Development of an autopilot system for rapid prototyping of high level control algorithms

This paper describes the development of a system for the rapid prototyping of high level control algorithms using an Arduino based commercial off the shelf autopilot called ArduPilot. It is capable of controlling multiple vehicle types, including fixed, and rotary wing aircraft as well as ground vehicles. The inner loop control is performed by ArduPilot, so the high level control can be rapidly prototyped and tested in Simulink, or an embedded system. The ability to conduct tests in software and hardware in the loop has also be developed, to enable safe testing of algorithms, which will speed up the development process. To show its functionality and ability to assist with the development process of algorithms, ArduPilot is used with a remote controlled aircraft in simulation and in real world testing to verify newly developed high level algorithms for UAVs

Design methodology and performance of an indraft wind tunnel

The design methodology and performance of Loughborough University’s new 1·9m × 1·3m, indraft wind tunnel is discussed in the following paper. To overcome severe spatial and financial constraints, a novel configuration was employed, with the inlet and exit placed adjacent to each other and opened to atmosphere. Using a fine filter mesh, honeycomb, two turbulence reduction screens and a contraction ratio of 7·3, flow uniformity in the working area of the jet at 40ms-1 is shown to be within 0·3% deviation from the mean velocity, with turbulence intensity in the region of 0·15%. Working section boundary layer characteristics are shown to be consistent with that of a turbulent boundary layer growing along a flat plate, which originates at the point of inflection of the contraction. A maximum velocity of 46ms-1 was achieved from a 140kW motor, compared to a prediction of 44ms-1, giving an energy ratio of 1·42. Comparison between theoretical and measured performance metrics indicate differences between the way modules perform when part of a wind tunnel system compared to data gathered from test rigs

Development of an autopilot system for rapid prototyping of high level control algorithms

This paper describes the development of a system for the rapid prototyping of high level control algorithms using an Arduino based commercial off the shelf autopilot called ArduPilot. It is capable of controlling multiple vehicle types, including fixed, and rotary wing aircraft as well as ground vehicles. The inner loop control is performed by ArduPilot, so the high level control can be rapidly prototyped and tested in Simulink, or an embedded system. The ability to conduct tests in software and hardware in the loop has also be developed, to enable safe testing of algorithms, which will speed up the development process. To show its functionality and ability to assist with the development process of algorithms, ArduPilot is used with a remote controlled aircraft in simulation and in real world testing to verify newly developed high level algorithms for UAVs

Characterization of arbuscular mycorrhizal fungus communities of Aquilaria crassna and Tectona grandis roots and soils in Thailand plantations

Aquilaria crassna Pierre ex Lec. and Tectona grandis Linn.f. are sources of resin-suffused agarwood and teak timber, respectively. This study investigated arbuscular mycorrhizal (AM) fungus community structure in roots and rhizosphere soils of A. crassna and T. grandis from plantations in Thailand to understand whether AM fungal communities present in roots and rhizosphere soils vary with host plant species and study sites. Terminal restriction fragment length polymorphism complemented with clone libraries revealed that AM fungal community composition in A. crassna and T. grandis were similar. A total of 38 distinct terminal restriction fragments (TRFs) were found, 31 of which were shared between A. crassna and T. grandis. AM fungal communities in T. grandis samples from different sites were similar, as were those in A. crassna. The estimated average minimum numbers of AM fungal taxa per sample in roots and soils of T. grandis were at least 1.89 vs. 2.55, respectively, and those of A. crassna were 2.85 vs. 2.33 respectively. The TRFs were attributed to Claroideoglomeraceae, Diversisporaceae, Gigasporaceae and Glomeraceae. The Glomeraceae were found to be common in all study sites. Specific AM taxa in roots and soils of T. grandis and A. crassna were not affected by host plant species and sample source (root vs. soil) but affected by collecting site. Future inoculum production and utilization efforts can be directed toward the identified symbiotic associates of these valuable tree species to enhance reforestation efforts

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Design and performance of thin, circular arc, wind-tunnel turning vanes

The design methodology and performance of Loughborough University’s new 1·9m × 1·3m, indraft wind tunnel is discussed in the following paper. To overcome severe spatial and financial constraints, a novel configuration was employed, with the inlet and exit placed adjacent to each other and opened to atmosphere. Using a fine filter mesh, honeycomb, two turbulence reduction screens and a contraction ratio of 7·3, flow uniformity in the working area of the jet at 40ms-1 is shown to be within 0·3% deviation from the mean velocity, with turbulence intensity in the region of 0·15%

Aerodynamics of Battle-damaged Finite-Aspect-Ratio Wings

Wind-tunnel tests have been carried out on a battle-damaged NACA 641412 half-wing aspect ratio of 8.2. The simulated gunfire damage had a diameter of 0.2 wing chord and was located at midchord and at one of two spanwise locations. Tests were carried out at a Reynolds number of 5:5 105. Compared with an undamaged wing, the damage resulted in reduced lift, increased drag and a positive increase in pitching moment at zero lift. Moving the damage to near the tip reduced the magnitude of these effects. Using the static pressure difference between the upper and lower surfaces of the undamaged wing allowed the data from the present study to be successfully compared with previously published drag and lift data for a two-dimensional damaged airfoil. Tests on wings with aspect ratios of 6.2 and 10.3 produced similar trends in the aerodynamic characteristics and showed that the use of static pressure difference was equally effective in allowing comparisons with two-dimensional data

The Goursat problem for a generalized Helmholtz operator in the plane

We consider the Goursat problem in the plane for partial differential operators whose principal part is the pth power of the standard Laplace operator. The data is posed on a union of 2p distinct lines through the origin. We show that the solvability of this Goursat problem depends on Diophantine properties of the geometry of lines on which the data is posed.AD 26/03/201