Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992. / Includes bibliographical references (p. 251-257). / by Rodger J. Biasca. / Sc.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004. / Includes bibliographical references (p. 177-181). / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / A flight control system was developed to achieve mid-air rendezvous of two unmanned aerial vehicles (UAVs) as a part of the Parent Child Unmanned Aerial Vehicle (PCUAV) project at MIT and the Draper Laboratory. A lateral guidance logic was developed for tightly tracking a desired flight path. The guidance logic is derived from geometric and kinematic properties, and has been demonstrated to work better than the conventional aircraft guidance method in waypoint navigation. A simple, low-order attitude estimation was developed that combines aircraft kinematics, GPS and low-quality rate gyros. It is demonstrated in simulation that the performance of the proposed method is as good as other advanced complex methods when the aircraft bank angle is relative small(<40 degrees). The end-game control strategy for the final phase of the rendezvous was also developed, using proportional navigation guidance in conjunction with an optical sensor. The associated miss distance was analyzed with regard to the wind effect and initial conditions. A series of flight tests was performed using two UAVs which were built as a part of the project. It was demonstrated that each individual aircraft can follow a desired flight path within a position accuracy of 2 meters (based on sensor data) while also tracking the air speed command to within 1 m/s. At the time of this thesis writing, it has been demonstrated that the developed control system can bring the two UAVs from any arbitrary initial positions into a configuration of a tight formation flight, where one vehicle trails the other with a commanded separation of 12 meters while maintaining the relative position error within 2 meters in both horizontal and vertical directions for 85% of the flight time. / by Sanghyuk Park. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004. / Includes bibliographical references (p. 235-236). / Autonomous orbital rendezvous with an orbiting sample (OS) is seen as an enabling technology for a Mars Sample Return (MSR) mission, so several demonstrations have been planned. With CNES cooperation a proposed rendezvous demonstration was governed by ITAR restrictions, and a guidance and navigation system was designed using a Precomputed Gain Kalman filter and targeting algorithms. Having lost CNES participation, the opportunity now exists to use a full Extended Kalman filter with onboard targeting algorithms on a new demonstration using the Mars Telecommunications Orbiter (MTO). This creates an impetus to compare the Precomputed Gain system with the Extended system to determine their relative performance. This thesis aims to compare the Precomputed Gain and Extended Kalman filters and associated targeting algorithms using a Monte-Carlo analysis, and based on quantitative performance metrics including: total change in velocity required, navigation errors, target pointing errors. In addition, other aspects of the algorithms will be studied including: technology readiness level (TRL) data uplink requirements, and complexity and computational burden for the onboard algorithms. Monte-Carlo analysis will reveal that the Extended system modestly outperforms the Precomputed Gain system in total change in velocity required, navigation error, and target pointing error, with a larger performance envelope. The Extended system will also be found to have a greater technology readiness and require substantially less data uplink. The Precomputed Gain system will be found to be a significantly less complex algorithm for the onboard flight computer. / by Andrew Thomas Vaughan. / S.M.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1991. / Includes bibliographical references (leaves 83-84). / M.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1993. / Includes bibliographical references (leaf 67). / by William Djaja Tjokroaminata. / M.S.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2015. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 113-116). / This thesis describes (i) guidelines for propulsor sizing, and (ii) strategies for fan turbomachinery conceptual design, for a boundary layer ingesting (BLI) propulsion system for advanced civil transport aircraft. For the former, configuration performance analysis shows BLI yields a reduction in mechanical power required to propel a given aircraft. For the latter, fan turbomachinery design attributes are identified to mitigate the impact of BLI inlet distortion on propulsor performance. The propulsion system requirements are determined using a mechanical energy analysis, in which the performance of the airframe and propulsor are characterized in terms of sources and sinks of power. Using this framework, the propulsor can be sized based on the performance of the isolated airframe. Analysis of the power savings due to BLI (from reduction of viscous dissipation both in the aircraft wake and the propulsor jet) leads to scaling choices for the sizing of propulsor simulators for wind tunnel experiments to assess BLI benefit. Fan stage distortion response is assessed computationally for a range of turbomachinery design parameters and for distortions characteristic of BLI. The numerical results show the importance of three-dimensional flow redistribution upstream of the fan, and indicate that, for the parameters examined, non-axisymmetric fan stators have the largest effect on decreasing blade row velocity distortions and thus mitigating losses due to flow non-uniformity. / by David Kenneth Hall. / Ph. D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1989. / Includes bibliographical references (leaves 259-272). / by Ming-Sang Li. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1997. / Includes bibliographical references (p. 192-195). / by Daniel Kew Skwarek. / M.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992. / Includes bibliographical references (leaves 219-225). / by Victor D. Lupi. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1994. / GRSN 698605 / Includes bibliographical references (p. 231-232). / by Lisa D. Wetherbee. / M.S.