ToF measurement based novel top edge detection algorithm for a smart security system

This paper describes a security system capable of identifying the presence of moving object using ultrasonic sensor, without human intervention. A constrained optimization of the Time of Flight (ToF) technique is employed to obtain the reflected pulses that are easily detectable by means of threshold comparator. Converting the ultrasonic sensor's output into predefined value based on ToF and our novel Top Edge Detection (TED) algorithm, the system is able to fix a position from where CMOS image capturing sensor can capture an instance of image of the object

Design and synthesis of PID controller based on fuzzy

This paper describes the hardware implementation of a PID-type (Proportional- Integral - Derivative) Fuzzy Logic Controller (FLC) algorithm using VHDL to use in transportation cruising system. The cruising system has developed to avoid the collisions between vehicles on the road. The PID-type FLC provides a reference for a car to either increase or decrease the speed of the vehicle depending on the distance of the preceding vehicle when it gets too close or alert the driver when necessary. The PID-type Fuzzy Controller algorithm is first developed using Matlab platform. The Mamdani Fuzzy Inference is studied and applied to design the PID-type Fuzzy controller hardware system. The controller system then is implemented using VHDL. The synthesis tool, Quartus II is used to synthesize the VHDL codes to obtain the Register Transfer Level (RTL) view of the FLC hardware. The motivation in designing is the Fuzzy based PID cruising controller is cheaper controller in cost compare to conventional PID controller system and thus make it available to the entry-level vehicles such as the national car. This can be further reduced the road accident and ensure the safety of the road users in the future

FPGA realization of mobile robot controller using fuzzy algorithm

This paper describes a Fuzzy Logic Controller (FLC) algorithm for designing an autonomous mobile robot controller (MRC). The controller enables the robot to navigate in an unstructured environment and that avoid any encountered obstacles without human intervention. The autonomous mobile robot is found to be able to react to the environment appropriately during its navigation to avoid crashing with obstacles by turning to the proper angle while moving. The Fuzzy Logic algorithm has proven a commendable solution in dealing with certain control problems when the situation is ambiguous. One of the main difficulties faced by conventional control systems is the inability to operate in a condition with incomplete and imprecise information. As the complexity of a situation increases, a traditional mathematical model will be difficult if not impossible to implement. Fuzzy Logic is a tool for modeling uncertain systems by facilitating common sense reasoning in decision-making in the absence of complete and precise information. In this paper, the controller of an autonomous mobile robot is designed based on the theories of Fuzzy algorithm. The wheeled robot is able to navigate by itself in a completely unstructured environment. The codes of MRC has written for implementing the separate modules of the Fuzzifier, Fuzzy Rule Base, Inference mechanism and Defuzzifier as hardware blocks. A behavioral model of MRC algorithm is first developed in MATLAB platform with numerous data to evaluate its algorithm functionality. The development of MATLAB codes has converted into VHDL codes for hardware implementation. Comparison results between MATLAB and VHDL of MRC algorithm also have presented. Then the VHDL codes are synthesized to get MRC hardware blocks using synthesis tool, Quartus II from Altera environment. Finally the designed codes of MRC algorithm has been downloaded into FPGA board for verifying the functionality of algorithm for VLSI implementation

Zinc Oxide Nanoparticles for Removal of Arsenic from Water

Removal of arsenate, As(V) from water was achieved using zinc oxide nanoparticles. The nanoparticles were synthesised from zinc acetate dihydrate and sodium hydroxide (NaOH) using the wet chemical sol-gel method. Different synthesis parameters were explored; including different ratios of Zn:NaOH and calcination temperatures. The synthesised samples were subsequently characterised and tested to investigate the adsorption capabilities of ZnO towards As(V). The colourimetric approach was utilised to analyse the samples’ performance. The particles had a relatively large average size as tested by the nanoparticle size analyser and the X-Ray Diffraction (XRD) characterisation of the samples confirmed the formation of ZnO. The peaks were narrow with high intensity, which indicates a larger crystal size and stable crystallinity. The samples showed a linear trend of increased adsorption capacity with the contact time. However, as indicated by the XRD and nanoparticle size analyser results, the particles had agglomerated and this has caused the total surface area to shrink. In summary, ZnO nanoparticles were successfully synthesised and were successful in adsorbing As(V) with different percentages for each sample. The adsorption trend was clear with respect to the changing parameters

An integrated hybrid energy harvester for autonomous wireless sensor network nodes

Profiling environmental parameter using a large number of spatially distributed wireless sensor network (WSN) NODEs is an extensive illustration of advanced modern technologies, but high power requirement for WSN NODEs limits the widespread deployment of these technologies. Currently, WSN NODEs are extensively powered up using batteries, but the battery has limitation of lifetime, power density, and environmental concerns. To overcome this issue, energy harvester (EH) is developed and presented in this paper. Solar-based EH has been identified as the most viable source of energy to be harvested for autonomous WSN NODEs. Besides, a novel chemical-based EH is reported as the potential secondary source for harvesting energy because of its uninterrupted availability. By integrating both solar-based EH and chemical-based EH, a hybrid energy harvester (HEH) is developed to power up WSN NODEs. Experimental results from the real-time deployment shows that, besides supporting the daily operation of WSN NODE and Router, the developed HEH is capable of producing a surplus of 971 mA·hr equivalent energy to be stored inside the storage for NODE and 528.24 mA·hr equivalent energy for Router, which is significantly enough for perpetual operation of autonomous WSN NODEs used in environmental parameter profiling

Recent advances in utilization of graphene for filtration and desalination of water: A review

Water as a basic necessity is an influential factor in our everyday lives but water pollution, urbanization, and huge population growth has led humankind to the brink of water resource scarcity. To address this issue, water filtration as well as desalination got enormous interest by the research community. Recently graphene, a new two dimensional material with exceptional capabilities and characteristics, has become apposite in the field of water filtration and desalination. This paper reviews the recent progress in Graphene research for water desalination using novel methods such as Nanoporous Graphene (NG) sheets as well as Capacitive Deionization (CDI) method. Among which most promising uniform NG sheets can be used for water filtration and desalination at a removal efficiency of 33–100% depending on the pore size as well as the applied pressure [1] and has a water flow rate of 10–100 L/cm2/day/MPa [1] and by adjusting the pore size, different mineral filtrations can take place [1]. The main drawback which limits the widespread utilization of NG is the mechanical stability of NG sheets as the pore number increases since water permeability is directly proportional to the number of pores, pore distribution as well as the mass production of graphene sheets which has not been solved [1,2]. Apart from this, in CDI method, filtration is done by applying a certain potential difference between arrays of paired electrodes. The mentioned CDI method has moderate removal efficiency but has higher energy efficiency compared to the reverse osmosis method due to minimal energy requirement of only 0.1–2.03 kWh/m3 [3]. Graphene oxide based desalination is another emerging desalination method which is gaining popularity because of its ease of fabrication, industry scale production, and strong mechanical stability [4,5]. It uses the “ion sponging” effect and can block hydrated ions with a radius greater than 4.5 A°. But still this method should be further improved as small seawater salts are able to pass from the GO sieve [6,7]

Fabrication and Characterization of Graphene-on-Silicon Schottky Diode for Advanced Power Electronic Design

In this study, graphene-on-silicon process technology was developed to fabricate a power rectifier Schottky diode for efficiency improvement in high operating temperature. Trench-MOS-Barrier-Schottky (TMBS) diode structure was used to enhance the device performance. The main objective of this research was to study the effect of reduced graphene oxide (RGO) deposited on silicon surface for Schottky barrier formation and heat transfer in Schottky junction. The study showed RGO deposited on silicon as a heat spreader could help to reduce the effect of heat generated in the Schottky junction that leads to a leakage current reduction and efficiency improvement in the device. With comparison to the conventional metal silicide (titanium silicide and cobalt silicide), the leakage reduced by two-orders of magnitude when tested under high operating temperature (>100°C). TMBS rectifier diode that uses graphene-based heat spreader could produce highly reliable product able to withstand high temperature operating condition