A Real-time Near-optimal Guidance Approach for Launch Vehicles

A Real-time Near-optimal Guidance Approach for Launch Vehicles PDF Author: Martin S. K. Leung
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 252

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A Real-time Near-optimal Guidance Approach for Launch Vehicles

A Real-time Near-optimal Guidance Approach for Launch Vehicles PDF Author: Martin S. K. Leung
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 252

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Optimal Guidance Law Development for an Advanced Launch System

Optimal Guidance Law Development for an Advanced Launch System PDF Author: National Aeronautics and Space Adm Nasa
Publisher:
ISBN: 9781731025708
Category :
Languages : en
Pages : 110

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Book Description
The objective of this research effort was to develop a real-time guidance approach for launch vehicles ascent to orbit injection. Various analytical approaches combined with a variety of model order and model complexity reduction have been investigated. Singular perturbation methods were first attempted and found to be unsatisfactory. The second approach based on regular perturbation analysis was subsequently investigated. It also fails because the aerodynamic effects (ignored in the zero order solution) are too large to be treated as perturbations. Therefore, the study demonstrates that perturbation methods alone (both regular and singular perturbations) are inadequate for use in developing a guidance algorithm for the atmospheric flight phase of a launch vehicle. During a second phase of the research effort, a hybrid analytic/numerical approach was developed and evaluated. The approach combines the numerical methods of collocation and the analytical method of regular perturbations. The concept of choosing intelligent interpolating functions is also introduced. Regular perturbation analysis allows the use of a crude representation for the collocation solution, and intelligent interpolating functions further reduce the number of elements without sacrificing the approximation accuracy. As a result, the combined method forms a powerful tool for solving real-time optimal control problems. Details of the approach are illustrated in a fourth order nonlinear example. The hybrid approach is then applied to the launch vehicle problem. The collocation solution is derived from a bilinear tangent steering law, and results in a guidance solution for the entire flight regime that includes both atmospheric and exoatmospheric flight phases. Calise, Anthony J. and Leung, Martin S. K. Unspecified Center ADVANCED LAUNCH SYSTEM (STS); ALGORITHMS; ASCENT TRAJECTORIES; INJECTION GUIDANCE; LAUNCH VEHICLES; OPTIMAL CONTROL; PERTURBATION THEORY; PROBLEM SOLVING; REAL TIME OPERATION; SPACEC...

Autonomous Trajectory Planning and Guidance Control for Launch Vehicles

Autonomous Trajectory Planning and Guidance Control for Launch Vehicles PDF Author: Zhengyu Song
Publisher: Springer Nature
ISBN: 981990613X
Category : Science
Languages : en
Pages : 229

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Book Description
This open access book highlights the autonomous and intelligent flight control of future launch vehicles for improving flight autonomy to plan ascent and descent trajectories onboard, and autonomously handle unexpected events or failures during the flight. Since the beginning of the twenty-first century, space launch activities worldwide have grown vigorously. Meanwhile, commercial launches also account for the booming trend. Unfortunately, the risk of space launches still exists and is gradually increasing in line with the rapidly rising launch activities and commercial rockets. In the history of space launches, propulsion and control systems are the two main contributors to launch failures. With the development of information technologies, the increase of the functional density of hardware products, the application of redundant or fault-tolerant solutions, and the improvement of the testability of avionics, the launch losses caused by control systems exhibit a downward trend, and the failures induced by propulsion systems become the focus of attention. Under these failures, the autonomous planning and guidance control may save the missions. This book focuses on the latest progress of relevant projects and academic studies of autonomous guidance, especially on some advanced methods which can be potentially real-time implemented in the future control system of launch vehicles. In Chapter 1, the prospect and technical challenges are summarized by reviewing the development of launch vehicles. Chapters 2 to 4 mainly focus on the flight in the ascent phase, in which the autonomous guidance is mainly reflected in the online planning. Chapters 5 and 6 mainly discuss the powered descent guidance technologies. Finally, since aerodynamic uncertainties exert a significant impact on the performance of the ascent / landing guidance control systems, the estimation of aerodynamic parameters, which are helpful to improve flight autonomy, is discussed in Chapter 7. The book serves as a valuable reference for researchers and engineers working on launch vehicles. It is also a timely source of information for graduate students interested in the subject.

Approximate Optimal Guidance for the Advanced Launch System

Approximate Optimal Guidance for the Advanced Launch System PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722949082
Category :
Languages : en
Pages : 164

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Book Description
A real-time guidance scheme for the problem of maximizing the payload into orbit subject to the equations of motion for a rocket over a spherical, non-rotating earth is presented. An approximate optimal launch guidance law is developed based upon an asymptotic expansion of the Hamilton - Jacobi - Bellman or dynamic programming equation. The expansion is performed in terms of a small parameter, which is used to separate the dynamics of the problem into primary and perturbation dynamics. For the zeroth-order problem the small parameter is set to zero and a closed-form solution to the zeroth-order expansion term of Hamilton - Jacobi - Bellman equation is obtained. Higher-order terms of the expansion include the effects of the neglected perturbation dynamics. These higher-order terms are determined from the solution of first-order linear partial differential equations requiring only the evaluation of quadratures. This technique is preferred as a real-time, on-line guidance scheme to alternative numerical iterative optimization schemes because of the unreliable convergence properties of these iterative guidance schemes and because the quadratures needed for the approximate optimal guidance law can be performed rapidly and by parallel processing. Even if the approximate solution is not nearly optimal, when using this technique the zeroth-order solution always provides a path which satisfies the terminal constraints. Results for two-degree-of-freedom simulations are presented for the simplified problem of flight in the equatorial plane and compared to the guidance scheme generated by the shooting method which is an iterative second-order technique. Feeley, T. S. and Speyer, J. L. Unspecified Center ADVANCED LAUNCH SYSTEM (STS); APPROXIMATION; ASYMPTOTIC SERIES; BELLMAN THEORY; DYNAMIC PROGRAMMING; HAMILTON-JACOBI EQUATION; OPTIMAL CONTROL; PERTURBATION THEORY; SERIES EXPANSION; TRAJECTORY OPTIMIZATION; AERODYNAMIC FORCES; EQUATIONS OF MOTION; GUIDANCE (MOTION); METHOD OF C...

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 376

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Automated Trajectory Generation and Guidance for a New Launch Vehicle Flight Phases

Automated Trajectory Generation and Guidance for a New Launch Vehicle Flight Phases PDF Author: Kenneth R. Horneman
Publisher:
ISBN:
Category : Electronic Dissertations
Languages : en
Pages : 129

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Book Description
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.

High-Fidelity Real-Time Trajectory Optimization for Reusable Launch Vehicles

High-Fidelity Real-Time Trajectory Optimization for Reusable Launch Vehicles PDF Author: Kevin P. Bollino
Publisher:
ISBN:
Category : Engineering
Languages : en
Pages : 445

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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.

Optimal Guidance Law Development for an Advanced Launch System

Optimal Guidance Law Development for an Advanced Launch System PDF Author: Anthony J. Calise
Publisher:
ISBN:
Category :
Languages : en
Pages : 112

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Applied Mechanics Reviews

Applied Mechanics Reviews PDF Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 1000

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92-4301 to 92-4413

92-4301 to 92-4413 PDF Author:
Publisher:
ISBN:
Category : Flight control
Languages : en
Pages : 666

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