A series of RDT&E activities is proposed to create and demonstrate a reconfigurable, autonomous flight controller for the Aircraft for Distributed Electric Propulsion Throttle-based Flight Control (ADEPT-FC) which was designed and built in Phase I, a 33 lb remote controlled aircraft featuring eight overwing electric ducted fans (EDFs) distributed spanwise along the wing’s trailing edge. The proposed study will be the first to show that a complete and accurate description of the propulsion airframe integration (PAI) effects enables autonomous flight of a DEP aircraft using a standard approach to model-based flight control. A combination of modeling & 6DoF dynamic simulation leveraging OpenVSP/VSPAERO, wind-tunnel and hardware-in-the-loop (HITL) ground testing, and system identification (SysID) flight testing will be completed to support the design of the autonomous controller. The resultant controller will be demonstrated in flight on the ADEPT-FC research aircraft at multiple stages of development, including trim flight with uniform and asymmetric throttle mixing as well as DEP system fault tolerance through autonomous controller reconfiguration. Additional research products from the study will include an empirically-derived body of knowledge pertaining to PAI for DEP aircraft, a “DEP Array” custom component for OpenVSP, and VSPAERO validation artifacts to characterize the tool’s ability to predict PAI behaviors, all of which are intended to be disseminated open source to the aerospace community. Autonomous flight control of DEP aircraft with strong PAI effects is one piece of a greater integrated autonomous controller (IAC) envisioned for hybrid electric distributed propulsion (HEDP) aircraft, a technology foreseen by ESAero to enable substantial risk probability and criticality reduction, improved energy efficiency, and reduced pilot workload.
One of the three commercialization strategies envisioned by ESAero for the proposed autonomous controller technology and the IAC product it would be a part of is to develop and integrate an IAC for NASA’s X-57 “Maxwell” aircraft. There are presently no active efforts by NASA to integrate health-aware, autonomous flight control capability on NASA’s X-57 Maxwell aircraft despite the fact that most subject matter experts on DEP agree that such a technology is strongly recommended for safe and efficient operation. Introduction of an IAC could benefit the SCEPTOR mission objectives through risk probability and criticality reduction, improving cruise efficiency, and by fostering the validation and demonstration of an enabling technology for future commercial DEP aircraft. Additional potential NASA commercial applications are known to be numerous but have not yet been specifically identified. The topics of DEP, PAI, OpenVSP, and autonomy relate to Strategic Thrusts 3a, 4, and 6 of the ARMD and have ties to several NASA programs including TACP, AAVP, AOSP, and IASP through projects including CAS, TTT, AATT, SASO, and UAS in the NAS. As an engineering services contractor with close ties to all aeronautics centers of NASA, ESAero will actively pursue follow-on efforts to leverage its newfound core competencies and intellectual property in support of any these programs and projects.
ESAero has targeted the rapidly growing Urban Air Mobility (UAM) market led by Uber for the eventual Non-NASA commercialization of the IAC technology and product. The eVTOL aircraft being developed for this market features many of the hallmark characteristics that call for IAC technology, including numerous high-power electric propulsors, DEP-based control concepts, and strong PAI-related dynamical complexities. Additionally, autonomous systems have already been identified by Uber Elevate as a future feature of their fleet, owing to their superior safety and operating costs. ESAero’s end-goal for this path of commercialization is to sell or license the IAC technology to Uber and/or one or more of the aircraft developers in the UAM market. Post-Phase II activities needed to enter this market include the development and demonstration of the IAC technology on a larger aircraft with features matching that of eVTOL aircraft, such as Uber Elevate’s eCRM-001 concept, to increase the TRL to 7 and attract the interest of airframes in the eVTOL community. ESAero intends to leverage their strong relationship with Uber and/or their partners to secure funding for this first activity. The next milestone will be to attract strategic investment from Uber or their partners to fund additional RDT&E needed to achieve TRL 8&9 for the IAC in time for adoption of autonomous flight in the Uber Air fleet in the early-to-mid 2020’s.