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Agriculture drones face important challenges regarding autonomy and construction, as flying time below the 9-minute mark is the norm, and their manufacture requires several tests and research before reaching proper flight dynamics. Therefore, correct design, analysis, and manufacture of the structure are imperative to address the aforementioned problems and ensure a robust build that withstands the tough environments of this application. In this work, the analysis and implementation of a Nylamid motor bracket, aluminum sandwich-type skeleton, and carbon fiber tube arm in a 30 kg agriculture drone is presented. The mechanical response of these components is evaluated using the finite element method in ANSYS Workbench, and the material behavior assumptions are assessed using a universal testing machine before their implementations. The general description of these models and the numerical results are presented. This early prediction of the behavior of the structure allows for mass optimization and cost reductions. The fast dynamics of drone applications set important restrictions in ductile materials such as this, requiring extensive structural analysis before manufacture. Experimental and numerical results showed a maximum variation of 8.7% for the carbon fiber composite and 13% for the Nylamid material. The mechanical properties of polyamide nylon allowed for a 51% mass reduction compared to a 6061 aluminum alloy structure optimized for the same load case in the motor brackets design. The low mechanical complexity of sandwich-type skeletons translated into fast implementation. Finally, the overall performance of the agriculture drone is evaluated through the data gathered during the flight test, showing the adequate design process. [ABSTRACT FROM AUTHOR]

The present paper addresses linear parameter-varying systems with high-order time-varying parameter dependency known as polynomial LPV systems and their controller design. Throughout this work, a procedure ensuring a state-feedback controller from a parameterized linear matrix inequality (PLMI) solution is presented. As the main contribution of this paper, the controller is designed by considering the time-varying parameter rate as a tuning parameter with a continuous control gain in such a way that the closed-loop eigenvalues lie in a complex plane subset, with high-order time-varying parameters defining the system dynamics. Simulation results are presented, aiming to show the effectiveness of the proposed controller design. [ABSTRACT FROM AUTHOR]

This paper shows the implementation of the Moth–Flame Optimization algorithm in a Cascade-H multilevel inverter with five and seven levels to determine the optimal switching sequence of the inverter's semiconductor devices. The algorithm was coded in Matlab software, and the obtained switching sequences were implemented in a Cascade-H multilevel inverter laboratory prototype, where the output voltage waveform was obtained using a digital oscilloscope. The experimental Total Harmonic Distortion was obtained using a power quality analyzer. The experimental results show the improvement of the Total Harmonic Distortion in the voltage output. These results were compared with other papers in the literature with different metaheuristic methods concerning the same modulation. These findings demonstrate the feasibility of employing the Moth–Flame Optimization Algorithm to significantly reduce the Total Harmonic Distortion, obtaining a lower value than most analyzed papers. [ABSTRACT FROM AUTHOR]

This paper addresses the challenge of evaluating control structures for a salt extractive distillation column producing absolute ethanol for use as biofuel. A sensitivity analysis aided with designing a pseudo-binary distillation pilot plant and examining the conceived process and the influence of the reflux ratio on both product purity and energy consumption. We compare three control structures for inferential tracking of the distillate composition: a dual-temperature control with an RV (reflux/boilup) structure and two single-end temperature control configurations, and their performance is measured using deterministic indicators. The result is the proposal of a pilot plant design for treating 15 kg/h of a diluted mixture with mole fraction of ethanol equal to 0.2 and assuming a column efficiency of 50%. The R/F (reflux to feed ratio) configuration is the best control structure, given that its corresponding performance indicators conduct lowest steady-state errors, less oscillating responses, and reduced settling times. For this configuration, the reflux flow rate is rationed to the feed flow rate, and the temperature is controlled manipulating the distillate flow rate. Even subject to perturbations, the energy consumption of the plant remains close to the nominal value. The three evaluated control structures consistently met international quality standards for fuel ethanol and enhanced the use of salts in ethanol dehydration. [ABSTRACT FROM AUTHOR]