for Unmanned Aerial Vehicles.
Towards enabling a UAV to autonomously sense and avoid moving obstacles, this thesis makes the following contributions. Initially, an image-based reactive motion planner is developed for a quadrotor to avoid a fast approaching obstacle. Furthermore, A Dubin’s curve based geometry method is developed as a global path planner for a fixed-wing UAV to avoid collisions with aircraft. The image-based method is unable to produce an optimal path and the geometry method uses a simplified UAV model. To compensate
these two disadvantages, a series of algorithms built upon the Closed-Loop Rapid Exploratory Random Tree are developed as global path planners to generate collision avoidance paths in real time. The algorithms are validated in Software-In-the-Loop (SITL) and Hardware-In-the-Loop (HIL) simulations using a fixed-wing UAV model and in real flight experiments using quadrotors. It is observed that the algorithm enables a UAV to avoid moving obstacles approaching to it with different directions and speeds.
Domestic energy is an important component of our day to day lives and is something we cannot live without. Imagine how life would be without a means to cook our food, to warm our house, life would be unbearable. As we enjoy these comforts rarely do we stop to think what the opportunity cost is. For those using renewable sources, it is not a big issue, but for those who rely on wood fuel, they have to strike a delicate balance between need for fuel and the need to conserve the greatest support systems of their livelihoods, the forests. The main source of energy for households in many developing countries is biomass, mainly from forests and woodlands. The continued use of firewood and charcoal fuel puts a strain on forests, resulting in adverse effects on the environment such as prolonged droughts, loss of biodiversity, dwindling water resources, changing weather patterns among other sustainability challenges. An alternative to firewood to charcoal lies in biochar briquettes. This paper discusses the role of biochar briquettes in mitigating climate change and serves as a step by step guide on how biochar briquettes may be produced.