ARL HBCU/MI Undergraduate Design Competition: Retrofitting of Small UAVs for Internal Power Transfer using 3D-Printing Tools
Abstract
Because small well-selected unmanned aerial vehicles (UAVs) can provide overhead situational awareness under complex and dynamic combat scenarios, they have expectedly attracted the attention of the military. In practice, tactical environments to be encountered, and thus the number and/or type of needed UAVs), are a-priori unknown. Consequently, the transportation and/or storage of many UAVs of various types, which may never be needed for missions, are clearly not the most effective utilization of logistical resources. In order to facilitate on-demand mission-tailored UAVs production in the field, the US Army Research Laboratory (ARL) investigated and successfully demonstrated the concept of forward-deployed fabrication of UAVs through additive manufacturing (i.e., 3D printing). Results from user feedbacks indicated that certain aspects of current UAVs are serious impediments. The goal of this project is the formation of a team of Tuskegee University (TU) undergraduate engineering students that will utilize additive manufacturing tools and the Design Thinking methodology to investigate, implement and test new approaches to address one of these existing shortcomings; namely, the presence of motor wiring bundle through the arm structures of small UAVs. The TU studentsÕ solution approach will revolve around the retrofitting of judiciously selected off-the-shelf UAVs (see Figure 1) with arms that have been manufactured such that transfer of power can be effectively done through the arm structures from the flight controller to the automatic speed controllers (ESCs), and then to the motors. Toward this end, students will explore several design/construction approaches. Approach 1: Students will investigate the potential usage of conductive PLA filaments to assess, among other parameters, the electrical and mechanical performances of printed-in-place component (i.e., internal wiring traces and contacts) for power transfer within arm structures. Although, in principle, conductive filaments can be seamlessly incorporated into products during the printing process, they tend to exhibit some noticeable shortcomings. First, they are generally not as conductive as metallic wires and their mechanical strength is typically inferior to those of standard plastic counterparts. Second, they may require special handling and tend to accelerate the breaking down of the hot-end nozzle of printers. Nevertheless, the team will investigate ways for incorporating conductive filaments into their design solutions because of their great potential for the targeted application. The envisioned solution is to acquire highly conductive filaments and experiment with 3D- printing processes that could enable the replacement of wires and connections on UAV arm structures with fully 3D-printed internal power traces that go from the flight controller to the ESCs and, more critically, from the ESCs to the motors. This class of carbon nanotube-based filament has been reported to have relatively low resistivity with flexural modulus and tensile strength that are stronger than those of standard PLA filaments. Approach 2: Students will evaluate different construction techniques for most efficiently inserting solid metal wiring into arm structures during the 3D printing process. In this design approach, the transfer of power would then be completely done within the arm structure via embedded metallic wires that would be terminated with female bullet connectors. 3D printing processes would also be sought to best embed the female bullet terminals at the edges of arm structures to provide quick and solid connections to ESCs and motors. Students will also have the opportunity to investigate the possibility of using the highly conductive PLA filaments, discussed above, and directly printing the female bullet connectors as integral parts of the arms. Under the above scenario, the analysis of contact resistance between the embedded metallic wires and the PLA based terminals
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 04, 2019
- Source ID
- W911NF1910188
Entities
People
- Mandoye Ndoye
Organizations
- Army Contracting Command
- Tuskegee University
- United States Army