on Total Modified Coupling Factors (T...
ABSTRACT The requirements of a standard 3-phase Induction Motor driven by a Voltage Source Inverter studied. A ful I 3-phase Variable Speed Drive and its controller have been designed, constructed and tested. Gate Turn-Off Thyristors used as the main switching elements in the Inverter stage of the Drive. The drive requirements of GTO's are studied in detai 1.
ABSTRACT The e-beam stimulated reaction, CdCI2(s) ---> Cd (s) + CI(g), has been studied in casmium chloride thin films between 303 and 483 K using 2-keV electrons. The dose required to make 90-nm-deep holes at 483 K is 3x10-3 C cm -2. Extrapolated dosing levels of 6x10-5 C cm -2 are expected. The use of CdCI2 as a positive-type electron resist in a new scheme is proposed. A working model, useful for considering the e-beam stimulated decomposition energetics and mechanism is briefly discussed.
ABSTRACT In this thesis, a current source inverter fed squirrel cage induction motor drive at constant air gap flux is presented. The drive scheme is conceived to take advantage of the short circuit withstand capability of the current source inverter and the ruggedness (even under harsh conditions) of the squirrel cage induction motor. The variable inverter input dc link current is derivable from either a controlled ac to dc converter or a controlled dc to dc converter. The constant motor air...
ABSTRACT Interior Permanent Magnet (IPM) motor is widely used for many industrial applications and has relatively high torque ripple generated by reluctance torque. Since the configuration of the stator has great influence on reluctance torque, different stator configuration is necessary to improve the torque performance of IPM motor. Natural variable modeling and performance comparison of Interior Permanent Magnet Motor with Concentrated winding (CW), Short pitched and Full pitched distribu...
ABSTRACT Condition monitoring of Electrical power equipment has attracted considerable attention for years. The aim of this work is to use Fuzzy logic (FL) Tool Box in building a simulation system that will diagnose all kinds of incipient faults, phase to phase fault and overloading in a transformer and monitor its conditions. Current and rate of change of current with time have been identified as the input variables, duly represented in the programme as “Error” and “Error-Dot”. ...
ABSTRACT In Nigeria, a satisfactory degree of reliability has not been attained in our power systems in recent times. The average duration of interruptions that customers experience is quite high and the degree varies from place to place. This is evident all around the nation, most especially in urban commercial cities. Previous researchers have focused on the assessment of power system reliability indices using different models. In this work, a computationally efficient modified linear con...
Abstract The electric vehicle relies on electric motors for propulsion. In this report, the case was made for the induction motor as a suitable candidate for this tractive application. Being able to control the electric motor invariably implies efficient control of the vehicle. This work reports the six-step operation of the constant volts/hertz (V/f) control technique for voltage fed induction motor drives. Mathematical equations supporting the principle is discussed and the drive is m...