Engineering

Permanent URI for this community

https://repository.elizadeuniversity.edu.ng/handle/20.500.12398/6

These are the scholarly outputs of the Faculty of Engineering

Browse

Now showing 1 - 20 of 331

Intelligent Control for Automation of Yam Storage System Using Fuzzy Logic Controller
(IEEE, 1985-06-01) Abdulazeez, Murtala; Salami, Momoh-Jimoh E.; Tijani, Ismaila B.
This paper presents the development of intelligent control technique for yam storage system based on fuzzy logic controller (FLC). The expert control of yam storage system is formulated in the form of fuzzy rules. The inputs to the controller are the outside and inside temperature, wind speed and presences of rain. The output is the window opening angle. Simulations were performed for different typical levels of input parameters and also for extreme fictitious conditions. The results shown that, the controller is capable of responding to the changes in temperature conditions by adjusting the window opening angle to keep the internal temperature within acceptable range. The controller also satisfies security requirements due to sudden changes in wind velocity and presence of rain.
Application of ARMA modeling to multicomponent signals
(Elsevier, 1985-07-01) Nichols, S. T.; Smith, M. R.; Salami, Momoh-Jimoh E.
This paper investigates the problem of estimating the parameters of a multicomponent signal observed in noise. The process is modeled las a special nonstationary autoregressive moving average (ARMA) process. The parameters of the multicomponent signal are determined from the spectral estimate of the ARMA model The spectral lines are closely spaced and the ARMA model must be determined from very short data records. Two high-resolution ARMA algorithms are developed for determining the spectral estimates. The first ARMA algorithm modifies the extended Prony method to account for the nonstationary aspects of noise in the model.For comPonents signals with good signal to noise ratio (SNR) this algorithm provides excellent results, but for a lower SNR the performance degrades resulting in a loss in resolution. The second algorithm is based on the work of Cadzow. The algorithm presented overcomes the difficulties of Cadzow's and Kaye's algorithms and provides the coefficients for the complete model not just the spen ral estimate. This algorithm performs well in resolving multicomponent signals when the SNR is low.
A SVD-based transient error method for analyzing noisy multicomponent exponential signals
(IEEE, 1987-04-06) Salami, Momoh-Jimoh E.; Nichols, S.; Smith, M.
The problem of estimating the parameters of noisy multicomponent signals using parametric modeling technique is considered in this paper. The multicomponent signal of interest is formed by a superposition of basic functions having the same location in time but different widths and amplitudes. Based on the modified Gardner transformation, some samples of deconvolved data are derived from the multicomponent signals. The deconvolved data are then modeled using a special nonstationary autoregressive moving average (ARMA) process in which the parameters of the ARMA model are obtained by linear least-squares procedure. The least-squares procedure is based on the singular value decomposition (SVD) to overcome the limitations of the transient error method (TEM) of analysis that uses cholesky decomposition to determine its AR coefficients. The moving average (MA) coefficients corresponds to the initial residual error sequences so as to account for the nonstationary noise in the deconvolved data. This new method of analysis, termed the SVD-based transient error method, produces high resolution estimates of the exponents of multicomponent signals at both low and high signal to noise (SNR) ratios.
Design, construction and testing of a dehuller for African breadfruit (Treculia africana) seeds
(Elsevier, 1999-11-01) Omobuwajo, T. O.; Ikegwuoha, H. C.; Koya, Olufemi A.; Ige, M. T.
The African breadfruit seed is a popular food resource in several parts of West Africa. It is presently being dehulled manually in the absence of a suitable mechanical device. A machine was designed in order to remove the drudgery involved in dehulling the seeds. The machine comprised of a roller which cracks the hull, an oscillating cam follower which removes the cracked hull through repeated shearing against a stationary wall, and an aspiration unit which sifts the hull from the endosperm. A prototype was constructed and tested. Throughput was 64 kg/h; yield, 75%; completely dehulled seeds, 85%; breakage, 1% and sifting efficiency was practically 100%.
Design of intelligent braking system
(IEEE, 2000-09-24) Sidek, S. N.; Salami, Momoh-Jimoh E.
It is anticipated that a variety of cars with diversified features that include anti-lock braking system (ABS), traction control system (TCS), antiskid Steering, collision warning system (CWS) will be more commercially produced to satis@ the consumer needs in the near future. This is parallel to the trend of current technology of manufhcturing smart cars and the &sires of people who always want to have comfortable and safe ride in their vehicles. Mower this type of vehicles can fit much better into the intelligent highway that Malaysian government is planning to have in the near future. Consequently, there is a need to modify the current conventional braking system so as to make it work automatically. This paper considers the use of intelligent controller to achieve the above objective. To ensure high speed of system response, the DSP controller TMS320C24x with - fuzzy algorithm is used in the implementation of this new device. Results of simulation studies using the MATLAB have demonstrated the feasibility of this new system under investigation.
Performance evaluation of the deconvolution techniques used in analyzing multicomponent transient signals
(IEEE, 2000-09-24) Salami, Momoh-Jimoh E.; Sidek, S. N.
Deconvolution is an important preprocessing procedure often needed in the spectral analysis of transient exponentially decaying signals. Three deconvolution techniques are studied and applied to the problem of estimating the parameters of multiexponential signals observed in noise. Both the conventional and optimal compensated inverse filtering approaches produce data which are further analyzed by SVD-based autoregressive moving average (ARMA) modeling techniques. The third procedure is based on homomorphic filtering and it is implemented by fast Fourier transform (FFT) technique. A comparative study of the performance of the above deconvolution techniques in analyzing multicomponent exponential signals with varied signal-to-noise ratio (SNR) is examined in this paper. The results of simulation studies show that the homomorphic deconvolution technique is most computationally efficient, however, it produces inaccurate estimates of signal parameters even at high SNR, especially with closely related exponents. Simulation results show that the optimal compensation deconvolution technique is indeed a generalized form of the conventional inverse filtering and has the potential of producing accurate estimates of signal parameters from a substantial wide range of SNR data.
Machine condition monitoring and fault diagnosis using spectral analysis techniques
(Proc. 1st Int. Conf. Mechatronics, 2001) Salami, Momoh-Jimoh E.; Gani, Asan; Pervez, T.
There is need to continuously monitor the conditions of complex, expensive and process-critical machinery in order to detect its incipient breakdown as well as to ensure its high performance and operating safety. Depending on the application, several techniques are available for monitoring the condition of a machine. Vibration monitoring of rotating machinery is considered in this paper so as develop a selfdiagnosis tool for monitoring machines’ conditions. To achieve this a vibration fault simulation rig (VFSR) is designed and constructed so as to simulate and analyze some of the most common vibration signals encountered in rotating machinery. Vibration data are collected from the piezoelectric accelerometers placed at locations that provide rigid vibration transmission to them. Both normal and fault signals are analyzed using the singular value decomposition (SVD) algorithm so as to compute the parameters of the auto regressive moving average (ARMA) models. Machine condition monitoring is then based on the AR or ARMA spectra so as to overcome some of the limitations of the fast Fourier transform (FFT) techniques. Furthermore the estimated AR model parameters and the distribution of the singular values can be used in conjunction with the spectral peaks in making comparison between healthy and faulty conditions. Different fault conditions have been successfully simulated and analyzed using the VFSR in this paper. Results of analysis clearly indicate that this method of analysis can be further developed and used for self-diagnosis, predictive maintenance and intelligent-based monitoring.
Design And Implementation of Dsp-Based Intelligent Controller For Automobile Braking System
(IIUM Engineering Journal, 2001) Sidek, S. N.; Salami, Momoh-Jimoh E.
An intelligent braking system has great potential applications especially, in developed countries where research on smart vehicle and intelligent highways are receiving ample attention. The system when integrated with other subsystems like automatic traction control, intelligent throttle, and auto cruise systems, etc will result in smart vehicle maneuver. The driver at the end of the day will become the passenger, safety accorded the highest priority and the journey optimized in term of time duration, cost, efficiency and comfortability. The impact of such design and development will cater for the need of contemporary society that aspires to a quality drive as well as to accommodate the advancement of technology especially in the area of smart sensors and actuators. The emergence of digital signal processor enhances the capacity and features of universal microcontroller. This paper introduces the use of TI DSP, TMS320LF2407 as an engine of the system. The overall system is designed so that the value of inter-vehicle distance from infrared laser sensor and speed of follower car from speedometer are fed into the DSP for processing, resulting in the DSP issuing commands to the actuator to function appropriately.
A LabVIEW based data acquisition system for vibration monitoring and analysis
(IEEE, 2002-07-17) Gani, Asan; Salami, Momoh-Jimoh E.
LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is gaining popularity as a graphical programming language, especially for data acquisition and measurement. This is due to the vast array of data acquisition cards and measurement systems which can be supported by LabVIEW as well as the relative ease with which advanced software can be programmed. One area of application of LabVIEW is the monitoring and analysis of vibration signals. The analysis and monitoring of the signal are of concern for fault detection and predictive maintenance. This paper describes LabVIEW based data acquisition and analysis developed specifically for vibration monitoring and used with vibration fault simulation systems (VFSS). On-line displays of time and frequency domains of the vibration signal provide a user-friendly data acquisition interface.
A LabVIEW based data acquisition system for vibration monitoring and analysis
(2002/7/17, 2002-07-17) Gani, Asan; Salami, Momoh-Jimoh E.
LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is gaining popularity as a graphical programming language, especially for data acquisition and measurement. This is due to the vast array of data acquisition cards and measurement systems which can be supported by LabVIEW as well as the relative ease with which advanced software can be programmed. One area of application of LabVIEW is the monitoring and analysis of vibration signals. The analysis and monitoring of the signal are of concern for fault detection and predictive maintenance. This paper describes LabVIEW based data acquisition and analysis developed specifically for vibration monitoring and used with vibration fault simulation systems (VFSS). On-line displays of time and frequency domains of the vibration signal provide a user-friendly data acquisition interface.
Prediction of received signal power and propagation path loss in open/rural environments using modified free-space loss and Hata models
(IEEE, 2002-12-02) Shittu, W. A.; Bajoga, B. G.; Anwar, F.; Salami, Momoh-Jimoh E.
This paper describes a modification of the Free-Space and Hata formulae for the prediction of received signal power, P R and propagation path loss, L P , in two cellular mobile radio systems (CMRS), in the Northern Nigeria. Measurements of P R s were taken with a Cellular Mobile Radio test Receiver (Sagem OT 160), in some selected open/rural environments, when the receiver was being moved away from the base stations along the propagation paths. L P s were then obtained from values of measured P R s using an appropriate expression. A close comparison of measurement values and computed values from the free-space and Hata formulae revealed that direct application of these formulae is inappropriate for the prediction of these parameters in the region of investigation, as computed values fell short significantly from the corresponding measured values. Consequently, some correction factors have been introduced to both models and these have produced results which closely matched the measured values.
Design and implementation of fuzzy-based PID controller
(IEEE, 2002-12-11) Salami, Momoh-Jimoh E.; Bulale, Y. I.
Conventional proportional integral derivative (PID) controller is widely used in many industrial applications due to its simplicity in StmctllIe and ease of design. However, it is difficult to achieve .the desired control performance in the presence of unknown nonlinearities, time delays, disturbances as well as changes in system parameters. Consequently several PID models have been suggested so at to alleviate these effects on the performance of the PID controllers. One such method is based on fuzzy logic technique which is considered much more appropri.ate when precise mathematical formulation is infeasible or difficult to achieve. Furthermore, some applications such as semiconductor packaging, computer disk drives, and ultra-precision machining require a fast and high precision processing. Consequently, there is the need to consider digital signal processor (DSI?)- based fuzzy PID for use in such applications. Design and implementation of such technique is proposed in this paper. Results of simulation studies haw demonstrated the feasibility of this controller since: it produces fast response with smooth motion control.
Development of mechatronics engineering degree program: challenges and prospects
(Tempus Publications, 2003-01-01) Salami, Momoh-Jimoh E.; Mir-Nasiri, N.; Khan, M. R.
It is now becoming common practice to include some courses in mechatronics in the traditional electrical and mechanical engineering programs. Whilst many engineering faculties have realized the need for a full-fledged multidisciplinary mechatronics engineering program, only in very few places have such programs been developed along the lines of other engineering programs. The justification for the mechatronics engineering program becomes evident, as today's engineers must be acquainted with subjects that are not taught or given much emphasis in the traditional engineering curriculum. A good knowledge in those subjects, is however required if our graduate engineers are to be relevant to industry with time. The challenges in developing such program in terms of curriculum planning, laboratory facility needs and staff requirements are discussed in this paper. Whilst there are immense advantages of such a discipline, its success depends on a balanced curriculum with good laboratory facilities and appropriate industrial links, positive attitudes and well-oriented academic staff as well as students having the ability to cope with diversified subjects.
Design and development of DSP-based hybrid controller for servo driver applications
(IEEE, 2003-06-25) Bulale, Yusuf I.; Salami, Momoh-Jimoh E.; Sulaiman, Marizan
A hybrid system involving the conventional proportional-integral-derivative (PID) controller and fuzzy-logic system for servo drivers needed in many motion control applications is examined in this paper. The importance of this approach is the tuning of PID controller using fuzzy logic system, which by so doing enhances the performance of conventional PID controller in terms of settling time, percentage overshoot and steady-state-error. Thus, this proposed system is meant to compensate for the poor performance of the PID controller as a result of various factors such as unknown nonlinearities, time delays, disturbances as well as changes in system parameters. The second part of this work is the implementation of the hybrid controller using digital signal processor (DSP) as this offers high speed, number crunching capability and the ability to produce a good accurate tracking with minimum time delay for many industrial applications such as power inverters, motion controllers, semiconductor packaging, computer disk drives, packaging assembly, high speed, high precise motion of material transfer and automotive control applications where some of these applications may require a fast and high precision processing. Both simulation results and hardware implementation of the proposed controller have shown the feasibility of this approach as it produces fast response and smooth motion control.
Active vibration control of a beam with piezoelectric patches: real-time implementation with xPC target
(IEEE, 2003-06-25) Gani, Asan; Salami, Momoh-Jimoh E.; Khan, R.
Active control of a vibrating beam using smart materials such as piezoelectric materials is examined in this paper. A model based on Euler-Bernoulli beam equation has been developed and then extended with bonded three piezoelectric patches which act as sensor, actuator and exciter. The sensor and actuator are collocated to achieve a minimum phase. The aim of this research work is to control the first three resonant modes. To achieve this, a compensated inverse PID controller is developed and tuned to damp these modes using MATLAB. The designed controller for damping each mode is then combined in parallel to damp any of the three modes. Finally, the simulation results are verified experimentally and the real-time implementation is carried out with xPC target toolbox in MATLAB.
Optimum joint profile for constrained motion of a planar rigid-flexible manipulator
(2003-07) Ata, Atef A.; Salami, Momoh-Jimoh E.; Johar, Habib
Dynamic system performance of a constrained rigid-flexible manipulator in contact with a circular surface is considered here. A dynamic model with zero tip deformation constraint is derived using extended Hamilton’s principle. An analytical approach for vibration of the flexible link using the assumed modes technique is presented. The effect the force exerted at the end-effector and the required joint torque is investigated through the solution of the inverse dynamics problem. Optimum system performance is suggested for the circular contact surfaces considered in this study using the minimum energy criteria for three joint motion profiles.
Active suppression of vibration modes with piezoelectic patches: Modeling, Simulation and Experimentation”
(Proceedings of the IASTED International Conference, APPLIED SIMULATION AND MODELLING, 2003-09-03) Gani, Asan; Salami, Momoh-Jimoh E.; Khan, R.
Active vibration control of the first three modes of a vibrating cantilever beam using piezoelectric patches is examined in this paper. A model based on Euler-Bemoulli beam equation is adopted and extended to the case of three bonded piezoelectric patches which act as sensor. actuator and exciter respectively. The sensor and the actualor are collocated to achieve a minimum phase. A compensated inverse PID controller has been designed and developed to damp these modes. Simulation studies are caried using MATLAB. Individual controller has been designed for each mode and then combined in parallel to damp any of the three modes. Finally, the simulation results are compared and verified experimentally and the real-tinie implementation is carried out with xPC talget toolbox in MATLAB.
Parameter estimation of multicomponent transient signals using deconvolution and arma modelling techniques
(Academic Press, 2003-11-01) Salami, Momoh-Jimoh E.; Sidek, S. N.
Parameter estimation of transient signals, having real decaying exponential constants, is a difficult but important problem that often arises in many areas of scientific disciplines. The frequency domain method of analysis that involves Gardner transformation and conventional inverse filtering often degrades the quality of the deconvolved data, leading to inaccurate results, especially for noisy data. An improved method that is based on the combination of Gardner transformation, optimal compensation deconvolution, and signal modelling techniques is suggested in this paper. In this method of analysis the exponential signal is converted to a convolution model whose input is a train of weighted delta function that contains the signal parameters to be determined. The resolution of the estimated decay rates is poor if the conventional fast Fourier transform (FFT) algorithm is used to analyse the resulting deconvolved data. Using an autoregressive moving (ARMA) model whose AR parameters are determined by solving high-order Yule–Walker equations (HOYWE) via the singular value decomposition (SVD) algorithm can alleviate this shortcoming. The effect of sampling conditions, noise level, number of components and relative sizes of the signal parameters on the performance of this modified method of analysis is examined in this paper. Simulation results show that high-resolution estimates of decay constants can be obtained when the above signal processing techniques are used to analyse multiexponential signals with varied signal-to-noise ratio (SNR). This approach also provides a graphical procedure for detecting and validating the number of exponential signals present in the data. Some computer simulation results are presented to justify the need for this modified method of analysis.
Hardware design, development and evaluation of a pressure-based typing biometrics authentication system
(Proceedings of the Eighth Australian and New Zealand Intelligent Information Systems Conference (ANZIIS), 2003-12) Eltahir, Wasil E.; Lai, W. K.; Salami, Momoh-Jimoh E.; Ismail, A. F.
The hardware design of a pressure based typing biometrics authentication system (BAS) is discussed in this paper. The dynamic keystroke is represented by its time duration (t) and force (F) applied to constitute a waveform, which when concatenated compose a complete pattern for the entered password. Hardware design is the first part in designing the complete pressure-based typing (BAS) in order to ensure that the best data to represent the keystroke pattern of the user is captured. The system has been designed using LabVIEW software. Several data preprocessing techniques have been used to improve the acquired waveforms. An experiment was conducted to show the validity of the design in representing keystroke dynamics and preliminary results have shown that the designed system can successfully capture password patterns.
An effective vision technique for microchip lead inspection
(IEEE, 2003-12-10) Mir-Nasiri, Nazim; Al-Obaidy, Haitham H. L.; Salami, Momoh-Jimoh E.; Amin, Shamsuddin
A new effective method for the microchip lead inspection for the chip manufacturing industry has been developed in this work. In contrast to the gray scale pattern matching technique this approach employs selected parameters of binary blobs to perform fault detection and measurements. This leads to a significant reduction of image processing time. A special combination of gray level filtering techniques with gray morphological operations enhances the borders of the lead images. Newly developed threshold calibration technique significantly improves the measurement accuracy. A unique statistical analysis has been developed to identify all possible lead defects in the chips. This method is rotationally and scale invariant and able to detect defective leads for the chips with different specifications. The minimum required information about the microchip is the number of leads.

Browse

Browsing Engineering by Issue Date

Results Per Page

Sort Options