Optimal Trajectory Reconfiguration and Retargeting for the X-33 Reusable Launch Vehicle - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Optimal Trajectory Reconfiguration and Retargeting for the X-33 Reusable Launch Vehicle write by Patrick J. Shaffer. This book was released on 2004-09-01. Optimal Trajectory Reconfiguration and Retargeting for the X-33 Reusable Launch Vehicle available in PDF, EPUB and Kindle. This thesis considers the problem of generating optimal entry trajectories for a reusable launch vehicle following a control surface failure. The thesis builds upon the work of Dr. David Doman, Dr. Michael Oppenheimer and Dr. Michael Bolender of the Air Vehicles Directorate, Air Force Research Lab Dayton Ohio. The primary focus of this work is to demonstrate the feasibility of inner loop reconfiguration and outer loop trajectory retargeting and replanning for the X-33 reusable launch vehicle (RLV) following the imposition of a control surface failure. The trajectory generation model employs path constraints generated by an AFRL trim deficiency algorithm coupled with an inner loop control allocator and aerodynamic database that captures the full 6-DOF vehicle aerodynamic effects while utilizing an outer loop 3-DOF model. The resulting optimal trajectory does not violate the trim deficiency constraints and provides additional margins for trajectories flown during failure conditions. The footprints generated by the thesis show that contemporary footprint analysis for vehicles experiencing control surface failures are overly optimistic when compared to those footprints that consider vehicle aerodynamic stability and realistic landable attitudes at the threshold of the landing runway. The results of the thesis also show the performance reductions resulting from decoupling the inner and outer loop and that trajectories can be generated to the landing runway without using a region of terminal area energy management.
Optimal Trajectory Reconfiguration and Retargeting for a Reusable Launch Vehicle
Optimal Trajectory Reconfiguration and Retargeting for a Reusable Launch Vehicle - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Optimal Trajectory Reconfiguration and Retargeting for a Reusable Launch Vehicle write by . This book was released on 2005. Optimal Trajectory Reconfiguration and Retargeting for a Reusable Launch Vehicle available in PDF, EPUB and Kindle. Autonomous reusable launch vehicles (RLV) are being pursued as low-cost alternatives to expendable launch vehicles and the Shuttle. The employment of autonomous reusable launch vehicles requires additional guidance and control robustness to fulfill the role of an adaptive human pilot, in the event of failures or unanticipated conditions. The guidance and control of these vehicles mandate new guidance strategies that are able to identify and adapt to vehicle failures during the flight and still return to earth safely. This work utilizes an online trim algorithm that provides the outer loop with the feasible range of Mach number and angle of attack, for which the vehicle can be rotationally trimmed. The algorithm allows one to include 6-degree-of-freedom (DOF) trim effects and constraints in a reduced order dynamical model which is used in the solution of an optimal control problem. A direct pseudospectral method is used to solve a two-point-boundary-value problem which determines the optimal entry trajectory subject to appropriate constraints such as normal load, dynamic pressure limits, heat load limits, and state dependent constraints.
Reusable Launch Vehicle
Reusable Launch Vehicle - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Reusable Launch Vehicle write by Committee on Reusable Launch Vehicle Technology and Test Program. This book was released on 1996-01-22. Reusable Launch Vehicle available in PDF, EPUB and Kindle. The key to opening the use of space to private enterprise and to broader public uses lies in reducing the cost of the transportation to space. More routine, affordable access to space will entail aircraft-like quick turnaround and reliable operations. Currently, the space Shuttle is the only reusable launch vehicle, and even parts of it are expendable while other parts require frequent and extensive refurbishment. NASA's highest priority new activity, the Reusable Launch Vehicle program, is directed toward developing technologies to enable a new generation of space launchers, perhaps but not necessarily with single stage to orbit capability. This book assesses whether the technology development, test and analysis programs in propulsion and materials-related technologies are properly constituted to provide the information required to support a December 1996 decision to build the X-33, a technology demonstrator vehicle; and suggest, as appropriate, necessary changes in these programs to ensure that they will support vehicle feasibility goals.
Fault Tolerant Optimal Trajectory Generation for Reusable Launch Vehicles
Fault Tolerant Optimal Trajectory Generation for Reusable Launch Vehicles - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Fault Tolerant Optimal Trajectory Generation for Reusable Launch Vehicles write by Patrick J. Shaffer. This book was released on 2006. Fault Tolerant Optimal Trajectory Generation for Reusable Launch Vehicles available in PDF, EPUB and Kindle. Reconfigurable inner-loop control laws improve the fault tolerance of a vehicle to control effector failures; however, in order to preserve stability, the unfailed effectors may be deployed to off-nominal positions to compensate for undesirable perturbations caused by the failed effectors. The effectors acting under the influence of a reconfigurable control law can produce significant perturbations to the nominal forces produced by the wing and body and can also affect the range of flight conditions over which the vehicle can be controlled. Three degree-of-freedom (3 DOF) dynamical models used in trajectory optimization for aerospace vehicles typically include wing-body aerodynamic force effects but ignore the aerodynamic forces produced by the control surfaces. In this work, a method for including these trim effects as well as control induced trajectory constraints in a 3 DOF model is presented.
Optimal Trajectory Designs and Systems Engineering Analyses of Reusable Launch Vehicles
Optimal Trajectory Designs and Systems Engineering Analyses of Reusable Launch Vehicles - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Optimal Trajectory Designs and Systems Engineering Analyses of Reusable Launch Vehicles write by Hung-i Bruce Tsai. This book was released on 2003. Optimal Trajectory Designs and Systems Engineering Analyses of Reusable Launch Vehicles available in PDF, EPUB and Kindle. Realizing a reusable launch vehicle (RLV) that is low cost with highly effective launch capability has become the "Holy Grail" within the aerospace community world-wide. Clear understanding of the vehicle's operational limitations and flight characteristics in all phases of the flight are preponderant components in developing such a launch system. This dissertation focuses on characterizing and designing the RLV optimal trajectories in order to aid in strategic decision making during mission planning in four areas: 1) nominal ascent phase, 2) abort scenarios and trajectories during ascent phase including abort-to-orbit (ATO), transoceanic-abort-landing (TAL) and return-to-launch-site (RTLS), 3) entry phase (including footprint), and 4) systems engineering aspects of such flight trajectory design. The vehicle chosen for this study is the Lockheed Martin X-33 lifting-body design that lifts off vertically with two linear aerospike rocket engines and lands horizontally. An in-depth investigation of the optimal endo-atmospheric ascent guidance parameters such as earliest abort time, engine throttle setting, number of flight phases, flight characteristics and structural design limitations will be performed and analyzed to establish a set of benchmarks for making better trade-off decisions. Parametric analysis of the entry guidance will also be investigated to allow the trajectory designer to pinpoint relevant parameters and to generate optimal constrained trajectories. Optimal ascent and entry trajectories will be generated using a direct transcription method to cast the optimal control problem as a nonlinear programming problem. The solution to the sparse nonlinear programming problem is then solved using sequential quadratic programming. Finally, guidance system hierarchy studies such as work breakdown structure, functional analysis, fault-tree analysis, and configuration management will be developed to ensure that the guidance system meets the definition of vehicle design requirements and constraints.
