A5074061342- Spacecraft Dynamics and Control
- Space Satellite Systems and Control
- Aerospace Engineering and Control Systems
- Astro and Planetary Science
- Guidance and Control Systems
- Inertial Sensor and Navigation
- Rocket and propulsion systems research
- Aerospace Engineering and Energy Systems
- Advanced Optimization Algorithms Research
- Space Exploration and Technology
- Adaptive Control of Nonlinear Systems
- Advanced Control Systems Optimization
- Gas Dynamics and Kinetic Theory
- Planetary Science and Exploration
- Computational Fluid Dynamics and Aerodynamics
- Robotics and Sensor-Based Localization
- Fault Detection and Control Systems
- Robotic Path Planning Algorithms
- Spacecraft Design and Technology
- Real-time simulation and control systems
- Stability and Control of Uncertain Systems
- Numerical methods for differential equations
- Aerospace and Aviation Technology
- Air Traffic Management and Optimization
- Quantum chaos and dynamical systems
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2016-2025
Institute for Applied Systems Technology Bremen
2020-2021
Guidance (United Kingdom)
2018
Over the last years, two new technologies to solve optimal-control problems were successfully developed: that is, pseudospectral optimal control and convex optimization, with former for solving general nonlinear programming problem latter aimed at (for example, second-order conic problems) in real time. In this paper, a framework combining them, motivational is described. The benefits of proposed method are demonstrated descent phase NASA Mars Science Laboratory. Numerical simulations show...
Membertranscribe optimal control problems (OCPs), including the powered descent guidance problem [21].Pseudospectral methods are characterized by use of non-uniform distributions discrete nodes, which generally lead to more accurate results if compared with standard transcriptions [22].The resulting nonlinear programming (NLP) is solved one well-known off-the-shelf NLP packages, such as SNOPT [23] or IPOPT [24].The drawback represented fact that pseudospectral cannot in general guarantee...
In this paper an augmented convex–concave decomposition (ACCD) method for treating nonlinear equality constraints in otherwise convex problem is proposed. This augmentation improves greatly the feasibility of when compared to original approach. The effectiveness ACCD demonstrated by solving a fuel-optimal six-degree-of-freedom rocket landing atmosphere, subject multiple constraints. Compared with known approaches such as sequential programming, where conventional linearization (with or...
In this paper, an adaptive, disturbance-based sliding-mode controller for hypersonic-entry vehicles is proposed. The scheme based on high-order theory, and coupled to extended observer, able reconstruct online the disturbances. result a numerically stable control scheme, adapt reduce error in presence of multiple uncertainties. transformation technique into adaptive law by using observer is, together with multi-input/multi-output formulation vehicles, main contribution paper. robustness...
This work formulates a fully-consistent 6-DoF entry trajectory optimization problem. In addition to the rotational dynamics, problem is further complicated by simultaneous presence of aerodynamic controls continuous deflections surfaces, and set reaction control system thrusters which intrinsically represent discrete (on off) controls. The transcription relies on recently developed approach augmented convex-concave decomposition. A successive convex method used for generation numerical...
Since the beginning of Apollo space ight program, entry guidance has been widely treated by engineers and researchers.The rst, successful approach, used for several programs (Apollo, Space Transportation System [1]), was based on planning an trajectory in terms drag-velocity plane.The rationale this choice resides fact that typical environmental constraints (dynamic pressure, heat ux load factor), as well range-to-go, can be eciently represented longitudinal then derived ways.For instance,...
View Video Presentation: https://doi.org/10.2514/6.2021-0862.vid This paper describes a novel general on-board guidance strategy which can be applied to both the aerodynamically-controlled descent and powered landing phase of reusable rockets. The proposed method is based on sequential convex optimization Cartesian representation equations motion. contributions are an exploitation non-convex contributions, processed separately maximize computational efficiency approach, inclusion highly...
This paper focuses on the different powered descent and landing studies in atmosphere performed to formulate guidance problem for CALLISTO vehicle, a technological demonstrator jointly developed by DLR, JAXA, CNES. By formulating solving optimal control problems we critically compare results come up with satisfactory trade-off that balances performance safety concerns.
While there is a strong current interest in and an increasing body of the latest numerical work on fuel-optimal powered descent inside atmosphere, little recent analytical understanding problem has been reported. This paper analyzes endo-atmospheric rocket landing three-dimensional motion. The necessary conditions for that account both propulsive aerodynamic forces are derived. They include full set costate equations optimality attitude terms angle attack sideslip angle. In contrast to...
This paper investigates the use of structured robust techniques for control design aerodynamic descent phase a reusable rocket. A unified strategy based on linear-time-invariant [Formula: see text] controllers both attitude and position is proposed verified in frequency time domains. The architecture controller observed performance are discussed. Moreover, nonlinear behavior analyzed by looking at gain-scheduling law conditions plant-controller misalignment through matrices, simulation...
This research revisits the Desensitized Optimal Control Theory for its application to a computationally challenging numerical benchmark, specifically descent and landing scenario involving rocket propulsion system. The primary objective is assess efficacy of proposed method in mitigating impact perturbations on final state, thereby establishing framework capable simultaneously optimizing Guidance specified case. Additionally, our focus formulating rapid efficient approach enhance speed...
Reusable rockets must rely on well-designed Guidance, Navigation and Control (GNC) algorithms. Because they are tested verified in closed-loop, high-fidelity simulators, emphasizing the strategy to achieve such advanced models is of paramount importance. A wide spectrum complex dynamic behaviors their cross-couplings be captured sufficiently representative simulations, hence a better assessment GNC performance robustness. This paper focuses main aspects related physical (acausal) modeling...
In this paper a new drag-energy scheme, based on the use of pseudospectral methods and convex optimization, is proposed.One most successful technologies to deal with atmospheric entry class drag-tracking schemes, direct heritage Space Shuttle program.The method that we propose exploits drag-dynamics, allows for an efficient automatic design optimal profile satisfying all longitudinal constraints acting vehicle.A representation entry-guidance problem, able loss-less convexify formulation,...
A hybrid algorithm to solve optimal control problems is discussed in the present paper and applied powered descent guidance (PDG) problem. reference solution first obtained via a convex direct solver then used as guess for primal–dual boundary-value problem associated with initial In this context, covector mapping theorem map multipliers of corresponding discrete costates indirect method. Collocation based on hp pseudospectral scheme employed step, while single shooting step....
JAXA, CNES and DLR have decided to join their force develop fly a scaled reusable VTVL rocket stage called CALLISTO (Cooperative Action Leading Launcher Innovation in Stage Toss - back Operations). This vehicle will pave the way for future launch vehicles. One of its main goals is demonstrate mastering key techniques technologies that be needed later by operational Indeed frame numerous challenging are being matured specific case The challenges selection developed discussed solutions...
Nowadays the new, increased capabilities of CPUs have constantly encouraged researchers and engineers towards investigation numerical optimization as an analysis synthesis tool in order to generate optimal trajectories controls track them. In particular, one most promising techniques is represented by direct collocation methods. Among these, Pseudospectral Methods are gaining popularity for their straightforward implementation some useful properties, like possibility remove Runge phenomenon...