ABSTRACT This study presents lessons learned from a proof of concept evaluating the feasibility of using remotely piloted aircraft (RPA) for small cargo transport in offshore oil and gas operations in the Sergipe Basin, Brazil. Conducted by Petrobras in partnership with Speedbird Aero, the proof of concept involved 27 missions across 12 platforms and the Inácio Barbosa Maritime Terminal port, achieving up to 36% reduction in logistical service time and CO2 emissions. The analysis employed the Bowtie methodology in conjunction with the specific operational risk assessment (SORA) framework to evaluate operational risks. National Aeronautics and Space Administration (NASA) expertise over lessons learned and the Project Management Institute oriented framework for lessons learned were used to identifying critical factors such as environmental monitoring, airspace integration, electromagnetic interference, and contingency coordination with aeromedical flights. Technical insights include the use of portable anemometers, geofencing strategies, and moving baseline global positioning system (GPS) technology to mitigate navigation challenges. Operational recommendations emphasize improved information management, horizontal signage, and periodic team training. Results confirm the technical and economic viability of RPAs in offshore environments and highlight their potential contribution to advanced air mobility ecosystems like the research (safety assurance and integrity level II). These findings support the development of regulatory frameworks and integration protocols, reinforcing RPAs as a safe and scalable solution for logistics scenarios.
This paper presents the main results of a case study on the attitude control of a satellite launch vehicle using a novel model predictive control (MPC). Design and simulations were based on the Brazilian VLS-1 launcher during the maximum dynamic pressure regime. Such a model was characterized by a 16th-order state-space realization with asymmetrical and coupled attitude dynamics, bending modes, non-collocated sensor-actuator, actuator saturation, wind disturbances, and sensor noise. The idea was to recreate, from a control theory perspective, a scenario similar to the 1999 explosion of the VLS-1 V02, exploring the thesis that the intense vibratory regime could have contributed to the failure. It is demonstrated that when non-collocated sensor-actuator or measurement noise is introduced into the simulations, the control-loop performance degrades and stability may be lost with proportional-integral-derivative-based controllers. To overcome such problems, a new MPC technology is proposed, predictive minimum variance control with full state-feedback. The adopted methodology inherits the advantages of linear quadratic Gaussian with loop-transfer recovery and adds the enhancements of MPC to mitigate the effects of time delays. The results were compared to those obtained by applying a functional approximation of the PI-D controller once designed for the real VLS-1 launcher.
The objective of this study was to evaluate a shared regional airport site for Pato Branco and Francisco Beltrão, Paraná, Brazil, using airport site selection methodology. Ten sites were identified within a 550 km2 search area. Five were excluded because of obstacle or infrastructure constraints; the remaining sites were surveyed and ranked using the analytic hierarchy process. Thirty-three federal, academic, and regional experts assessed the criteria independently, and 18 judgments met the prescribed consistency threshold. Group priorities were compared using exploratory Wilcoxon–Mann–Whitney’s tests, and weight sensitivity was assessed one criterion at a time. Sites 2, 2C, and 2A were the three highest-ranked alternatives under every group-specific weighting scheme. The regional group assigned greater weight to earthmoving volume and land access than the federal and academic groups. Earthmoving volume accounted for 25–67% of the global weight, whereas the noise criterion did not discriminate among the sites. The conclusion was that the three-site short list was stable across stakeholder groups and more stable than its internal ordering.
This paper proposes an accurate mathematical model and a fault-tolerant control system (FTCS) with an adaptive neural network (ANN) observer that considers structural damage of an aircraft. Structural damage causes substantial variations in aerodynamic coefficients and mass properties. Due to these variations, the mathematical modeling of a damaged aircraft becomes highly challenging. Moreover, since the aircraft flight control system has a fixed architecture, changes in the aircraft model may lead to instability. In order to accurately model damaged aircraft, a new uncertainty term and a damage severity coefficient have been defined as damage parameters. Based on the proposed model, an FTCS is developed, which combines an ANN observer with a modified nonlinear dynamic inversion (NDI) controller. The ANN observer is utilized for real-time estimation of damage parameters. Afterwards, the dynamic inversion control law is reconfigured based on the estimated damage parameters. The simulation results demonstrate the impact of the uncertainty parameter on the flight control system and verify the effectiveness of the proposed method under damage to the vertical tail.
The specific surface area of a filler influences its dispersion and interaction with the rubber and consequently the properties of thermal insulation in aerospace components. However, its determination generally requires complex instrumental methods. Therefore, the development of simpler methodologies with equivalent or higher precision remains of scientific interest. This study investigates the application of Fourier transform infrared spectroscopy using near-infrared (NIR) reflectance and the more conventional diffuse reflectance for silica analysis, a filler widely used in polymeric formulations. The analyzed samples presented surface area values between 170 and 800 m2·g-1. Results showed a methodological error within the instrumental limit (2%), lower than that reported for conventional methods (4-7%). The NIR reflectance methodology based on the relative band (A5260/A4540) provided the most accurate results and can be considered a practical alternative to conventional gas adsorption techniques, enabling shorter analysis times, a feature that is particularly relevant for aerospace processes subject to demanding project schedules.
