Acoustic Doppler Current Profiler (ADCP) sensors measure water inflows and are essential to evaluate the Flow Curve (FC) of rivers. The FC is used to calibrate hydrological models responsible for planning the electrical dispatch of all power plants in several countries. Therefore, errors in those measures propagate to the final energy cost evaluation. One problem regarding this sensor is its positioning on the vessel. If placed on the bow, it becomes exposed to flowing obstacles, and if it is installed on the stern, the redirected water from the boat and its propulsion system change the sensor readings. To improve the sensor readings, this paper proposes the design of a catamaran-like Autonomous Surface Vessel (ASV) with an optimized hull design, aerial propulsion, and optimal sensor placement to keep them protected and precise, allowing inspections in critical areas such as ultra-shallow waters and mangroves.
The following topics are dealt with: control system synthesis; stability; nonlinear control systems; mobile robots; linear systems; feedback; discrete time systems; learning (artificial intelligence); variable structure systems; autonomous aerial vehicles.
It is known that new power transmission line inspection techniques have been developed over the last few years with great potential to improve and, in some cases, even replace traditional inspection procedures such as using helicopters and cars. A series of Unmanned Aerial Vehicles (UAVs) such as fixed-wing or rotary-wing UAVs, and vehicles that climb on the power transmission line, promise to revolutionize the inspection market. In this light, at least 39 new research studies and/or products have been conducted and/or introduced to the market, respectively. However, in an incipient way, some works point to the fusion of some technologies: the development of multi-rotor UAVs and the ability to connect and move over the power transmission line. In line with this, the current work was proposed, with significant unprecedented advances (such as an over-actuated control capacity with tilt rotors, the capability of a displacement in the angle, and the maintenance of active motors on the power transmission line), and the design, modeling, and control of an over-actuated UAV able to move over the conductor cable without the need for a new locomotion system is presented. The aircraft allows for a greater response and the indispensable ability to approximate landing in a power transmission line arbitrary position rather than the catenary lowest point (due to its ability to forward/backward move using the tilting rotors). Its design is detailed, its subsystems are described, and its normal and coupled flight mode dynamics are modeled. The results show good stability and reliable maneuvers for the coupling-to-power-transmission-line flight mode, without any overshoots, and the ability to follow the entire catenary through different Real Control Action (RCA) sets.
This work aims to show kinematics and dynamics modelling of a fixed-wing UAV type, as well as Proportional and Proportional, Integral and Derivative controllers for multirate cascade control loop, one internal for angular attitude and another external for the inertial position. The control loops are designed for roll, pitch, yaw, altitude and linear velocity in forwarding and backward aircraft nose direction. These dynamics are controlled by the integration of loops in different levels using the Successive Loop Closure technique. The results were satisfactory, considering that the simulation tests took into account the parameters of an already developed aircraft.
O movimento do ar do ambiente para os alvéolos é um fenômeno vital e complexo que ocorre devido às variações nas pressões intratorácicas e nas vias aéreas em relação à atmosfera. A construção de protótipos didáticos pode minimizar a abstração necessária nestes fenômenos in vivo. Neste estudo, automatizamos um protótipo didático de ventilação pulmonar já descrito na literatura para simular e exibir variações na pressão intratorácica durante a função diafragmática. Um protótipo de ventilação pulmonar (PV) foi produzido com materiais recicláveis, e automatizado adaptando um sensor de pressão no sistema para gerar curvas de pressão em função do tempo durante a simulação da função diafragmática. A tração descendente do êmbolo automatizado induzida pelo servomotor (como o diafragmático) reduziu a pressão dentro da garrafa (intratorácica), e esta variação pode ser observada graficamente em uma interface de computador enquanto o balão foi expandido, e o ar atmosférico invadiu seu interior. Conclusão: A incorporação da tecnologia em um protótipo PV simples permitiu uma demonstração segura e simulada de como o diafragma induz a variação da pressão intratorácica em relação à atmosfera concomitantemente com a deformação pulmonar que ocorre durante a inspiração e a exalação.