Abdulrahman Yusuf
Verified @unilorin.edu.ng
University of Ilorin
RESEARCH, TEACHING, or OTHER INTERESTS
Computer Engineering, Electrical and Electronic Engineering, Biomedical Engineering, Engineering
Scopus Publications
Scopus Publications
Aye Taiwo Ajiboye, Jayeola Femi Opadiji, Abdulrahman Olalekan Yusuf, Olusogo Joshua Popoola, Esther Toyin Olawole, and Olalekan Femi Adebayo
Institute of Advanced Engineering and Science
The development of structured methods for proportional-integral (PI) controller design for systems with time delay are proposed in this article. Several PI controller design methods for time-delay systems have been reported. However, combining two or more methods to form new ones have not been given serious attention. The system stability region in the controller parameters space was determined by plotting the stability boundaries. In this study, the controller gains were first obtained using genetic algorithm (GA), weighted geometric center (WGC), and centroid of convex stability region (CCSR). Thereafter, these gains were combined by finding the centroids of lines joining any of the two gain locations, and triangle whose vertices are the location of the three gains in the convex stability region, thus yielding four additional methods, M1, M2, M3, and M4. Compared to a particular existing method, some of the proposed methods yield faster response speed at the expense of reference input tracking, while the reverse is the case for others. Any of the proposed methods (M1, M2, M3, and M4) can be selected depending on the system performance specifications.
Aye Taiwo Ajiboye, Jayeola Femi Opadiji, Olusogo Joshua Popoola, Abdulrahman Olalekan Yusuf, Olalekan Femi Adebayo, and Esther Toyin Olawole
Institute of Advanced Engineering and Science
Design of proportional-integral-derivative (PID) controller with proportional, integral, and derivative gains given by , and respectively, for time-delay systems is presented in this study. The centroid of the convex stability region (CCSR) method in the - plane for fixed is used. PID controller design for time-delay systems in the - plane for a fixed and - plane for a fixed have been extensively researched. Despite the amenability of CCSR method to design of PID controller in the - plane for fixed , its application in this regard has not been given serious attention. The stability region in - plane for fixed was determined and the required controller gains in the region were determined using the CCSR method. Using the determined controller gains, the system closed loop unit step response for all the considered regions was plotted on same axes. Based on the obtained results, different combinations of controller gains can be implemented depending on the system time domain performance measures (TDPMs) requirements. However, selection of an appropriate controller gains combinations, requires compromise among any of the conflicting TDPMs.
K.R. Kamil, A.O. Yusuf, S.A. Yakubu, and S.B. Seriki
African Journals Online (AJOL)
Majority of electricity generation in Nigeria comes from fossil fuels, with about two-thirds of thermal power derived from natural gas and the rest from oil, resulting in the emission of carbon dioxide (𝐶𝑂2). With the prevailing global climate change, shifting to renewable energy would reduce the greenhouse gas emission which would be the salvaging option to help our degrading environment. The aim of the resource’s hybridization process is to generate enough electricity that would help the supplementing for the inadequate electricity supply in the local province at the least detrimental effect on the environment. This work discusses the renewable energy potential of Nigeria and raises the possibility of having Nigeria electricity grid powered by small, medium and large-scale renewable energy systems. The hybridised power generation system simulations were done using HOMER simulation software. The hybridisation of the resources was able to generate 149,313 kWh/yr to adequately sustain the estimated electrical load of 126,027kWh/yr. Conclusively, cost effectiveness of the individual and hybridised systems was also considered.
Ajiboye A. T., Opadiji J. F., Yusuf A. O., and Popoola J. O.
Universitas Ahmad Dahlan
The MQ-series gas sensors are attractive candidates in the area of gas concentration sensing due to their high sensitivity and low cost. Even though the sensor circuit sensitivity and sensor power dissipation level both depend on load resistance, the process of the load resistance selection has not been well researched, hence the need for this study. The derivation of model equations for determining the sensor circuit sensitivity and sensor power dissipation is presented. The derived equations were used to investigate a typical scenario of MQ-6 gas sensor under the influence of liquified petroleum gas (LPG). The variation of sensitivity with load resistance and that of power dissipation with sensor resistance were parametrically investigated. The load resistance that yields maximum sensor circuit sensitivity with the maximum sensor power dissipation less than the set threshold is the candidate resistance for the sensor circuit. The 20 kΩ load resistance recommended for MQ-6 in the datasheet was authenticated in this study, yielding the maximum possible sensor circuit sensitivity and tolerable sensor power dissipation of 0.195 mV/ppm and 3.125×10−4 W, respectively.
A.T. Ajiboye, A.O. Yusuf, and A.R. Ajayi
African Journals Online (AJOL)
NigComSat-1R could be part of Networked Control Systems (NCSs) to link plants, controllers, sensors and actuators which may be distributed within the satellite footprints. Associated with NCSs is location-dependent time delay which can drastically reduce system Quality of Performance (QoP), or in the worst case lead to system instability. To ameliorate these effects, the network delay should be taken into consideration at design stage. In order to achieve this, the ranges of propagation time delay incurred within a particular footprint or between two footprints of NigComSat-1R are modelled, simulated, characterized and analyzed. It was observed that the minimum and maximum possible time delays between the boundary of NigComSat-1R footprints and the satellite are 0.1193 sec and 0.141 sec respectively. Also, the minimum possible propagation time delay between any two footprints is that between C-band ECOWAS 1 beam and itself with value of 0.2386 sec while the maximum possible propagation time delay between any two footprints is that between L-band Navigation payload L1 beam and itself or L-band Navigation payload L5 beam and itself with value of 0.2832 sec. Keywords: Footprint, networked control system, Nigcomsat-1R, propagation time delay, quality of performance