The objective of this project is to design, manufacture, and test an unmanned aircraft system capable of vertical takeoff and landing for wildlife surveillance. Red Cactus is a blended-body flying wing with vertical-thrusting ducted propellers and a horizontal-thrusting pusher propeller that enable vertical, horizontal, and hover flight modes. This hybrid design allows the aircraft to take off from a stationary ground position, cruise four miles to a desired target, loiter over the target for 15 minutes, and cruise back to the original location to land. Hybrid aircraft combine elements of fixed-wing aircraft with elements of multirotor aircraft to deliver multifaceted mission capabilities. The aircraft has no tail so its wing is constructed with an Eppler 330 reflex airfoil to provide stability during cruise. The aircraft cruises at 36 mph at of 500 feet above ground level, using elevons (ailerons combined with an elevator) on each wing as control surfaces. The aircraft weighs 12 pounds and is fabricated from various weights of vacuum-formed composite fiberglass for the outer skin, carbon fiber tubing, plastic parts made using a 3-D printer, and balsa wood ribs for the internal structure. The internal structure consists of a network of spars joined to a large, stiff duct located in the center of the blended body, which houses two 15-inch counter-rotating lifting propellers.

When at rest on the water, the Clipper Spirit seaplane has one wing buoyed and the other suspended in air, which requires additional roll authority to stabilize the aircraft during takeoff and landing. The project goal is to design a mechanism that droops or retracts the ailerons during takeoff and landing, creating more lift at the wing tips, where the ailerons are located, which effectively adds roll authority. The droop mechanism must be purely mechanical, be independent from and not interfere with the aileron control system, retract or extend the bias linearly from 75 to 100 knots, and be free from pilot input. The design meets this requirement by using dynamic pressure to displace a piston. The piston linearly displaces a rack that turns a set of gears, the last of which is mounted on the aileron control shaft. When the gear rotates it will also rotate the shaft, which will effectively lengthen or shorten the control shaft depending on whether the ailerons are being drooped or retracted. Rotation changes shaft length by threading it into or out of the control horn, which translates into a droop or retraction of the aileron.

The team’s objective is to build two radio-controlled electric-powered aircraft in accordance with the rules of the American Institute of Aeronautics and Astronautics Design/Build/Fly competition. The production aircraft must be able to carry a 32-ounce soft drink bottle internally and complete a timed flight mission. It must be able to be disassembled and loaded into a manufacturing support aircraft, which also has to complete the flight mission. The team’s objectives are to build the lightest possible planes and to minimize the subassemblies of the production aircraft. The team opted for two subassemblies and designed an aircraft with a minimized front profile that enabled optimization of size and weight. Manufacturing techniques include foam core composite prototyping, 3-D printing, carbon fiber wing layups, and precision, laser-cut wood structures. Using these techniques in tandem with mission-specific designs resulted in two aircraft capable of achieving a maximum score under competition rules.

The goal of this project is to design, construct and fly an unmanned aerial vehicle, or UAV, by computer control using a feedback-based program. Feedback loops take the system output into consideration, which enables the system to adjust its performance to meet a desired output response. For aircraft, a human pilot traditionally does this. For a UAV, the controller receives a signal and compares it to the desired signal value, then sends a corrected signal based on this comparison. This process repeats rapidly throughout the mission. In this design, the feedback-control system sends thrust and angle values to the flight controller, analyzes the reaction, and then sends corrected values. The control program can be uploaded to the aircraft for a mission instead of using a human pilot. The small, durable UAV is designed for indoor flight to enhance a control theory class by adding hands-on experience. The communication ground station can toggle between manual and computer control. The scope of this project is to demonstrate system communication, simple computer-controlled commands, and aircraft flight performance.

This project seeks to continue the development of a one-third aeroelastically scaled model of the X-56A, an unmanned aerial vehicle designed by Lockheed Martin. The X-56A Multi-Utility Technology Test bed is used by the Air Force Research Laboratory to research flutter suppression on flexible wings. The team’s design maintains the modularity of the full-scale X-56A, allowing for wing sets of varying stiffness to be combined with a single fuselage and radio control system. Straight-wing planforms and empennage were designed and integrated for increased stability during flight research. The use of room-temperature composite manufacturing techniques allowed the flexural properties of each wing set to be tailored to dynamically and elastically match the low- and high-stiffness wings of the full-size X-56A. Using fiber-reinforced composites allowed exact surfaces to be replicated across iterations of wing sets and parts to be easily reproduced. Ultimately, the team’s design will be used by the Air Force Office of Scientific Research to investigate fluid-structure interaction and novel fluid dynamics models.

The goal of this project is to design a roadway in Tucson, Arizona, that extends from the existing Sabino Canyon Road south to connect to Kolb Road over the Vincent Mullins Landfill and across Pantano Wash. The roadway would ease traffic conditions at this site, which exceed design capacity during morning and evening peak hours. The project encompasses transportation, hydrological, structural and geotechnical design, and an environmental assessment. The team followed City of Tucson design codes and regulations, load and resistance factor design, and American Association of State Highway and Transportation Officials bridge design manuals during the design process. Different load combinations were used to design the 43-foot bridge deck span, which includes four traffic lanes, two pedestrian pathways, and parapet walls for safety. The team chose a slab design for its constructability. Based on soil types and soil borings, a geotechnical support structure was designed to elevate the span above the Vincent Mullins Landfill. A full hydrological analysis was conducted to evaluate the runoff from a neighboring park into an existing culvert, as well as drainage from the roadway. The Hydrologic Engineering Center’s River Analysis System, or HEC-RAS, developed for the U.S. Army Corps of Engineers, was used to determine if channel improvements were necessary to convey stormwater runoff from the roadway and park to Pantano Wash. Environmental permitting and stormwater pollution prevention plan were completed to satisfy City of Tucson codes.

Macadamia nuts are a valuable cash crop in Hawaii. Commercial harvesting requires at least three types of heavy machinery, each with a single specialized function. The project’s purpose is to design and prototype a single robotic nut-harvesting vehicle to replace the multiple machines currently used, facilitating faster harvesting and eliminating the cost of harvesting by hand. The robotic machine must be able to navigate a macadamia nut orchard with minimum human interaction for the nine-month harvesting season. The objective is to increase crop yield from conventional small-scale harvesting methods, and to provide a consistent harvesting schedule for Kawainui Farm. The vehicle platform was designed to accommodate a hopper in which to collect nuts, electrical components for power and navigation, and a pickup head to collect nuts on the ground. The vehicle relies on GPS and computer vision to navigate a preprogrammed path through the orchard. Hawaii’s heavy rainfall limits GPS use, so the vehicle can be manually radio controlled.

Contamination of food and water by E. coli is a major global health problem. Although most strains are harmless, some are pathogenic and can cause food poisoning, severe infection, and death. The goal of this project is to design a system to optically detect E. coli in real time, with a focus on developing a device to read paper microfluidic chips, which are a low-cost, biodegradable sensing platform. Antibody-conjugated particles placed on a paper chip bind when exposed to E. coli, resulting in a change in optical signal caused by particle-size-dependent scattering. Current detection methods require smartphone processing and computational software, and are prone to error and false readings caused by inconsistent ambient lighting. The process was made more precise by creating a device that reads red, green and blue values of scattered light in a closed casing produced by 3-D printing. Using an Arduino microcontroller instead of a smartphone and desktop software reduces cost and makes the sensor more feasible for use in developing nations. The device could be adapted to detect other bacteria.

While satisfying nutritional needs, mushroom cultivation is financially sustainable and can supplement carbon dioxide required by plants in a crop-production system. The goal of this project is to design and build an efficient and cost-effective mushroom growth chamber as part of a larger system of crop production. The mushroom-growing system design consists of storage shelves, fruiting chambers, a laminar flow hood, and a humidity control system. The design includes a cabinet to convert the laminar flow hood to an inoculation station and a humidifier with microcontroller-based sensor control. The layout of the fruiting chambers and walking areas meet safety requirements and were designed in cooperation with the plant production and irrigation infrastructure teams (Teams 15090 and 15091). Through controlled environment practices, the mushroom growing system will deliver a nutritionally dense product to offset food insecurity, and provide an opportunity for further research.

The purpose of this project is to design and install an irrigation system for a greenhouse built inside a shipping container. This system needs to provide sufficient quantity and quality of water to plants in a nutrient film technique system and in deep-flow hydroponics trays. A closed, self-sustaining system, with an ultraviolet filter on its exit pipes, was designed to allow reuse of irrigation water. The team chose a one-tank design to save space and water. When the deep flow hydroponics trays are filling, no water is running through the nutrient film technique system. When the trays are full, the pump switches to circulating water through the nutrient film technique system. Shelf and outlet height are adjustable to accommodate different plants, which are fertilized by depositing nutrients directly into the water. A water outlet is provided for humidifiers.