In this paper, a particle swarm optimization (PSO) method is proposed to design Quantitative Feedback Theory (QFT) control. This method minimizes a proposed cost function subject to appropriate robust stability and performance QFT constraints. The PSO algorithm is simple and easy to implement, and can be used to automate the loop shaping procedures of the standard QFT. The proposed method is applied to the high uncertainty pneumatic servo actuator system as an example to illustrate the design procedure of the proposed algorithm. The proposed method is compared with the standard QFT control. The results show that the superiority of the proposed method in that it can achieve the same robustness requirements of standard QFT control with simple structure and low order controller.

Power line communication (PLC), a technology that uses the existing infrastructure for electric power for the provision of data, is fast becoming the choice for smart grid system. As good a choice as the PLC is for smart grid applications, it has some characteristics that poses hazards to signal transmitted through it. The topology of the power network (star) poses challenges of attenuation and multipath to high-speed signal transmission. The noise in PLC is not only AWGN as in other communication system but also impulsive. In this paper, selective relaying is considered for improving the reliability of the power line cooperative communication system. Selective relaying was implemented in both amplify-And-forward and decode and forward links on the PLC. Best channel SNR was the selection criterion for the best relay. Performances of symbol error rate and channel capacity was compared for fixed and selective relaying cooperation on the PLC system. Over a specified SNR range, the selective amplify-And-forward achieved a 6% SER improvement over the fixed relaying, while 1% SER improvement was achieved by the selective relaying over the fixed relaying on the decode-And-forward link. The channel capacity performance comparison reveals that the selective relaying in all scenarios in PLC achieved appreciable improvement on both cooperative protocols than in the fixed relaying.

In this paper a fuzzy logic controller was developed for a parabolic dish antenna system. Friction is one of the disturbances associated such systems and was represented with dead zone in the Simulink block. The effect of the disturbance due to the friction was investigated by simulation using Simulink/MATLAB 2012a software. The results obtained from the system with the fuzzy logic controller were compared with the ones obtained with equivalent proportional derivative controller and it showed that with the fuzzy logic controller the system had better performance and also demonstrates its ability to reduce the effect of friction in parabolic antenna dish systems and most likely other nonlinearities in such systems.

A fuzzy logic based controller (FLC) was proposed for position control of a parabolic dish antenna system with the major aim of eradicating the effect backlash disturbance which may be present in the system. The disturbance is nonlinear and is capable of generating steady state positional errors. Simulation results obtained using SIMULINK/MATLAB 2012a were compared with those obtained when the controller was proportional-derivative controller (PDC). The fuzzy controller portrays that it has the capability of reducing the noise due to backlash and possibly others more than the proportional-derivative controller.