ROBUST TRAJECTORY TRACKING FOR A SMALL-SCALE HYBRID AIRCRAFT
By hybrid aircraft, we mean a UAV that can vertically take-off, land and hover like a helicopter, and meanwhile can be converted to a fixed wing airplane to achieve high forward speed and long endurance than normal helicopters. This paper presents our recent work on control of a novel small scale hybrid aircraft. The proposed aircraft should follow a specific trend of trajectory to be able to convert from helicopter to airplane. For such a purpose, we design a robust trajectory tracking controller for helicopter mode of the aircraft. Finally, the simulation results are presented to demonstrate effectiveness of the proposed controller.
Inventing the F-35 Joint Strike Fighter
The F-35 Joint Strike Fighter is a single aircraft developed to meet the multirole fighter requirements of the US Air Force, Navy, Marine Corps, and our allies. The Air Force variant is a supersonic, single engine stealth fighter. The Navy variant has a larger wing and more robust structure in order to operate from an aircraft carrier, while the Marine Corps variant incorporates an innovative propulsion system that can be switched from a turbofan cycle to a turboshaft cycle for vertical take off and landing. This novel propulsion system enabled the X-35 demonstrator to become the first aircraft in history to fly at supersonic speeds, hover, and land vertically. The F-35 program grew out of a design study of a supersonic replacement for the AV-8 Harrier, through the absorption of several other tactical aircraft initiatives. It became an international program with engineers from half a dozen countries developing a replacement for multiple aircraft Types.
Semiautomated quantification of the fibrous tissue response to complex three-dimensional filamentous scaffolds using digital image analysis.
Fibrosis represents a relevant response to the implantation of biomaterials, which occurs not only at the tissue-material interface (fibrotic encapsulation) but also within the void fraction of complex three-dimensional (3D) biomaterial constructions (fibrotic ingrowth). Usual evaluation of the biocompatibility mostly depicts fibrosis at the interface of the biomaterial using semiquantitative scores. Here, the relations between encapsulation and infiltrating fibrotic growth are poorly represented. Virtual pathology and digital image analysis provide new strategies to assess fibrosis in a more differentiated way. In this study, we adopted a method previously used to quantify fibrosis in visceral organs to the quantification of fibrosis to 3D biomaterials. In a proof-of-concept study, we transferred the "Collagen Proportionate Area" (CPA) analysis from hepatology to the field of biomaterials. As one task of an experimental animal study, we used CPA analysis to quantify the fibrotic ingrowth into a filamentous scaffold after subcutaneous implantation. We were able to demonstrate that the application of the CPA analysis is well suited as an additional fibrosis evaluation strategy for new biomaterial constructions. The CPA method can contribute to a better understanding of the fibrotic interactions between 3D scaffolds and the host tissue responses.