ملخص البحث :

Finding the optimal path for a mobile robot in complex environments is a crucial part of automation. In this application, we seek a path that avoids obstacles inside the scene. This paper discusses the path planning problem in cases where 2D obstacles change their areas in stochastic form. The trade-off between shortness and safety of the path is captured by two objective functions: distance-based and risk-based objective functions. The Risk-based objective function describes how likely the suggested path avoids the obstacles. Particle swarm optimization (PSO) is employed to find the best path. A new set of parameters are introduced to the problem model to capture the stochastic nature of the environment. The range and behavior of these parameters are studied under different difficulty-level scenarios. The results show that the proposed approach can predict the stochastic changes in obstacles and plan a path that is simultaneously safe and short, as compared to the regular approach with a standard distance-only cost function. These results manifest the use of the proposed approach in environments where there are elastic objects that can block the path between two points.

ملخص البحث :

Checking fresh water quality cannot be done by using our naked eyes. People always use sensors to evaluate water quality. Here in Iraq, people cannot drink tank water which supplied by local water plant systems since it is not pure. In this paper, we implemented a WiFi based sensor to classify pure versus non-pure water. The sensor was built using the ubiquitous WLAN and Intel 5300 NIC with its modified firmware. The sensor uses the extracted Channel State Information (CSI) of the received WiFi signals, along with Machine Learning (ML) approaches in order to perform the classification process. Promising results were obtained, where the observed accuracies reached up to 98.8% in differentiating pure water from tank water. This paves the road for new type of water quality sensors which characterized by lower cost, less effort, and easier to implement.

ملخص البحث :

In this thesis, a Frequency Hopping Spread Spectrum (FHSS) System is designed and implemented in order to generate a higher hopping rate in comparison with previous works and to expose the capabilities of FHSS technique based on recent implementation methods. The implementation is based on two models. The first model is carried out by Matlab Simulink 2017b. While the other model is based on Field-Programmable Gate Arrays (FPGA) technique, where the model is designed and simulated by using Vivado IDE 2018.2 then implemented by ARTY 7 35T FPGA board. By using Matlab Simulink, the model is constructed to work on data rate of 1 Mbps and a hopping rate of 1600 hop/sec. Seven different hops are used with a spacing of 8 MHz between each other, hence the system occupies a band of 48 MHz. Also, BER calculations are performed for three modulations techniques which they are BFSK (Binary Frequency Shift Keying), CPM (Continuous Phase Modulation) and MSK (Minimum Shift Keying). Then three types of channels are tested by using the proposed model. These channels are AWGN, Rician and Rayleigh. After that, curves are plotted against Eb/No values, where BFSK modulation technique gave better performance than other two types of modulation. While, by using FPGA technique, the model is implemented by ARTY 7 35T board to work on a data rate of 1 kbps and a hopping rate of 2000 hop/sec. The hopping rate could be simply changed by manipulating HDL (Hardware Descriptive Language) code. The system is designed with 7 different hops with a spacing of 8 kHz form each other, hence the system occupies a band of 48 kHz. Also, the waveform of frequency hopping (FH) signal and spreaded signal are recorded using digital storage oscilloscope (DSO) model ATTEN ADS 1062CML. In addition to spectrum of each individual hop and spectrum of the FH signal is visualized by usingv spectrum analyzer model ED PSA-3000. Furthermore, the generated power report showed that only about 0.314 Watt is consumed by this system. While, the generated utilization report showed that less than half of the board resources are used to build this system. To sum up, FHSS technique shows a superior performance in combating jamming, since the Simulink model showed an accepted performance during AWGN channel. On the other side, by leveraging FPGA capabilities it is possible to implement a flexible FHSS system, since it is possible to modify the system characteristics just by doing some changes in HDL code. Moreover, the FPGA showed better performance than conventional controllers to build a FHSS in comparison with the previous work. Where it is capable of performing a higher number of hops per second due its parallel processing capability, in addition to the low power consumption by FPGA technique.