This work shows the utilization of a coaxial cable for the fabrication of a long period Bragg grating. The grating is fabricated removing the dielectric in short pieces of the cable so that the discontinuities account for the variation in the medium refractive index. Simulated and experimental results of the grating resonances are shown as a function of the scattering parameters S, demonstrating the feasibility of the technique. By using the sensor in the MHz frequency range cheaper electronics can be employed, which reduce the overall cost of the sensing system.
This work aims to analyze two metaheuristics optimization techniques, Genetic Algorithm (GA) and Particle Swarm Optimization (PSO), with six variations each, and compare them regarding their convergence, quality, and dispersion of solutions. The optimization target is the Gaussian Adaptive PID control (GAPID) to find the best parameters to achieve enhanced performance and robustness to load variations related to the traditional PID. The adaptive rule of GAPID is based on a Gaussian function that has as adjustment parameters its concavity and the lower and upper bound of the gains. It is a smooth function with smooth derivatives. As a result, it helps avoid problems related to abrupt increases transition, commonly found in other adaptive methods. Because there is no mathematical methodology to set these parameters, this work used bio-inspired optimization algorithms. The test plant is a DC motor with a beam with a variable load. Results obtained by load and gain sweep tests prove the GAPID presents fast responses with very low overshoot and good robustness to load changes, with minimal variations, which is impossible to achieve when using the linear PID.