Optimal Guidance Command Generation And Tracking For Reusable Launch Vehicle Reentry Preprint
DOWNLOAD
Download Optimal Guidance Command Generation And Tracking For Reusable Launch Vehicle Reentry Preprint PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Optimal Guidance Command Generation And Tracking For Reusable Launch Vehicle Reentry Preprint book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Optimal Guidance Command Generation And Tracking For Reusable Launch Vehicle Reentry Preprint
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2006
Optimal Guidance Command Generation And Tracking For Reusable Launch Vehicle Reentry Preprint written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006 with categories.
The objective of this work is to develop a robust guidance and control architecture for autonomous reusable launch vehicles that incorporates elements of recent advances in the areas of optimal trajectory generation and reconfigurable control. This work integrates three separately developed methods to form a coherent architecture with the potential to manage control effector failures, vehicle structural/aerodynamic degradation, uncertainty, and external disturbances. Outer-loop guidance commands in the form of body-frame angular rates (roll, pitch, and yaw) are generated from an optimal reference trajectory that is computed off-line with a direct pseudospectral method and then tracked by a reconfigurable inner-loop control law. The appropriate open-loop state histories from the pseudo-four-degree-of-freedom reference trajectory are converted using a modified backstepping approach that complements the inner-loop control law in a six-degree-of-freedom simulation. The inner-loop control law is capable of reacting and compensating for off-nominal conditions by employing nonlinear reconfigurable control allocation, dynamic inversion, and model-following/anti-windup prefilters. The results show that the inner loop control can adequately track the desired optimal guidance commands; thus, confirming that applicability of this control architecture for future development involving on-line, optimal trajectory generation and high-fidelity guidance and control for reentry vehicles.
Optimal Guidance Command Generation And Tracking For The Reentry Of A Reusable Launch Vehicle Preprint
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2006
Optimal Guidance Command Generation And Tracking For The Reentry Of A Reusable Launch Vehicle Preprint written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006 with categories.
In this work, optimal outer-loop guidance commands are generated from an off-line reference trajectory and then tracked by a reconfigurable inner-loop control law. The primary motivation for this work is a "stepping-stone" towards online, optimal trajectory generation, footprint determination, and retargeting capabilities in the presence of control effector failures or vehicle structural/ aerodynamic degradation, uncertainty, and external disturbances. The presented guidance and control architecture uses a 6-degree-of-freedom simulation and an inner-loop controller to track body-name angular rates (roll, pitch, and yaw), generated from an optimal psuedo-4-degree-of-freedom reference trajectory that is computed using a direct pseudo spectral method. The innerloop control law is capable of reacting and compensating for off-nominal conditions by employing its nonlinear control allocation, dynamic inversion, and model-following/anti-windup prefilters. The results show that the inner-loop control can adequately track the desired optimal guidance commands; thus, confirming the applicability of this control architecture for future development involving on-line, optimal trajectory generation and high-fidelity footprint determination for reentry vehicles.
Neural Dynamic Trajectory Design For Reentry Vehicles
DOWNLOAD
Author : Ajay Verma
language : en
Publisher:
Release Date : 2007
Neural Dynamic Trajectory Design For Reentry Vehicles written by Ajay Verma and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007 with Guided missiles categories.
The next generation of reentry vehicles is envisioned to have onboard autonomous capability of real-time trajectory planning to provide capability of responsive launch and delivering payload anywhere with precise flight termination. This capability is also desired to overcome, if possible, in-flight vehicle damage or control effector failure resulting in degraded vehicle performance. An aerial vehicle is modeled as a nonlinear multi-input-multi-output (MIMO) system. An ideal optimal trajectory control design system generates a series of control commands to achieve a desired trajectory under various disturbances and vehicle model uncertainties including aerodynamic perturbations caused by geometric damage to the vehicle. Conventional approaches suffer from the nonlinearity of the MIMO system, and the high-dimensionality of the system state space. In this paper, we apply a Neural Dynamic Optimization (NDO) based approach to overcome these difficulties. The core of an NDO model is a multilayer perceptron (MLP) neural network, which generates the control parameters online. The advantage of the NDO system is that it is very fast and gives the trajectory almost instantaneously. The bulk of the time consuming computation is required only during off-line training. The inputs of the MLP are the time-variant states of the MIMO systems. The outputs of the MLP are the near optimal control parameters.
High Fidelity Real Time Trajectory Optimization For Reusable Launch Vehicles
DOWNLOAD
Author : Kevin P. Bollino
language : en
Publisher:
Release Date : 2006
High Fidelity Real Time Trajectory Optimization For Reusable Launch Vehicles written by Kevin P. Bollino and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006 with Engineering categories.
Creating simplicity out of complexity, this research abandons the traditional guidance and control architecture for aerospace vehicles and embraces a revolutionary concept based on the principles of nonlinear optimal control theory. Motivated by the emerging needs of the next generation of reusable space vehicles, an autonomous integrated guidance and control system is developed that provides a safe approach to the highly constrained and nonlinear reentry problem. A pseudospectral-based optimal guidance scheme is used to generate high-fidelity, vehicle-tailored solutions to reentry trajectory optimization and guidance problems. To provide an autonomous, onboard capability of satisfying final-approach requirements, a new method is developed that includes an automatic generation of landing constraints given any runway geometry. This unique and simple approach avoids significant complexities arising from previous ideas of trajectory segmentation, trimmed flight, and trajectory tracking schemes. When demonstrating the new ideas, it is shown that the proposed approach can easily compensate for large uncertainties and disturbances consisting of hurricane-force wind gusts. An investigation of these new principles for the complete, nonlinear six degree-of-freedom system dynamics indicates that while the results are quite promising, a substantial amount of new theoretical and computational problems remain open, particularly in the area of over-actuated dynamical systems.
Fault Tolerant Optimal Trajectory Generation For Reusable Launch Vehicles
DOWNLOAD
Author : Patrick J. Shaffer
language : en
Publisher:
Release Date : 2006
Fault Tolerant Optimal Trajectory Generation For Reusable Launch Vehicles written by Patrick J. Shaffer and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006 with Launch vehicles (Astronautics) categories.
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.
Automated Trajectory Generation And Guidance For A New Launch Vehicle Flight Phases
DOWNLOAD
Author : Kenneth R. Horneman
language : en
Publisher:
Release Date : 2010
Automated Trajectory Generation And Guidance For A New Launch Vehicle Flight Phases written by Kenneth R. Horneman and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with Electronic Dissertations categories.
Much effort has been put into developing technologies for next generation re-usable launch vehicles. Fully re-usable launch vehicles include a booster stage that is designed to land, usually near the launch site, after it has released the upper-stage, which continues to orbit. The fuel reserve needed to turn the booster stage around will usually be minimal For this reason, once the booster stage has completed a rocket-back maneuver, it will typically be at a high altitude (exo-atmospheric) but with low kinetic energy and a steep flight path angle on re-entry. Traditional re-entry guidance is designed for vehicles with a high velocity, and shallow flight path angle, and thus these traditional approaches are not appropriate for a low energy re-entry (LOER). The current research presents a set of guidance algorithms that will successfully guide a vehicle to landing starting from LOER condition. The guidance algorithms are designed to ensure the vehicle can achieve near optimal range performance when required and also to execute a sharp pull-up maneuver that balances the load factor constraint against the need to pull-up quickly before the dynamic pressure constraint is exceeded. The guidance approach has been tested for a wide variety of vehicles and mission scenarios, including more traditional initial conditions that would occur at the end of a High Energy Re-entry (HIER) from orbit. Thus, the guidance approach we have developed can be used as a more robust version of Terminal Area Energy Management (TAEM) guidance, as well as for LOER and has been tested for a wide range of vehicles, including the Space Shuttle and vehicles with a wide variety of L/D capability. Significant development has also gone into the engineering considerations needed to implement the guidance algorithms on a real vehicle. Program execution time, application of vehicle constraints, trajectory repeatability and other factors are all addressed in order to meet this need.
Sub Optimal Analytic Guidance For Reusable Launch Vehicles
DOWNLOAD
Author : Katie Amanda Grantham
language : en
Publisher:
Release Date : 2003
Sub Optimal Analytic Guidance For Reusable Launch Vehicles written by Katie Amanda Grantham and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2003 with Guidance systems (Flight) categories.
"This thesis presents a guidance scheme for the Terminal Area Energy Management (TAEM) and Approach and Landing phases of flight for the next generation of reusable launch vehicles (RLVs). The guidance scheme presented is developed in two parts, the kappa guidance section and the touchdown trajectory section."--Abstract, p. iii.
A Reconfigurable Guidance Approach For Reusable Launch Vehicles
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2001
A Reconfigurable Guidance Approach For Reusable Launch Vehicles written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2001 with categories.
A guidance system with reconfiguration capabilities has been developed for reusable launch vehicles (RLVs). The focus of the development is on reconfiguration after a catastrophic effector failure during final approach - a failure that would otherwise cause loss of the vehicle. We assume here that the vehicle employs a reconfigurable inner-loop control system that recovers some maneuvering capabilities and maintains attitude stability. However, for RLVs, it is often the case that nominal performance cannot be fully recovered, and the outer-loop guidance system must account for the degraded response characteristics. Two approaches are presented. The first approach augments the existing production guidance system with adaptation capabilities. A case study shows that stability is maintained following a primary pitch effector failure. However, it is shown that the trajectory commands to the guidance loops must also be re-targeted in order to achieve a safe landing. The second approach employs an on-line optimal trajectory re-targeting algorithm. A database of neighboring optimal trajectories is encoded in an efficient manner and interrogated on line at regular intervals. Given the current states and certain vehicle parameters, this procedure generates optimal guidance commands and integrates the optimal trajectory to the next update point. A proof-of-concept study of this approach was performed. Following a primary speed control failure, the study shows that this approach achieves acceptable landing conditions.
Model Predictive Control For Terminal Area Energy Management And Approach And Landing For A Reusable Launch Vehicle
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2002
Model Predictive Control For Terminal Area Energy Management And Approach And Landing For A Reusable Launch Vehicle written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2002 with categories.
The space industry plans to develop new reusable launch vehicles. The new vehicles will need advanced, new guidance and control systems. Since 1996 Draper Laboratory has been developing the next generation guidance and control for reusable launch vehicles in which guidance and control is integrated into one correlated system. Draper's research of integrated guidance and control originated with a single loop multivariable control scheme using time-invariant linear quadratic regulator theory. The research has since evolved into the use of model predictive control theory. The main focus of this thesis is the theory and design of model predictive control for entry of aerospace vehicles. The goal is to develop design criteria and guidelines explaining how to select the model predictive control parameters: prediction horizon, simulation rates, and weighting matrices. A secondary goal is to tightly couple an onboard trajectory generation algorithm with the model predictive controller to improve tracking performance and robustness. Favorable tracking is achieved through two model predictive control architectures, which are discussed. The first architecture has an inner loop stability augmentation system with model predictive control used as an outer loop. The second architecture replaces the inner and outer loops with a single model predictive controller. The two architectures demonstrate the flexibility of model predictive control to adapt to new vehicles; the model predictive control may be used to augment an existing inner loop or may be used as a stand-alone controller. The design focuses primarily on the architecture without a stability augmentation system.
Model Predictive Control For Terminal Area Energy Management And Approach And Landing For A Reusable Launch Vehicle
DOWNLOAD
Author : Robert Charles LePome
language : en
Publisher:
Release Date : 2002
Model Predictive Control For Terminal Area Energy Management And Approach And Landing For A Reusable Launch Vehicle written by Robert Charles LePome and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2002 with categories.